/*
 * Copyright (C) Ericsson AB 2007-2008
 * Copyright (C) ST-Ericsson SA 2008-2010
 * Author: Per Forlin <per.forlin@stericsson.com> for ST-Ericsson
 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
 * License terms: GNU General Public License (GPL) version 2
 */

#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/dmaengine.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/err.h>
#include <linux/amba/bus.h>
#include <linux/regulator/consumer.h>

#include <plat/ste_dma40.h>

#include "dmaengine.h"
#include "ste_dma40_ll.h"

#define D40_NAME "dma40"

#define D40_PHY_CHAN -1

/* For masking out/in 2 bit channel positions */
#define D40_CHAN_POS(chan)  (2 * (chan / 2))
#define D40_CHAN_POS_MASK(chan) (0x3 << D40_CHAN_POS(chan))

/* Maximum iterations taken before giving up suspending a channel */
#define D40_SUSPEND_MAX_IT 500

/* Milliseconds */
#define DMA40_AUTOSUSPEND_DELAY 100

/* Hardware requirement on LCLA alignment */
#define LCLA_ALIGNMENT 0x40000

/* Max number of links per event group */
#define D40_LCLA_LINK_PER_EVENT_GRP 128
#define D40_LCLA_END D40_LCLA_LINK_PER_EVENT_GRP

/* Attempts before giving up to trying to get pages that are aligned */
#define MAX_LCLA_ALLOC_ATTEMPTS 256

/* Bit markings for allocation map */
#define D40_ALLOC_FREE          (1 << 31)
#define D40_ALLOC_PHY           (1 << 30)
#define D40_ALLOC_LOG_FREE      0

/**
 * enum 40_command - The different commands and/or statuses.
 *
 * @D40_DMA_STOP: DMA channel command STOP or status STOPPED,
 * @D40_DMA_RUN: The DMA channel is RUNNING of the command RUN.
 * @D40_DMA_SUSPEND_REQ: Request the DMA to SUSPEND as soon as possible.
 * @D40_DMA_SUSPENDED: The DMA channel is SUSPENDED.
 */
enum d40_command {
        D40_DMA_STOP            = 0,
        D40_DMA_RUN             = 1,
        D40_DMA_SUSPEND_REQ     = 2,
        D40_DMA_SUSPENDED       = 3
};

/*
 * enum d40_events - The different Event Enables for the event lines.
 *
 * @D40_DEACTIVATE_EVENTLINE: De-activate Event line, stopping the logical chan.
 * @D40_ACTIVATE_EVENTLINE: Activate the Event line, to start a logical chan.
 * @D40_SUSPEND_REQ_EVENTLINE: Requesting for suspending a event line.
 * @D40_ROUND_EVENTLINE: Status check for event line.
 */

enum d40_events {
        D40_DEACTIVATE_EVENTLINE        = 0,
        D40_ACTIVATE_EVENTLINE          = 1,
        D40_SUSPEND_REQ_EVENTLINE       = 2,
        D40_ROUND_EVENTLINE             = 3
};

/*
 * These are the registers that has to be saved and later restored
 * when the DMA hw is powered off.
 * TODO: Add save/restore of D40_DREG_GCC on dma40 v3 or later, if that works.
 */
static u32 d40_backup_regs[] = {
        D40_DREG_LCPA,
        D40_DREG_LCLA,
        D40_DREG_PRMSE,
        D40_DREG_PRMSO,
        D40_DREG_PRMOE,
        D40_DREG_PRMOO,
};

#define BACKUP_REGS_SZ ARRAY_SIZE(d40_backup_regs)

/* TODO: Check if all these registers have to be saved/restored on dma40 v3 */
static u32 d40_backup_regs_v3[] = {
        D40_DREG_PSEG1,
        D40_DREG_PSEG2,
        D40_DREG_PSEG3,
        D40_DREG_PSEG4,
        D40_DREG_PCEG1,
        D40_DREG_PCEG2,
        D40_DREG_PCEG3,
        D40_DREG_PCEG4,
        D40_DREG_RSEG1,
        D40_DREG_RSEG2,
        D40_DREG_RSEG3,
        D40_DREG_RSEG4,
        D40_DREG_RCEG1,
        D40_DREG_RCEG2,
        D40_DREG_RCEG3,
        D40_DREG_RCEG4,
};

#define BACKUP_REGS_SZ_V3 ARRAY_SIZE(d40_backup_regs_v3)

static u32 d40_backup_regs_chan[] = {
        D40_CHAN_REG_SSCFG,
        D40_CHAN_REG_SSELT,
        D40_CHAN_REG_SSPTR,
        D40_CHAN_REG_SSLNK,
        D40_CHAN_REG_SDCFG,
        D40_CHAN_REG_SDELT,
        D40_CHAN_REG_SDPTR,
        D40_CHAN_REG_SDLNK,
};

/**
 * struct d40_lli_pool - Structure for keeping LLIs in memory
 *
 * @base: Pointer to memory area when the pre_alloc_lli's are not large
 * enough, IE bigger than the most common case, 1 dst and 1 src. NULL if
 * pre_alloc_lli is used.
 * @dma_addr: DMA address, if mapped
 * @size: The size in bytes of the memory at base or the size of pre_alloc_lli.
 * @pre_alloc_lli: Pre allocated area for the most common case of transfers,
 * one buffer to one buffer.
 */
struct d40_lli_pool {
        void    *base;
        int      size;
        dma_addr_t      dma_addr;
        /* Space for dst and src, plus an extra for padding */
        u8       pre_alloc_lli[3 * sizeof(struct d40_phy_lli)];
};

/**
 * struct d40_desc - A descriptor is one DMA job.
 *
 * @lli_phy: LLI settings for physical channel. Both src and dst=
 * points into the lli_pool, to base if lli_len > 1 or to pre_alloc_lli if
 * lli_len equals one.
 * @lli_log: Same as above but for logical channels.
 * @lli_pool: The pool with two entries pre-allocated.
 * @lli_len: Number of llis of current descriptor.
 * @lli_current: Number of transferred llis.
 * @lcla_alloc: Number of LCLA entries allocated.
 * @txd: DMA engine struct. Used for among other things for communication
 * during a transfer.
 * @node: List entry.
 * @is_in_client_list: true if the client owns this descriptor.
 * @cyclic: true if this is a cyclic job
 *
 * This descriptor is used for both logical and physical transfers.
 */
struct d40_desc {
        /* LLI physical */
        struct d40_phy_lli_bidir         lli_phy;
        /* LLI logical */
        struct d40_log_lli_bidir         lli_log;

        struct d40_lli_pool              lli_pool;
        int                              lli_len;
        int                              lli_current;
        int                              lcla_alloc;

        struct dma_async_tx_descriptor   txd;
        struct list_head                 node;

        bool                             is_in_client_list;
        bool                             cyclic;
};

/**
 * struct d40_lcla_pool - LCLA pool settings and data.
 *
 * @base: The virtual address of LCLA. 18 bit aligned.
 * @base_unaligned: The orignal kmalloc pointer, if kmalloc is used.
 * This pointer is only there for clean-up on error.
 * @pages: The number of pages needed for all physical channels.
 * Only used later for clean-up on error
 * @lock: Lock to protect the content in this struct.
 * @alloc_map: big map over which LCLA entry is own by which job.
 */
struct d40_lcla_pool {
        void            *base;
        dma_addr_t      dma_addr;
        void            *base_unaligned;
        int              pages;
        spinlock_t       lock;
        struct d40_desc **alloc_map;
};

/**
 * struct d40_phy_res - struct for handling eventlines mapped to physical
 * channels.
 *
 * @lock: A lock protection this entity.
 * @reserved: True if used by secure world or otherwise.
 * @num: The physical channel number of this entity.
 * @allocated_src: Bit mapped to show which src event line's are mapped to
 * this physical channel. Can also be free or physically allocated.
 * @allocated_dst: Same as for src but is dst.
 * allocated_dst and allocated_src uses the D40_ALLOC* defines as well as
 * event line number.
 */
struct d40_phy_res {
        spinlock_t lock;
        bool       reserved;
        int        num;
        u32        allocated_src;
        u32        allocated_dst;
};

struct d40_base;

/**
 * struct d40_chan - Struct that describes a channel.
 *
 * @lock: A spinlock to protect this struct.
 * @log_num: The logical number, if any of this channel.
 * @pending_tx: The number of pending transfers. Used between interrupt handler
 * and tasklet.
 * @busy: Set to true when transfer is ongoing on this channel.
 * @phy_chan: Pointer to physical channel which this instance runs on. If this
 * point is NULL, then the channel is not allocated.
 * @chan: DMA engine handle.
 * @tasklet: Tasklet that gets scheduled from interrupt context to complete a
 * transfer and call client callback.
 * @client: Cliented owned descriptor list.
 * @pending_queue: Submitted jobs, to be issued by issue_pending()
 * @active: Active descriptor.
 * @queue: Queued jobs.
 * @prepare_queue: Prepared jobs.
 * @dma_cfg: The client configuration of this dma channel.
 * @configured: whether the dma_cfg configuration is valid
 * @base: Pointer to the device instance struct.
 * @src_def_cfg: Default cfg register setting for src.
 * @dst_def_cfg: Default cfg register setting for dst.
 * @log_def: Default logical channel settings.
 * @lcpa: Pointer to dst and src lcpa settings.
 * @runtime_addr: runtime configured address.
 * @runtime_direction: runtime configured direction.
 *
 * This struct can either "be" a logical or a physical channel.
 */
struct d40_chan {
        spinlock_t                       lock;
        int                              log_num;
        int                              pending_tx;
        bool                             busy;
        struct d40_phy_res              *phy_chan;
        struct dma_chan                  chan;
        struct tasklet_struct            tasklet;
        struct list_head                 client;
        struct list_head                 pending_queue;
        struct list_head                 active;
        struct list_head                 queue;
        struct list_head                 prepare_queue;
        struct stedma40_chan_cfg         dma_cfg;
        bool                             configured;
        struct d40_base                 *base;
        /* Default register configurations */
        u32                              src_def_cfg;
        u32                              dst_def_cfg;
        struct d40_def_lcsp              log_def;
        struct d40_log_lli_full         *lcpa;
        /* Runtime reconfiguration */
        dma_addr_t                      runtime_addr;
        enum dma_transfer_direction     runtime_direction;
};

/**
 * struct d40_base - The big global struct, one for each probe'd instance.
 *
 * @interrupt_lock: Lock used to make sure one interrupt is handle a time.
 * @execmd_lock: Lock for execute command usage since several channels share
 * the same physical register.
 * @dev: The device structure.
 * @virtbase: The virtual base address of the DMA's register.
 * @rev: silicon revision detected.
 * @clk: Pointer to the DMA clock structure.
 * @phy_start: Physical memory start of the DMA registers.
 * @phy_size: Size of the DMA register map.
 * @irq: The IRQ number.
 * @num_phy_chans: The number of physical channels. Read from HW. This
 * is the number of available channels for this driver, not counting "Secure
 * mode" allocated physical channels.
 * @num_log_chans: The number of logical channels. Calculated from
 * num_phy_chans.
 * @dma_both: dma_device channels that can do both memcpy and slave transfers.
 * @dma_slave: dma_device channels that can do only do slave transfers.
 * @dma_memcpy: dma_device channels that can do only do memcpy transfers.
 * @phy_chans: Room for all possible physical channels in system.
 * @log_chans: Room for all possible logical channels in system.
 * @lookup_log_chans: Used to map interrupt number to logical channel. Points
 * to log_chans entries.
 * @lookup_phy_chans: Used to map interrupt number to physical channel. Points
 * to phy_chans entries.
 * @plat_data: Pointer to provided platform_data which is the driver
 * configuration.
 * @lcpa_regulator: Pointer to hold the regulator for the esram bank for lcla.
 * @phy_res: Vector containing all physical channels.
 * @lcla_pool: lcla pool settings and data.
 * @lcpa_base: The virtual mapped address of LCPA.
 * @phy_lcpa: The physical address of the LCPA.
 * @lcpa_size: The size of the LCPA area.
 * @desc_slab: cache for descriptors.
 * @reg_val_backup: Here the values of some hardware registers are stored
 * before the DMA is powered off. They are restored when the power is back on.
 * @reg_val_backup_v3: Backup of registers that only exits on dma40 v3 and
 * later.
 * @reg_val_backup_chan: Backup data for standard channel parameter registers.
 * @gcc_pwr_off_mask: Mask to maintain the channels that can be turned off.
 * @initialized: true if the dma has been initialized
 */
struct d40_base {
        spinlock_t                       interrupt_lock;
        spinlock_t                       execmd_lock;
        struct device                    *dev;
        void __iomem                     *virtbase;
        u8                                rev:4;
        struct clk                       *clk;
        phys_addr_t                       phy_start;
        resource_size_t                   phy_size;
        int                               irq;
        int                               num_phy_chans;
        int                               num_log_chans;
        struct dma_device                 dma_both;
        struct dma_device                 dma_slave;
        struct dma_device                 dma_memcpy;
        struct d40_chan                  *phy_chans;
        struct d40_chan                  *log_chans;
        struct d40_chan                 **lookup_log_chans;
        struct d40_chan                 **lookup_phy_chans;
        struct stedma40_platform_data    *plat_data;
        struct regulator                 *lcpa_regulator;
        /* Physical half channels */
        struct d40_phy_res               *phy_res;
        struct d40_lcla_pool              lcla_pool;
        void                             *lcpa_base;
        dma_addr_t                        phy_lcpa;
        resource_size_t                   lcpa_size;
        struct kmem_cache                *desc_slab;
        u32                               reg_val_backup[BACKUP_REGS_SZ];
        u32                               reg_val_backup_v3[BACKUP_REGS_SZ_V3];
        u32                              *reg_val_backup_chan;
        u16                               gcc_pwr_off_mask;
        bool                              initialized;
};

/**
 * struct d40_interrupt_lookup - lookup table for interrupt handler
 *
 * @src: Interrupt mask register.
 * @clr: Interrupt clear register.
 * @is_error: true if this is an error interrupt.
 * @offset: start delta in the lookup_log_chans in d40_base. If equals to
 * D40_PHY_CHAN, the lookup_phy_chans shall be used instead.
 */
struct d40_interrupt_lookup {
        u32 src;
        u32 clr;
        bool is_error;
        int offset;
};

/**
 * struct d40_reg_val - simple lookup struct
 *
 * @reg: The register.
 * @val: The value that belongs to the register in reg.
 */
struct d40_reg_val {
        unsigned int reg;
        unsigned int val;
};

static struct device *chan2dev(struct d40_chan *d40c)
{
        return &d40c->chan.dev->device;
}

static bool chan_is_physical(struct d40_chan *chan)
{
        return chan->log_num == D40_PHY_CHAN;
}

static bool chan_is_logical(struct d40_chan *chan)
{
        return !chan_is_physical(chan);
}

static void __iomem *chan_base(struct d40_chan *chan)
{
        return chan->base->virtbase + D40_DREG_PCBASE +
               chan->phy_chan->num * D40_DREG_PCDELTA;
}

#define d40_err(dev, format, arg...)            \
        dev_err(dev, "[%s] " format, __func__, ## arg)

#define chan_err(d40c, format, arg...)          \
        d40_err(chan2dev(d40c), format, ## arg)

static int d40_pool_lli_alloc(struct d40_chan *d40c, struct d40_desc *d40d,
                              int lli_len)
{
        bool is_log = chan_is_logical(d40c);
        u32 align;
        void *base;

        if (is_log)
                align = sizeof(struct d40_log_lli);
        else
                align = sizeof(struct d40_phy_lli);

        if (lli_len == 1) {
                base = d40d->lli_pool.pre_alloc_lli;
                d40d->lli_pool.size = sizeof(d40d->lli_pool.pre_alloc_lli);
                d40d->lli_pool.base = NULL;
        } else {
                d40d->lli_pool.size = lli_len * 2 * align;

                base = kmalloc(d40d->lli_pool.size + align, GFP_NOWAIT);
                d40d->lli_pool.base = base;

                if (d40d->lli_pool.base == NULL)
                        return -ENOMEM;
        }

        if (is_log) {
                d40d->lli_log.src = PTR_ALIGN(base, align);
                d40d->lli_log.dst = d40d->lli_log.src + lli_len;

                d40d->lli_pool.dma_addr = 0;
        } else {
                d40d->lli_phy.src = PTR_ALIGN(base, align);
                d40d->lli_phy.dst = d40d->lli_phy.src + lli_len;

                d40d->lli_pool.dma_addr = dma_map_single(d40c->base->dev,
                                                         d40d->lli_phy.src,
                                                         d40d->lli_pool.size,
                                                         DMA_TO_DEVICE);

                if (dma_mapping_error(d40c->base->dev,
                                      d40d->lli_pool.dma_addr)) {
                        kfree(d40d->lli_pool.base);
                        d40d->lli_pool.base = NULL;
                        d40d->lli_pool.dma_addr = 0;
                        return -ENOMEM;
                }
        }

        return 0;
}

static void d40_pool_lli_free(struct d40_chan *d40c, struct d40_desc *d40d)
{
        if (d40d->lli_pool.dma_addr)
                dma_unmap_single(d40c->base->dev, d40d->lli_pool.dma_addr,
                                 d40d->lli_pool.size, DMA_TO_DEVICE);

        kfree(d40d->lli_pool.base);
        d40d->lli_pool.base = NULL;
        d40d->lli_pool.size = 0;
        d40d->lli_log.src = NULL;
        d40d->lli_log.dst = NULL;
        d40d->lli_phy.src = NULL;
        d40d->lli_phy.dst = NULL;
}

static int d40_lcla_alloc_one(struct d40_chan *d40c,
                              struct d40_desc *d40d)
{
        unsigned long flags;
        int i;
        int ret = -EINVAL;
        int p;

        spin_lock_irqsave(&d40c->base->lcla_pool.lock, flags);

        p = d40c->phy_chan->num * D40_LCLA_LINK_PER_EVENT_GRP;

        /*
         * Allocate both src and dst at the same time, therefore the half
         * start on 1 since 0 can't be used since zero is used as end marker.
         */
        for (i = 1 ; i < D40_LCLA_LINK_PER_EVENT_GRP / 2; i++) {
                if (!d40c->base->lcla_pool.alloc_map[p + i]) {
                        d40c->base->lcla_pool.alloc_map[p + i] = d40d;
                        d40d->lcla_alloc++;
                        ret = i;
                        break;
                }
        }

        spin_unlock_irqrestore(&d40c->base->lcla_pool.lock, flags);

        return ret;
}

static int d40_lcla_free_all(struct d40_chan *d40c,
                             struct d40_desc *d40d)
{
        unsigned long flags;
        int i;
        int ret = -EINVAL;

        if (chan_is_physical(d40c))
                return 0;

        spin_lock_irqsave(&d40c->base->lcla_pool.lock, flags);

        for (i = 1 ; i < D40_LCLA_LINK_PER_EVENT_GRP / 2; i++) {
                if (d40c->base->lcla_pool.alloc_map[d40c->phy_chan->num *
                                                    D40_LCLA_LINK_PER_EVENT_GRP + i] == d40d) {
                        d40c->base->lcla_pool.alloc_map[d40c->phy_chan->num *
                                                        D40_LCLA_LINK_PER_EVENT_GRP + i] = NULL;
                        d40d->lcla_alloc--;
                        if (d40d->lcla_alloc == 0) {
                                ret = 0;
                                break;
                        }
                }
        }

        spin_unlock_irqrestore(&d40c->base->lcla_pool.lock, flags);

        return ret;

}

static void d40_desc_remove(struct d40_desc *d40d)
{
        list_del(&d40d->node);
}

static struct d40_desc *d40_desc_get(struct d40_chan *d40c)
{
        struct d40_desc *desc = NULL;

        if (!list_empty(&d40c->client)) {
                struct d40_desc *d;
                struct d40_desc *_d;

                list_for_each_entry_safe(d, _d, &d40c->client, node) {
                        if (async_tx_test_ack(&d->txd)) {
                                d40_desc_remove(d);
                                desc = d;
                                memset(desc, 0, sizeof(*desc));
                                break;
                        }
                }
        }

        if (!desc)
                desc = kmem_cache_zalloc(d40c->base->desc_slab, GFP_NOWAIT);

        if (desc)
                INIT_LIST_HEAD(&desc->node);

        return desc;
}

static void d40_desc_free(struct d40_chan *d40c, struct d40_desc *d40d)
{

        d40_pool_lli_free(d40c, d40d);
        d40_lcla_free_all(d40c, d40d);
        kmem_cache_free(d40c->base->desc_slab, d40d);
}

static void d40_desc_submit(struct d40_chan *d40c, struct d40_desc *desc)
{
        list_add_tail(&desc->node, &d40c->active);
}

static void d40_phy_lli_load(struct d40_chan *chan, struct d40_desc *desc)
{
        struct d40_phy_lli *lli_dst = desc->lli_phy.dst;
        struct d40_phy_lli *lli_src = desc->lli_phy.src;
        void __iomem *base = chan_base(chan);

        writel(lli_src->reg_cfg, base + D40_CHAN_REG_SSCFG);
        writel(lli_src->reg_elt, base + D40_CHAN_REG_SSELT);
        writel(lli_src->reg_ptr, base + D40_CHAN_REG_SSPTR);
        writel(lli_src->reg_lnk, base + D40_CHAN_REG_SSLNK);

        writel(lli_dst->reg_cfg, base + D40_CHAN_REG_SDCFG);
        writel(lli_dst->reg_elt, base + D40_CHAN_REG_SDELT);
        writel(lli_dst->reg_ptr, base + D40_CHAN_REG_SDPTR);
        writel(lli_dst->reg_lnk, base + D40_CHAN_REG_SDLNK);
}

static void d40_log_lli_to_lcxa(struct d40_chan *chan, struct d40_desc *desc)
{
        struct d40_lcla_pool *pool = &chan->base->lcla_pool;
        struct d40_log_lli_bidir *lli = &desc->lli_log;
        int lli_current = desc->lli_current;
        int lli_len = desc->lli_len;
        bool cyclic = desc->cyclic;
        int curr_lcla = -EINVAL;
        int first_lcla = 0;
        bool use_esram_lcla = chan->base->plat_data->use_esram_lcla;
        bool linkback;

        /*
         * We may have partially running cyclic transfers, in case we did't get
         * enough LCLA entries.
         */
        linkback = cyclic && lli_current == 0;

        /*
         * For linkback, we need one LCLA even with only one link, because we
         * can't link back to the one in LCPA space
         */
        if (linkback || (lli_len - lli_current > 1)) {
                curr_lcla = d40_lcla_alloc_one(chan, desc);
                first_lcla = curr_lcla;
        }

        /*
         * For linkback, we normally load the LCPA in the loop since we need to
         * link it to the second LCLA and not the first.  However, if we
         * couldn't even get a first LCLA, then we have to run in LCPA and
         * reload manually.
         */
        if (!linkback || curr_lcla == -EINVAL) {
                unsigned int flags = 0;

                if (curr_lcla == -EINVAL)
                        flags |= LLI_TERM_INT;

                d40_log_lli_lcpa_write(chan->lcpa,
                                       &lli->dst[lli_current],
                                       &lli->src[lli_current],
                                       curr_lcla,
                                       flags);
                lli_current++;
        }

        if (curr_lcla < 0)
                goto out;

        for (; lli_current < lli_len; lli_current++) {
                unsigned int lcla_offset = chan->phy_chan->num * 1024 +
                                           8 * curr_lcla * 2;
                struct d40_log_lli *lcla = pool->base + lcla_offset;
                unsigned int flags = 0;
                int next_lcla;

                if (lli_current + 1 < lli_len)
                        next_lcla = d40_lcla_alloc_one(chan, desc);
                else
                        next_lcla = linkback ? first_lcla : -EINVAL;

                if (cyclic || next_lcla == -EINVAL)
                        flags |= LLI_TERM_INT;

                if (linkback && curr_lcla == first_lcla) {
                        /* First link goes in both LCPA and LCLA */
                        d40_log_lli_lcpa_write(chan->lcpa,
                                               &lli->dst[lli_current],
                                               &lli->src[lli_current],
                                               next_lcla, flags);
                }

                /*
                 * One unused LCLA in the cyclic case if the very first
                 * next_lcla fails...
                 */
                d40_log_lli_lcla_write(lcla,
                                       &lli->dst[lli_current],
                                       &lli->src[lli_current],
                                       next_lcla, flags);

                /*
                 * Cache maintenance is not needed if lcla is
                 * mapped in esram
                 */
                if (!use_esram_lcla) {
                        dma_sync_single_range_for_device(chan->base->dev,
                                                pool->dma_addr, lcla_offset,
                                                2 * sizeof(struct d40_log_lli),
                                                DMA_TO_DEVICE);
                }
                curr_lcla = next_lcla;

                if (curr_lcla == -EINVAL || curr_lcla == first_lcla) {
                        lli_current++;
                        break;
                }
        }

out:
        desc->lli_current = lli_current;
}

static void d40_desc_load(struct d40_chan *d40c, struct d40_desc *d40d)
{
        if (chan_is_physical(d40c)) {
                d40_phy_lli_load(d40c, d40d);
                d40d->lli_current = d40d->lli_len;
        } else
                d40_log_lli_to_lcxa(d40c, d40d);
}

static struct d40_desc *d40_first_active_get(struct d40_chan *d40c)
{
        struct d40_desc *d;

        if (list_empty(&d40c->active))
                return NULL;

        d = list_first_entry(&d40c->active,
                             struct d40_desc,
                             node);
        return d;
}

/* remove desc from current queue and add it to the pending_queue */
static void d40_desc_queue(struct d40_chan *d40c, struct d40_desc *desc)
{
        d40_desc_remove(desc);
        desc->is_in_client_list = false;
        list_add_tail(&desc->node, &d40c->pending_queue);
}

static struct d40_desc *d40_first_pending(struct d40_chan *d40c)
{
        struct d40_desc *d;

        if (list_empty(&d40c->pending_queue))
                return NULL;

        d = list_first_entry(&d40c->pending_queue,
                             struct d40_desc,
                             node);
        return d;
}

static struct d40_desc *d40_first_queued(struct d40_chan *d40c)
{
        struct d40_desc *d;

        if (list_empty(&d40c->queue))
                return NULL;

        d = list_first_entry(&d40c->queue,
                             struct d40_desc,
                             node);
        return d;
}

static int d40_psize_2_burst_size(bool is_log, int psize)
{
        if (is_log) {
                if (psize == STEDMA40_PSIZE_LOG_1)
                        return 1;
        } else {
                if (psize == STEDMA40_PSIZE_PHY_1)
                        return 1;
        }

        return 2 << psize;
}

/*
 * The dma only supports transmitting packages up to
 * STEDMA40_MAX_SEG_SIZE << data_width. Calculate the total number of
 * dma elements required to send the entire sg list
 */
static int d40_size_2_dmalen(int size, u32 data_width1, u32 data_width2)
{
        int dmalen;
        u32 max_w = max(data_width1, data_width2);
        u32 min_w = min(data_width1, data_width2);
        u32 seg_max = ALIGN(STEDMA40_MAX_SEG_SIZE << min_w, 1 << max_w);

        if (seg_max > STEDMA40_MAX_SEG_SIZE)
                seg_max -= (1 << max_w);

        if (!IS_ALIGNED(size, 1 << max_w))
                return -EINVAL;

        if (size <= seg_max)
                dmalen = 1;
        else {
                dmalen = size / seg_max;
                if (dmalen * seg_max < size)
                        dmalen++;
        }
        return dmalen;
}

static int d40_sg_2_dmalen(struct scatterlist *sgl, int sg_len,
                           u32 data_width1, u32 data_width2)
{
        struct scatterlist *sg;
        int i;
        int len = 0;
        int ret;

        for_each_sg(sgl, sg, sg_len, i) {
                ret = d40_size_2_dmalen(sg_dma_len(sg),
                                        data_width1, data_width2);
                if (ret < 0)
                        return ret;
                len += ret;
        }
        return len;
}


#ifdef CONFIG_PM
static void dma40_backup(void __iomem *baseaddr, u32 *backup,
                         u32 *regaddr, int num, bool save)
{
        int i;

        for (i = 0; i < num; i++) {
                void __iomem *addr = baseaddr + regaddr[i];

                if (save)
                        backup[i] = readl_relaxed(addr);
                else
                        writel_relaxed(backup[i], addr);
        }
}

static void d40_save_restore_registers(struct d40_base *base, bool save)
{
        int i;

        /* Save/Restore channel specific registers */
        for (i = 0; i < base->num_phy_chans; i++) {
                void __iomem *addr;
                int idx;

                if (base->phy_res[i].reserved)
                        continue;

                addr = base->virtbase + D40_DREG_PCBASE + i * D40_DREG_PCDELTA;
                idx = i * ARRAY_SIZE(d40_backup_regs_chan);

                dma40_backup(addr, &base->reg_val_backup_chan[idx],
                             d40_backup_regs_chan,
                             ARRAY_SIZE(d40_backup_regs_chan),
                             save);
        }

        /* Save/Restore global registers */
        dma40_backup(base->virtbase, base->reg_val_backup,
                     d40_backup_regs, ARRAY_SIZE(d40_backup_regs),
                     save);

        /* Save/Restore registers only existing on dma40 v3 and later */
        if (base->rev >= 3)
                dma40_backup(base->virtbase, base->reg_val_backup_v3,
                             d40_backup_regs_v3,
                             ARRAY_SIZE(d40_backup_regs_v3),
                             save);
}
#else
static void d40_save_restore_registers(struct d40_base *base, bool save)
{
}
#endif

static int __d40_execute_command_phy(struct d40_chan *d40c,
                                     enum d40_command command)
{
        u32 status;
        int i;
        void __iomem *active_reg;
        int ret = 0;
        unsigned long flags;
        u32 wmask;

        if (command == D40_DMA_STOP) {
                ret = __d40_execute_command_phy(d40c, D40_DMA_SUSPEND_REQ);
                if (ret)
                        return ret;
        }

        spin_lock_irqsave(&d40c->base->execmd_lock, flags);

        if (d40c->phy_chan->num % 2 == 0)
                active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
        else
                active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;

        if (command == D40_DMA_SUSPEND_REQ) {
                status = (readl(active_reg) &
                          D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
                        D40_CHAN_POS(d40c->phy_chan->num);

                if (status == D40_DMA_SUSPENDED || status == D40_DMA_STOP)
                        goto done;
        }

        wmask = 0xffffffff & ~(D40_CHAN_POS_MASK(d40c->phy_chan->num));
        writel(wmask | (command << D40_CHAN_POS(d40c->phy_chan->num)),
               active_reg);

        if (command == D40_DMA_SUSPEND_REQ) {

                for (i = 0 ; i < D40_SUSPEND_MAX_IT; i++) {
                        status = (readl(active_reg) &
                                  D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
                                D40_CHAN_POS(d40c->phy_chan->num);

                        cpu_relax();
                        /*
                         * Reduce the number of bus accesses while
                         * waiting for the DMA to suspend.
                         */
                        udelay(3);

                        if (status == D40_DMA_STOP ||
                            status == D40_DMA_SUSPENDED)
                                break;
                }

                if (i == D40_SUSPEND_MAX_IT) {
                        chan_err(d40c,
                                "unable to suspend the chl %d (log: %d) status %x\n",
                                d40c->phy_chan->num, d40c->log_num,
                                status);
                        dump_stack();
                        ret = -EBUSY;
                }

        }
done:
        spin_unlock_irqrestore(&d40c->base->execmd_lock, flags);
        return ret;
}

static void d40_term_all(struct d40_chan *d40c)
{
        struct d40_desc *d40d;
        struct d40_desc *_d;

        /* Release active descriptors */
        while ((d40d = d40_first_active_get(d40c))) {
                d40_desc_remove(d40d);
                d40_desc_free(d40c, d40d);
        }

        /* Release queued descriptors waiting for transfer */
        while ((d40d = d40_first_queued(d40c))) {
                d40_desc_remove(d40d);
                d40_desc_free(d40c, d40d);
        }

        /* Release pending descriptors */
        while ((d40d = d40_first_pending(d40c))) {
                d40_desc_remove(d40d);
                d40_desc_free(d40c, d40d);
        }

        /* Release client owned descriptors */
        if (!list_empty(&d40c->client))
                list_for_each_entry_safe(d40d, _d, &d40c->client, node) {
                        d40_desc_remove(d40d);
                        d40_desc_free(d40c, d40d);
                }

        /* Release descriptors in prepare queue */
        if (!list_empty(&d40c->prepare_queue))
                list_for_each_entry_safe(d40d, _d,
                                         &d40c->prepare_queue, node) {
                        d40_desc_remove(d40d);
                        d40_desc_free(d40c, d40d);
                }

        d40c->pending_tx = 0;
}

static void __d40_config_set_event(struct d40_chan *d40c,
                                   enum d40_events event_type, u32 event,
                                   int reg)
{
        void __iomem *addr = chan_base(d40c) + reg;
        int tries;
        u32 status;

        switch (event_type) {

        case D40_DEACTIVATE_EVENTLINE:

                writel((D40_DEACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
                       | ~D40_EVENTLINE_MASK(event), addr);
                break;

        case D40_SUSPEND_REQ_EVENTLINE:
                status = (readl(addr) & D40_EVENTLINE_MASK(event)) >>
                          D40_EVENTLINE_POS(event);

                if (status == D40_DEACTIVATE_EVENTLINE ||
                    status == D40_SUSPEND_REQ_EVENTLINE)
                        break;

                writel((D40_SUSPEND_REQ_EVENTLINE << D40_EVENTLINE_POS(event))
                       | ~D40_EVENTLINE_MASK(event), addr);

                for (tries = 0 ; tries < D40_SUSPEND_MAX_IT; tries++) {

                        status = (readl(addr) & D40_EVENTLINE_MASK(event)) >>
                                  D40_EVENTLINE_POS(event);

                        cpu_relax();
                        /*
                         * Reduce the number of bus accesses while
                         * waiting for the DMA to suspend.
                         */
                        udelay(3);

                        if (status == D40_DEACTIVATE_EVENTLINE)
                                break;
                }

                if (tries == D40_SUSPEND_MAX_IT) {
                        chan_err(d40c,
                                "unable to stop the event_line chl %d (log: %d)"
                                "status %x\n", d40c->phy_chan->num,
                                 d40c->log_num, status);
                }
                break;

        case D40_ACTIVATE_EVENTLINE:
        /*
         * The hardware sometimes doesn't register the enable when src and dst
         * event lines are active on the same logical channel.  Retry to ensure
         * it does.  Usually only one retry is sufficient.
         */
                tries = 100;
                while (--tries) {
                        writel((D40_ACTIVATE_EVENTLINE <<
                                D40_EVENTLINE_POS(event)) |
                                ~D40_EVENTLINE_MASK(event), addr);

                        if (readl(addr) & D40_EVENTLINE_MASK(event))
                                break;
                }

                if (tries != 99)
                        dev_dbg(chan2dev(d40c),
                                "[%s] workaround enable S%cLNK (%d tries)\n",
                                __func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
                                100 - tries);

                WARN_ON(!tries);
                break;

        case D40_ROUND_EVENTLINE:
                BUG();
                break;

        }
}

static void d40_config_set_event(struct d40_chan *d40c,
                                 enum d40_events event_type)
{
        /* Enable event line connected to device (or memcpy) */
        if ((d40c->dma_cfg.dir ==  STEDMA40_PERIPH_TO_MEM) ||
            (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH)) {
                u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);

                __d40_config_set_event(d40c, event_type, event,
                                       D40_CHAN_REG_SSLNK);
        }

        if (d40c->dma_cfg.dir !=  STEDMA40_PERIPH_TO_MEM) {
                u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);

                __d40_config_set_event(d40c, event_type, event,
                                       D40_CHAN_REG_SDLNK);
        }
}

static u32 d40_chan_has_events(struct d40_chan *d40c)
{
        void __iomem *chanbase = chan_base(d40c);
        u32 val;

        val = readl(chanbase + D40_CHAN_REG_SSLNK);
        val |= readl(chanbase + D40_CHAN_REG_SDLNK);

        return val;
}

static int
__d40_execute_command_log(struct d40_chan *d40c, enum d40_command command)
{
        unsigned long flags;
        int ret = 0;
        u32 active_status;
        void __iomem *active_reg;

        if (d40c->phy_chan->num % 2 == 0)
                active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
        else
                active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;


        spin_lock_irqsave(&d40c->phy_chan->lock, flags);

        switch (command) {
        case D40_DMA_STOP:
        case D40_DMA_SUSPEND_REQ:

                active_status = (readl(active_reg) &
                                 D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
                                 D40_CHAN_POS(d40c->phy_chan->num);

                if (active_status == D40_DMA_RUN)
                        d40_config_set_event(d40c, D40_SUSPEND_REQ_EVENTLINE);
                else
                        d40_config_set_event(d40c, D40_DEACTIVATE_EVENTLINE);

                if (!d40_chan_has_events(d40c) && (command == D40_DMA_STOP))
                        ret = __d40_execute_command_phy(d40c, command);

                break;

        case D40_DMA_RUN:

                d40_config_set_event(d40c, D40_ACTIVATE_EVENTLINE);
                ret = __d40_execute_command_phy(d40c, command);
                break;

        case D40_DMA_SUSPENDED:
                BUG();
                break;
        }

        spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
        return ret;
}

static int d40_channel_execute_command(struct d40_chan *d40c,
                                       enum d40_command command)
{
        if (chan_is_logical(d40c))
                return __d40_execute_command_log(d40c, command);
        else
                return __d40_execute_command_phy(d40c, command);
}

static u32 d40_get_prmo(struct d40_chan *d40c)
{
        static const unsigned int phy_map[] = {
                [STEDMA40_PCHAN_BASIC_MODE]
                        = D40_DREG_PRMO_PCHAN_BASIC,
                [STEDMA40_PCHAN_MODULO_MODE]
                        = D40_DREG_PRMO_PCHAN_MODULO,
                [STEDMA40_PCHAN_DOUBLE_DST_MODE]
                        = D40_DREG_PRMO_PCHAN_DOUBLE_DST,
        };
        static const unsigned int log_map[] = {
                [STEDMA40_LCHAN_SRC_PHY_DST_LOG]
                        = D40_DREG_PRMO_LCHAN_SRC_PHY_DST_LOG,
                [STEDMA40_LCHAN_SRC_LOG_DST_PHY]
                        = D40_DREG_PRMO_LCHAN_SRC_LOG_DST_PHY,
                [STEDMA40_LCHAN_SRC_LOG_DST_LOG]
                        = D40_DREG_PRMO_LCHAN_SRC_LOG_DST_LOG,
        };

        if (chan_is_physical(d40c))
                return phy_map[d40c->dma_cfg.mode_opt];
        else
                return log_map[d40c->dma_cfg.mode_opt];
}

static void d40_config_write(struct d40_chan *d40c)
{
        u32 addr_base;
        u32 var;

        /* Odd addresses are even addresses + 4 */
        addr_base = (d40c->phy_chan->num % 2) * 4;
        /* Setup channel mode to logical or physical */
        var = ((u32)(chan_is_logical(d40c)) + 1) <<
                D40_CHAN_POS(d40c->phy_chan->num);
        writel(var, d40c->base->virtbase + D40_DREG_PRMSE + addr_base);

        /* Setup operational mode option register */
        var = d40_get_prmo(d40c) << D40_CHAN_POS(d40c->phy_chan->num);

        writel(var, d40c->base->virtbase + D40_DREG_PRMOE + addr_base);

        if (chan_is_logical(d40c)) {
                int lidx = (d40c->phy_chan->num << D40_SREG_ELEM_LOG_LIDX_POS)
                           & D40_SREG_ELEM_LOG_LIDX_MASK;
                void __iomem *chanbase = chan_base(d40c);

                /* Set default config for CFG reg */
                writel(d40c->src_def_cfg, chanbase + D40_CHAN_REG_SSCFG);
                writel(d40c->dst_def_cfg, chanbase + D40_CHAN_REG_SDCFG);

                /* Set LIDX for lcla */
                writel(lidx, chanbase + D40_CHAN_REG_SSELT);
                writel(lidx, chanbase + D40_CHAN_REG_SDELT);

                /* Clear LNK which will be used by d40_chan_has_events() */
                writel(0, chanbase + D40_CHAN_REG_SSLNK);
                writel(0, chanbase + D40_CHAN_REG_SDLNK);
        }
}

static u32 d40_residue(struct d40_chan *d40c)
{
        u32 num_elt;

        if (chan_is_logical(d40c))
                num_elt = (readl(&d40c->lcpa->lcsp2) & D40_MEM_LCSP2_ECNT_MASK)
                        >> D40_MEM_LCSP2_ECNT_POS;
        else {
                u32 val = readl(chan_base(d40c) + D40_CHAN_REG_SDELT);
                num_elt = (val & D40_SREG_ELEM_PHY_ECNT_MASK)
                          >> D40_SREG_ELEM_PHY_ECNT_POS;
        }

        return num_elt * (1 << d40c->dma_cfg.dst_info.data_width);
}

static bool d40_tx_is_linked(struct d40_chan *d40c)
{
        bool is_link;

        if (chan_is_logical(d40c))
                is_link = readl(&d40c->lcpa->lcsp3) &  D40_MEM_LCSP3_DLOS_MASK;
        else
                is_link = readl(chan_base(d40c) + D40_CHAN_REG_SDLNK)
                          & D40_SREG_LNK_PHYS_LNK_MASK;

        return is_link;
}

static int d40_pause(struct d40_chan *d40c)
{
        int res = 0;
        unsigned long flags;

        if (!d40c->busy)
                return 0;

        pm_runtime_get_sync(d40c->base->dev);
        spin_lock_irqsave(&d40c->lock, flags);

        res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);

        pm_runtime_mark_last_busy(d40c->base->dev);
        pm_runtime_put_autosuspend(d40c->base->dev);
        spin_unlock_irqrestore(&d40c->lock, flags);
        return res;
}

static int d40_resume(struct d40_chan *d40c)
{
        int res = 0;
        unsigned long flags;

        if (!d40c->busy)
                return 0;

        spin_lock_irqsave(&d40c->lock, flags);
        pm_runtime_get_sync(d40c->base->dev);

        /* If bytes left to transfer or linked tx resume job */
        if (d40_residue(d40c) || d40_tx_is_linked(d40c))
                res = d40_channel_execute_command(d40c, D40_DMA_RUN);

        pm_runtime_mark_last_busy(d40c->base->dev);
        pm_runtime_put_autosuspend(d40c->base->dev);
        spin_unlock_irqrestore(&d40c->lock, flags);
        return res;
}

static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
{
        struct d40_chan *d40c = container_of(tx->chan,
                                             struct d40_chan,
                                             chan);
        struct d40_desc *d40d = container_of(tx, struct d40_desc, txd);
        unsigned long flags;
        dma_cookie_t cookie;

        spin_lock_irqsave(&d40c->lock, flags);
        cookie = dma_cookie_assign(tx);
        d40_desc_queue(d40c, d40d);
        spin_unlock_irqrestore(&d40c->lock, flags);

        return cookie;
}

static int d40_start(struct d40_chan *d40c)
{
        return d40_channel_execute_command(d40c, D40_DMA_RUN);
}

static struct d40_desc *d40_queue_start(struct d40_chan *d40c)
{
        struct d40_desc *d40d;
        int err;

        /* Start queued jobs, if any */
        d40d = d40_first_queued(d40c);

        if (d40d != NULL) {
                if (!d40c->busy) {
                        d40c->busy = true;
                        pm_runtime_get_sync(d40c->base->dev);
                }

                /* Remove from queue */
                d40_desc_remove(d40d);

                /* Add to active queue */
                d40_desc_submit(d40c, d40d);

                /* Initiate DMA job */
                d40_desc_load(d40c, d40d);

                /* Start dma job */
                err = d40_start(d40c);

                if (err)
                        return NULL;
        }

        return d40d;
}

/* called from interrupt context */
static void dma_tc_handle(struct d40_chan *d40c)
{
        struct d40_desc *d40d;

        /* Get first active entry from list */
        d40d = d40_first_active_get(d40c);

        if (d40d == NULL)
                return;

        if (d40d->cyclic) {
                /*
                 * If this was a paritially loaded list, we need to reloaded
                 * it, and only when the list is completed.  We need to check
                 * for done because the interrupt will hit for every link, and
                 * not just the last one.
                 */
                if (d40d->lli_current < d40d->lli_len
                    && !d40_tx_is_linked(d40c)
                    && !d40_residue(d40c)) {
                        d40_lcla_free_all(d40c, d40d);
                        d40_desc_load(d40c, d40d);
                        (void) d40_start(d40c);

                        if (d40d->lli_current == d40d->lli_len)
                                d40d->lli_current = 0;
                }
        } else {
                d40_lcla_free_all(d40c, d40d);

                if (d40d->lli_current < d40d->lli_len) {
                        d40_desc_load(d40c, d40d);
                        /* Start dma job */
                        (void) d40_start(d40c);
                        return;
                }

                if (d40_queue_start(d40c) == NULL)
                        d40c->busy = false;
                pm_runtime_mark_last_busy(d40c->base->dev);
                pm_runtime_put_autosuspend(d40c->base->dev);
        }

        d40c->pending_tx++;
        tasklet_schedule(&d40c->tasklet);

}

static void dma_tasklet(unsigned long data)
{
        struct d40_chan *d40c = (struct d40_chan *) data;
        struct d40_desc *d40d;
        unsigned long flags;
        dma_async_tx_callback callback;
        void *callback_param;

        spin_lock_irqsave(&d40c->lock, flags);

        /* Get first active entry from list */
        d40d = d40_first_active_get(d40c);
        if (d40d == NULL)
                goto err;

        if (!d40d->cyclic)
                dma_cookie_complete(&d40d->txd);

        /*
         * If terminating a channel pending_tx is set to zero.
         * This prevents any finished active jobs to return to the client.
         */
        if (d40c->pending_tx == 0) {
                spin_unlock_irqrestore(&d40c->lock, flags);
                return;
        }

        /* Callback to client */
        callback = d40d->txd.callback;
        callback_param = d40d->txd.callback_param;

        if (!d40d->cyclic) {
                if (async_tx_test_ack(&d40d->txd)) {
                        d40_desc_remove(d40d);
                        d40_desc_free(d40c, d40d);
                } else {
                        if (!d40d->is_in_client_list) {
                                d40_desc_remove(d40d);
                                d40_lcla_free_all(d40c, d40d);
                                list_add_tail(&d40d->node, &d40c->client);
                                d40d->is_in_client_list = true;
                        }
                }
        }

        d40c->pending_tx--;

        if (d40c->pending_tx)
                tasklet_schedule(&d40c->tasklet);

        spin_unlock_irqrestore(&d40c->lock, flags);

        if (callback && (d40d->txd.flags & DMA_PREP_INTERRUPT))
                callback(callback_param);

        return;

err:
        /* Rescue manouver if receiving double interrupts */
        if (d40c->pending_tx > 0)
                d40c->pending_tx--;
        spin_unlock_irqrestore(&d40c->lock, flags);
}

static irqreturn_t d40_handle_interrupt(int irq, void *data)
{
        static const struct d40_interrupt_lookup il[] = {
                {D40_DREG_LCTIS0, D40_DREG_LCICR0, false,  0},
                {D40_DREG_LCTIS1, D40_DREG_LCICR1, false, 32},
                {D40_DREG_LCTIS2, D40_DREG_LCICR2, false, 64},
                {D40_DREG_LCTIS3, D40_DREG_LCICR3, false, 96},
                {D40_DREG_LCEIS0, D40_DREG_LCICR0, true,   0},
                {D40_DREG_LCEIS1, D40_DREG_LCICR1, true,  32},
                {D40_DREG_LCEIS2, D40_DREG_LCICR2, true,  64},
                {D40_DREG_LCEIS3, D40_DREG_LCICR3, true,  96},
                {D40_DREG_PCTIS,  D40_DREG_PCICR,  false, D40_PHY_CHAN},
                {D40_DREG_PCEIS,  D40_DREG_PCICR,  true,  D40_PHY_CHAN},
        };

        int i;
        u32 regs[ARRAY_SIZE(il)];
        u32 idx;
        u32 row;
        long chan = -1;
        struct d40_chan *d40c;
        unsigned long flags;
        struct d40_base *base = data;

        spin_lock_irqsave(&base->interrupt_lock, flags);

        /* Read interrupt status of both logical and physical channels */
        for (i = 0; i < ARRAY_SIZE(il); i++)
                regs[i] = readl(base->virtbase + il[i].src);

        for (;;) {

                chan = find_next_bit((unsigned long *)regs,
                                     BITS_PER_LONG * ARRAY_SIZE(il), chan + 1);

                /* No more set bits found? */
                if (chan == BITS_PER_LONG * ARRAY_SIZE(il))
                        break;

                row = chan / BITS_PER_LONG;
                idx = chan & (BITS_PER_LONG - 1);

                /* ACK interrupt */
                writel(1 << idx, base->virtbase + il[row].clr);

                if (il[row].offset == D40_PHY_CHAN)
                        d40c = base->lookup_phy_chans[idx];
                else
                        d40c = base->lookup_log_chans[il[row].offset + idx];
                spin_lock(&d40c->lock);

                if (!il[row].is_error)
                        dma_tc_handle(d40c);
                else
                        d40_err(base->dev, "IRQ chan: %ld offset %d idx %d\n",
                                chan, il[row].offset, idx);

                spin_unlock(&d40c->lock);
        }

        spin_unlock_irqrestore(&base->interrupt_lock, flags);

        return IRQ_HANDLED;
}

static int d40_validate_conf(struct d40_chan *d40c,
                             struct stedma40_chan_cfg *conf)
{
        int res = 0;
        u32 dst_event_group = D40_TYPE_TO_GROUP(conf->dst_dev_type);
        u32 src_event_group = D40_TYPE_TO_GROUP(conf->src_dev_type);
        bool is_log = conf->mode == STEDMA40_MODE_LOGICAL;

        if (!conf->dir) {
                chan_err(d40c, "Invalid direction.\n");
                res = -EINVAL;
        }

        if (conf->dst_dev_type != STEDMA40_DEV_DST_MEMORY &&
            d40c->base->plat_data->dev_tx[conf->dst_dev_type] == 0 &&
            d40c->runtime_addr == 0) {

                chan_err(d40c, "Invalid TX channel address (%d)\n",
                         conf->dst_dev_type);
                res = -EINVAL;
        }

        if (conf->src_dev_type != STEDMA40_DEV_SRC_MEMORY &&
            d40c->base->plat_data->dev_rx[conf->src_dev_type] == 0 &&
            d40c->runtime_addr == 0) {
                chan_err(d40c, "Invalid RX channel address (%d)\n",
                        conf->src_dev_type);
                res = -EINVAL;
        }

        if (conf->dir == STEDMA40_MEM_TO_PERIPH &&
            dst_event_group == STEDMA40_DEV_DST_MEMORY) {
                chan_err(d40c, "Invalid dst\n");
                res = -EINVAL;
        }

        if (conf->dir == STEDMA40_PERIPH_TO_MEM &&
            src_event_group == STEDMA40_DEV_SRC_MEMORY) {
                chan_err(d40c, "Invalid src\n");
                res = -EINVAL;
        }

        if (src_event_group == STEDMA40_DEV_SRC_MEMORY &&
            dst_event_group == STEDMA40_DEV_DST_MEMORY && is_log) {
                chan_err(d40c, "No event line\n");
                res = -EINVAL;
        }

        if (conf->dir == STEDMA40_PERIPH_TO_PERIPH &&
            (src_event_group != dst_event_group)) {
                chan_err(d40c, "Invalid event group\n");
                res = -EINVAL;
        }

        if (conf->dir == STEDMA40_PERIPH_TO_PERIPH) {
                /*
                 * DMAC HW supports it. Will be added to this driver,
                 * in case any dma client requires it.
                 */
                chan_err(d40c, "periph to periph not supported\n");
                res = -EINVAL;
        }

        if (d40_psize_2_burst_size(is_log, conf->src_info.psize) *
            (1 << conf->src_info.data_width) !=
            d40_psize_2_burst_size(is_log, conf->dst_info.psize) *
            (1 << conf->dst_info.data_width)) {
                /*
                 * The DMAC hardware only supports
                 * src (burst x width) == dst (burst x width)
                 */

                chan_err(d40c, "src (burst x width) != dst (burst x width)\n");
                res = -EINVAL;
        }

        return res;
}

static bool d40_alloc_mask_set(struct d40_phy_res *phy,
                               bool is_src, int log_event_line, bool is_log,
                               bool *first_user)
{
        unsigned long flags;
        spin_lock_irqsave(&phy->lock, flags);

        *first_user = ((phy->allocated_src | phy->allocated_dst)
                        == D40_ALLOC_FREE);

        if (!is_log) {
                /* Physical interrupts are masked per physical full channel */
                if (phy->allocated_src == D40_ALLOC_FREE &&
                    phy->allocated_dst == D40_ALLOC_FREE) {
                        phy->allocated_dst = D40_ALLOC_PHY;
                        phy->allocated_src = D40_ALLOC_PHY;
                        goto found;
                } else
                        goto not_found;
        }

        /* Logical channel */
        if (is_src) {
                if (phy->allocated_src == D40_ALLOC_PHY)
                        goto not_found;

                if (phy->allocated_src == D40_ALLOC_FREE)
                        phy->allocated_src = D40_ALLOC_LOG_FREE;

                if (!(phy->allocated_src & (1 << log_event_line))) {
                        phy->allocated_src |= 1 << log_event_line;
                        goto found;
                } else
                        goto not_found;
        } else {
                if (phy->allocated_dst == D40_ALLOC_PHY)
                        goto not_found;

                if (phy->allocated_dst == D40_ALLOC_FREE)
                        phy->allocated_dst = D40_ALLOC_LOG_FREE;

                if (!(phy->allocated_dst & (1 << log_event_line))) {
                        phy->allocated_dst |= 1 << log_event_line;
                        goto found;
                } else
                        goto not_found;
        }

not_found:
        spin_unlock_irqrestore(&phy->lock, flags);
        return false;
found:
        spin_unlock_irqrestore(&phy->lock, flags);
        return true;
}

static bool d40_alloc_mask_free(struct d40_phy_res *phy, bool is_src,
                               int log_event_line)
{
        unsigned long flags;
        bool is_free = false;

        spin_lock_irqsave(&phy->lock, flags);
        if (!log_event_line) {
                phy->allocated_dst = D40_ALLOC_FREE;
                phy->allocated_src = D40_ALLOC_FREE;
                is_free = true;
                goto out;
        }

        /* Logical channel */
        if (is_src) {
                phy->allocated_src &= ~(1 << log_event_line);
                if (phy->allocated_src == D40_ALLOC_LOG_FREE)
                        phy->allocated_src = D40_ALLOC_FREE;
        } else {
                phy->allocated_dst &= ~(1 << log_event_line);
                if (phy->allocated_dst == D40_ALLOC_LOG_FREE)
                        phy->allocated_dst = D40_ALLOC_FREE;
        }

        is_free = ((phy->allocated_src | phy->allocated_dst) ==
                   D40_ALLOC_FREE);

out:
        spin_unlock_irqrestore(&phy->lock, flags);

        return is_free;
}

static int d40_allocate_channel(struct d40_chan *d40c, bool *first_phy_user)
{
        int dev_type;
        int event_group;
        int event_line;
        struct d40_phy_res *phys;
        int i;
        int j;
        int log_num;
        bool is_src;
        bool is_log = d40c->dma_cfg.mode == STEDMA40_MODE_LOGICAL;

        phys = d40c->base->phy_res;

        if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM) {
                dev_type = d40c->dma_cfg.src_dev_type;
                log_num = 2 * dev_type;
                is_src = true;
        } else if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_PERIPH ||
                   d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM) {
                /* dst event lines are used for logical memcpy */
                dev_type = d40c->dma_cfg.dst_dev_type;
                log_num = 2 * dev_type + 1;
                is_src = false;
        } else
                return -EINVAL;

        event_group = D40_TYPE_TO_GROUP(dev_type);
        event_line = D40_TYPE_TO_EVENT(dev_type);

        if (!is_log) {
                if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM) {
                        /* Find physical half channel */
                        for (i = 0; i < d40c->base->num_phy_chans; i++) {

                                if (d40_alloc_mask_set(&phys[i], is_src,
                                                       0, is_log,
                                                       first_phy_user))
                                        goto found_phy;
                        }
                } else
                        for (j = 0; j < d40c->base->num_phy_chans; j += 8) {
                                int phy_num = j  + event_group * 2;
                                for (i = phy_num; i < phy_num + 2; i++) {
                                        if (d40_alloc_mask_set(&phys[i],
                                                               is_src,
                                                               0,
                                                               is_log,
                                                               first_phy_user))
                                                goto found_phy;
                                }
                        }
                return -EINVAL;
found_phy:
                d40c->phy_chan = &phys[i];
                d40c->log_num = D40_PHY_CHAN;
                goto out;
        }
        if (dev_type == -1)
                return -EINVAL;

        /* Find logical channel */
        for (j = 0; j < d40c->base->num_phy_chans; j += 8) {
                int phy_num = j + event_group * 2;

                if (d40c->dma_cfg.use_fixed_channel) {
                        i = d40c->dma_cfg.phy_channel;

                        if ((i != phy_num) && (i != phy_num + 1)) {
                                dev_err(chan2dev(d40c),
                                        "invalid fixed phy channel %d\n", i);
                                return -EINVAL;
                        }

                        if (d40_alloc_mask_set(&phys[i], is_src, event_line,
                                               is_log, first_phy_user))
                                goto found_log;

                        dev_err(chan2dev(d40c),
                                "could not allocate fixed phy channel %d\n", i);
                        return -EINVAL;
                }

                /*
                 * Spread logical channels across all available physical rather
                 * than pack every logical channel at the first available phy
                 * channels.
                 */
                if (is_src) {
                        for (i = phy_num; i < phy_num + 2; i++) {
                                if (d40_alloc_mask_set(&phys[i], is_src,
                                                       event_line, is_log,
                                                       first_phy_user))
                                        goto found_log;
                        }
                } else {
                        for (i = phy_num + 1; i >= phy_num; i--) {
                                if (d40_alloc_mask_set(&phys[i], is_src,
                                                       event_line, is_log,
                                                       first_phy_user))
                                        goto found_log;
                        }
                }
        }
        return -EINVAL;

found_log:
        d40c->phy_chan = &phys[i];
        d40c->log_num = log_num;
out:

        if (is_log)
                d40c->base->lookup_log_chans[d40c->log_num] = d40c;
        else
                d40c->base->lookup_phy_chans[d40c->phy_chan->num] = d40c;

        return 0;

}

static int d40_config_memcpy(struct d40_chan *d40c)
{
        dma_cap_mask_t cap = d40c->chan.device->cap_mask;

        if (dma_has_cap(DMA_MEMCPY, cap) && !dma_has_cap(DMA_SLAVE, cap)) {
                d40c->dma_cfg = *d40c->base->plat_data->memcpy_conf_log;
                d40c->dma_cfg.src_dev_type = STEDMA40_DEV_SRC_MEMORY;
                d40c->dma_cfg.dst_dev_type = d40c->base->plat_data->
                        memcpy[d40c->chan.chan_id];

        } else if (dma_has_cap(DMA_MEMCPY, cap) &&
                   dma_has_cap(DMA_SLAVE, cap)) {
                d40c->dma_cfg = *d40c->base->plat_data->memcpy_conf_phy;
        } else {
                chan_err(d40c, "No memcpy\n");
                return -EINVAL;
        }

        return 0;
}

static int d40_free_dma(struct d40_chan *d40c)
{

        int res = 0;
        u32 event;
        struct d40_phy_res *phy = d40c->phy_chan;
        bool is_src;

        /* Terminate all queued and active transfers */
        d40_term_all(d40c);

        if (phy == NULL) {
                chan_err(d40c, "phy == null\n");
                return -EINVAL;
        }

        if (phy->allocated_src == D40_ALLOC_FREE &&
            phy->allocated_dst == D40_ALLOC_FREE) {
                chan_err(d40c, "channel already free\n");
                return -EINVAL;
        }

        if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_PERIPH ||
            d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM) {
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
                is_src = false;
        } else if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM) {
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);
                is_src = true;
        } else {
                chan_err(d40c, "Unknown direction\n");
                return -EINVAL;
        }

        pm_runtime_get_sync(d40c->base->dev);
        res = d40_channel_execute_command(d40c, D40_DMA_STOP);
        if (res) {
                chan_err(d40c, "stop failed\n");
                goto out;
        }

        d40_alloc_mask_free(phy, is_src, chan_is_logical(d40c) ? event : 0);

        if (chan_is_logical(d40c))
                d40c->base->lookup_log_chans[d40c->log_num] = NULL;
        else
                d40c->base->lookup_phy_chans[phy->num] = NULL;

        if (d40c->busy) {
                pm_runtime_mark_last_busy(d40c->base->dev);
                pm_runtime_put_autosuspend(d40c->base->dev);
        }

        d40c->busy = false;
        d40c->phy_chan = NULL;
        d40c->configured = false;
out:

        pm_runtime_mark_last_busy(d40c->base->dev);
        pm_runtime_put_autosuspend(d40c->base->dev);
        return res;
}

static bool d40_is_paused(struct d40_chan *d40c)
{
        void __iomem *chanbase = chan_base(d40c);
        bool is_paused = false;
        unsigned long flags;
        void __iomem *active_reg;
        u32 status;
        u32 event;

        spin_lock_irqsave(&d40c->lock, flags);

        if (chan_is_physical(d40c)) {
                if (d40c->phy_chan->num % 2 == 0)
                        active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
                else
                        active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;

                status = (readl(active_reg) &
                          D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
                        D40_CHAN_POS(d40c->phy_chan->num);
                if (status == D40_DMA_SUSPENDED || status == D40_DMA_STOP)
                        is_paused = true;

                goto _exit;
        }

        if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_PERIPH ||
            d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM) {
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
                status = readl(chanbase + D40_CHAN_REG_SDLNK);
        } else if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM) {
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);
                status = readl(chanbase + D40_CHAN_REG_SSLNK);
        } else {
                chan_err(d40c, "Unknown direction\n");
                goto _exit;
        }

        status = (status & D40_EVENTLINE_MASK(event)) >>
                D40_EVENTLINE_POS(event);

        if (status != D40_DMA_RUN)
                is_paused = true;
_exit:
        spin_unlock_irqrestore(&d40c->lock, flags);
        return is_paused;

}


static u32 stedma40_residue(struct dma_chan *chan)
{
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        u32 bytes_left;
        unsigned long flags;

        spin_lock_irqsave(&d40c->lock, flags);
        bytes_left = d40_residue(d40c);
        spin_unlock_irqrestore(&d40c->lock, flags);

        return bytes_left;
}

static int
d40_prep_sg_log(struct d40_chan *chan, struct d40_desc *desc,
                struct scatterlist *sg_src, struct scatterlist *sg_dst,
                unsigned int sg_len, dma_addr_t src_dev_addr,
                dma_addr_t dst_dev_addr)
{
        struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
        struct stedma40_half_channel_info *src_info = &cfg->src_info;
        struct stedma40_half_channel_info *dst_info = &cfg->dst_info;
        int ret;

        ret = d40_log_sg_to_lli(sg_src, sg_len,
                                src_dev_addr,
                                desc->lli_log.src,
                                chan->log_def.lcsp1,
                                src_info->data_width,
                                dst_info->data_width);

        ret = d40_log_sg_to_lli(sg_dst, sg_len,
                                dst_dev_addr,
                                desc->lli_log.dst,
                                chan->log_def.lcsp3,
                                dst_info->data_width,
                                src_info->data_width);

        return ret < 0 ? ret : 0;
}

static int
d40_prep_sg_phy(struct d40_chan *chan, struct d40_desc *desc,
                struct scatterlist *sg_src, struct scatterlist *sg_dst,
                unsigned int sg_len, dma_addr_t src_dev_addr,
                dma_addr_t dst_dev_addr)
{
        struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
        struct stedma40_half_channel_info *src_info = &cfg->src_info;
        struct stedma40_half_channel_info *dst_info = &cfg->dst_info;
        unsigned long flags = 0;
        int ret;

        if (desc->cyclic)
                flags |= LLI_CYCLIC | LLI_TERM_INT;

        ret = d40_phy_sg_to_lli(sg_src, sg_len, src_dev_addr,
                                desc->lli_phy.src,
                                virt_to_phys(desc->lli_phy.src),
                                chan->src_def_cfg,
                                src_info, dst_info, flags);

        ret = d40_phy_sg_to_lli(sg_dst, sg_len, dst_dev_addr,
                                desc->lli_phy.dst,
                                virt_to_phys(desc->lli_phy.dst),
                                chan->dst_def_cfg,
                                dst_info, src_info, flags);

        dma_sync_single_for_device(chan->base->dev, desc->lli_pool.dma_addr,
                                   desc->lli_pool.size, DMA_TO_DEVICE);

        return ret < 0 ? ret : 0;
}


static struct d40_desc *
d40_prep_desc(struct d40_chan *chan, struct scatterlist *sg,
              unsigned int sg_len, unsigned long dma_flags)
{
        struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
        struct d40_desc *desc;
        int ret;

        desc = d40_desc_get(chan);
        if (!desc)
                return NULL;

        desc->lli_len = d40_sg_2_dmalen(sg, sg_len, cfg->src_info.data_width,
                                        cfg->dst_info.data_width);
        if (desc->lli_len < 0) {
                chan_err(chan, "Unaligned size\n");
                goto err;
        }

        ret = d40_pool_lli_alloc(chan, desc, desc->lli_len);
        if (ret < 0) {
                chan_err(chan, "Could not allocate lli\n");
                goto err;
        }


        desc->lli_current = 0;
        desc->txd.flags = dma_flags;
        desc->txd.tx_submit = d40_tx_submit;

        dma_async_tx_descriptor_init(&desc->txd, &chan->chan);

        return desc;

err:
        d40_desc_free(chan, desc);
        return NULL;
}

static dma_addr_t
d40_get_dev_addr(struct d40_chan *chan, enum dma_transfer_direction direction)
{
        struct stedma40_platform_data *plat = chan->base->plat_data;
        struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
        dma_addr_t addr = 0;

        if (chan->runtime_addr)
                return chan->runtime_addr;

        if (direction == DMA_DEV_TO_MEM)
                addr = plat->dev_rx[cfg->src_dev_type];
        else if (direction == DMA_MEM_TO_DEV)
                addr = plat->dev_tx[cfg->dst_dev_type];

        return addr;
}

static struct dma_async_tx_descriptor *
d40_prep_sg(struct dma_chan *dchan, struct scatterlist *sg_src,
            struct scatterlist *sg_dst, unsigned int sg_len,
            enum dma_transfer_direction direction, unsigned long dma_flags)
{
        struct d40_chan *chan = container_of(dchan, struct d40_chan, chan);
        dma_addr_t src_dev_addr = 0;
        dma_addr_t dst_dev_addr = 0;
        struct d40_desc *desc;
        unsigned long flags;
        int ret;

        if (!chan->phy_chan) {
                chan_err(chan, "Cannot prepare unallocated channel\n");
                return NULL;
        }


        spin_lock_irqsave(&chan->lock, flags);

        desc = d40_prep_desc(chan, sg_src, sg_len, dma_flags);
        if (desc == NULL)
                goto err;

        if (sg_next(&sg_src[sg_len - 1]) == sg_src)
                desc->cyclic = true;

        if (direction != DMA_TRANS_NONE) {
                dma_addr_t dev_addr = d40_get_dev_addr(chan, direction);

                if (direction == DMA_DEV_TO_MEM)
                        src_dev_addr = dev_addr;
                else if (direction == DMA_MEM_TO_DEV)
                        dst_dev_addr = dev_addr;
        }

        if (chan_is_logical(chan))
                ret = d40_prep_sg_log(chan, desc, sg_src, sg_dst,
                                      sg_len, src_dev_addr, dst_dev_addr);
        else
                ret = d40_prep_sg_phy(chan, desc, sg_src, sg_dst,
                                      sg_len, src_dev_addr, dst_dev_addr);

        if (ret) {
                chan_err(chan, "Failed to prepare %s sg job: %d\n",
                         chan_is_logical(chan) ? "log" : "phy", ret);
                goto err;
        }

        /*
         * add descriptor to the prepare queue in order to be able
         * to free them later in terminate_all
         */
        list_add_tail(&desc->node, &chan->prepare_queue);

        spin_unlock_irqrestore(&chan->lock, flags);

        return &desc->txd;

err:
        if (desc)
                d40_desc_free(chan, desc);
        spin_unlock_irqrestore(&chan->lock, flags);
        return NULL;
}

bool stedma40_filter(struct dma_chan *chan, void *data)
{
        struct stedma40_chan_cfg *info = data;
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        int err;

        if (data) {
                err = d40_validate_conf(d40c, info);
                if (!err)
                        d40c->dma_cfg = *info;
        } else
                err = d40_config_memcpy(d40c);

        if (!err)
                d40c->configured = true;

        return err == 0;
}
EXPORT_SYMBOL(stedma40_filter);

static void __d40_set_prio_rt(struct d40_chan *d40c, int dev_type, bool src)
{
        bool realtime = d40c->dma_cfg.realtime;
        bool highprio = d40c->dma_cfg.high_priority;
        u32 prioreg = highprio ? D40_DREG_PSEG1 : D40_DREG_PCEG1;
        u32 rtreg = realtime ? D40_DREG_RSEG1 : D40_DREG_RCEG1;
        u32 event = D40_TYPE_TO_EVENT(dev_type);
        u32 group = D40_TYPE_TO_GROUP(dev_type);
        u32 bit = 1 << event;

        /* Destination event lines are stored in the upper halfword */
        if (!src)
                bit <<= 16;

        writel(bit, d40c->base->virtbase + prioreg + group * 4);
        writel(bit, d40c->base->virtbase + rtreg + group * 4);
}

static void d40_set_prio_realtime(struct d40_chan *d40c)
{
        if (d40c->base->rev < 3)
                return;

        if ((d40c->dma_cfg.dir ==  STEDMA40_PERIPH_TO_MEM) ||
            (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH))
                __d40_set_prio_rt(d40c, d40c->dma_cfg.src_dev_type, true);

        if ((d40c->dma_cfg.dir ==  STEDMA40_MEM_TO_PERIPH) ||
            (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH))
                __d40_set_prio_rt(d40c, d40c->dma_cfg.dst_dev_type, false);
}

/* DMA ENGINE functions */
static int d40_alloc_chan_resources(struct dma_chan *chan)
{
        int err;
        unsigned long flags;
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        bool is_free_phy;
        spin_lock_irqsave(&d40c->lock, flags);

        dma_cookie_init(chan);

        /* If no dma configuration is set use default configuration (memcpy) */
        if (!d40c->configured) {
                err = d40_config_memcpy(d40c);
                if (err) {
                        chan_err(d40c, "Failed to configure memcpy channel\n");
                        goto fail;
                }
        }

        err = d40_allocate_channel(d40c, &is_free_phy);
        if (err) {
                chan_err(d40c, "Failed to allocate channel\n");
                d40c->configured = false;
                goto fail;
        }

        pm_runtime_get_sync(d40c->base->dev);
        /* Fill in basic CFG register values */
        d40_phy_cfg(&d40c->dma_cfg, &d40c->src_def_cfg,
                    &d40c->dst_def_cfg, chan_is_logical(d40c));

        d40_set_prio_realtime(d40c);

        if (chan_is_logical(d40c)) {
                d40_log_cfg(&d40c->dma_cfg,
                            &d40c->log_def.lcsp1, &d40c->log_def.lcsp3);

                if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM)
                        d40c->lcpa = d40c->base->lcpa_base +
                          d40c->dma_cfg.src_dev_type * D40_LCPA_CHAN_SIZE;
                else
                        d40c->lcpa = d40c->base->lcpa_base +
                          d40c->dma_cfg.dst_dev_type *
                          D40_LCPA_CHAN_SIZE + D40_LCPA_CHAN_DST_DELTA;
        }

        dev_dbg(chan2dev(d40c), "allocated %s channel (phy %d%s)\n",
                 chan_is_logical(d40c) ? "logical" : "physical",
                 d40c->phy_chan->num,
                 d40c->dma_cfg.use_fixed_channel ? ", fixed" : "");


        /*
         * Only write channel configuration to the DMA if the physical
         * resource is free. In case of multiple logical channels
         * on the same physical resource, only the first write is necessary.
         */
        if (is_free_phy)
                d40_config_write(d40c);
fail:
        pm_runtime_mark_last_busy(d40c->base->dev);
        pm_runtime_put_autosuspend(d40c->base->dev);
        spin_unlock_irqrestore(&d40c->lock, flags);
        return err;
}

static void d40_free_chan_resources(struct dma_chan *chan)
{
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        int err;
        unsigned long flags;

        if (d40c->phy_chan == NULL) {
                chan_err(d40c, "Cannot free unallocated channel\n");
                return;
        }


        spin_lock_irqsave(&d40c->lock, flags);

        err = d40_free_dma(d40c);

        if (err)
                chan_err(d40c, "Failed to free channel\n");
        spin_unlock_irqrestore(&d40c->lock, flags);
}

static struct dma_async_tx_descriptor *d40_prep_memcpy(struct dma_chan *chan,
                                                       dma_addr_t dst,
                                                       dma_addr_t src,
                                                       size_t size,
                                                       unsigned long dma_flags)
{
        struct scatterlist dst_sg;
        struct scatterlist src_sg;

        sg_init_table(&dst_sg, 1);
        sg_init_table(&src_sg, 1);

        sg_dma_address(&dst_sg) = dst;
        sg_dma_address(&src_sg) = src;

        sg_dma_len(&dst_sg) = size;
        sg_dma_len(&src_sg) = size;

        return d40_prep_sg(chan, &src_sg, &dst_sg, 1, DMA_NONE, dma_flags);
}

static struct dma_async_tx_descriptor *
d40_prep_memcpy_sg(struct dma_chan *chan,
                   struct scatterlist *dst_sg, unsigned int dst_nents,
                   struct scatterlist *src_sg, unsigned int src_nents,
                   unsigned long dma_flags)
{
        if (dst_nents != src_nents)
                return NULL;

        return d40_prep_sg(chan, src_sg, dst_sg, src_nents, DMA_NONE, dma_flags);
}

static struct dma_async_tx_descriptor *d40_prep_slave_sg(struct dma_chan *chan,
                                                         struct scatterlist *sgl,
                                                         unsigned int sg_len,
                                                         enum dma_transfer_direction direction,
                                                         unsigned long dma_flags,
                                                         void *context)
{
        if (direction != DMA_DEV_TO_MEM && direction != DMA_MEM_TO_DEV)
                return NULL;

        return d40_prep_sg(chan, sgl, sgl, sg_len, direction, dma_flags);
}

static struct dma_async_tx_descriptor *
dma40_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t dma_addr,
                     size_t buf_len, size_t period_len,
                     enum dma_transfer_direction direction, unsigned long flags,
                     void *context)
{
        unsigned int periods = buf_len / period_len;
        struct dma_async_tx_descriptor *txd;
        struct scatterlist *sg;
        int i;

        sg = kcalloc(periods + 1, sizeof(struct scatterlist), GFP_NOWAIT);
        for (i = 0; i < periods; i++) {
                sg_dma_address(&sg[i]) = dma_addr;
                sg_dma_len(&sg[i]) = period_len;
                dma_addr += period_len;
        }

        sg[periods].offset = 0;
        sg_dma_len(&sg[periods]) = 0;
        sg[periods].page_link =
                ((unsigned long)sg | 0x01) & ~0x02;

        txd = d40_prep_sg(chan, sg, sg, periods, direction,
                          DMA_PREP_INTERRUPT);

        kfree(sg);

        return txd;
}

static enum dma_status d40_tx_status(struct dma_chan *chan,
                                     dma_cookie_t cookie,
                                     struct dma_tx_state *txstate)
{
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
        enum dma_status ret;

        if (d40c->phy_chan == NULL) {
                chan_err(d40c, "Cannot read status of unallocated channel\n");
                return -EINVAL;
        }

        ret = dma_cookie_status(chan, cookie, txstate);
        if (ret != DMA_SUCCESS)
                dma_set_residue(txstate, stedma40_residue(chan));

        if (d40_is_paused(d40c))
                ret = DMA_PAUSED;

        return ret;
}

static void d40_issue_pending(struct dma_chan *chan)
{
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
        unsigned long flags;

        if (d40c->phy_chan == NULL) {
                chan_err(d40c, "Channel is not allocated!\n");
                return;
        }

        spin_lock_irqsave(&d40c->lock, flags);

        list_splice_tail_init(&d40c->pending_queue, &d40c->queue);

        /* Busy means that queued jobs are already being processed */
        if (!d40c->busy)
                (void) d40_queue_start(d40c);

        spin_unlock_irqrestore(&d40c->lock, flags);
}

static void d40_terminate_all(struct dma_chan *chan)
{
        unsigned long flags;
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
        int ret;

        spin_lock_irqsave(&d40c->lock, flags);

        pm_runtime_get_sync(d40c->base->dev);
        ret = d40_channel_execute_command(d40c, D40_DMA_STOP);
        if (ret)
                chan_err(d40c, "Failed to stop channel\n");

        d40_term_all(d40c);
        pm_runtime_mark_last_busy(d40c->base->dev);
        pm_runtime_put_autosuspend(d40c->base->dev);
        if (d40c->busy) {
                pm_runtime_mark_last_busy(d40c->base->dev);
                pm_runtime_put_autosuspend(d40c->base->dev);
        }
        d40c->busy = false;

        spin_unlock_irqrestore(&d40c->lock, flags);
}

static int
dma40_config_to_halfchannel(struct d40_chan *d40c,
                            struct stedma40_half_channel_info *info,
                            enum dma_slave_buswidth width,
                            u32 maxburst)
{
        enum stedma40_periph_data_width addr_width;
        int psize;

        switch (width) {
        case DMA_SLAVE_BUSWIDTH_1_BYTE:
                addr_width = STEDMA40_BYTE_WIDTH;
                break;
        case DMA_SLAVE_BUSWIDTH_2_BYTES:
                addr_width = STEDMA40_HALFWORD_WIDTH;
                break;
        case DMA_SLAVE_BUSWIDTH_4_BYTES:
                addr_width = STEDMA40_WORD_WIDTH;
                break;
        case DMA_SLAVE_BUSWIDTH_8_BYTES:
                addr_width = STEDMA40_DOUBLEWORD_WIDTH;
                break;
        default:
                dev_err(d40c->base->dev,
                        "illegal peripheral address width "
                        "requested (%d)\n",
                        width);
                return -EINVAL;
        }

        if (chan_is_logical(d40c)) {
                if (maxburst >= 16)
                        psize = STEDMA40_PSIZE_LOG_16;
                else if (maxburst >= 8)
                        psize = STEDMA40_PSIZE_LOG_8;
                else if (maxburst >= 4)
                        psize = STEDMA40_PSIZE_LOG_4;
                else
                        psize = STEDMA40_PSIZE_LOG_1;
        } else {
                if (maxburst >= 16)
                        psize = STEDMA40_PSIZE_PHY_16;
                else if (maxburst >= 8)
                        psize = STEDMA40_PSIZE_PHY_8;
                else if (maxburst >= 4)
                        psize = STEDMA40_PSIZE_PHY_4;
                else
                        psize = STEDMA40_PSIZE_PHY_1;
        }

        info->data_width = addr_width;
        info->psize = psize;
        info->flow_ctrl = STEDMA40_NO_FLOW_CTRL;

        return 0;
}

/* Runtime reconfiguration extension */
static int d40_set_runtime_config(struct dma_chan *chan,
                                  struct dma_slave_config *config)
{
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
        struct stedma40_chan_cfg *cfg = &d40c->dma_cfg;
        enum dma_slave_buswidth src_addr_width, dst_addr_width;
        dma_addr_t config_addr;
        u32 src_maxburst, dst_maxburst;
        int ret;

        src_addr_width = config->src_addr_width;
        src_maxburst = config->src_maxburst;
        dst_addr_width = config->dst_addr_width;
        dst_maxburst = config->dst_maxburst;

        if (config->direction == DMA_DEV_TO_MEM) {
                dma_addr_t dev_addr_rx =
                        d40c->base->plat_data->dev_rx[cfg->src_dev_type];

                config_addr = config->src_addr;
                if (dev_addr_rx)
                        dev_dbg(d40c->base->dev,
                                "channel has a pre-wired RX address %08x "
                                "overriding with %08x\n",
                                dev_addr_rx, config_addr);
                if (cfg->dir != STEDMA40_PERIPH_TO_MEM)
                        dev_dbg(d40c->base->dev,
                                "channel was not configured for peripheral "
                                "to memory transfer (%d) overriding\n",
                                cfg->dir);
                cfg->dir = STEDMA40_PERIPH_TO_MEM;

                /* Configure the memory side */
                if (dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
                        dst_addr_width = src_addr_width;
                if (dst_maxburst == 0)
                        dst_maxburst = src_maxburst;

        } else if (config->direction == DMA_MEM_TO_DEV) {
                dma_addr_t dev_addr_tx =
                        d40c->base->plat_data->dev_tx[cfg->dst_dev_type];

                config_addr = config->dst_addr;
                if (dev_addr_tx)
                        dev_dbg(d40c->base->dev,
                                "channel has a pre-wired TX address %08x "
                                "overriding with %08x\n",
                                dev_addr_tx, config_addr);
                if (cfg->dir != STEDMA40_MEM_TO_PERIPH)
                        dev_dbg(d40c->base->dev,
                                "channel was not configured for memory "
                                "to peripheral transfer (%d) overriding\n",
                                cfg->dir);
                cfg->dir = STEDMA40_MEM_TO_PERIPH;

                /* Configure the memory side */
                if (src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
                        src_addr_width = dst_addr_width;
                if (src_maxburst == 0)
                        src_maxburst = dst_maxburst;
        } else {
                dev_err(d40c->base->dev,
                        "unrecognized channel direction %d\n",
                        config->direction);
                return -EINVAL;
        }

        if (src_maxburst * src_addr_width != dst_maxburst * dst_addr_width) {
                dev_err(d40c->base->dev,
                        "src/dst width/maxburst mismatch: %d*%d != %d*%d\n",
                        src_maxburst,
                        src_addr_width,
                        dst_maxburst,
                        dst_addr_width);
                return -EINVAL;
        }

        ret = dma40_config_to_halfchannel(d40c, &cfg->src_info,
                                          src_addr_width,
                                          src_maxburst);
        if (ret)
                return ret;

        ret = dma40_config_to_halfchannel(d40c, &cfg->dst_info,
                                          dst_addr_width,
                                          dst_maxburst);
        if (ret)
                return ret;

        /* Fill in register values */
        if (chan_is_logical(d40c))
                d40_log_cfg(cfg, &d40c->log_def.lcsp1, &d40c->log_def.lcsp3);
        else
                d40_phy_cfg(cfg, &d40c->src_def_cfg,
                            &d40c->dst_def_cfg, false);

        /* These settings will take precedence later */
        d40c->runtime_addr = config_addr;
        d40c->runtime_direction = config->direction;
        dev_dbg(d40c->base->dev,
                "configured channel %s for %s, data width %d/%d, "
                "maxburst %d/%d elements, LE, no flow control\n",
                dma_chan_name(chan),
                (config->direction == DMA_DEV_TO_MEM) ? "RX" : "TX",
                src_addr_width, dst_addr_width,
                src_maxburst, dst_maxburst);

        return 0;
}

static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
                       unsigned long arg)
{
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);

        if (d40c->phy_chan == NULL) {
                chan_err(d40c, "Channel is not allocated!\n");
                return -EINVAL;
        }

        switch (cmd) {
        case DMA_TERMINATE_ALL:
                d40_terminate_all(chan);
                return 0;
        case DMA_PAUSE:
                return d40_pause(d40c);
        case DMA_RESUME:
                return d40_resume(d40c);
        case DMA_SLAVE_CONFIG:
                return d40_set_runtime_config(chan,
                        (struct dma_slave_config *) arg);
        default:
                break;
        }

        /* Other commands are unimplemented */
        return -ENXIO;
}

/* Initialization functions */

static void __init d40_chan_init(struct d40_base *base, struct dma_device *dma,
                                 struct d40_chan *chans, int offset,
                                 int num_chans)
{
        int i = 0;
        struct d40_chan *d40c;

        INIT_LIST_HEAD(&dma->channels);

        for (i = offset; i < offset + num_chans; i++) {
                d40c = &chans[i];
                d40c->base = base;
                d40c->chan.device = dma;

                spin_lock_init(&d40c->lock);

                d40c->log_num = D40_PHY_CHAN;

                INIT_LIST_HEAD(&d40c->active);
                INIT_LIST_HEAD(&d40c->queue);
                INIT_LIST_HEAD(&d40c->pending_queue);
                INIT_LIST_HEAD(&d40c->client);
                INIT_LIST_HEAD(&d40c->prepare_queue);

                tasklet_init(&d40c->tasklet, dma_tasklet,
                             (unsigned long) d40c);

                list_add_tail(&d40c->chan.device_node,
                              &dma->channels);
        }
}

static void d40_ops_init(struct d40_base *base, struct dma_device *dev)
{
        if (dma_has_cap(DMA_SLAVE, dev->cap_mask))
                dev->device_prep_slave_sg = d40_prep_slave_sg;

        if (dma_has_cap(DMA_MEMCPY, dev->cap_mask)) {
                dev->device_prep_dma_memcpy = d40_prep_memcpy;

                /*
                 * This controller can only access address at even
                 * 32bit boundaries, i.e. 2^2
                 */
                dev->copy_align = 2;
        }

        if (dma_has_cap(DMA_SG, dev->cap_mask))
                dev->device_prep_dma_sg = d40_prep_memcpy_sg;

        if (dma_has_cap(DMA_CYCLIC, dev->cap_mask))
                dev->device_prep_dma_cyclic = dma40_prep_dma_cyclic;

        dev->device_alloc_chan_resources = d40_alloc_chan_resources;
        dev->device_free_chan_resources = d40_free_chan_resources;
        dev->device_issue_pending = d40_issue_pending;
        dev->device_tx_status = d40_tx_status;
        dev->device_control = d40_control;
        dev->dev = base->dev;
}

static int __init d40_dmaengine_init(struct d40_base *base,
                                     int num_reserved_chans)
{
        int err ;

        d40_chan_init(base, &base->dma_slave, base->log_chans,
                      0, base->num_log_chans);

        dma_cap_zero(base->dma_slave.cap_mask);
        dma_cap_set(DMA_SLAVE, base->dma_slave.cap_mask);
        dma_cap_set(DMA_CYCLIC, base->dma_slave.cap_mask);

        d40_ops_init(base, &base->dma_slave);

        err = dma_async_device_register(&base->dma_slave);

        if (err) {
                d40_err(base->dev, "Failed to register slave channels\n");
                goto failure1;
        }

        d40_chan_init(base, &base->dma_memcpy, base->log_chans,
                      base->num_log_chans, base->plat_data->memcpy_len);

        dma_cap_zero(base->dma_memcpy.cap_mask);
        dma_cap_set(DMA_MEMCPY, base->dma_memcpy.cap_mask);
        dma_cap_set(DMA_SG, base->dma_memcpy.cap_mask);

        d40_ops_init(base, &base->dma_memcpy);

        err = dma_async_device_register(&base->dma_memcpy);

        if (err) {
                d40_err(base->dev,
                        "Failed to regsiter memcpy only channels\n");
                goto failure2;
        }

        d40_chan_init(base, &base->dma_both, base->phy_chans,
                      0, num_reserved_chans);

        dma_cap_zero(base->dma_both.cap_mask);
        dma_cap_set(DMA_SLAVE, base->dma_both.cap_mask);
        dma_cap_set(DMA_MEMCPY, base->dma_both.cap_mask);
        dma_cap_set(DMA_SG, base->dma_both.cap_mask);
        dma_cap_set(DMA_CYCLIC, base->dma_slave.cap_mask);

        d40_ops_init(base, &base->dma_both);
        err = dma_async_device_register(&base->dma_both);

        if (err) {
                d40_err(base->dev,
                        "Failed to register logical and physical capable channels\n");
                goto failure3;
        }
        return 0;
failure3:
        dma_async_device_unregister(&base->dma_memcpy);
failure2:
        dma_async_device_unregister(&base->dma_slave);
failure1:
        return err;
}

/* Suspend resume functionality */
#ifdef CONFIG_PM
static int dma40_pm_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct d40_base *base = platform_get_drvdata(pdev);
        int ret = 0;
        if (!pm_runtime_suspended(dev))
                return -EBUSY;

        if (base->lcpa_regulator)
                ret = regulator_disable(base->lcpa_regulator);
        return ret;
}

static int dma40_runtime_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct d40_base *base = platform_get_drvdata(pdev);

        d40_save_restore_registers(base, true);

        /* Don't disable/enable clocks for v1 due to HW bugs */
        if (base->rev != 1)
                writel_relaxed(base->gcc_pwr_off_mask,
                               base->virtbase + D40_DREG_GCC);

        return 0;
}

static int dma40_runtime_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct d40_base *base = platform_get_drvdata(pdev);

        if (base->initialized)
                d40_save_restore_registers(base, false);

        writel_relaxed(D40_DREG_GCC_ENABLE_ALL,
                       base->virtbase + D40_DREG_GCC);
        return 0;
}

static int dma40_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct d40_base *base = platform_get_drvdata(pdev);
        int ret = 0;

        if (base->lcpa_regulator)
                ret = regulator_enable(base->lcpa_regulator);

        return ret;
}

static const struct dev_pm_ops dma40_pm_ops = {
        .suspend                = dma40_pm_suspend,
        .runtime_suspend        = dma40_runtime_suspend,
        .runtime_resume         = dma40_runtime_resume,
        .resume                 = dma40_resume,
};
#define DMA40_PM_OPS    (&dma40_pm_ops)
#else
#define DMA40_PM_OPS    NULL
#endif

/* Initialization functions. */

static int __init d40_phy_res_init(struct d40_base *base)
{
        int i;
        int num_phy_chans_avail = 0;
        u32 val[2];
        int odd_even_bit = -2;
        int gcc = D40_DREG_GCC_ENA;

        val[0] = readl(base->virtbase + D40_DREG_PRSME);
        val[1] = readl(base->virtbase + D40_DREG_PRSMO);

        for (i = 0; i < base->num_phy_chans; i++) {
                base->phy_res[i].num = i;
                odd_even_bit += 2 * ((i % 2) == 0);
                if (((val[i % 2] >> odd_even_bit) & 3) == 1) {
                        /* Mark security only channels as occupied */
                        base->phy_res[i].allocated_src = D40_ALLOC_PHY;
                        base->phy_res[i].allocated_dst = D40_ALLOC_PHY;
                        base->phy_res[i].reserved = true;
                        gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(i),
                                                       D40_DREG_GCC_SRC);
                        gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(i),
                                                       D40_DREG_GCC_DST);


                } else {
                        base->phy_res[i].allocated_src = D40_ALLOC_FREE;
                        base->phy_res[i].allocated_dst = D40_ALLOC_FREE;
                        base->phy_res[i].reserved = false;
                        num_phy_chans_avail++;
                }
                spin_lock_init(&base->phy_res[i].lock);
        }

        /* Mark disabled channels as occupied */
        for (i = 0; base->plat_data->disabled_channels[i] != -1; i++) {
                int chan = base->plat_data->disabled_channels[i];

                base->phy_res[chan].allocated_src = D40_ALLOC_PHY;
                base->phy_res[chan].allocated_dst = D40_ALLOC_PHY;
                base->phy_res[chan].reserved = true;
                gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(chan),
                                               D40_DREG_GCC_SRC);
                gcc |= D40_DREG_GCC_EVTGRP_ENA(D40_PHYS_TO_GROUP(chan),
                                               D40_DREG_GCC_DST);
                num_phy_chans_avail--;
        }

        dev_info(base->dev, "%d of %d physical DMA channels available\n",
                 num_phy_chans_avail, base->num_phy_chans);

        /* Verify settings extended vs standard */
        val[0] = readl(base->virtbase + D40_DREG_PRTYP);

        for (i = 0; i < base->num_phy_chans; i++) {

                if (base->phy_res[i].allocated_src == D40_ALLOC_FREE &&
                    (val[0] & 0x3) != 1)
                        dev_info(base->dev,
                                 "[%s] INFO: channel %d is misconfigured (%d)\n",
                                 __func__, i, val[0] & 0x3);

                val[0] = val[0] >> 2;
        }

        /*
         * To keep things simple, Enable all clocks initially.
         * The clocks will get managed later post channel allocation.
         * The clocks for the event lines on which reserved channels exists
         * are not managed here.
         */
        writel(D40_DREG_GCC_ENABLE_ALL, base->virtbase + D40_DREG_GCC);
        base->gcc_pwr_off_mask = gcc;

        return num_phy_chans_avail;
}

static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
{
        struct stedma40_platform_data *plat_data;
        struct clk *clk = NULL;
        void __iomem *virtbase = NULL;
        struct resource *res = NULL;
        struct d40_base *base = NULL;
        int num_log_chans = 0;
        int num_phy_chans;
        int clk_ret = -EINVAL;
        int i;
        u32 pid;
        u32 cid;
        u8 rev;

        clk = clk_get(&pdev->dev, NULL);
        if (IS_ERR(clk)) {
                d40_err(&pdev->dev, "No matching clock found\n");
                goto failure;
        }

        clk_ret = clk_prepare_enable(clk);
        if (clk_ret) {
                d40_err(&pdev->dev, "Failed to prepare/enable clock\n");
                goto failure;
        }

        /* Get IO for DMAC base address */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "base");
        if (!res)
                goto failure;

        if (request_mem_region(res->start, resource_size(res),
                               D40_NAME " I/O base") == NULL)
                goto failure;

        virtbase = ioremap(res->start, resource_size(res));
        if (!virtbase)
                goto failure;

        /* This is just a regular AMBA PrimeCell ID actually */
        for (pid = 0, i = 0; i < 4; i++)
                pid |= (readl(virtbase + resource_size(res) - 0x20 + 4 * i)
                        & 255) << (i * 8);
        for (cid = 0, i = 0; i < 4; i++)
                cid |= (readl(virtbase + resource_size(res) - 0x10 + 4 * i)
                        & 255) << (i * 8);

        if (cid != AMBA_CID) {
                d40_err(&pdev->dev, "Unknown hardware! No PrimeCell ID\n");
                goto failure;
        }
        if (AMBA_MANF_BITS(pid) != AMBA_VENDOR_ST) {
                d40_err(&pdev->dev, "Unknown designer! Got %x wanted %x\n",
                        AMBA_MANF_BITS(pid),
                        AMBA_VENDOR_ST);
                goto failure;
        }
        /*
         * HW revision:
         * DB8500ed has revision 0
         * ? has revision 1
         * DB8500v1 has revision 2
         * DB8500v2 has revision 3
         */
        rev = AMBA_REV_BITS(pid);

        /* The number of physical channels on this HW */
        num_phy_chans = 4 * (readl(virtbase + D40_DREG_ICFG) & 0x7) + 4;

        dev_info(&pdev->dev, "hardware revision: %d @ 0x%x\n",
                 rev, res->start);

        if (rev < 2) {
                d40_err(&pdev->dev, "hardware revision: %d is not supported",
                        rev);
                goto failure;
        }

        plat_data = pdev->dev.platform_data;

        /* Count the number of logical channels in use */
        for (i = 0; i < plat_data->dev_len; i++)
                if (plat_data->dev_rx[i] != 0)
                        num_log_chans++;