/*
 * Driver for M-5MOLS 8M Pixel camera sensor with ISP
 *
 * Copyright (C) 2011 Samsung Electronics Co., Ltd.
 * Author: HeungJun Kim <riverful.kim@samsung.com>
 *
 * Copyright (C) 2009 Samsung Electronics Co., Ltd.
 * Author: Dongsoo Nathaniel Kim <dongsoo45.kim@samsung.com>
 *
 * 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.
 */

#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/videodev2.h>
#include <linux/module.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-subdev.h>
#include <media/m5mols.h>

#include "m5mols.h"
#include "m5mols_reg.h"

int m5mols_debug;
module_param(m5mols_debug, int, 0644);

#define MODULE_NAME             "M5MOLS"
#define M5MOLS_I2C_CHECK_RETRY  500

/* The regulator consumer names for external voltage regulators */
static struct regulator_bulk_data supplies[] = {
        {
                .supply = "core",       /* ARM core power, 1.2V */
        }, {
                .supply = "dig_18",     /* digital power 1, 1.8V */
        }, {
                .supply = "d_sensor",   /* sensor power 1, 1.8V */
        }, {
                .supply = "dig_28",     /* digital power 2, 2.8V */
        }, {
                .supply = "a_sensor",   /* analog power */
        }, {
                .supply = "dig_12",     /* digital power 3, 1.2V */
        },
};

static struct v4l2_mbus_framefmt m5mols_default_ffmt[M5MOLS_RESTYPE_MAX] = {
        [M5MOLS_RESTYPE_MONITOR] = {
                .width          = 1920,
                .height         = 1080,
                .code           = V4L2_MBUS_FMT_VYUY8_2X8,
                .field          = V4L2_FIELD_NONE,
                .colorspace     = V4L2_COLORSPACE_JPEG,
        },
        [M5MOLS_RESTYPE_CAPTURE] = {
                .width          = 1920,
                .height         = 1080,
                .code           = V4L2_MBUS_FMT_JPEG_1X8,
                .field          = V4L2_FIELD_NONE,
                .colorspace     = V4L2_COLORSPACE_JPEG,
        },
};
#define SIZE_DEFAULT_FFMT       ARRAY_SIZE(m5mols_default_ffmt)

static const struct m5mols_resolution m5mols_reg_res[] = {
        { 0x01, M5MOLS_RESTYPE_MONITOR, 128, 96 },      /* SUB-QCIF */
        { 0x03, M5MOLS_RESTYPE_MONITOR, 160, 120 },     /* QQVGA */
        { 0x05, M5MOLS_RESTYPE_MONITOR, 176, 144 },     /* QCIF */
        { 0x06, M5MOLS_RESTYPE_MONITOR, 176, 176 },
        { 0x08, M5MOLS_RESTYPE_MONITOR, 240, 320 },     /* QVGA */
        { 0x09, M5MOLS_RESTYPE_MONITOR, 320, 240 },     /* QVGA */
        { 0x0c, M5MOLS_RESTYPE_MONITOR, 240, 400 },     /* WQVGA */
        { 0x0d, M5MOLS_RESTYPE_MONITOR, 400, 240 },     /* WQVGA */
        { 0x0e, M5MOLS_RESTYPE_MONITOR, 352, 288 },     /* CIF */
        { 0x13, M5MOLS_RESTYPE_MONITOR, 480, 360 },
        { 0x15, M5MOLS_RESTYPE_MONITOR, 640, 360 },     /* qHD */
        { 0x17, M5MOLS_RESTYPE_MONITOR, 640, 480 },     /* VGA */
        { 0x18, M5MOLS_RESTYPE_MONITOR, 720, 480 },
        { 0x1a, M5MOLS_RESTYPE_MONITOR, 800, 480 },     /* WVGA */
        { 0x1f, M5MOLS_RESTYPE_MONITOR, 800, 600 },     /* SVGA */
        { 0x21, M5MOLS_RESTYPE_MONITOR, 1280, 720 },    /* HD */
        { 0x25, M5MOLS_RESTYPE_MONITOR, 1920, 1080 },   /* 1080p */
        { 0x29, M5MOLS_RESTYPE_MONITOR, 3264, 2448 },   /* 2.63fps 8M */
        { 0x39, M5MOLS_RESTYPE_MONITOR, 800, 602 },     /* AHS_MON debug */

        { 0x02, M5MOLS_RESTYPE_CAPTURE, 320, 240 },     /* QVGA */
        { 0x04, M5MOLS_RESTYPE_CAPTURE, 400, 240 },     /* WQVGA */
        { 0x07, M5MOLS_RESTYPE_CAPTURE, 480, 360 },
        { 0x08, M5MOLS_RESTYPE_CAPTURE, 640, 360 },     /* qHD */
        { 0x09, M5MOLS_RESTYPE_CAPTURE, 640, 480 },     /* VGA */
        { 0x0a, M5MOLS_RESTYPE_CAPTURE, 800, 480 },     /* WVGA */
        { 0x10, M5MOLS_RESTYPE_CAPTURE, 1280, 720 },    /* HD */
        { 0x14, M5MOLS_RESTYPE_CAPTURE, 1280, 960 },    /* 1M */
        { 0x17, M5MOLS_RESTYPE_CAPTURE, 1600, 1200 },   /* 2M */
        { 0x19, M5MOLS_RESTYPE_CAPTURE, 1920, 1080 },   /* Full-HD */
        { 0x1a, M5MOLS_RESTYPE_CAPTURE, 2048, 1152 },   /* 3Mega */
        { 0x1b, M5MOLS_RESTYPE_CAPTURE, 2048, 1536 },
        { 0x1c, M5MOLS_RESTYPE_CAPTURE, 2560, 1440 },   /* 4Mega */
        { 0x1d, M5MOLS_RESTYPE_CAPTURE, 2560, 1536 },
        { 0x1f, M5MOLS_RESTYPE_CAPTURE, 2560, 1920 },   /* 5Mega */
        { 0x21, M5MOLS_RESTYPE_CAPTURE, 3264, 1836 },   /* 6Mega */
        { 0x22, M5MOLS_RESTYPE_CAPTURE, 3264, 1960 },
        { 0x25, M5MOLS_RESTYPE_CAPTURE, 3264, 2448 },   /* 8Mega */
};

/**
 * m5mols_swap_byte - an byte array to integer conversion function
 * @size: size in bytes of I2C packet defined in the M-5MOLS datasheet
 *
 * Convert I2C data byte array with performing any required byte
 * reordering to assure proper values for each data type, regardless
 * of the architecture endianness.
 */
static u32 m5mols_swap_byte(u8 *data, u8 length)
{
        if (length == 1)
                return *data;
        else if (length == 2)
                return be16_to_cpu(*((u16 *)data));
        else
                return be32_to_cpu(*((u32 *)data));
}

/**
 * m5mols_read -  I2C read function
 * @reg: combination of size, category and command for the I2C packet
 * @size: desired size of I2C packet
 * @val: read value
 *
 * Returns 0 on success, or else negative errno.
 */
static int m5mols_read(struct v4l2_subdev *sd, u32 size, u32 reg, u32 *val)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct m5mols_info *info = to_m5mols(sd);
        u8 rbuf[M5MOLS_I2C_MAX_SIZE + 1];
        u8 category = I2C_CATEGORY(reg);
        u8 cmd = I2C_COMMAND(reg);
        struct i2c_msg msg[2];
        u8 wbuf[5];
        int ret;

        if (!client->adapter)
                return -ENODEV;

        msg[0].addr = client->addr;
        msg[0].flags = 0;
        msg[0].len = 5;
        msg[0].buf = wbuf;
        wbuf[0] = 5;
        wbuf[1] = M5MOLS_BYTE_READ;
        wbuf[2] = category;
        wbuf[3] = cmd;
        wbuf[4] = size;

        msg[1].addr = client->addr;
        msg[1].flags = I2C_M_RD;
        msg[1].len = size + 1;
        msg[1].buf = rbuf;

        /* minimum stabilization time */
        usleep_range(200, 200);

        ret = i2c_transfer(client->adapter, msg, 2);

        if (ret == 2) {
                *val = m5mols_swap_byte(&rbuf[1], size);
                return 0;
        }

        if (info->isp_ready)
                v4l2_err(sd, "read failed: size:%d cat:%02x cmd:%02x. %d\n",
                         size, category, cmd, ret);

        return ret < 0 ? ret : -EIO;
}

int m5mols_read_u8(struct v4l2_subdev *sd, u32 reg, u8 *val)
{
        u32 val_32;
        int ret;

        if (I2C_SIZE(reg) != 1) {
                v4l2_err(sd, "Wrong data size\n");
                return -EINVAL;
        }

        ret = m5mols_read(sd, I2C_SIZE(reg), reg, &val_32);
        if (ret)
                return ret;

        *val = (u8)val_32;
        return ret;
}

int m5mols_read_u16(struct v4l2_subdev *sd, u32 reg, u16 *val)
{
        u32 val_32;
        int ret;

        if (I2C_SIZE(reg) != 2) {
                v4l2_err(sd, "Wrong data size\n");
                return -EINVAL;
        }

        ret = m5mols_read(sd, I2C_SIZE(reg), reg, &val_32);
        if (ret)
                return ret;

        *val = (u16)val_32;
        return ret;
}

int m5mols_read_u32(struct v4l2_subdev *sd, u32 reg, u32 *val)
{
        if (I2C_SIZE(reg) != 4) {
                v4l2_err(sd, "Wrong data size\n");
                return -EINVAL;
        }

        return m5mols_read(sd, I2C_SIZE(reg), reg, val);
}

/**
 * m5mols_write - I2C command write function
 * @reg: combination of size, category and command for the I2C packet
 * @val: value to write
 *
 * Returns 0 on success, or else negative errno.
 */
int m5mols_write(struct v4l2_subdev *sd, u32 reg, u32 val)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct m5mols_info *info = to_m5mols(sd);
        u8 wbuf[M5MOLS_I2C_MAX_SIZE + 4];
        u8 category = I2C_CATEGORY(reg);
        u8 cmd = I2C_COMMAND(reg);
        u8 size = I2C_SIZE(reg);
        u32 *buf = (u32 *)&wbuf[4];
        struct i2c_msg msg[1];
        int ret;

        if (!client->adapter)
                return -ENODEV;

        if (size != 1 && size != 2 && size != 4) {
                v4l2_err(sd, "Wrong data size\n");
                return -EINVAL;
        }

        msg->addr = client->addr;
        msg->flags = 0;
        msg->len = (u16)size + 4;
        msg->buf = wbuf;
        wbuf[0] = size + 4;
        wbuf[1] = M5MOLS_BYTE_WRITE;
        wbuf[2] = category;
        wbuf[3] = cmd;

        *buf = m5mols_swap_byte((u8 *)&val, size);

        usleep_range(200, 200);

        ret = i2c_transfer(client->adapter, msg, 1);
        if (ret == 1)
                return 0;

        if (info->isp_ready)
                v4l2_err(sd, "write failed: cat:%02x cmd:%02x ret:%d\n",
                         category, cmd, ret);

        return ret < 0 ? ret : -EIO;
}

/**
 * m5mols_busy_wait - Busy waiting with I2C register polling
 * @reg: the I2C_REG() address of an 8-bit status register to check
 * @value: expected status register value
 * @mask: bit mask for the read status register value
 * @timeout: timeout in miliseconds, or -1 for default timeout
 *
 * The @reg register value is ORed with @mask before comparing with @value.
 *
 * Return: 0 if the requested condition became true within less than
 *         @timeout ms, or else negative errno.
 */
int m5mols_busy_wait(struct v4l2_subdev *sd, u32 reg, u32 value, u32 mask,
                     int timeout)
{
        int ms = timeout < 0 ? M5MOLS_BUSY_WAIT_DEF_TIMEOUT : timeout;
        unsigned long end = jiffies + msecs_to_jiffies(ms);
        u8 status;

        do {
                int ret = m5mols_read_u8(sd, reg, &status);

                if (ret < 0 && !(mask & M5MOLS_I2C_RDY_WAIT_FL))
                        return ret;
                if (!ret && (status & mask & 0xff) == (value & 0xff))
                        return 0;
                usleep_range(100, 250);
        } while (ms > 0 && time_is_after_jiffies(end));

        return -EBUSY;
}

/**
 * m5mols_enable_interrupt - Clear interrupt pending bits and unmask interrupts
 *
 * Before writing desired interrupt value the INT_FACTOR register should
 * be read to clear pending interrupts.
 */
int m5mols_enable_interrupt(struct v4l2_subdev *sd, u8 reg)
{
        struct m5mols_info *info = to_m5mols(sd);
        u8 mask = is_available_af(info) ? REG_INT_AF : 0;
        u8 dummy;
        int ret;

        ret = m5mols_read_u8(sd, SYSTEM_INT_FACTOR, &dummy);
        if (!ret)
                ret = m5mols_write(sd, SYSTEM_INT_ENABLE, reg & ~mask);
        return ret;
}

int m5mols_wait_interrupt(struct v4l2_subdev *sd, u8 irq_mask, u32 timeout)
{
        struct m5mols_info *info = to_m5mols(sd);

        int ret = wait_event_interruptible_timeout(info->irq_waitq,
                                atomic_add_unless(&info->irq_done, -1, 0),
                                msecs_to_jiffies(timeout));
        if (ret <= 0)
                return ret ? ret : -ETIMEDOUT;

        return m5mols_busy_wait(sd, SYSTEM_INT_FACTOR, irq_mask,
                                M5MOLS_I2C_RDY_WAIT_FL | irq_mask, -1);
}

/**
 * m5mols_reg_mode - Write the mode and check busy status
 *
 * It always accompanies a little delay changing the M-5MOLS mode, so it is
 * needed checking current busy status to guarantee right mode.
 */
static int m5mols_reg_mode(struct v4l2_subdev *sd, u8 mode)
{
        int ret = m5mols_write(sd, SYSTEM_SYSMODE, mode);
        if (ret < 0)
                return ret;
        return m5mols_busy_wait(sd, SYSTEM_SYSMODE, mode, 0xff,
                                M5MOLS_MODE_CHANGE_TIMEOUT);
}

/**
 * m5mols_set_mode - set the M-5MOLS controller mode
 * @mode: the required operation mode
 *
 * The commands of M-5MOLS are grouped into specific modes. Each functionality
 * can be guaranteed only when the sensor is operating in mode which a command
 * belongs to.
 */
int m5mols_set_mode(struct m5mols_info *info, u8 mode)
{
        struct v4l2_subdev *sd = &info->sd;
        int ret = -EINVAL;
        u8 reg;

        if (mode < REG_PARAMETER || mode > REG_CAPTURE)
                return ret;

        ret = m5mols_read_u8(sd, SYSTEM_SYSMODE, &reg);
        if (ret || reg == mode)
                return ret;

        switch (reg) {
        case REG_PARAMETER:
                ret = m5mols_reg_mode(sd, REG_MONITOR);
                if (mode == REG_MONITOR)
                        break;
                if (!ret)
                        ret = m5mols_reg_mode(sd, REG_CAPTURE);
                break;

        case REG_MONITOR:
                if (mode == REG_PARAMETER) {
                        ret = m5mols_reg_mode(sd, REG_PARAMETER);
                        break;
                }

                ret = m5mols_reg_mode(sd, REG_CAPTURE);
                break;

        case REG_CAPTURE:
                ret = m5mols_reg_mode(sd, REG_MONITOR);
                if (mode == REG_MONITOR)
                        break;
                if (!ret)
                        ret = m5mols_reg_mode(sd, REG_PARAMETER);
                break;

        default:
                v4l2_warn(sd, "Wrong mode: %d\n", mode);
        }

        if (!ret)
                info->mode = mode;

        return ret;
}

/**
 * m5mols_get_version - retrieve full revisions information of M-5MOLS
 *
 * The version information includes revisions of hardware and firmware,
 * AutoFocus alghorithm version and the version string.
 */
static int m5mols_get_version(struct v4l2_subdev *sd)
{
        struct m5mols_info *info = to_m5mols(sd);
        struct m5mols_version *ver = &info->ver;
        u8 *str = ver->str;
        int i;
        int ret;

        ret = m5mols_read_u8(sd, SYSTEM_VER_CUSTOMER, &ver->customer);
        if (!ret)
                ret = m5mols_read_u8(sd, SYSTEM_VER_PROJECT, &ver->project);
        if (!ret)
                ret = m5mols_read_u16(sd, SYSTEM_VER_FIRMWARE, &ver->fw);
        if (!ret)
                ret = m5mols_read_u16(sd, SYSTEM_VER_HARDWARE, &ver->hw);
        if (!ret)
                ret = m5mols_read_u16(sd, SYSTEM_VER_PARAMETER, &ver->param);
        if (!ret)
                ret = m5mols_read_u16(sd, SYSTEM_VER_AWB, &ver->awb);
        if (!ret)
                ret = m5mols_read_u8(sd, AF_VERSION, &ver->af);
        if (ret)
                return ret;

        for (i = 0; i < VERSION_STRING_SIZE; i++) {
                ret = m5mols_read_u8(sd, SYSTEM_VER_STRING, &str[i]);
                if (ret)
                        return ret;
        }

        ver->fw = be16_to_cpu(ver->fw);
        ver->hw = be16_to_cpu(ver->hw);
        ver->param = be16_to_cpu(ver->param);
        ver->awb = be16_to_cpu(ver->awb);

        v4l2_info(sd, "Manufacturer\t[%s]\n",
                        is_manufacturer(info, REG_SAMSUNG_ELECTRO) ?
                        "Samsung Electro-Machanics" :
                        is_manufacturer(info, REG_SAMSUNG_OPTICS) ?
                        "Samsung Fiber-Optics" :
                        is_manufacturer(info, REG_SAMSUNG_TECHWIN) ?
                        "Samsung Techwin" : "None");
        v4l2_info(sd, "Customer/Project\t[0x%02x/0x%02x]\n",
                        info->ver.customer, info->ver.project);

        if (!is_available_af(info))
                v4l2_info(sd, "No support Auto Focus on this firmware\n");

        return ret;
}

/**
 * __find_restype - Lookup M-5MOLS resolution type according to pixel code
 * @code: pixel code
 */
static enum m5mols_restype __find_restype(enum v4l2_mbus_pixelcode code)
{
        enum m5mols_restype type = M5MOLS_RESTYPE_MONITOR;

        do {
                if (code == m5mols_default_ffmt[type].code)
                        return type;
        } while (type++ != SIZE_DEFAULT_FFMT);

        return 0;
}

/**
 * __find_resolution - Lookup preset and type of M-5MOLS's resolution
 * @mf: pixel format to find/negotiate the resolution preset for
 * @type: M-5MOLS resolution type
 * @resolution: M-5MOLS resolution preset register value
 *
 * Find nearest resolution matching resolution preset and adjust mf
 * to supported values.
 */
static int __find_resolution(struct v4l2_subdev *sd,
                             struct v4l2_mbus_framefmt *mf,
                             enum m5mols_restype *type,
                             u32 *resolution)
{
        const struct m5mols_resolution *fsize = &m5mols_reg_res[0];
        const struct m5mols_resolution *match = NULL;
        enum m5mols_restype stype = __find_restype(mf->code);
        int i = ARRAY_SIZE(m5mols_reg_res);
        unsigned int min_err = ~0;

        while (i--) {
                int err;
                if (stype == fsize->type) {
                        err = abs(fsize->width - mf->width)
                                + abs(fsize->height - mf->height);

                        if (err < min_err) {
                                min_err = err;
                                match = fsize;
                        }
                }
                fsize++;
        }
        if (match) {
                mf->width  = match->width;
                mf->height = match->height;
                *resolution = match->reg;
                *type = stype;
                return 0;
        }

        return -EINVAL;
}

static struct v4l2_mbus_framefmt *__find_format(struct m5mols_info *info,
                                struct v4l2_subdev_fh *fh,
                                enum v4l2_subdev_format_whence which,
                                enum m5mols_restype type)
{
        if (which == V4L2_SUBDEV_FORMAT_TRY)
                return fh ? v4l2_subdev_get_try_format(fh, 0) : NULL;

        return &info->ffmt[type];
}

static int m5mols_get_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
                          struct v4l2_subdev_format *fmt)
{
        struct m5mols_info *info = to_m5mols(sd);
        struct v4l2_mbus_framefmt *format;
        int ret = 0;

        mutex_lock(&info->lock);

        format = __find_format(info, fh, fmt->which, info->res_type);
        if (format)
                fmt->format = *format;
        else
                ret = -EINVAL;

        mutex_unlock(&info->lock);
        return ret;
}

static int m5mols_set_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
                          struct v4l2_subdev_format *fmt)
{
        struct m5mols_info *info = to_m5mols(sd);
        struct v4l2_mbus_framefmt *format = &fmt->format;
        struct v4l2_mbus_framefmt *sfmt;
        enum m5mols_restype type;
        u32 resolution = 0;
        int ret;

        ret = __find_resolution(sd, format, &type, &resolution);
        if (ret < 0)
                return ret;

        sfmt = __find_format(info, fh, fmt->which, type);
        if (!sfmt)
                return 0;

        mutex_lock(&info->lock);

        format->code = m5mols_default_ffmt[type].code;
        format->colorspace = V4L2_COLORSPACE_JPEG;
        format->field = V4L2_FIELD_NONE;

        if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
                *sfmt = *format;
                info->resolution = resolution;
                info->res_type = type;
        }

        mutex_unlock(&info->lock);
        return ret;
}

static int m5mols_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
                                 struct v4l2_mbus_frame_desc *fd)
{
        struct m5mols_info *info = to_m5mols(sd);

        if (pad != 0 || fd == NULL)
                return -EINVAL;

        mutex_lock(&info->lock);
        /*
         * .get_frame_desc is only used for compressed formats,
         * thus we always return the capture frame parameters here.
         */
        fd->entry[0].length = info->cap.buf_size;
        fd->entry[0].pixelcode = info->ffmt[M5MOLS_RESTYPE_CAPTURE].code;
        mutex_unlock(&info->lock);

        fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
        fd->num_entries = 1;

        return 0;
}

static int m5mols_set_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
                                 struct v4l2_mbus_frame_desc *fd)
{
        struct m5mols_info *info = to_m5mols(sd);
        struct v4l2_mbus_framefmt *mf = &info->ffmt[M5MOLS_RESTYPE_CAPTURE];

        if (pad != 0 || fd == NULL)
                return -EINVAL;

        fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
        fd->num_entries = 1;
        fd->entry[0].length = clamp_t(u32, fd->entry[0].length,
                                      mf->width * mf->height,
                                      M5MOLS_MAIN_JPEG_SIZE_MAX);
        mutex_lock(&info->lock);
        info->cap.buf_size = fd->entry[0].length;
        mutex_unlock(&info->lock);

        return 0;
}


static int m5mols_enum_mbus_code(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_fh *fh,
                                 struct v4l2_subdev_mbus_code_enum *code)
{
        if (!code || code->index >= SIZE_DEFAULT_FFMT)
                return -EINVAL;

        code->code = m5mols_default_ffmt[code->index].code;

        return 0;
}

static struct v4l2_subdev_pad_ops m5mols_pad_ops = {
        .enum_mbus_code = m5mols_enum_mbus_code,
        .get_fmt        = m5mols_get_fmt,
        .set_fmt        = m5mols_set_fmt,
        .get_frame_desc = m5mols_get_frame_desc,
        .set_frame_desc = m5mols_set_frame_desc,
};

/**
 * m5mols_restore_controls - Apply current control values to the registers
 *
 * m5mols_do_scenemode() handles all parameters for which there is yet no
 * individual control. It should be replaced at some point by setting each
 * control individually, in required register set up order.
 */
int m5mols_restore_controls(struct m5mols_info *info)
{
        int ret;

        if (info->ctrl_sync)
                return 0;

        ret = m5mols_do_scenemode(info, REG_SCENE_NORMAL);
        if (ret)
                return ret;

        ret = v4l2_ctrl_handler_setup(&info->handle);
        info->ctrl_sync = !ret;

        return ret;
}

/**
 * m5mols_start_monitor - Start the monitor mode
 *
 * Before applying the controls setup the resolution and frame rate
 * in PARAMETER mode, and then switch over to MONITOR mode.
 */
static int m5mols_start_monitor(struct m5mols_info *info)
{
        struct v4l2_subdev *sd = &info->sd;
        int ret;

        ret = m5mols_set_mode(info, REG_PARAMETER);
        if (!ret)
                ret = m5mols_write(sd, PARM_MON_SIZE, info->resolution);
        if (!ret)
                ret = m5mols_write(sd, PARM_MON_FPS, REG_FPS_30);
        if (!ret)
                ret = m5mols_set_mode(info, REG_MONITOR);
        if (!ret)
                ret = m5mols_restore_controls(info);

        return ret;
}

static int m5mols_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct m5mols_info *info = to_m5mols(sd);
        u32 code;
        int ret;

        mutex_lock(&info->lock);
        code = info->ffmt[info->res_type].code;

        if (enable) {
                if (is_code(code, M5MOLS_RESTYPE_MONITOR))
                        ret = m5mols_start_monitor(info);
                else if (is_code(code, M5MOLS_RESTYPE_CAPTURE))
                        ret = m5mols_start_capture(info);
                else
                        ret = -EINVAL;
        } else {
                ret = m5mols_set_mode(info, REG_PARAMETER);
        }

        mutex_unlock(&info->lock);
        return ret;
}

static const struct v4l2_subdev_video_ops m5mols_video_ops = {
        .s_stream       = m5mols_s_stream,
};

static int m5mols_sensor_power(struct m5mols_info *info, bool enable)
{
        struct v4l2_subdev *sd = &info->sd;
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        const struct m5mols_platform_data *pdata = info->pdata;
        int ret;

        if (info->power == enable)
                return 0;

        if (enable) {
                if (info->set_power) {
                        ret = info->set_power(&client->dev, 1);
                        if (ret)
                                return ret;
                }

                ret = regulator_bulk_enable(ARRAY_SIZE(supplies), supplies);
                if (ret) {
                        info->set_power(&client->dev, 0);
                        return ret;
                }

                gpio_set_value(pdata->gpio_reset, !pdata->reset_polarity);
                info->power = 1;

                return ret;
        }

        ret = regulator_bulk_disable(ARRAY_SIZE(supplies), supplies);
        if (ret)
                return ret;

        if (info->set_power)
                info->set_power(&client->dev, 0);

        gpio_set_value(pdata->gpio_reset, pdata->reset_polarity);

        info->isp_ready = 0;
        info->power = 0;

        return ret;
}

/* m5mols_update_fw - optional firmware update routine */
int __attribute__ ((weak)) m5mols_update_fw(struct v4l2_subdev *sd,
                int (*set_power)(struct m5mols_info *, bool))
{
        return 0;
}

/**
 * m5mols_fw_start - M-5MOLS internal ARM controller initialization
 *
 * Execute the M-5MOLS internal ARM controller initialization sequence.
 * This function should be called after the supply voltage has been
 * applied and before any requests to the device are made.
 */
static int m5mols_fw_start(struct v4l2_subdev *sd)
{
        struct m5mols_info *info = to_m5mols(sd);
        int ret;

        atomic_set(&info->irq_done, 0);
        /* Wait until I2C slave is initialized in Flash Writer mode */
        ret = m5mols_busy_wait(sd, FLASH_CAM_START, REG_IN_FLASH_MODE,
                               M5MOLS_I2C_RDY_WAIT_FL | 0xff, -1);
        if (!ret)
                ret = m5mols_write(sd, FLASH_CAM_START, REG_START_ARM_BOOT);
        if (!ret)
                ret = m5mols_wait_interrupt(sd, REG_INT_MODE, 2000);
        if (ret < 0)
                return ret;

        info->isp_ready = 1;

        ret = m5mols_get_version(sd);
        if (!ret)
                ret = m5mols_update_fw(sd, m5mols_sensor_power);
        if (ret)
                return ret;

        v4l2_dbg(1, m5mols_debug, sd, "Success ARM Booting\n");

        ret = m5mols_write(sd, PARM_INTERFACE, REG_INTERFACE_MIPI);
        if (!ret)
                ret = m5mols_enable_interrupt(sd,
                                REG_INT_AF | REG_INT_CAPTURE);

        return ret;
}

/* Execute the lens soft-landing algorithm */
static int m5mols_auto_focus_stop(struct m5mols_info *info)
{
        int ret;

        ret = m5mols_write(&info->sd, AF_EXECUTE, REG_AF_STOP);
        if (!ret)
                ret = m5mols_write(&info->sd, AF_MODE, REG_AF_POWEROFF);
        if (!ret)
                ret = m5mols_busy_wait(&info->sd, SYSTEM_STATUS, REG_AF_IDLE,
                                       0xff, -1);
        return ret;
}

/**
 * m5mols_s_power - Main sensor power control function
 *
 * To prevent breaking the lens when the sensor is powered off the Soft-Landing
 * algorithm is called where available. The Soft-Landing algorithm availability
 * dependends on the firmware provider.
 */
static int m5mols_s_power(struct v4l2_subdev *sd, int on)
{
        struct m5mols_info *info = to_m5mols(sd);
        int ret;

        mutex_lock(&info->lock);

        if (on) {
                ret = m5mols_sensor_power(info, true);
                if (!ret)
                        ret = m5mols_fw_start(sd);
        } else {
                if (is_manufacturer(info, REG_SAMSUNG_TECHWIN)) {
                        ret = m5mols_set_mode(info, REG_MONITOR);
                        if (!ret)
                                ret = m5mols_auto_focus_stop(info);
                        if (ret < 0)
                                v4l2_warn(sd, "Soft landing lens failed\n");
                }
                ret = m5mols_sensor_power(info, false);

                info->ctrl_sync = 0;
        }

        mutex_unlock(&info->lock);
        return ret;
}

static int m5mols_log_status(struct v4l2_subdev *sd)
{
        struct m5mols_info *info = to_m5mols(sd);

        v4l2_ctrl_handler_log_status(&info->handle, sd->name);

        return 0;
}

static const struct v4l2_subdev_core_ops m5mols_core_ops = {
        .s_power        = m5mols_s_power,
        .log_status     = m5mols_log_status,
};

/*
 * V4L2 subdev internal operations
 */
static int m5mols_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
        struct v4l2_mbus_framefmt *format = v4l2_subdev_get_try_format(fh, 0);

        *format = m5mols_default_ffmt[0];
        return 0;
}

static const struct v4l2_subdev_internal_ops m5mols_subdev_internal_ops = {
        .open           = m5mols_open,
};

static const struct v4l2_subdev_ops m5mols_ops = {
        .core           = &m5mols_core_ops,
        .pad            = &m5mols_pad_ops,
        .video          = &m5mols_video_ops,
};

static irqreturn_t m5mols_irq_handler(int irq, void *data)
{
        struct m5mols_info *info = to_m5mols(data);

        atomic_set(&info->irq_done, 1);
        wake_up_interruptible(&info->irq_waitq);

        return IRQ_HANDLED;
}

static int m5mols_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
{
        const struct m5mols_platform_data *pdata = client->dev.platform_data;
        unsigned long gpio_flags;
        struct m5mols_info *info;
        struct v4l2_subdev *sd;
        int ret;

        if (pdata == NULL) {
                dev_err(&client->dev, "No platform data\n");
                return -EINVAL;
        }

        if (!gpio_is_valid(pdata->gpio_reset)) {
                dev_err(&client->dev, "No valid RESET GPIO specified\n");
                return -EINVAL;
        }

        if (!client->irq) {
                dev_err(&client->dev, "Interrupt not assigned\n");
                return -EINVAL;
        }

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

        info->pdata = pdata;
        info->set_power = pdata->set_power;

        gpio_flags = pdata->reset_polarity
                   ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
        ret = devm_gpio_request_one(&client->dev, pdata->gpio_reset, gpio_flags,
                                    "M5MOLS_NRST");
        if (ret) {
                dev_err(&client->dev, "Failed to request gpio: %d\n", ret);
                return ret;
        }

        ret = devm_regulator_bulk_get(&client->dev, ARRAY_SIZE(supplies),
                                      supplies);
        if (ret) {
                dev_err(&client->dev, "Failed to get regulators: %d\n", ret);
                return ret;
        }

        sd = &info->sd;
        v4l2_i2c_subdev_init(sd, client, &m5mols_ops);
        strlcpy(sd->name, MODULE_NAME, sizeof(sd->name));
        sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

        sd->internal_ops = &m5mols_subdev_internal_ops;
        info->pad.flags = MEDIA_PAD_FL_SOURCE;
        ret = media_entity_init(&sd->entity, 1, &info->pad, 0);
        if (ret < 0)
                return ret;
        sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV_SENSOR;

        init_waitqueue_head(&info->irq_waitq);
        mutex_init(&info->lock);

        ret = devm_request_irq(&client->dev, client->irq, m5mols_irq_handler,
                               IRQF_TRIGGER_RISING, MODULE_NAME, sd);
        if (ret) {
                dev_err(&client->dev, "Interrupt request failed: %d\n", ret);
                goto error;
        }
        info->res_type = M5MOLS_RESTYPE_MONITOR;
        info->ffmt[0] = m5mols_default_ffmt[0];
        info->ffmt[1] = m5mols_default_ffmt[1];

        ret = m5mols_sensor_power(info, true);
        if (ret)
                goto error;

        ret = m5mols_fw_start(sd);
        if (!ret)
                ret = m5mols_init_controls(sd);

        ret = m5mols_sensor_power(info, false);
        if (!ret)
                return 0;
error:
        media_entity_cleanup(&sd->entity);
        return ret;
}

static int m5mols_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);

        v4l2_device_unregister_subdev(sd);
        v4l2_ctrl_handler_free(sd->ctrl_handler);
        media_entity_cleanup(&sd->entity);

        return 0;
}

static const struct i2c_device_id m5mols_id[] = {
        { MODULE_NAME, 0 },
        { },
};
MODULE_DEVICE_TABLE(i2c, m5mols_id);

static struct i2c_driver m5mols_i2c_driver = {
        .driver = {
                .name   = MODULE_NAME,
        },
        .probe          = m5mols_probe,
        .remove         = m5mols_remove,
        .id_table       = m5mols_id,
};

module_i2c_driver(m5mols_i2c_driver);

MODULE_AUTHOR("HeungJun Kim <riverful.kim@samsung.com>");
MODULE_AUTHOR("Dongsoo Kim <dongsoo45.kim@samsung.com>");
MODULE_DESCRIPTION("Fujitsu M-5MOLS 8M Pixel camera driver");
MODULE_LICENSE("GPL");