/*
 *  linux/drivers/net/wireless/libertas/if_sdio.c
 *
 *  Copyright 2007-2008 Pierre Ossman
 *
 * Inspired by if_cs.c, Copyright 2007 Holger Schurig
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This hardware has more or less no CMD53 support, so all registers
 * must be accessed using sdio_readb()/sdio_writeb().
 *
 * Transfers must be in one transaction or the firmware goes bonkers.
 * This means that the transfer must either be small enough to do a
 * byte based transfer or it must be padded to a multiple of the
 * current block size.
 *
 * As SDIO is still new to the kernel, it is unfortunately common with
 * bugs in the host controllers related to that. One such bug is that
 * controllers cannot do transfers that aren't a multiple of 4 bytes.
 * If you don't have time to fix the host controller driver, you can
 * work around the problem by modifying if_sdio_host_to_card() and
 * if_sdio_card_to_host() to pad the data.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/firmware.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sdio_func.h>
#include <linux/mmc/sdio_ids.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/host.h>
#include <linux/pm_runtime.h>

#include "host.h"
#include "decl.h"
#include "defs.h"
#include "dev.h"
#include "cmd.h"
#include "if_sdio.h"

static void if_sdio_interrupt(struct sdio_func *func);

/* The if_sdio_remove() callback function is called when
 * user removes this module from kernel space or ejects
 * the card from the slot. The driver handles these 2 cases
 * differently for SD8688 combo chip.
 * If the user is removing the module, the FUNC_SHUTDOWN
 * command for SD8688 is sent to the firmware.
 * If the card is removed, there is no need to send this command.
 *
 * The variable 'user_rmmod' is used to distinguish these two
 * scenarios. This flag is initialized as FALSE in case the card
 * is removed, and will be set to TRUE for module removal when
 * module_exit function is called.
 */
static u8 user_rmmod;

static const struct sdio_device_id if_sdio_ids[] = {
        { SDIO_DEVICE(SDIO_VENDOR_ID_MARVELL,
                        SDIO_DEVICE_ID_MARVELL_LIBERTAS) },
        { SDIO_DEVICE(SDIO_VENDOR_ID_MARVELL,
                        SDIO_DEVICE_ID_MARVELL_8688WLAN) },
        { /* end: all zeroes */                         },
};

MODULE_DEVICE_TABLE(sdio, if_sdio_ids);

#define MODEL_8385      0x04
#define MODEL_8686      0x0b
#define MODEL_8688      0x10

static const struct lbs_fw_table fw_table[] = {
        { MODEL_8385, "libertas/sd8385_helper.bin", "libertas/sd8385.bin" },
        { MODEL_8385, "sd8385_helper.bin", "sd8385.bin" },
        { MODEL_8686, "libertas/sd8686_v9_helper.bin", "libertas/sd8686_v9.bin" },
        { MODEL_8686, "libertas/sd8686_v8_helper.bin", "libertas/sd8686_v8.bin" },
        { MODEL_8686, "sd8686_helper.bin", "sd8686.bin" },
        { MODEL_8688, "libertas/sd8688_helper.bin", "libertas/sd8688.bin" },
        { MODEL_8688, "sd8688_helper.bin", "sd8688.bin" },
        { 0, NULL, NULL }
};
MODULE_FIRMWARE("libertas/sd8385_helper.bin");
MODULE_FIRMWARE("libertas/sd8385.bin");
MODULE_FIRMWARE("sd8385_helper.bin");
MODULE_FIRMWARE("sd8385.bin");
MODULE_FIRMWARE("libertas/sd8686_v9_helper.bin");
MODULE_FIRMWARE("libertas/sd8686_v9.bin");
MODULE_FIRMWARE("libertas/sd8686_v8_helper.bin");
MODULE_FIRMWARE("libertas/sd8686_v8.bin");
MODULE_FIRMWARE("sd8686_helper.bin");
MODULE_FIRMWARE("sd8686.bin");
MODULE_FIRMWARE("libertas/sd8688_helper.bin");
MODULE_FIRMWARE("libertas/sd8688.bin");
MODULE_FIRMWARE("sd8688_helper.bin");
MODULE_FIRMWARE("sd8688.bin");

struct if_sdio_packet {
        struct if_sdio_packet   *next;
        u16                     nb;
        u8                      buffer[0] __attribute__((aligned(4)));
};

struct if_sdio_card {
        struct sdio_func        *func;
        struct lbs_private      *priv;

        int                     model;
        unsigned long           ioport;
        unsigned int            scratch_reg;
        bool                    started;
        wait_queue_head_t       pwron_waitq;

        u8                      buffer[65536] __attribute__((aligned(4)));

        spinlock_t              lock;
        struct if_sdio_packet   *packets;

        struct workqueue_struct *workqueue;
        struct work_struct      packet_worker;

        u8                      rx_unit;
};

static void if_sdio_finish_power_on(struct if_sdio_card *card);
static int if_sdio_power_off(struct if_sdio_card *card);

/********************************************************************/
/* I/O                                                              */
/********************************************************************/

/*
 *  For SD8385/SD8686, this function reads firmware status after
 *  the image is downloaded, or reads RX packet length when
 *  interrupt (with IF_SDIO_H_INT_UPLD bit set) is received.
 *  For SD8688, this function reads firmware status only.
 */
static u16 if_sdio_read_scratch(struct if_sdio_card *card, int *err)
{
        int ret;
        u16 scratch;

        scratch = sdio_readb(card->func, card->scratch_reg, &ret);
        if (!ret)
                scratch |= sdio_readb(card->func, card->scratch_reg + 1,
                                        &ret) << 8;

        if (err)
                *err = ret;

        if (ret)
                return 0xffff;

        return scratch;
}

static u8 if_sdio_read_rx_unit(struct if_sdio_card *card)
{
        int ret;
        u8 rx_unit;

        rx_unit = sdio_readb(card->func, IF_SDIO_RX_UNIT, &ret);

        if (ret)
                rx_unit = 0;

        return rx_unit;
}

static u16 if_sdio_read_rx_len(struct if_sdio_card *card, int *err)
{
        int ret;
        u16 rx_len;

        switch (card->model) {
        case MODEL_8385:
        case MODEL_8686:
                rx_len = if_sdio_read_scratch(card, &ret);
                break;
        case MODEL_8688:
        default: /* for newer chipsets */
                rx_len = sdio_readb(card->func, IF_SDIO_RX_LEN, &ret);
                if (!ret)
                        rx_len <<= card->rx_unit;
                else
                        rx_len = 0xffff;        /* invalid length */

                break;
        }

        if (err)
                *err = ret;

        return rx_len;
}

static int if_sdio_handle_cmd(struct if_sdio_card *card,
                u8 *buffer, unsigned size)
{
        struct lbs_private *priv = card->priv;
        int ret;
        unsigned long flags;
        u8 i;

        lbs_deb_enter(LBS_DEB_SDIO);

        if (size > LBS_CMD_BUFFER_SIZE) {
                lbs_deb_sdio("response packet too large (%d bytes)\n",
                        (int)size);
                ret = -E2BIG;
                goto out;
        }

        spin_lock_irqsave(&priv->driver_lock, flags);

        i = (priv->resp_idx == 0) ? 1 : 0;
        BUG_ON(priv->resp_len[i]);
        priv->resp_len[i] = size;
        memcpy(priv->resp_buf[i], buffer, size);
        lbs_notify_command_response(priv, i);

        spin_unlock_irqrestore(&card->priv->driver_lock, flags);

        ret = 0;

out:
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
        return ret;
}

static int if_sdio_handle_data(struct if_sdio_card *card,
                u8 *buffer, unsigned size)
{
        int ret;
        struct sk_buff *skb;
        char *data;

        lbs_deb_enter(LBS_DEB_SDIO);

        if (size > MRVDRV_ETH_RX_PACKET_BUFFER_SIZE) {
                lbs_deb_sdio("response packet too large (%d bytes)\n",
                        (int)size);
                ret = -E2BIG;
                goto out;
        }

        skb = dev_alloc_skb(MRVDRV_ETH_RX_PACKET_BUFFER_SIZE + NET_IP_ALIGN);
        if (!skb) {
                ret = -ENOMEM;
                goto out;
        }

        skb_reserve(skb, NET_IP_ALIGN);

        data = skb_put(skb, size);

        memcpy(data, buffer, size);

        lbs_process_rxed_packet(card->priv, skb);

        ret = 0;

out:
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);

        return ret;
}

static int if_sdio_handle_event(struct if_sdio_card *card,
                u8 *buffer, unsigned size)
{
        int ret;
        u32 event;

        lbs_deb_enter(LBS_DEB_SDIO);

        if (card->model == MODEL_8385) {
                event = sdio_readb(card->func, IF_SDIO_EVENT, &ret);
                if (ret)
                        goto out;

                /* right shift 3 bits to get the event id */
                event >>= 3;
        } else {
                if (size < 4) {
                        lbs_deb_sdio("event packet too small (%d bytes)\n",
                                (int)size);
                        ret = -EINVAL;
                        goto out;
                }
                event = buffer[3] << 24;
                event |= buffer[2] << 16;
                event |= buffer[1] << 8;
                event |= buffer[0] << 0;
        }

        lbs_queue_event(card->priv, event & 0xFF);
        ret = 0;

out:
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);

        return ret;
}

static int if_sdio_wait_status(struct if_sdio_card *card, const u8 condition)
{
        u8 status;
        unsigned long timeout;
        int ret = 0;

        timeout = jiffies + HZ;
        while (1) {
                status = sdio_readb(card->func, IF_SDIO_STATUS, &ret);
                if (ret)
                        return ret;
                if ((status & condition) == condition)
                        break;
                if (time_after(jiffies, timeout))
                        return -ETIMEDOUT;
                mdelay(1);
        }
        return ret;
}

static int if_sdio_card_to_host(struct if_sdio_card *card)
{
        int ret;
        u16 size, type, chunk;

        lbs_deb_enter(LBS_DEB_SDIO);

        size = if_sdio_read_rx_len(card, &ret);
        if (ret)
                goto out;

        if (size < 4) {
                lbs_deb_sdio("invalid packet size (%d bytes) from firmware\n",
                        (int)size);
                ret = -EINVAL;
                goto out;
        }

        ret = if_sdio_wait_status(card, IF_SDIO_IO_RDY);
        if (ret)
                goto out;

        /*
         * The transfer must be in one transaction or the firmware
         * goes suicidal. There's no way to guarantee that for all
         * controllers, but we can at least try.
         */
        chunk = sdio_align_size(card->func, size);

        ret = sdio_readsb(card->func, card->buffer, card->ioport, chunk);
        if (ret)
                goto out;

        chunk = card->buffer[0] | (card->buffer[1] << 8);
        type = card->buffer[2] | (card->buffer[3] << 8);

        lbs_deb_sdio("packet of type %d and size %d bytes\n",
                (int)type, (int)chunk);

        if (chunk > size) {
                lbs_deb_sdio("packet fragment (%d > %d)\n",
                        (int)chunk, (int)size);
                ret = -EINVAL;
                goto out;
        }

        if (chunk < size) {
                lbs_deb_sdio("packet fragment (%d < %d)\n",
                        (int)chunk, (int)size);
        }

        switch (type) {
        case MVMS_CMD:
                ret = if_sdio_handle_cmd(card, card->buffer + 4, chunk - 4);
                if (ret)
                        goto out;
                break;
        case MVMS_DAT:
                ret = if_sdio_handle_data(card, card->buffer + 4, chunk - 4);
                if (ret)
                        goto out;
                break;
        case MVMS_EVENT:
                ret = if_sdio_handle_event(card, card->buffer + 4, chunk - 4);
                if (ret)
                        goto out;
                break;
        default:
                lbs_deb_sdio("invalid type (%d) from firmware\n",
                                (int)type);
                ret = -EINVAL;
                goto out;
        }

out:
        if (ret)
                pr_err("problem fetching packet from firmware\n");

        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);

        return ret;
}

static void if_sdio_host_to_card_worker(struct work_struct *work)
{
        struct if_sdio_card *card;
        struct if_sdio_packet *packet;
        int ret;
        unsigned long flags;

        lbs_deb_enter(LBS_DEB_SDIO);

        card = container_of(work, struct if_sdio_card, packet_worker);

        while (1) {
                spin_lock_irqsave(&card->lock, flags);
                packet = card->packets;
                if (packet)
                        card->packets = packet->next;
                spin_unlock_irqrestore(&card->lock, flags);

                if (!packet)
                        break;

                sdio_claim_host(card->func);

                ret = if_sdio_wait_status(card, IF_SDIO_IO_RDY);
                if (ret == 0) {
                        ret = sdio_writesb(card->func, card->ioport,
                                           packet->buffer, packet->nb);
                }

                if (ret)
                        pr_err("error %d sending packet to firmware\n", ret);

                sdio_release_host(card->func);

                kfree(packet);
        }

        lbs_deb_leave(LBS_DEB_SDIO);
}

/********************************************************************/
/* Firmware                                                         */
/********************************************************************/

#define FW_DL_READY_STATUS (IF_SDIO_IO_RDY | IF_SDIO_DL_RDY)

static int if_sdio_prog_helper(struct if_sdio_card *card,
                                const struct firmware *fw)
{
        int ret;
        unsigned long timeout;
        u8 *chunk_buffer;
        u32 chunk_size;
        const u8 *firmware;
        size_t size;

        lbs_deb_enter(LBS_DEB_SDIO);

        chunk_buffer = kzalloc(64, GFP_KERNEL);
        if (!chunk_buffer) {
                ret = -ENOMEM;
                goto out;
        }

        sdio_claim_host(card->func);

        ret = sdio_set_block_size(card->func, 32);
        if (ret)
                goto release;

        firmware = fw->data;
        size = fw->size;

        while (size) {
                ret = if_sdio_wait_status(card, FW_DL_READY_STATUS);
                if (ret)
                        goto release;

                /* On some platforms (like Davinci) the chip needs more time
                 * between helper blocks.
                 */
                mdelay(2);

                chunk_size = min(size, (size_t)60);

                *((__le32*)chunk_buffer) = cpu_to_le32(chunk_size);
                memcpy(chunk_buffer + 4, firmware, chunk_size);
/*
                lbs_deb_sdio("sending %d bytes chunk\n", chunk_size);
*/
                ret = sdio_writesb(card->func, card->ioport,
                                chunk_buffer, 64);
                if (ret)
                        goto release;

                firmware += chunk_size;
                size -= chunk_size;
        }

        /* an empty block marks the end of the transfer */
        memset(chunk_buffer, 0, 4);
        ret = sdio_writesb(card->func, card->ioport, chunk_buffer, 64);
        if (ret)
                goto release;

        lbs_deb_sdio("waiting for helper to boot...\n");

        /* wait for the helper to boot by looking at the size register */
        timeout = jiffies + HZ;
        while (1) {
                u16 req_size;

                req_size = sdio_readb(card->func, IF_SDIO_RD_BASE, &ret);
                if (ret)
                        goto release;

                req_size |= sdio_readb(card->func, IF_SDIO_RD_BASE + 1, &ret) << 8;
                if (ret)
                        goto release;

                if (req_size != 0)
                        break;

                if (time_after(jiffies, timeout)) {
                        ret = -ETIMEDOUT;
                        goto release;
                }

                msleep(10);
        }

        ret = 0;

release:
        sdio_release_host(card->func);
        kfree(chunk_buffer);

out:
        if (ret)
                pr_err("failed to load helper firmware\n");

        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
        return ret;
}

static int if_sdio_prog_real(struct if_sdio_card *card,
                                const struct firmware *fw)
{
        int ret;
        unsigned long timeout;
        u8 *chunk_buffer;
        u32 chunk_size;
        const u8 *firmware;
        size_t size, req_size;

        lbs_deb_enter(LBS_DEB_SDIO);

        chunk_buffer = kzalloc(512, GFP_KERNEL);
        if (!chunk_buffer) {
                ret = -ENOMEM;
                goto out;
        }

        sdio_claim_host(card->func);

        ret = sdio_set_block_size(card->func, 32);
        if (ret)
                goto release;

        firmware = fw->data;
        size = fw->size;

        while (size) {
                timeout = jiffies + HZ;
                while (1) {
                        ret = if_sdio_wait_status(card, FW_DL_READY_STATUS);
                        if (ret)
                                goto release;

                        req_size = sdio_readb(card->func, IF_SDIO_RD_BASE,
                                        &ret);
                        if (ret)
                                goto release;

                        req_size |= sdio_readb(card->func, IF_SDIO_RD_BASE + 1,
                                        &ret) << 8;
                        if (ret)
                                goto release;

                        /*
                         * For SD8688 wait until the length is not 0, 1 or 2
                         * before downloading the first FW block,
                         * since BOOT code writes the register to indicate the
                         * helper/FW download winner,
                         * the value could be 1 or 2 (Func1 or Func2).
                         */
                        if ((size != fw->size) || (req_size > 2))
                                break;
                        if (time_after(jiffies, timeout)) {
                                ret = -ETIMEDOUT;
                                goto release;
                        }
                        mdelay(1);
                }

/*
                lbs_deb_sdio("firmware wants %d bytes\n", (int)req_size);
*/
                if (req_size == 0) {
                        lbs_deb_sdio("firmware helper gave up early\n");
                        ret = -EIO;
                        goto release;
                }

                if (req_size & 0x01) {
                        lbs_deb_sdio("firmware helper signalled error\n");
                        ret = -EIO;
                        goto release;
                }

                if (req_size > size)
                        req_size = size;

                while (req_size) {
                        chunk_size = min(req_size, (size_t)512);

                        memcpy(chunk_buffer, firmware, chunk_size);
/*
                        lbs_deb_sdio("sending %d bytes (%d bytes) chunk\n",
                                chunk_size, (chunk_size + 31) / 32 * 32);
*/
                        ret = sdio_writesb(card->func, card->ioport,
                                chunk_buffer, roundup(chunk_size, 32));
                        if (ret)
                                goto release;

                        firmware += chunk_size;
                        size -= chunk_size;
                        req_size -= chunk_size;
                }
        }

        ret = 0;

        lbs_deb_sdio("waiting for firmware to boot...\n");

        /* wait for the firmware to boot */
        timeout = jiffies + HZ;
        while (1) {
                u16 scratch;

                scratch = if_sdio_read_scratch(card, &ret);
                if (ret)
                        goto release;

                if (scratch == IF_SDIO_FIRMWARE_OK)
                        break;

                if (time_after(jiffies, timeout)) {
                        ret = -ETIMEDOUT;
                        goto release;
                }

                msleep(10);
        }

        ret = 0;

release:
        sdio_release_host(card->func);
        kfree(chunk_buffer);

out:
        if (ret)
                pr_err("failed to load firmware\n");

        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
        return ret;
}

static void if_sdio_do_prog_firmware(struct lbs_private *priv, int ret,
                                     const struct firmware *helper,
                                     const struct firmware *mainfw)
{
        struct if_sdio_card *card = priv->card;

        if (ret) {
                pr_err("failed to find firmware (%d)\n", ret);
                return;
        }

        ret = if_sdio_prog_helper(card, helper);
        if (ret)
                goto out;

        lbs_deb_sdio("Helper firmware loaded\n");

        ret = if_sdio_prog_real(card, mainfw);
        if (ret)
                goto out;

        lbs_deb_sdio("Firmware loaded\n");
        if_sdio_finish_power_on(card);

out:
        release_firmware(helper);
        release_firmware(mainfw);
}

static int if_sdio_prog_firmware(struct if_sdio_card *card)
{
        int ret;
        u16 scratch;

        lbs_deb_enter(LBS_DEB_SDIO);

        /*
         * Disable interrupts
         */
        sdio_claim_host(card->func);
        sdio_writeb(card->func, 0x00, IF_SDIO_H_INT_MASK, &ret);
        sdio_release_host(card->func);

        sdio_claim_host(card->func);
        scratch = if_sdio_read_scratch(card, &ret);
        sdio_release_host(card->func);

        lbs_deb_sdio("firmware status = %#x\n", scratch);
        lbs_deb_sdio("scratch ret = %d\n", ret);

        if (ret)
                goto out;


        /*
         * The manual clearly describes that FEDC is the right code to use
         * to detect firmware presence, but for SD8686 it is not that simple.
         * Scratch is also used to store the RX packet length, so we lose
         * the FEDC value early on. So we use a non-zero check in order
         * to validate firmware presence.
         * Additionally, the SD8686 in the Gumstix always has the high scratch
         * bit set, even when the firmware is not loaded. So we have to
         * exclude that from the test.
         */
        if (scratch == IF_SDIO_FIRMWARE_OK) {
                lbs_deb_sdio("firmware already loaded\n");
                if_sdio_finish_power_on(card);
                return 0;
        } else if ((card->model == MODEL_8686) && (scratch & 0x7fff)) {
                lbs_deb_sdio("firmware may be running\n");
                if_sdio_finish_power_on(card);
                return 0;
        }

        ret = lbs_get_firmware_async(card->priv, &card->func->dev, card->model,
                                     fw_table, if_sdio_do_prog_firmware);

out:
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
        return ret;
}

/********************************************************************/
/* Power management                                                 */
/********************************************************************/

/* Finish power on sequence (after firmware is loaded) */
static void if_sdio_finish_power_on(struct if_sdio_card *card)
{
        struct sdio_func *func = card->func;
        struct lbs_private *priv = card->priv;
        int ret;

        sdio_claim_host(func);
        sdio_set_block_size(card->func, IF_SDIO_BLOCK_SIZE);

        /*
         * Get rx_unit if the chip is SD8688 or newer.
         * SD8385 & SD8686 do not have rx_unit.
         */
        if ((card->model != MODEL_8385)
                        && (card->model != MODEL_8686))
                card->rx_unit = if_sdio_read_rx_unit(card);
        else
                card->rx_unit = 0;

        /*
         * Set up the interrupt handler late.
         *
         * If we set it up earlier, the (buggy) hardware generates a spurious
         * interrupt, even before the interrupt has been enabled, with
         * CCCR_INTx = 0.
         *
         * We register the interrupt handler late so that we can handle any
         * spurious interrupts, and also to avoid generation of that known
         * spurious interrupt in the first place.
         */
        ret = sdio_claim_irq(func, if_sdio_interrupt);
        if (ret)
                goto release;

        /*
         * Enable interrupts now that everything is set up
         */
        sdio_writeb(func, 0x0f, IF_SDIO_H_INT_MASK, &ret);
        if (ret)
                goto release_irq;

        sdio_release_host(func);

        /* Set fw_ready before queuing any commands so that
         * lbs_thread won't block from sending them to firmware.
         */
        priv->fw_ready = 1;

        /*
         * FUNC_INIT is required for SD8688 WLAN/BT multiple functions
         */
        if (card->model == MODEL_8688) {
                struct cmd_header cmd;

                memset(&cmd, 0, sizeof(cmd));

                lbs_deb_sdio("send function INIT command\n");
                if (__lbs_cmd(priv, CMD_FUNC_INIT, &cmd, sizeof(cmd),
                                lbs_cmd_copyback, (unsigned long) &cmd))
                        netdev_alert(priv->dev, "CMD_FUNC_INIT cmd failed\n");
        }

        wake_up(&card->pwron_waitq);

        if (!card->started) {
                ret = lbs_start_card(priv);
                if_sdio_power_off(card);
                if (ret == 0) {
                        card->started = true;
                        /* Tell PM core that we don't need the card to be
                         * powered now */
                        pm_runtime_put_noidle(&func->dev);
                }
        }

        return;

release_irq:
        sdio_release_irq(func);
release:
        sdio_release_host(func);
}

static int if_sdio_power_on(struct if_sdio_card *card)
{
        struct sdio_func *func = card->func;
        struct mmc_host *host = func->card->host;
        int ret;

        sdio_claim_host(func);

        ret = sdio_enable_func(func);
        if (ret)
                goto release;

        /* For 1-bit transfers to the 8686 model, we need to enable the
         * interrupt flag in the CCCR register. Set the MMC_QUIRK_LENIENT_FN0
         * bit to allow access to non-vendor registers. */
        if ((card->model == MODEL_8686) &&
            (host->caps & MMC_CAP_SDIO_IRQ) &&
            (host->ios.bus_width == MMC_BUS_WIDTH_1)) {
                u8 reg;

                func->card->quirks |= MMC_QUIRK_LENIENT_FN0;
                reg = sdio_f0_readb(func, SDIO_CCCR_IF, &ret);
                if (ret)
                        goto disable;

                reg |= SDIO_BUS_ECSI;
                sdio_f0_writeb(func, reg, SDIO_CCCR_IF, &ret);
                if (ret)
                        goto disable;
        }

        card->ioport = sdio_readb(func, IF_SDIO_IOPORT, &ret);
        if (ret)
                goto disable;

        card->ioport |= sdio_readb(func, IF_SDIO_IOPORT + 1, &ret) << 8;
        if (ret)
                goto disable;

        card->ioport |= sdio_readb(func, IF_SDIO_IOPORT + 2, &ret) << 16;
        if (ret)
                goto disable;

        sdio_release_host(func);
        ret = if_sdio_prog_firmware(card);
        if (ret) {
                sdio_disable_func(func);
                return ret;
        }

        return 0;

disable:
        sdio_disable_func(func);
release:
        sdio_release_host(func);
        return ret;
}

static int if_sdio_power_off(struct if_sdio_card *card)
{
        struct sdio_func *func = card->func;
        struct lbs_private *priv = card->priv;

        priv->fw_ready = 0;

        sdio_claim_host(func);
        sdio_release_irq(func);
        sdio_disable_func(func);
        sdio_release_host(func);
        return 0;
}


/*******************************************************************/
/* Libertas callbacks                                              */
/*******************************************************************/

static int if_sdio_host_to_card(struct lbs_private *priv,
                u8 type, u8 *buf, u16 nb)
{
        int ret;
        struct if_sdio_card *card;
        struct if_sdio_packet *packet, *cur;
        u16 size;
        unsigned long flags;

        lbs_deb_enter_args(LBS_DEB_SDIO, "type %d, bytes %d", type, nb);

        card = priv->card;

        if (nb > (65536 - sizeof(struct if_sdio_packet) - 4)) {
                ret = -EINVAL;
                goto out;
        }

        /*
         * The transfer must be in one transaction or the firmware
         * goes suicidal. There's no way to guarantee that for all
         * controllers, but we can at least try.
         */
        size = sdio_align_size(card->func, nb + 4);

        packet = kzalloc(sizeof(struct if_sdio_packet) + size,
                        GFP_ATOMIC);
        if (!packet) {
                ret = -ENOMEM;
                goto out;
        }

        packet->next = NULL;
        packet->nb = size;

        /*
         * SDIO specific header.
         */
        packet->buffer[0] = (nb + 4) & 0xff;
        packet->buffer[1] = ((nb + 4) >> 8) & 0xff;
        packet->buffer[2] = type;
        packet->buffer[3] = 0;

        memcpy(packet->buffer + 4, buf, nb);

        spin_lock_irqsave(&card->lock, flags);

        if (!card->packets)
                card->packets = packet;
        else {
                cur = card->packets;
                while (cur->next)
                        cur = cur->next;
                cur->next = packet;
        }

        switch (type) {
        case MVMS_CMD:
                priv->dnld_sent = DNLD_CMD_SENT;
                break;
        case MVMS_DAT:
                priv->dnld_sent = DNLD_DATA_SENT;
                break;
        default:
                lbs_deb_sdio("unknown packet type %d\n", (int)type);
        }

        spin_unlock_irqrestore(&card->lock, flags);

        queue_work(card->workqueue, &card->packet_worker);

        ret = 0;

out:
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);

        return ret;
}

static int if_sdio_enter_deep_sleep(struct lbs_private *priv)
{
        int ret = -1;
        struct cmd_header cmd;

        memset(&cmd, 0, sizeof(cmd));

        lbs_deb_sdio("send DEEP_SLEEP command\n");
        ret = __lbs_cmd(priv, CMD_802_11_DEEP_SLEEP, &cmd, sizeof(cmd),
                        lbs_cmd_copyback, (unsigned long) &cmd);
        if (ret)
                netdev_err(priv->dev, "DEEP_SLEEP cmd failed\n");

        mdelay(200);
        return ret;
}

static int if_sdio_exit_deep_sleep(struct lbs_private *priv)
{
        struct if_sdio_card *card = priv->card;
        int ret = -1;

        lbs_deb_enter(LBS_DEB_SDIO);
        sdio_claim_host(card->func);

        sdio_writeb(card->func, HOST_POWER_UP, CONFIGURATION_REG, &ret);
        if (ret)
                netdev_err(priv->dev, "sdio_writeb failed!\n");

        sdio_release_host(card->func);
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
        return ret;
}

static int if_sdio_reset_deep_sleep_wakeup(struct lbs_private *priv)
{
        struct if_sdio_card *card = priv->card;
        int ret = -1;

        lbs_deb_enter(LBS_DEB_SDIO);
        sdio_claim_host(card->func);

        sdio_writeb(card->func, 0, CONFIGURATION_REG, &ret);
        if (ret)
                netdev_err(priv->dev, "sdio_writeb failed!\n");

        sdio_release_host(card->func);
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
        return ret;

}

static struct mmc_host *reset_host;

static void if_sdio_reset_card_worker(struct work_struct *work)
{
        /*
         * The actual reset operation must be run outside of lbs_thread. This
         * is because mmc_remove_host() will cause the device to be instantly
         * destroyed, and the libertas driver then needs to end lbs_thread,
         * leading to a deadlock.
         *
         * We run it in a workqueue totally independent from the if_sdio_card
         * instance for that reason.
         */

        pr_info("Resetting card...");
        mmc_remove_host(reset_host);
        mmc_add_host(reset_host);
}
static DECLARE_WORK(card_reset_work, if_sdio_reset_card_worker);

static void if_sdio_reset_card(struct lbs_private *priv)
{
        struct if_sdio_card *card = priv->card;

        if (work_pending(&card_reset_work))
                return;

        reset_host = card->func->card->host;
        schedule_work(&card_reset_work);
}

static int if_sdio_power_save(struct lbs_private *priv)
{
        struct if_sdio_card *card = priv->card;
        int ret;

        flush_workqueue(card->workqueue);

        ret = if_sdio_power_off(card);

        /* Let runtime PM know the card is powered off */
        pm_runtime_put_sync(&card->func->dev);

        return ret;
}

static int if_sdio_power_restore(struct lbs_private *priv)
{
        struct if_sdio_card *card = priv->card;
        int r;

        /* Make sure the card will not be powered off by runtime PM */
        pm_runtime_get_sync(&card->func->dev);

        r = if_sdio_power_on(card);
        if (r)
                return r;

        wait_event(card->pwron_waitq, priv->fw_ready);
        return 0;
}


/*******************************************************************/
/* SDIO callbacks                                                  */
/*******************************************************************/

static void if_sdio_interrupt(struct sdio_func *func)
{
        int ret;
        struct if_sdio_card *card;
        u8 cause;

        lbs_deb_enter(LBS_DEB_SDIO);

        card = sdio_get_drvdata(func);

        cause = sdio_readb(card->func, IF_SDIO_H_INT_STATUS, &ret);
        if (ret || !cause)
                goto out;

        lbs_deb_sdio("interrupt: 0x%X\n", (unsigned)cause);

        sdio_writeb(card->func, ~cause, IF_SDIO_H_INT_STATUS, &ret);
        if (ret)
                goto out;

        /*
         * Ignore the define name, this really means the card has
         * successfully received the command.
         */
        card->priv->is_activity_detected = 1;
        if (cause & IF_SDIO_H_INT_DNLD)
                lbs_host_to_card_done(card->priv);


        if (cause & IF_SDIO_H_INT_UPLD) {
                ret = if_sdio_card_to_host(card);
                if (ret)
                        goto out;
        }

        ret = 0;

out:
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
}

static int if_sdio_probe(struct sdio_func *func,
                const struct sdio_device_id *id)
{
        struct if_sdio_card *card;
        struct lbs_private *priv;
        int ret, i;
        unsigned int model;
        struct if_sdio_packet *packet;

        lbs_deb_enter(LBS_DEB_SDIO);

        for (i = 0;i < func->card->num_info;i++) {
                if (sscanf(func->card->info[i],
                                "802.11 SDIO ID: %x", &model) == 1)
                        break;
                if (sscanf(func->card->info[i],
                                "ID: %x", &model) == 1)
                        break;
                if (!strcmp(func->card->info[i], "IBIS Wireless SDIO Card")) {
                        model = MODEL_8385;
                        break;
                }
        }

        if (i == func->card->num_info) {
                pr_err("unable to identify card model\n");
                return -ENODEV;
        }

        card = kzalloc(sizeof(struct if_sdio_card), GFP_KERNEL);
        if (!card)
                return -ENOMEM;

        card->func = func;
        card->model = model;

        switch (card->model) {
        case MODEL_8385:
                card->scratch_reg = IF_SDIO_SCRATCH_OLD;
                break;
        case MODEL_8686:
                card->scratch_reg = IF_SDIO_SCRATCH;
                break;
        case MODEL_8688:
        default: /* for newer chipsets */
                card->scratch_reg = IF_SDIO_FW_STATUS;
                break;
        }

        spin_lock_init(&card->lock);
        card->workqueue = create_workqueue("libertas_sdio");
        INIT_WORK(&card->packet_worker, if_sdio_host_to_card_worker);
        init_waitqueue_head(&card->pwron_waitq);

        /* Check if we support this card */
        for (i = 0; i < ARRAY_SIZE(fw_table); i++) {
                if (card->model == fw_table[i].model)
                        break;
        }
        if (i == ARRAY_SIZE(fw_table)) {
                pr_err("unknown card model 0x%x\n", card->model);
                ret = -ENODEV;
                goto free;
        }

        sdio_set_drvdata(func, card);

        lbs_deb_sdio("class = 0x%X, vendor = 0x%X, "
                        "device = 0x%X, model = 0x%X, ioport = 0x%X\n",
                        func->class, func->vendor, func->device,
                        model, (unsigned)card->ioport);


        priv = lbs_add_card(card, &func->dev);
        if (!priv) {
                ret = -ENOMEM;
                goto free;
        }

        card->priv = priv;

        priv->card = card;
        priv->hw_host_to_card = if_sdio_host_to_card;
        priv->enter_deep_sleep = if_sdio_enter_deep_sleep;
        priv->exit_deep_sleep = if_sdio_exit_deep_sleep;
        priv->reset_deep_sleep_wakeup = if_sdio_reset_deep_sleep_wakeup;
        priv->reset_card = if_sdio_reset_card;
        priv->power_save = if_sdio_power_save;
        priv->power_restore = if_sdio_power_restore;

        ret = if_sdio_power_on(card);
        if (ret)
                goto err_activate_card;

out:
        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);

        return ret;

err_activate_card:
        flush_workqueue(card->workqueue);
        lbs_remove_card(priv);
free:
        destroy_workqueue(card->workqueue);
        while (card->packets) {
                packet = card->packets;
                card->packets = card->packets->next;
                kfree(packet);
        }

        kfree(card);

        goto out;
}

static void if_sdio_remove(struct sdio_func *func)
{
        struct if_sdio_card *card;
        struct if_sdio_packet *packet;

        lbs_deb_enter(LBS_DEB_SDIO);

        card = sdio_get_drvdata(func);

        /* Undo decrement done above in if_sdio_probe */
        pm_runtime_get_noresume(&func->dev);

        if (user_rmmod && (card->model == MODEL_8688)) {
                /*
                 * FUNC_SHUTDOWN is required for SD8688 WLAN/BT
                 * multiple functions
                 */
                struct cmd_header cmd;

                memset(&cmd, 0, sizeof(cmd));

                lbs_deb_sdio("send function SHUTDOWN command\n");
                if (__lbs_cmd(card->priv, CMD_FUNC_SHUTDOWN,
                                &cmd, sizeof(cmd), lbs_cmd_copyback,
                                (unsigned long) &cmd))
                        pr_alert("CMD_FUNC_SHUTDOWN cmd failed\n");
        }


        lbs_deb_sdio("call remove card\n");
        lbs_stop_card(card->priv);
        lbs_remove_card(card->priv);

        flush_workqueue(card->workqueue);
        destroy_workqueue(card->workqueue);

        while (card->packets) {
                packet = card->packets;
                card->packets = card->packets->next;
                kfree(packet);
        }

        kfree(card);
        lbs_deb_leave(LBS_DEB_SDIO);
}

static int if_sdio_suspend(struct device *dev)
{
        struct sdio_func *func = dev_to_sdio_func(dev);
        int ret;
        struct if_sdio_card *card = sdio_get_drvdata(func);

        mmc_pm_flag_t flags = sdio_get_host_pm_caps(func);

        /* If we're powered off anyway, just let the mmc layer remove the
         * card. */
        if (!lbs_iface_active(card->priv))
                return -ENOSYS;

        dev_info(dev, "%s: suspend: PM flags = 0x%x\n",
                 sdio_func_id(func), flags);

        /* If we aren't being asked to wake on anything, we should bail out
         * and let the SD stack power down the card.
         */
        if (card->priv->wol_criteria == EHS_REMOVE_WAKEUP) {
                dev_info(dev, "Suspend without wake params -- powering down card\n");
                return -ENOSYS;
        }

        if (!(flags & MMC_PM_KEEP_POWER)) {
                dev_err(dev, "%s: cannot remain alive while host is suspended\n",
                        sdio_func_id(func));
                return -ENOSYS;
        }

        ret = sdio_set_host_pm_flags(func, MMC_PM_KEEP_POWER);
        if (ret)
                return ret;

        ret = lbs_suspend(card->priv);
        if (ret)
                return ret;

        return sdio_set_host_pm_flags(func, MMC_PM_WAKE_SDIO_IRQ);
}

static int if_sdio_resume(struct device *dev)
{
        struct sdio_func *func = dev_to_sdio_func(dev);
        struct if_sdio_card *card = sdio_get_drvdata(func);
        int ret;

        dev_info(dev, "%s: resume: we're back\n", sdio_func_id(func));

        ret = lbs_resume(card->priv);

        return ret;
}

static const struct dev_pm_ops if_sdio_pm_ops = {
        .suspend        = if_sdio_suspend,
        .resume         = if_sdio_resume,
};

static struct sdio_driver if_sdio_driver = {
        .name           = "libertas_sdio",
        .id_table       = if_sdio_ids,
        .probe          = if_sdio_probe,
        .remove         = if_sdio_remove,
        .drv = {
                .pm = &if_sdio_pm_ops,
        },
};

/*******************************************************************/
/* Module functions                                                */
/*******************************************************************/

static int __init if_sdio_init_module(void)
{
        int ret = 0;

        lbs_deb_enter(LBS_DEB_SDIO);

        printk(KERN_INFO "libertas_sdio: Libertas SDIO driver\n");
        printk(KERN_INFO "libertas_sdio: Copyright Pierre Ossman\n");

        ret = sdio_register_driver(&if_sdio_driver);

        /* Clear the flag in case user removes the card. */
        user_rmmod = 0;

        lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);

        return ret;
}

static void __exit if_sdio_exit_module(void)
{
        lbs_deb_enter(LBS_DEB_SDIO);

        /* Set the flag as user is removing this module. */
        user_rmmod = 1;

        cancel_work_sync(&card_reset_work);

        sdio_unregister_driver(&if_sdio_driver);

        lbs_deb_leave(LBS_DEB_SDIO);
}

module_init(if_sdio_init_module);
module_exit(if_sdio_exit_module);

MODULE_DESCRIPTION("Libertas SDIO WLAN Driver");
MODULE_AUTHOR("Pierre Ossman");
MODULE_LICENSE("GPL");