// SPDX-License-Identifier: GPL-2.0
/*
 * Support for GalaxyCore GC2235 2M camera sensor.
 *
 * Copyright (c) 2014 Intel Corporation. All Rights Reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/moduleparam.h>
#include <media/v4l2-device.h>
#include "../include/linux/atomisp_gmin_platform.h"
#include <linux/acpi.h>
#include <linux/io.h>

#include "gc2235.h"

/* i2c read/write stuff */
static int gc2235_read_reg(struct i2c_client *client,
                           u16 data_length, u16 reg, u16 *val)
{
        int err;
        struct i2c_msg msg[2];
        unsigned char data[6];

        if (!client->adapter) {
                dev_err(&client->dev, "%s error, no client->adapter\n",
                        __func__);
                return -ENODEV;
        }

        if (data_length != GC2235_8BIT) {
                dev_err(&client->dev, "%s error, invalid data length\n",
                        __func__);
                return -EINVAL;
        }

        memset(msg, 0, sizeof(msg));

        msg[0].addr = client->addr;
        msg[0].flags = 0;
        msg[0].len = 1;
        msg[0].buf = data;

        /* high byte goes out first */
        data[0] = (u8)(reg & 0xff);

        msg[1].addr = client->addr;
        msg[1].len = data_length;
        msg[1].flags = I2C_M_RD;
        msg[1].buf = data;

        err = i2c_transfer(client->adapter, msg, 2);
        if (err != 2) {
                if (err >= 0)
                        err = -EIO;
                dev_err(&client->dev,
                        "read from offset 0x%x error %d", reg, err);
                return err;
        }

        *val = 0;
        /* high byte comes first */
        if (data_length == GC2235_8BIT)
                *val = (u8)data[0];

        return 0;
}

static int gc2235_i2c_write(struct i2c_client *client, u16 len, u8 *data)
{
        struct i2c_msg msg;
        const int num_msg = 1;
        int ret;

        msg.addr = client->addr;
        msg.flags = 0;
        msg.len = len;
        msg.buf = data;
        ret = i2c_transfer(client->adapter, &msg, 1);

        return ret == num_msg ? 0 : -EIO;
}

static int gc2235_write_reg(struct i2c_client *client, u16 data_length,
                            u8 reg, u8 val)
{
        int ret;
        unsigned char data[4] = {0};
        const u16 len = data_length + sizeof(u8); /* 16-bit address + data */

        if (data_length != GC2235_8BIT) {
                dev_err(&client->dev,
                        "%s error, invalid data_length\n", __func__);
                return -EINVAL;
        }

        /* high byte goes out first */
        data[0] = reg;
        data[1] = val;

        ret = gc2235_i2c_write(client, len, data);
        if (ret)
                dev_err(&client->dev,
                        "write error: wrote 0x%x to offset 0x%x error %d",
                        val, reg, ret);

        return ret;
}

static int __gc2235_flush_reg_array(struct i2c_client *client,
                                    struct gc2235_write_ctrl *ctrl)
{
        u16 size;

        if (ctrl->index == 0)
                return 0;

        size = sizeof(u8) + ctrl->index; /* 8-bit address + data */
        ctrl->index = 0;

        return gc2235_i2c_write(client, size, (u8 *)&ctrl->buffer);
}

static int __gc2235_buf_reg_array(struct i2c_client *client,
                                  struct gc2235_write_ctrl *ctrl,
                                  const struct gc2235_reg *next)
{
        int size;

        if (next->type != GC2235_8BIT)
                return -EINVAL;

        size = 1;
        ctrl->buffer.data[ctrl->index] = (u8)next->val;

        /* When first item is added, we need to store its starting address */
        if (ctrl->index == 0)
                ctrl->buffer.addr = next->reg;

        ctrl->index += size;

        /*
         * Buffer cannot guarantee free space for u32? Better flush it to avoid
         * possible lack of memory for next item.
         */
        if (ctrl->index + sizeof(u8) >= GC2235_MAX_WRITE_BUF_SIZE)
                return __gc2235_flush_reg_array(client, ctrl);

        return 0;
}

static int __gc2235_write_reg_is_consecutive(struct i2c_client *client,
                                             struct gc2235_write_ctrl *ctrl,
                                             const struct gc2235_reg *next)
{
        if (ctrl->index == 0)
                return 1;

        return ctrl->buffer.addr + ctrl->index == next->reg;
}

static int gc2235_write_reg_array(struct i2c_client *client,
                                  const struct gc2235_reg *reglist)
{
        const struct gc2235_reg *next = reglist;
        struct gc2235_write_ctrl ctrl;
        int err;

        ctrl.index = 0;
        for (; next->type != GC2235_TOK_TERM; next++) {
                switch (next->type & GC2235_TOK_MASK) {
                case GC2235_TOK_DELAY:
                        err = __gc2235_flush_reg_array(client, &ctrl);
                        if (err)
                                return err;
                        msleep(next->val);
                        break;
                default:
                        /*
                         * If next address is not consecutive, data needs to be
                         * flushed before proceed.
                         */
                        if (!__gc2235_write_reg_is_consecutive(client, &ctrl,
                                                               next)) {
                                err = __gc2235_flush_reg_array(client, &ctrl);
                                if (err)
                                        return err;
                        }
                        err = __gc2235_buf_reg_array(client, &ctrl, next);
                        if (err) {
                                dev_err(&client->dev, "%s: write error, aborted\n",
                                        __func__);
                                return err;
                        }
                        break;
                }
        }

        return __gc2235_flush_reg_array(client, &ctrl);
}

static int gc2235_g_focal(struct v4l2_subdev *sd, s32 *val)
{
        *val = (GC2235_FOCAL_LENGTH_NUM << 16) | GC2235_FOCAL_LENGTH_DEM;
        return 0;
}

static int gc2235_g_fnumber(struct v4l2_subdev *sd, s32 *val)
{
        /* const f number for imx */
        *val = (GC2235_F_NUMBER_DEFAULT_NUM << 16) | GC2235_F_NUMBER_DEM;
        return 0;
}

static int gc2235_g_fnumber_range(struct v4l2_subdev *sd, s32 *val)
{
        *val = (GC2235_F_NUMBER_DEFAULT_NUM << 24) |
               (GC2235_F_NUMBER_DEM << 16) |
               (GC2235_F_NUMBER_DEFAULT_NUM << 8) | GC2235_F_NUMBER_DEM;
        return 0;
}

static int gc2235_get_intg_factor(struct i2c_client *client,
                                  struct camera_mipi_info *info,
                                  const struct gc2235_resolution *res)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        struct atomisp_sensor_mode_data *buf = &info->data;
        u16 reg_val, reg_val_h;
        int ret;

        if (!info)
                return -EINVAL;

        /* pixel clock calculattion */
        buf->vt_pix_clk_freq_mhz = dev->vt_pix_clk_freq_mhz = 30000000;

        /* get integration time */
        buf->coarse_integration_time_min = GC2235_COARSE_INTG_TIME_MIN;
        buf->coarse_integration_time_max_margin =
            GC2235_COARSE_INTG_TIME_MAX_MARGIN;

        buf->fine_integration_time_min = GC2235_FINE_INTG_TIME_MIN;
        buf->fine_integration_time_max_margin =
            GC2235_FINE_INTG_TIME_MAX_MARGIN;

        buf->fine_integration_time_def = GC2235_FINE_INTG_TIME_MIN;
        buf->frame_length_lines = res->lines_per_frame;
        buf->line_length_pck = res->pixels_per_line;
        buf->read_mode = res->bin_mode;

        /* get the cropping and output resolution to ISP for this mode. */
        ret =  gc2235_read_reg(client, GC2235_8BIT,
                               GC2235_H_CROP_START_H, &reg_val_h);
        ret =  gc2235_read_reg(client, GC2235_8BIT,
                               GC2235_H_CROP_START_L, &reg_val);
        if (ret)
                return ret;

        buf->crop_horizontal_start = (reg_val_h << 8) | reg_val;

        ret =  gc2235_read_reg(client, GC2235_8BIT,
                               GC2235_V_CROP_START_H, &reg_val_h);
        ret =  gc2235_read_reg(client, GC2235_8BIT,
                               GC2235_V_CROP_START_L, &reg_val);
        if (ret)
                return ret;

        buf->crop_vertical_start = (reg_val_h << 8) | reg_val;

        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_H_OUTSIZE_H, &reg_val_h);
        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_H_OUTSIZE_L, &reg_val);
        if (ret)
                return ret;
        buf->output_width = (reg_val_h << 8) | reg_val;

        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_V_OUTSIZE_H, &reg_val_h);
        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_V_OUTSIZE_L, &reg_val);
        if (ret)
                return ret;
        buf->output_height = (reg_val_h << 8) | reg_val;

        buf->crop_horizontal_end = buf->crop_horizontal_start +
                                   buf->output_width - 1;
        buf->crop_vertical_end = buf->crop_vertical_start +
                                 buf->output_height - 1;

        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_HB_H, &reg_val_h);
        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_HB_L, &reg_val);
        if (ret)
                return ret;

#if 0
        u16 dummy = (reg_val_h << 8) | reg_val;
#endif

        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_SH_DELAY_H, &reg_val_h);
        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_SH_DELAY_L, &reg_val);

#if 0
        buf->line_length_pck = buf->output_width + 16 + dummy +
                               (((u16)reg_val_h << 8) | (u16)reg_val) + 4;
#endif
        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_VB_H, &reg_val_h);
        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_VB_L, &reg_val);
        if (ret)
                return ret;

#if 0
        buf->frame_length_lines = buf->output_height + 32 +
                                  (((u16)reg_val_h << 8) | (u16)reg_val);
#endif
        buf->binning_factor_x = res->bin_factor_x ?
                                res->bin_factor_x : 1;
        buf->binning_factor_y = res->bin_factor_y ?
                                res->bin_factor_y : 1;
        return 0;
}

static long __gc2235_set_exposure(struct v4l2_subdev *sd, int coarse_itg,
                                  int gain, int digitgain)

{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        u16 coarse_integration = (u16)coarse_itg;
        int ret = 0;
        u16 expo_coarse_h, expo_coarse_l, gain_val = 0xF0, gain_val2 = 0xF0;

        expo_coarse_h = coarse_integration >> 8;
        expo_coarse_l = coarse_integration & 0xff;

        ret = gc2235_write_reg(client, GC2235_8BIT,
                               GC2235_EXPOSURE_H, expo_coarse_h);
        ret = gc2235_write_reg(client, GC2235_8BIT,
                               GC2235_EXPOSURE_L, expo_coarse_l);

        if (gain <= 0x58) {
                gain_val = 0x40;
                gain_val2 = 0x58;
        } else if (gain < 256) {
                gain_val = 0x40;
                gain_val2 = gain;
        } else {
                gain_val2 = 64 * gain / 256;
                gain_val = 0xff;
        }

        ret = gc2235_write_reg(client, GC2235_8BIT,
                               GC2235_GLOBAL_GAIN, (u8)gain_val);
        ret = gc2235_write_reg(client, GC2235_8BIT,
                               GC2235_PRE_GAIN, (u8)gain_val2);

        return ret;
}

static int gc2235_set_exposure(struct v4l2_subdev *sd, int exposure,
                               int gain, int digitgain)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        int ret;

        mutex_lock(&dev->input_lock);
        ret = __gc2235_set_exposure(sd, exposure, gain, digitgain);
        mutex_unlock(&dev->input_lock);

        return ret;
}

static long gc2235_s_exposure(struct v4l2_subdev *sd,
                              struct atomisp_exposure *exposure)
{
        int exp = exposure->integration_time[0];
        int gain = exposure->gain[0];
        int digitgain = exposure->gain[1];

        /* we should not accept the invalid value below. */
        if (gain == 0) {
                struct i2c_client *client = v4l2_get_subdevdata(sd);

                v4l2_err(client, "%s: invalid value\n", __func__);
                return -EINVAL;
        }

        return gc2235_set_exposure(sd, exp, gain, digitgain);
}

static long gc2235_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
{
        switch (cmd) {
        case ATOMISP_IOC_S_EXPOSURE:
                return gc2235_s_exposure(sd, arg);
        default:
                return -EINVAL;
        }
        return 0;
}

/*
 * This returns the exposure time being used. This should only be used
 * for filling in EXIF data, not for actual image processing.
 */
static int gc2235_q_exposure(struct v4l2_subdev *sd, s32 *value)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        u16 reg_v, reg_v2;
        int ret;

        /* get exposure */
        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_EXPOSURE_L,
                              &reg_v);
        if (ret)
                goto err;

        ret = gc2235_read_reg(client, GC2235_8BIT,
                              GC2235_EXPOSURE_H,
                              &reg_v2);
        if (ret)
                goto err;

        reg_v += reg_v2 << 8;

        *value = reg_v;
err:
        return ret;
}

static int gc2235_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
{
        struct gc2235_device *dev =
            container_of(ctrl->handler, struct gc2235_device, ctrl_handler);
        int ret = 0;

        switch (ctrl->id) {
        case V4L2_CID_EXPOSURE_ABSOLUTE:
                ret = gc2235_q_exposure(&dev->sd, &ctrl->val);
                break;
        case V4L2_CID_FOCAL_ABSOLUTE:
                ret = gc2235_g_focal(&dev->sd, &ctrl->val);
                break;
        case V4L2_CID_FNUMBER_ABSOLUTE:
                ret = gc2235_g_fnumber(&dev->sd, &ctrl->val);
                break;
        case V4L2_CID_FNUMBER_RANGE:
                ret = gc2235_g_fnumber_range(&dev->sd, &ctrl->val);
                break;
        default:
                ret = -EINVAL;
        }

        return ret;
}

static const struct v4l2_ctrl_ops ctrl_ops = {
        .g_volatile_ctrl = gc2235_g_volatile_ctrl
};

static struct v4l2_ctrl_config gc2235_controls[] = {
        {
                .ops = &ctrl_ops,
                .id = V4L2_CID_EXPOSURE_ABSOLUTE,
                .type = V4L2_CTRL_TYPE_INTEGER,
                .name = "exposure",
                .min = 0x0,
                .max = 0xffff,
                .step = 0x01,
                .def = 0x00,
                .flags = 0,
        },
        {
                .ops = &ctrl_ops,
                .id = V4L2_CID_FOCAL_ABSOLUTE,
                .type = V4L2_CTRL_TYPE_INTEGER,
                .name = "focal length",
                .min = GC2235_FOCAL_LENGTH_DEFAULT,
                .max = GC2235_FOCAL_LENGTH_DEFAULT,
                .step = 0x01,
                .def = GC2235_FOCAL_LENGTH_DEFAULT,
                .flags = 0,
        },
        {
                .ops = &ctrl_ops,
                .id = V4L2_CID_FNUMBER_ABSOLUTE,
                .type = V4L2_CTRL_TYPE_INTEGER,
                .name = "f-number",
                .min = GC2235_F_NUMBER_DEFAULT,
                .max = GC2235_F_NUMBER_DEFAULT,
                .step = 0x01,
                .def = GC2235_F_NUMBER_DEFAULT,
                .flags = 0,
        },
        {
                .ops = &ctrl_ops,
                .id = V4L2_CID_FNUMBER_RANGE,
                .type = V4L2_CTRL_TYPE_INTEGER,
                .name = "f-number range",
                .min = GC2235_F_NUMBER_RANGE,
                .max = GC2235_F_NUMBER_RANGE,
                .step = 0x01,
                .def = GC2235_F_NUMBER_RANGE,
                .flags = 0,
        },
};

static int __gc2235_init(struct v4l2_subdev *sd)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        /* restore settings */
        gc2235_res = gc2235_res_preview;
        N_RES = N_RES_PREVIEW;

        return gc2235_write_reg_array(client, gc2235_init_settings);
}

static int is_init;

static int power_ctrl(struct v4l2_subdev *sd, bool flag)
{
        int ret = -1;
        struct gc2235_device *dev = to_gc2235_sensor(sd);

        if (!dev || !dev->platform_data)
                return -ENODEV;

        if (flag) {
                ret = dev->platform_data->v1p8_ctrl(sd, 1);
                usleep_range(60, 90);
                if (ret == 0)
                        ret |= dev->platform_data->v2p8_ctrl(sd, 1);
        } else {
                ret = dev->platform_data->v1p8_ctrl(sd, 0);
                ret |= dev->platform_data->v2p8_ctrl(sd, 0);
        }
        return ret;
}

static int gpio_ctrl(struct v4l2_subdev *sd, bool flag)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        int ret = -1;

        if (!dev || !dev->platform_data)
                return -ENODEV;

        ret |= dev->platform_data->gpio1_ctrl(sd, !flag);
        usleep_range(60, 90);
        return dev->platform_data->gpio0_ctrl(sd, flag);
}

static int power_up(struct v4l2_subdev *sd)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int ret;

        if (!dev->platform_data) {
                dev_err(&client->dev,
                        "no camera_sensor_platform_data");
                return -ENODEV;
        }
        /* power control */
        ret = power_ctrl(sd, 1);
        if (ret)
                goto fail_power;

        /* according to DS, at least 5ms is needed between DOVDD and PWDN */
        usleep_range(5000, 6000);

        ret = dev->platform_data->flisclk_ctrl(sd, 1);
        if (ret)
                goto fail_clk;
        usleep_range(5000, 6000);

        /* gpio ctrl */
        ret = gpio_ctrl(sd, 1);
        if (ret) {
                ret = gpio_ctrl(sd, 1);
                if (ret)
                        goto fail_power;
        }

        msleep(5);
        return 0;

fail_clk:
        gpio_ctrl(sd, 0);
fail_power:
        power_ctrl(sd, 0);
        dev_err(&client->dev, "sensor power-up failed\n");

        return ret;
}

static int power_down(struct v4l2_subdev *sd)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int ret = 0;

        if (!dev->platform_data) {
                dev_err(&client->dev,
                        "no camera_sensor_platform_data");
                return -ENODEV;
        }
        /* gpio ctrl */
        ret = gpio_ctrl(sd, 0);
        if (ret) {
                ret = gpio_ctrl(sd, 0);
                if (ret)
                        dev_err(&client->dev, "gpio failed 2\n");
        }

        ret = dev->platform_data->flisclk_ctrl(sd, 0);
        if (ret)
                dev_err(&client->dev, "flisclk failed\n");

        /* power control */
        ret = power_ctrl(sd, 0);
        if (ret)
                dev_err(&client->dev, "vprog failed.\n");

        return ret;
}

static int gc2235_s_power(struct v4l2_subdev *sd, int on)
{
        int ret;

        if (on == 0) {
                ret = power_down(sd);
        } else {
                ret = power_up(sd);
                if (!ret)
                        ret = __gc2235_init(sd);
                is_init = 1;
        }
        return ret;
}

/*
 * distance - calculate the distance
 * @res: resolution
 * @w: width
 * @h: height
 *
 * Get the gap between resolution and w/h.
 * res->width/height smaller than w/h wouldn't be considered.
 * Returns the value of gap or -1 if fail.
 */
#define LARGEST_ALLOWED_RATIO_MISMATCH 800
static int distance(struct gc2235_resolution *res, u32 w, u32 h)
{
        unsigned int w_ratio = (res->width << 13) / w;
        unsigned int h_ratio;
        int match;

        if (h == 0)
                return -1;
        h_ratio = (res->height << 13) / h;
        if (h_ratio == 0)
                return -1;
        match   = abs(((w_ratio << 13) / h_ratio) - 8192);

        if ((w_ratio < 8192) || (h_ratio < 8192) ||
            (match > LARGEST_ALLOWED_RATIO_MISMATCH))
                return -1;

        return w_ratio + h_ratio;
}

/* Return the nearest higher resolution index */
static int nearest_resolution_index(int w, int h)
{
        int i;
        int idx = -1;
        int dist;
        int min_dist = INT_MAX;
        struct gc2235_resolution *tmp_res = NULL;

        for (i = 0; i < N_RES; i++) {
                tmp_res = &gc2235_res[i];
                dist = distance(tmp_res, w, h);
                if (dist == -1)
                        continue;
                if (dist < min_dist) {
                        min_dist = dist;
                        idx = i;
                }
        }

        return idx;
}

static int get_resolution_index(int w, int h)
{
        int i;

        for (i = 0; i < N_RES; i++) {
                if (w != gc2235_res[i].width)
                        continue;
                if (h != gc2235_res[i].height)
                        continue;

                return i;
        }

        return -1;
}

static int startup(struct v4l2_subdev *sd)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int ret = 0;

        if (is_init == 0) {
                /*
                 * force gc2235 to do a reset in res change, otherwise it
                 * can not output normal after switching res. and it is not
                 * necessary for first time run up after power on, for the sack
                 * of performance
                 */
                power_down(sd);
                power_up(sd);
                gc2235_write_reg_array(client, gc2235_init_settings);
        }

        ret = gc2235_write_reg_array(client, gc2235_res[dev->fmt_idx].regs);
        if (ret) {
                dev_err(&client->dev, "gc2235 write register err.\n");
                return ret;
        }
        is_init = 0;

        return ret;
}

static int gc2235_set_fmt(struct v4l2_subdev *sd,
                          struct v4l2_subdev_state *sd_state,
                          struct v4l2_subdev_format *format)
{
        struct v4l2_mbus_framefmt *fmt = &format->format;
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct camera_mipi_info *gc2235_info = NULL;
        int ret = 0;
        int idx;

        gc2235_info = v4l2_get_subdev_hostdata(sd);
        if (!gc2235_info)
                return -EINVAL;
        if (format->pad)
                return -EINVAL;
        if (!fmt)
                return -EINVAL;
        mutex_lock(&dev->input_lock);
        idx = nearest_resolution_index(fmt->width, fmt->height);
        if (idx == -1) {
                /* return the largest resolution */
                fmt->width = gc2235_res[N_RES - 1].width;
                fmt->height = gc2235_res[N_RES - 1].height;
        } else {
                fmt->width = gc2235_res[idx].width;
                fmt->height = gc2235_res[idx].height;
        }
        fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
        if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
                sd_state->pads->try_fmt = *fmt;
                mutex_unlock(&dev->input_lock);
                return 0;
        }

        dev->fmt_idx = get_resolution_index(fmt->width, fmt->height);
        if (dev->fmt_idx == -1) {
                dev_err(&client->dev, "get resolution fail\n");
                mutex_unlock(&dev->input_lock);
                return -EINVAL;
        }

        ret = startup(sd);
        if (ret) {
                dev_err(&client->dev, "gc2235 startup err\n");
                goto err;
        }

        ret = gc2235_get_intg_factor(client, gc2235_info,
                                     &gc2235_res[dev->fmt_idx]);
        if (ret)
                dev_err(&client->dev, "failed to get integration_factor\n");

err:
        mutex_unlock(&dev->input_lock);
        return ret;
}

static int gc2235_get_fmt(struct v4l2_subdev *sd,
                          struct v4l2_subdev_state *sd_state,
                          struct v4l2_subdev_format *format)
{
        struct v4l2_mbus_framefmt *fmt = &format->format;
        struct gc2235_device *dev = to_gc2235_sensor(sd);

        if (format->pad)
                return -EINVAL;

        if (!fmt)
                return -EINVAL;

        fmt->width = gc2235_res[dev->fmt_idx].width;
        fmt->height = gc2235_res[dev->fmt_idx].height;
        fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;

        return 0;
}

static int gc2235_detect(struct i2c_client *client)
{
        struct i2c_adapter *adapter = client->adapter;
        u16 high = 0, low = 0;
        u16 id;

        if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
                return -ENODEV;

        gc2235_read_reg(client, GC2235_8BIT, GC2235_SENSOR_ID_H, &high);
        gc2235_read_reg(client, GC2235_8BIT, GC2235_SENSOR_ID_L, &low);
        id = ((high << 8) | low);

        if (id != GC2235_ID) {
                dev_err(&client->dev, "sensor ID error, 0x%x\n", id);
                return -ENODEV;
        }

        dev_info(&client->dev, "detect gc2235 success\n");
        return 0;
}

static int gc2235_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int ret;

        mutex_lock(&dev->input_lock);

        if (enable)
                ret = gc2235_write_reg_array(client, gc2235_stream_on);
        else
                ret = gc2235_write_reg_array(client, gc2235_stream_off);

        mutex_unlock(&dev->input_lock);
        return ret;
}

static int gc2235_s_config(struct v4l2_subdev *sd,
                           int irq, void *platform_data)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int ret = 0;

        if (!platform_data)
                return -ENODEV;

        dev->platform_data =
            (struct camera_sensor_platform_data *)platform_data;

        mutex_lock(&dev->input_lock);
        /*
         * power off the module, then power on it in future
         * as first power on by board may not fulfill the
         * power on sequqence needed by the module
         */
        ret = power_down(sd);
        if (ret) {
                dev_err(&client->dev, "gc2235 power-off err.\n");
                goto fail_power_off;
        }

        ret = power_up(sd);
        if (ret) {
                dev_err(&client->dev, "gc2235 power-up err.\n");
                goto fail_power_on;
        }

        ret = dev->platform_data->csi_cfg(sd, 1);
        if (ret)
                goto fail_csi_cfg;

        /* config & detect sensor */
        ret = gc2235_detect(client);
        if (ret) {
                dev_err(&client->dev, "gc2235_detect err s_config.\n");
                goto fail_csi_cfg;
        }

        /* turn off sensor, after probed */
        ret = power_down(sd);
        if (ret) {
                dev_err(&client->dev, "gc2235 power-off err.\n");
                goto fail_csi_cfg;
        }
        mutex_unlock(&dev->input_lock);

        return 0;

fail_csi_cfg:
        dev->platform_data->csi_cfg(sd, 0);
fail_power_on:
        power_down(sd);
        dev_err(&client->dev, "sensor power-gating failed\n");
fail_power_off:
        mutex_unlock(&dev->input_lock);
        return ret;
}

static int gc2235_g_frame_interval(struct v4l2_subdev *sd,
                                   struct v4l2_subdev_frame_interval *interval)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);

        interval->interval.numerator = 1;
        interval->interval.denominator = gc2235_res[dev->fmt_idx].fps;

        return 0;
}

static int gc2235_enum_mbus_code(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_mbus_code_enum *code)
{
        if (code->index >= MAX_FMTS)
                return -EINVAL;

        code->code = MEDIA_BUS_FMT_SBGGR10_1X10;
        return 0;
}

static int gc2235_enum_frame_size(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_frame_size_enum *fse)
{
        int index = fse->index;

        if (index >= N_RES)
                return -EINVAL;

        fse->min_width = gc2235_res[index].width;
        fse->min_height = gc2235_res[index].height;
        fse->max_width = gc2235_res[index].width;
        fse->max_height = gc2235_res[index].height;

        return 0;
}

static int gc2235_g_skip_frames(struct v4l2_subdev *sd, u32 *frames)
{
        struct gc2235_device *dev = to_gc2235_sensor(sd);

        mutex_lock(&dev->input_lock);
        *frames = gc2235_res[dev->fmt_idx].skip_frames;
        mutex_unlock(&dev->input_lock);

        return 0;
}

static const struct v4l2_subdev_sensor_ops gc2235_sensor_ops = {

        .g_skip_frames  = gc2235_g_skip_frames,
};

static const struct v4l2_subdev_video_ops gc2235_video_ops = {
        .s_stream = gc2235_s_stream,
        .g_frame_interval = gc2235_g_frame_interval,
};

static const struct v4l2_subdev_core_ops gc2235_core_ops = {
        .s_power = gc2235_s_power,
        .ioctl = gc2235_ioctl,
};

static const struct v4l2_subdev_pad_ops gc2235_pad_ops = {
        .enum_mbus_code = gc2235_enum_mbus_code,
        .enum_frame_size = gc2235_enum_frame_size,
        .get_fmt = gc2235_get_fmt,
        .set_fmt = gc2235_set_fmt,
};

static const struct v4l2_subdev_ops gc2235_ops = {
        .core = &gc2235_core_ops,
        .video = &gc2235_video_ops,
        .pad = &gc2235_pad_ops,
        .sensor = &gc2235_sensor_ops,
};

static int gc2235_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct gc2235_device *dev = to_gc2235_sensor(sd);

        dev_dbg(&client->dev, "gc2235_remove...\n");

        dev->platform_data->csi_cfg(sd, 0);

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

        return 0;
}

static int gc2235_probe(struct i2c_client *client)
{
        struct gc2235_device *dev;
        void *gcpdev;
        int ret;
        unsigned int i;

        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        if (!dev)
                return -ENOMEM;

        mutex_init(&dev->input_lock);

        dev->fmt_idx = 0;
        v4l2_i2c_subdev_init(&dev->sd, client, &gc2235_ops);

        gcpdev = gmin_camera_platform_data(&dev->sd,
                                           ATOMISP_INPUT_FORMAT_RAW_10,
                                           atomisp_bayer_order_grbg);

        ret = gc2235_s_config(&dev->sd, client->irq, gcpdev);
        if (ret)
                goto out_free;

        dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        dev->pad.flags = MEDIA_PAD_FL_SOURCE;
        dev->format.code = MEDIA_BUS_FMT_SBGGR10_1X10;
        dev->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
        ret =
            v4l2_ctrl_handler_init(&dev->ctrl_handler,
                                   ARRAY_SIZE(gc2235_controls));
        if (ret) {
                gc2235_remove(client);
                return ret;
        }

        for (i = 0; i < ARRAY_SIZE(gc2235_controls); i++)
                v4l2_ctrl_new_custom(&dev->ctrl_handler, &gc2235_controls[i],
                                     NULL);

        if (dev->ctrl_handler.error) {
                gc2235_remove(client);
                return dev->ctrl_handler.error;
        }

        /* Use same lock for controls as for everything else. */
        dev->ctrl_handler.lock = &dev->input_lock;
        dev->sd.ctrl_handler = &dev->ctrl_handler;

        ret = media_entity_pads_init(&dev->sd.entity, 1, &dev->pad);
        if (ret)
                gc2235_remove(client);

        return atomisp_register_i2c_module(&dev->sd, gcpdev, RAW_CAMERA);

out_free:
        v4l2_device_unregister_subdev(&dev->sd);
        kfree(dev);

        return ret;
}

static const struct acpi_device_id gc2235_acpi_match[] = {
        { "INT33F8" },
        {},
};
MODULE_DEVICE_TABLE(acpi, gc2235_acpi_match);

static struct i2c_driver gc2235_driver = {
        .driver = {
                .name = "gc2235",
                .acpi_match_table = gc2235_acpi_match,
        },
        .probe_new = gc2235_probe,
        .remove = gc2235_remove,
};
module_i2c_driver(gc2235_driver);

MODULE_AUTHOR("Shuguang Gong <Shuguang.Gong@intel.com>");
MODULE_DESCRIPTION("A low-level driver for GC2235 sensors");
MODULE_LICENSE("GPL");