text: // 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_pad_config *cfg,
  			  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) {
  		cfg->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_pad_config *cfg,
  			  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, low;
  	int ret;
  	u16 id;
  
  	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
  		return -ENODEV;
  
  	ret = gc2235_read_reg(client, GC2235_8BIT,
  			      GC2235_SENSOR_ID_H, &high);
  	if (ret) {
  		dev_err(&client->dev, "sensor_id_high = 0x%x\n", high);
  		return -ENODEV;
  	}
  	ret = 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_pad_config *cfg,
  				 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_pad_config *cfg,
  				  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");
  