/*
 * Samsung S5P/EXYNOS4 SoC series MIPI-CSI receiver driver
 *
 * Copyright (C) 2011 - 2012 Samsung Electronics Co., Ltd.
 * Sylwester Nawrocki <s.nawrocki@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/memory.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/videodev2.h>
#include <media/v4l2-subdev.h>
#include <linux/platform_data/mipi-csis.h>
#include "mipi-csis.h"

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Debug level (0-2)");

/* Register map definition */

/* CSIS global control */
#define S5PCSIS_CTRL                    0x00
#define S5PCSIS_CTRL_DPDN_DEFAULT       (0 << 31)
#define S5PCSIS_CTRL_DPDN_SWAP          (1 << 31)
#define S5PCSIS_CTRL_ALIGN_32BIT        (1 << 20)
#define S5PCSIS_CTRL_UPDATE_SHADOW      (1 << 16)
#define S5PCSIS_CTRL_WCLK_EXTCLK        (1 << 8)
#define S5PCSIS_CTRL_RESET              (1 << 4)
#define S5PCSIS_CTRL_ENABLE             (1 << 0)

/* D-PHY control */
#define S5PCSIS_DPHYCTRL                0x04
#define S5PCSIS_DPHYCTRL_HSS_MASK       (0x1f << 27)
#define S5PCSIS_DPHYCTRL_ENABLE         (0x1f << 0)

#define S5PCSIS_CONFIG                  0x08
#define S5PCSIS_CFG_FMT_YCBCR422_8BIT   (0x1e << 2)
#define S5PCSIS_CFG_FMT_RAW8            (0x2a << 2)
#define S5PCSIS_CFG_FMT_RAW10           (0x2b << 2)
#define S5PCSIS_CFG_FMT_RAW12           (0x2c << 2)
/* User defined formats, x = 1...4 */
#define S5PCSIS_CFG_FMT_USER(x)         ((0x30 + x - 1) << 2)
#define S5PCSIS_CFG_FMT_MASK            (0x3f << 2)
#define S5PCSIS_CFG_NR_LANE_MASK        3

/* Interrupt mask */
#define S5PCSIS_INTMSK                  0x10
#define S5PCSIS_INTMSK_EN_ALL           0xf000103f
#define S5PCSIS_INTMSK_EVEN_BEFORE      (1 << 31)
#define S5PCSIS_INTMSK_EVEN_AFTER       (1 << 30)
#define S5PCSIS_INTMSK_ODD_BEFORE       (1 << 29)
#define S5PCSIS_INTMSK_ODD_AFTER        (1 << 28)
#define S5PCSIS_INTMSK_ERR_SOT_HS       (1 << 12)
#define S5PCSIS_INTMSK_ERR_LOST_FS      (1 << 5)
#define S5PCSIS_INTMSK_ERR_LOST_FE      (1 << 4)
#define S5PCSIS_INTMSK_ERR_OVER         (1 << 3)
#define S5PCSIS_INTMSK_ERR_ECC          (1 << 2)
#define S5PCSIS_INTMSK_ERR_CRC          (1 << 1)
#define S5PCSIS_INTMSK_ERR_UNKNOWN      (1 << 0)

/* Interrupt source */
#define S5PCSIS_INTSRC                  0x14
#define S5PCSIS_INTSRC_EVEN_BEFORE      (1 << 31)
#define S5PCSIS_INTSRC_EVEN_AFTER       (1 << 30)
#define S5PCSIS_INTSRC_EVEN             (0x3 << 30)
#define S5PCSIS_INTSRC_ODD_BEFORE       (1 << 29)
#define S5PCSIS_INTSRC_ODD_AFTER        (1 << 28)
#define S5PCSIS_INTSRC_ODD              (0x3 << 28)
#define S5PCSIS_INTSRC_NON_IMAGE_DATA   (0xff << 28)
#define S5PCSIS_INTSRC_ERR_SOT_HS       (0xf << 12)
#define S5PCSIS_INTSRC_ERR_LOST_FS      (1 << 5)
#define S5PCSIS_INTSRC_ERR_LOST_FE      (1 << 4)
#define S5PCSIS_INTSRC_ERR_OVER         (1 << 3)
#define S5PCSIS_INTSRC_ERR_ECC          (1 << 2)
#define S5PCSIS_INTSRC_ERR_CRC          (1 << 1)
#define S5PCSIS_INTSRC_ERR_UNKNOWN      (1 << 0)
#define S5PCSIS_INTSRC_ERRORS           0xf03f

/* Pixel resolution */
#define S5PCSIS_RESOL                   0x2c
#define CSIS_MAX_PIX_WIDTH              0xffff
#define CSIS_MAX_PIX_HEIGHT             0xffff

/* Non-image packet data buffers */
#define S5PCSIS_PKTDATA_ODD             0x2000
#define S5PCSIS_PKTDATA_EVEN            0x3000
#define S5PCSIS_PKTDATA_SIZE            SZ_4K

enum {
        CSIS_CLK_MUX,
        CSIS_CLK_GATE,
};

static char *csi_clock_name[] = {
        [CSIS_CLK_MUX]  = "sclk_csis",
        [CSIS_CLK_GATE] = "csis",
};
#define NUM_CSIS_CLOCKS ARRAY_SIZE(csi_clock_name)

static const char * const csis_supply_name[] = {
        "vddcore",  /* CSIS Core (1.0V, 1.1V or 1.2V) suppply */
        "vddio",    /* CSIS I/O and PLL (1.8V) supply */
};
#define CSIS_NUM_SUPPLIES ARRAY_SIZE(csis_supply_name)

enum {
        ST_POWERED      = 1,
        ST_STREAMING    = 2,
        ST_SUSPENDED    = 4,
};

struct s5pcsis_event {
        u32 mask;
        const char * const name;
        unsigned int counter;
};

static const struct s5pcsis_event s5pcsis_events[] = {
        /* Errors */
        { S5PCSIS_INTSRC_ERR_SOT_HS,    "SOT Error" },
        { S5PCSIS_INTSRC_ERR_LOST_FS,   "Lost Frame Start Error" },
        { S5PCSIS_INTSRC_ERR_LOST_FE,   "Lost Frame End Error" },
        { S5PCSIS_INTSRC_ERR_OVER,      "FIFO Overflow Error" },
        { S5PCSIS_INTSRC_ERR_ECC,       "ECC Error" },
        { S5PCSIS_INTSRC_ERR_CRC,       "CRC Error" },
        { S5PCSIS_INTSRC_ERR_UNKNOWN,   "Unknown Error" },
        /* Non-image data receive events */
        { S5PCSIS_INTSRC_EVEN_BEFORE,   "Non-image data before even frame" },
        { S5PCSIS_INTSRC_EVEN_AFTER,    "Non-image data after even frame" },
        { S5PCSIS_INTSRC_ODD_BEFORE,    "Non-image data before odd frame" },
        { S5PCSIS_INTSRC_ODD_AFTER,     "Non-image data after odd frame" },
};
#define S5PCSIS_NUM_EVENTS ARRAY_SIZE(s5pcsis_events)

struct csis_pktbuf {
        u32 *data;
        unsigned int len;
};

/**
 * struct csis_state - the driver's internal state data structure
 * @lock: mutex serializing the subdev and power management operations,
 *        protecting @format and @flags members
 * @pads: CSIS pads array
 * @sd: v4l2_subdev associated with CSIS device instance
 * @index: the hardware instance index
 * @pdev: CSIS platform device
 * @regs: mmaped I/O registers memory
 * @supplies: CSIS regulator supplies
 * @clock: CSIS clocks
 * @irq: requested s5p-mipi-csis irq number
 * @flags: the state variable for power and streaming control
 * @csis_fmt: current CSIS pixel format
 * @format: common media bus format for the source and sink pad
 * @slock: spinlock protecting structure members below
 * @pkt_buf: the frame embedded (non-image) data buffer
 * @events: MIPI-CSIS event (error) counters
 */
struct csis_state {
        struct mutex lock;
        struct media_pad pads[CSIS_PADS_NUM];
        struct v4l2_subdev sd;
        u8 index;
        struct platform_device *pdev;
        void __iomem *regs;
        struct regulator_bulk_data supplies[CSIS_NUM_SUPPLIES];
        struct clk *clock[NUM_CSIS_CLOCKS];
        int irq;
        u32 flags;
        const struct csis_pix_format *csis_fmt;
        struct v4l2_mbus_framefmt format;

        spinlock_t slock;
        struct csis_pktbuf pkt_buf;
        struct s5pcsis_event events[S5PCSIS_NUM_EVENTS];
};

/**
 * struct csis_pix_format - CSIS pixel format description
 * @pix_width_alignment: horizontal pixel alignment, width will be
 *                       multiple of 2^pix_width_alignment
 * @code: corresponding media bus code
 * @fmt_reg: S5PCSIS_CONFIG register value
 * @data_alignment: MIPI-CSI data alignment in bits
 */
struct csis_pix_format {
        unsigned int pix_width_alignment;
        enum v4l2_mbus_pixelcode code;
        u32 fmt_reg;
        u8 data_alignment;
};

static const struct csis_pix_format s5pcsis_formats[] = {
        {
                .code = V4L2_MBUS_FMT_VYUY8_2X8,
                .fmt_reg = S5PCSIS_CFG_FMT_YCBCR422_8BIT,
                .data_alignment = 32,
        }, {
                .code = V4L2_MBUS_FMT_JPEG_1X8,
                .fmt_reg = S5PCSIS_CFG_FMT_USER(1),
                .data_alignment = 32,
        }, {
                .code = V4L2_MBUS_FMT_S5C_UYVY_JPEG_1X8,
                .fmt_reg = S5PCSIS_CFG_FMT_USER(1),
                .data_alignment = 32,
        }, {
                .code = V4L2_MBUS_FMT_SGRBG8_1X8,
                .fmt_reg = S5PCSIS_CFG_FMT_RAW8,
                .data_alignment = 24,
        }, {
                .code = V4L2_MBUS_FMT_SGRBG10_1X10,
                .fmt_reg = S5PCSIS_CFG_FMT_RAW10,
                .data_alignment = 24,
        }, {
                .code = V4L2_MBUS_FMT_SGRBG12_1X12,
                .fmt_reg = S5PCSIS_CFG_FMT_RAW12,
                .data_alignment = 24,
        }
};

#define s5pcsis_write(__csis, __r, __v) writel(__v, __csis->regs + __r)
#define s5pcsis_read(__csis, __r) readl(__csis->regs + __r)

static struct csis_state *sd_to_csis_state(struct v4l2_subdev *sdev)
{
        return container_of(sdev, struct csis_state, sd);
}

static const struct csis_pix_format *find_csis_format(
        struct v4l2_mbus_framefmt *mf)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(s5pcsis_formats); i++)
                if (mf->code == s5pcsis_formats[i].code)
                        return &s5pcsis_formats[i];
        return NULL;
}

static void s5pcsis_enable_interrupts(struct csis_state *state, bool on)
{
        u32 val = s5pcsis_read(state, S5PCSIS_INTMSK);

        val = on ? val | S5PCSIS_INTMSK_EN_ALL :
                   val & ~S5PCSIS_INTMSK_EN_ALL;
        s5pcsis_write(state, S5PCSIS_INTMSK, val);
}

static void s5pcsis_reset(struct csis_state *state)
{
        u32 val = s5pcsis_read(state, S5PCSIS_CTRL);

        s5pcsis_write(state, S5PCSIS_CTRL, val | S5PCSIS_CTRL_RESET);
        udelay(10);
}

static void s5pcsis_system_enable(struct csis_state *state, int on)
{
        struct s5p_platform_mipi_csis *pdata = state->pdev->dev.platform_data;
        u32 val, mask;

        val = s5pcsis_read(state, S5PCSIS_CTRL);
        if (on)
                val |= S5PCSIS_CTRL_ENABLE;
        else
                val &= ~S5PCSIS_CTRL_ENABLE;
        s5pcsis_write(state, S5PCSIS_CTRL, val);

        val = s5pcsis_read(state, S5PCSIS_DPHYCTRL);
        val &= ~S5PCSIS_DPHYCTRL_ENABLE;
        if (on) {
                mask = (1 << (pdata->lanes + 1)) - 1;
                val |= (mask & S5PCSIS_DPHYCTRL_ENABLE);
        }
        s5pcsis_write(state, S5PCSIS_DPHYCTRL, val);
}

/* Called with the state.lock mutex held */
static void __s5pcsis_set_format(struct csis_state *state)
{
        struct v4l2_mbus_framefmt *mf = &state->format;
        u32 val;

        v4l2_dbg(1, debug, &state->sd, "fmt: %#x, %d x %d\n",
                 mf->code, mf->width, mf->height);

        /* Color format */
        val = s5pcsis_read(state, S5PCSIS_CONFIG);
        val = (val & ~S5PCSIS_CFG_FMT_MASK) | state->csis_fmt->fmt_reg;
        s5pcsis_write(state, S5PCSIS_CONFIG, val);

        /* Pixel resolution */
        val = (mf->width << 16) | mf->height;
        s5pcsis_write(state, S5PCSIS_RESOL, val);
}

static void s5pcsis_set_hsync_settle(struct csis_state *state, int settle)
{
        u32 val = s5pcsis_read(state, S5PCSIS_DPHYCTRL);

        val = (val & ~S5PCSIS_DPHYCTRL_HSS_MASK) | (settle << 27);
        s5pcsis_write(state, S5PCSIS_DPHYCTRL, val);
}

static void s5pcsis_set_params(struct csis_state *state)
{
        struct s5p_platform_mipi_csis *pdata = state->pdev->dev.platform_data;
        u32 val;

        val = s5pcsis_read(state, S5PCSIS_CONFIG);
        val = (val & ~S5PCSIS_CFG_NR_LANE_MASK) | (pdata->lanes - 1);
        s5pcsis_write(state, S5PCSIS_CONFIG, val);

        __s5pcsis_set_format(state);
        s5pcsis_set_hsync_settle(state, pdata->hs_settle);

        val = s5pcsis_read(state, S5PCSIS_CTRL);
        if (state->csis_fmt->data_alignment == 32)
                val |= S5PCSIS_CTRL_ALIGN_32BIT;
        else /* 24-bits */
                val &= ~S5PCSIS_CTRL_ALIGN_32BIT;

        val &= ~S5PCSIS_CTRL_WCLK_EXTCLK;
        if (pdata->wclk_source)
                val |= S5PCSIS_CTRL_WCLK_EXTCLK;
        s5pcsis_write(state, S5PCSIS_CTRL, val);

        /* Update the shadow register. */
        val = s5pcsis_read(state, S5PCSIS_CTRL);
        s5pcsis_write(state, S5PCSIS_CTRL, val | S5PCSIS_CTRL_UPDATE_SHADOW);
}

static void s5pcsis_clk_put(struct csis_state *state)
{
        int i;

        for (i = 0; i < NUM_CSIS_CLOCKS; i++) {
                if (IS_ERR(state->clock[i]))
                        continue;
                clk_unprepare(state->clock[i]);
                clk_put(state->clock[i]);
                state->clock[i] = ERR_PTR(-EINVAL);
        }
}

static int s5pcsis_clk_get(struct csis_state *state)
{
        struct device *dev = &state->pdev->dev;
        int i, ret;

        for (i = 0; i < NUM_CSIS_CLOCKS; i++)
                state->clock[i] = ERR_PTR(-EINVAL);

        for (i = 0; i < NUM_CSIS_CLOCKS; i++) {
                state->clock[i] = clk_get(dev, csi_clock_name[i]);
                if (IS_ERR(state->clock[i])) {
                        ret = PTR_ERR(state->clock[i]);
                        goto err;
                }
                ret = clk_prepare(state->clock[i]);
                if (ret < 0) {
                        clk_put(state->clock[i]);
                        state->clock[i] = ERR_PTR(-EINVAL);
                        goto err;
                }
        }
        return 0;
err:
        s5pcsis_clk_put(state);
        dev_err(dev, "failed to get clock: %s\n", csi_clock_name[i]);
        return ret;
}

static void dump_regs(struct csis_state *state, const char *label)
{
        struct {
                u32 offset;
                const char * const name;
        } registers[] = {
                { 0x00, "CTRL" },
                { 0x04, "DPHYCTRL" },
                { 0x08, "CONFIG" },
                { 0x0c, "DPHYSTS" },
                { 0x10, "INTMSK" },
                { 0x2c, "RESOL" },
                { 0x38, "SDW_CONFIG" },
        };
        u32 i;

        v4l2_info(&state->sd, "--- %s ---\n", label);

        for (i = 0; i < ARRAY_SIZE(registers); i++) {
                u32 cfg = s5pcsis_read(state, registers[i].offset);
                v4l2_info(&state->sd, "%10s: 0x%08x\n", registers[i].name, cfg);
        }
}

static void s5pcsis_start_stream(struct csis_state *state)
{
        s5pcsis_reset(state);
        s5pcsis_set_params(state);
        s5pcsis_system_enable(state, true);
        s5pcsis_enable_interrupts(state, true);
}

static void s5pcsis_stop_stream(struct csis_state *state)
{
        s5pcsis_enable_interrupts(state, false);
        s5pcsis_system_enable(state, false);
}

static void s5pcsis_clear_counters(struct csis_state *state)
{
        unsigned long flags;
        int i;

        spin_lock_irqsave(&state->slock, flags);
        for (i = 0; i < S5PCSIS_NUM_EVENTS; i++)
                state->events[i].counter = 0;
        spin_unlock_irqrestore(&state->slock, flags);
}

static void s5pcsis_log_counters(struct csis_state *state, bool non_errors)
{
        int i = non_errors ? S5PCSIS_NUM_EVENTS : S5PCSIS_NUM_EVENTS - 4;
        unsigned long flags;

        spin_lock_irqsave(&state->slock, flags);

        for (i--; i >= 0; i--) {
                if (state->events[i].counter > 0 || debug)
                        v4l2_info(&state->sd, "%s events: %d\n",
                                  state->events[i].name,
                                  state->events[i].counter);
        }
        spin_unlock_irqrestore(&state->slock, flags);
}

/*
 * V4L2 subdev operations
 */
static int s5pcsis_s_power(struct v4l2_subdev *sd, int on)
{
        struct csis_state *state = sd_to_csis_state(sd);
        struct device *dev = &state->pdev->dev;

        if (on)
                return pm_runtime_get_sync(dev);

        return pm_runtime_put_sync(dev);
}

static int s5pcsis_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct csis_state *state = sd_to_csis_state(sd);
        int ret = 0;

        v4l2_dbg(1, debug, sd, "%s: %d, state: 0x%x\n",
                 __func__, enable, state->flags);

        if (enable) {
                s5pcsis_clear_counters(state);
                ret = pm_runtime_get_sync(&state->pdev->dev);
                if (ret && ret != 1)
                        return ret;
        }

        mutex_lock(&state->lock);
        if (enable) {
                if (state->flags & ST_SUSPENDED) {
                        ret = -EBUSY;
                        goto unlock;
                }
                s5pcsis_start_stream(state);
                state->flags |= ST_STREAMING;
        } else {
                s5pcsis_stop_stream(state);
                state->flags &= ~ST_STREAMING;
                if (debug > 0)
                        s5pcsis_log_counters(state, true);
        }
unlock:
        mutex_unlock(&state->lock);
        if (!enable)
                pm_runtime_put(&state->pdev->dev);

        return ret == 1 ? 0 : ret;
}

static int s5pcsis_enum_mbus_code(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_fh *fh,
                                  struct v4l2_subdev_mbus_code_enum *code)
{
        if (code->index >= ARRAY_SIZE(s5pcsis_formats))
                return -EINVAL;

        code->code = s5pcsis_formats[code->index].code;
        return 0;
}

static struct csis_pix_format const *s5pcsis_try_format(
        struct v4l2_mbus_framefmt *mf)
{
        struct csis_pix_format const *csis_fmt;

        csis_fmt = find_csis_format(mf);
        if (csis_fmt == NULL)
                csis_fmt = &s5pcsis_formats[0];

        mf->code = csis_fmt->code;
        v4l_bound_align_image(&mf->width, 1, CSIS_MAX_PIX_WIDTH,
                              csis_fmt->pix_width_alignment,
                              &mf->height, 1, CSIS_MAX_PIX_HEIGHT, 1,
                              0);
        return csis_fmt;
}

static struct v4l2_mbus_framefmt *__s5pcsis_get_format(
                struct csis_state *state, struct v4l2_subdev_fh *fh,
                u32 pad, enum v4l2_subdev_format_whence which)
{
        if (which == V4L2_SUBDEV_FORMAT_TRY)
                return fh ? v4l2_subdev_get_try_format(fh, pad) : NULL;

        return &state->format;
}

static int s5pcsis_set_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
                           struct v4l2_subdev_format *fmt)
{
        struct csis_state *state = sd_to_csis_state(sd);
        struct csis_pix_format const *csis_fmt;
        struct v4l2_mbus_framefmt *mf;

        if (fmt->pad != CSIS_PAD_SOURCE && fmt->pad != CSIS_PAD_SINK)
                return -EINVAL;

        mf = __s5pcsis_get_format(state, fh, fmt->pad, fmt->which);

        if (fmt->pad == CSIS_PAD_SOURCE) {
                if (mf) {
                        mutex_lock(&state->lock);
                        fmt->format = *mf;
                        mutex_unlock(&state->lock);
                }
                return 0;
        }
        csis_fmt = s5pcsis_try_format(&fmt->format);
        if (mf) {
                mutex_lock(&state->lock);
                *mf = fmt->format;
                if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
                        state->csis_fmt = csis_fmt;
                mutex_unlock(&state->lock);
        }
        return 0;
}

static int s5pcsis_get_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
                           struct v4l2_subdev_format *fmt)
{
        struct csis_state *state = sd_to_csis_state(sd);
        struct v4l2_mbus_framefmt *mf;

        if (fmt->pad != CSIS_PAD_SOURCE && fmt->pad != CSIS_PAD_SINK)
                return -EINVAL;

        mf = __s5pcsis_get_format(state, fh, fmt->pad, fmt->which);
        if (!mf)
                return -EINVAL;

        mutex_lock(&state->lock);
        fmt->format = *mf;
        mutex_unlock(&state->lock);
        return 0;
}

static int s5pcsis_s_rx_buffer(struct v4l2_subdev *sd, void *buf,
                               unsigned int *size)
{
        struct csis_state *state = sd_to_csis_state(sd);
        unsigned long flags;

        *size = min_t(unsigned int, *size, S5PCSIS_PKTDATA_SIZE);

        spin_lock_irqsave(&state->slock, flags);
        state->pkt_buf.data = buf;
        state->pkt_buf.len = *size;
        spin_unlock_irqrestore(&state->slock, flags);

        return 0;
}

static int s5pcsis_log_status(struct v4l2_subdev *sd)
{
        struct csis_state *state = sd_to_csis_state(sd);

        mutex_lock(&state->lock);
        s5pcsis_log_counters(state, true);
        if (debug && (state->flags & ST_POWERED))
                dump_regs(state, __func__);
        mutex_unlock(&state->lock);
        return 0;
}

static int s5pcsis_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
        struct v4l2_mbus_framefmt *format = v4l2_subdev_get_try_format(fh, 0);

        format->colorspace = V4L2_COLORSPACE_JPEG;
        format->code = s5pcsis_formats[0].code;
        format->width = S5PCSIS_DEF_PIX_WIDTH;
        format->height = S5PCSIS_DEF_PIX_HEIGHT;
        format->field = V4L2_FIELD_NONE;

        return 0;
}

static const struct v4l2_subdev_internal_ops s5pcsis_sd_internal_ops = {
        .open = s5pcsis_open,
};

static struct v4l2_subdev_core_ops s5pcsis_core_ops = {
        .s_power = s5pcsis_s_power,
        .log_status = s5pcsis_log_status,
};

static struct v4l2_subdev_pad_ops s5pcsis_pad_ops = {
        .enum_mbus_code = s5pcsis_enum_mbus_code,
        .get_fmt = s5pcsis_get_fmt,
        .set_fmt = s5pcsis_set_fmt,
};

static struct v4l2_subdev_video_ops s5pcsis_video_ops = {
        .s_rx_buffer = s5pcsis_s_rx_buffer,
        .s_stream = s5pcsis_s_stream,
};

static struct v4l2_subdev_ops s5pcsis_subdev_ops = {
        .core = &s5pcsis_core_ops,
        .pad = &s5pcsis_pad_ops,
        .video = &s5pcsis_video_ops,
};

static irqreturn_t s5pcsis_irq_handler(int irq, void *dev_id)
{
        struct csis_state *state = dev_id;
        struct csis_pktbuf *pktbuf = &state->pkt_buf;
        unsigned long flags;
        u32 status;

        status = s5pcsis_read(state, S5PCSIS_INTSRC);
        spin_lock_irqsave(&state->slock, flags);

        if ((status & S5PCSIS_INTSRC_NON_IMAGE_DATA) && pktbuf->data) {
                u32 offset;

                if (status & S5PCSIS_INTSRC_EVEN)
                        offset = S5PCSIS_PKTDATA_EVEN;
                else
                        offset = S5PCSIS_PKTDATA_ODD;

                memcpy(pktbuf->data, state->regs + offset, pktbuf->len);
                pktbuf->data = NULL;
                rmb();
        }

        /* Update the event/error counters */
        if ((status & S5PCSIS_INTSRC_ERRORS) || debug) {
                int i;
                for (i = 0; i < S5PCSIS_NUM_EVENTS; i++) {
                        if (!(status & state->events[i].mask))
                                continue;
                        state->events[i].counter++;
                        v4l2_dbg(2, debug, &state->sd, "%s: %d\n",
                                 state->events[i].name,
                                 state->events[i].counter);
                }
                v4l2_dbg(2, debug, &state->sd, "status: %08x\n", status);
        }
        spin_unlock_irqrestore(&state->slock, flags);

        s5pcsis_write(state, S5PCSIS_INTSRC, status);
        return IRQ_HANDLED;
}

static int s5pcsis_probe(struct platform_device *pdev)
{
        struct s5p_platform_mipi_csis *pdata;
        struct resource *mem_res;
        struct csis_state *state;
        int ret = -ENOMEM;
        int i;

        state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
        if (!state)
                return -ENOMEM;

        mutex_init(&state->lock);
        spin_lock_init(&state->slock);

        state->pdev = pdev;
        state->index = max(0, pdev->id);

        pdata = pdev->dev.platform_data;
        if (pdata == NULL) {
                dev_err(&pdev->dev, "Platform data not fully specified\n");
                return -EINVAL;
        }

        if ((state->index == 1 && pdata->lanes > CSIS1_MAX_LANES) ||
            pdata->lanes > CSIS0_MAX_LANES) {
                dev_err(&pdev->dev, "Unsupported number of data lanes: %d\n",
                        pdata->lanes);
                return -EINVAL;
        }

        mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        state->regs = devm_ioremap_resource(&pdev->dev, mem_res);
        if (IS_ERR(state->regs))
                return PTR_ERR(state->regs);

        state->irq = platform_get_irq(pdev, 0);
        if (state->irq < 0) {
                dev_err(&pdev->dev, "Failed to get irq\n");
                return state->irq;
        }

        for (i = 0; i < CSIS_NUM_SUPPLIES; i++)
                state->supplies[i].supply = csis_supply_name[i];

        ret = devm_regulator_bulk_get(&pdev->dev, CSIS_NUM_SUPPLIES,
                                 state->supplies);
        if (ret)
                return ret;

        ret = s5pcsis_clk_get(state);
        if (ret < 0)
                return ret;

        if (pdata->clk_rate)
                ret = clk_set_rate(state->clock[CSIS_CLK_MUX],
                                   pdata->clk_rate);
        else
                dev_WARN(&pdev->dev, "No clock frequency specified!\n");
        if (ret < 0)
                goto e_clkput;

        ret = clk_enable(state->clock[CSIS_CLK_MUX]);
        if (ret < 0)
                goto e_clkput;

        ret = devm_request_irq(&pdev->dev, state->irq, s5pcsis_irq_handler,
                               0, dev_name(&pdev->dev), state);
        if (ret) {
                dev_err(&pdev->dev, "Interrupt request failed\n");
                goto e_clkdis;
        }

        v4l2_subdev_init(&state->sd, &s5pcsis_subdev_ops);
        state->sd.owner = THIS_MODULE;
        strlcpy(state->sd.name, dev_name(&pdev->dev), sizeof(state->sd.name));
        state->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        state->csis_fmt = &s5pcsis_formats[0];

        state->format.code = s5pcsis_formats[0].code;
        state->format.width = S5PCSIS_DEF_PIX_WIDTH;
        state->format.height = S5PCSIS_DEF_PIX_HEIGHT;

        state->pads[CSIS_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
        state->pads[CSIS_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
        ret = media_entity_init(&state->sd.entity,
                                CSIS_PADS_NUM, state->pads, 0);
        if (ret < 0)
                goto e_clkdis;

        /* This allows to retrieve the platform device id by the host driver */
        v4l2_set_subdevdata(&state->sd, pdev);

        /* .. and a pointer to the subdev. */
        platform_set_drvdata(pdev, &state->sd);

        memcpy(state->events, s5pcsis_events, sizeof(state->events));

        pm_runtime_enable(&pdev->dev);
        return 0;

e_clkdis:
        clk_disable(state->clock[CSIS_CLK_MUX]);
e_clkput:
        s5pcsis_clk_put(state);
        return ret;
}

static int s5pcsis_pm_suspend(struct device *dev, bool runtime)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct v4l2_subdev *sd = platform_get_drvdata(pdev);
        struct csis_state *state = sd_to_csis_state(sd);
        int ret = 0;

        v4l2_dbg(1, debug, sd, "%s: flags: 0x%x\n",
                 __func__, state->flags);

        mutex_lock(&state->lock);
        if (state->flags & ST_POWERED) {
                s5pcsis_stop_stream(state);
                ret = s5p_csis_phy_enable(state->index, false);
                if (ret)
                        goto unlock;
                ret = regulator_bulk_disable(CSIS_NUM_SUPPLIES,
                                             state->supplies);
                if (ret)
                        goto unlock;
                clk_disable(state->clock[CSIS_CLK_GATE]);
                state->flags &= ~ST_POWERED;
                if (!runtime)
                        state->flags |= ST_SUSPENDED;
        }
 unlock:
        mutex_unlock(&state->lock);
        return ret ? -EAGAIN : 0;
}

static int s5pcsis_pm_resume(struct device *dev, bool runtime)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct v4l2_subdev *sd = platform_get_drvdata(pdev);
        struct csis_state *state = sd_to_csis_state(sd);
        int ret = 0;

        v4l2_dbg(1, debug, sd, "%s: flags: 0x%x\n",
                 __func__, state->flags);

        mutex_lock(&state->lock);
        if (!runtime && !(state->flags & ST_SUSPENDED))
                goto unlock;

        if (!(state->flags & ST_POWERED)) {
                ret = regulator_bulk_enable(CSIS_NUM_SUPPLIES,
                                            state->supplies);
                if (ret)
                        goto unlock;
                ret = s5p_csis_phy_enable(state->index, true);
                if (!ret) {
                        state->flags |= ST_POWERED;
                } else {
                        regulator_bulk_disable(CSIS_NUM_SUPPLIES,
                                               state->supplies);
                        goto unlock;
                }
                clk_enable(state->clock[CSIS_CLK_GATE]);
        }
        if (state->flags & ST_STREAMING)
                s5pcsis_start_stream(state);

        state->flags &= ~ST_SUSPENDED;
 unlock:
        mutex_unlock(&state->lock);
        return ret ? -EAGAIN : 0;
}

#ifdef CONFIG_PM_SLEEP
static int s5pcsis_suspend(struct device *dev)
{
        return s5pcsis_pm_suspend(dev, false);
}

static int s5pcsis_resume(struct device *dev)
{
        return s5pcsis_pm_resume(dev, false);
}
#endif

#ifdef CONFIG_PM_RUNTIME
static int s5pcsis_runtime_suspend(struct device *dev)
{
        return s5pcsis_pm_suspend(dev, true);
}

static int s5pcsis_runtime_resume(struct device *dev)
{
        return s5pcsis_pm_resume(dev, true);
}
#endif

static int s5pcsis_remove(struct platform_device *pdev)
{
        struct v4l2_subdev *sd = platform_get_drvdata(pdev);
        struct csis_state *state = sd_to_csis_state(sd);

        pm_runtime_disable(&pdev->dev);
        s5pcsis_pm_suspend(&pdev->dev, false);
        clk_disable(state->clock[CSIS_CLK_MUX]);
        pm_runtime_set_suspended(&pdev->dev);
        s5pcsis_clk_put(state);

        media_entity_cleanup(&state->sd.entity);

        return 0;
}

static const struct dev_pm_ops s5pcsis_pm_ops = {
        SET_RUNTIME_PM_OPS(s5pcsis_runtime_suspend, s5pcsis_runtime_resume,
                           NULL)
        SET_SYSTEM_SLEEP_PM_OPS(s5pcsis_suspend, s5pcsis_resume)
};

static struct platform_driver s5pcsis_driver = {
        .probe          = s5pcsis_probe,
        .remove         = s5pcsis_remove,
        .driver         = {
                .name   = CSIS_DRIVER_NAME,
                .owner  = THIS_MODULE,
                .pm     = &s5pcsis_pm_ops,
        },
};

module_platform_driver(s5pcsis_driver);

MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
MODULE_DESCRIPTION("Samsung S5P/EXYNOS SoC MIPI-CSI2 receiver driver");
MODULE_LICENSE("GPL");