drivers/media/i2c/adp1653.c - kernel/msm-4.9 - Gitiles

 /*
  * drivers/media/i2c/adp1653.c
  *
  * Copyright (C) 2008--2011 Nokia Corporation
  *
  * Contact: Sakari Ailus <sakari.ailus@iki.fi>
  *
  * Contributors:
  *	Sakari Ailus <sakari.ailus@iki.fi>
  *	Tuukka Toivonen <tuukkat76@gmail.com>
  *	Pavel Machek <pavel@ucw.cz>
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA
  *
  * TODO:
  * - fault interrupt handling
  * - hardware strobe
  * - power doesn't need to be ON if all lights are off
  *
  */

 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/gpio/consumer.h>
 #include <media/i2c/adp1653.h>
 #include <media/v4l2-device.h>

 #define TIMEOUT_MAX		820000
 #define TIMEOUT_STEP		54600
 #define TIMEOUT_MIN		(TIMEOUT_MAX - ADP1653_REG_CONFIG_TMR_SET_MAX \
 				 * TIMEOUT_STEP)
 #define TIMEOUT_US_TO_CODE(t)	((TIMEOUT_MAX + (TIMEOUT_STEP / 2) - (t)) \
 				 / TIMEOUT_STEP)
 #define TIMEOUT_CODE_TO_US(c)	(TIMEOUT_MAX - (c) * TIMEOUT_STEP)

 /* Write values into ADP1653 registers. */
 static int adp1653_update_hw(struct adp1653_flash *flash)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
 	u8 out_sel;
 	u8 config = 0;
 	int rval;

 	out_sel = ADP1653_INDICATOR_INTENSITY_uA_TO_REG(
 		flash->indicator_intensity->val)
 		<< ADP1653_REG_OUT_SEL_ILED_SHIFT;

 	switch (flash->led_mode->val) {
 	case V4L2_FLASH_LED_MODE_NONE:
 		break;
 	case V4L2_FLASH_LED_MODE_FLASH:
 		/* Flash mode, light on with strobe, duration from timer */
 		config = ADP1653_REG_CONFIG_TMR_CFG;
 		config |= TIMEOUT_US_TO_CODE(flash->flash_timeout->val)
 			  << ADP1653_REG_CONFIG_TMR_SET_SHIFT;
 		break;
 	case V4L2_FLASH_LED_MODE_TORCH:
 		/* Torch mode, light immediately on, duration indefinite */
 		out_sel |= ADP1653_FLASH_INTENSITY_mA_TO_REG(
 			flash->torch_intensity->val)
 			<< ADP1653_REG_OUT_SEL_HPLED_SHIFT;
 		break;
 	}

 	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL, out_sel);
 	if (rval < 0)
 		return rval;

 	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_CONFIG, config);
 	if (rval < 0)
 		return rval;

 	return 0;
 }

 static int adp1653_get_fault(struct adp1653_flash *flash)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
 	int fault;
 	int rval;

 	fault = i2c_smbus_read_byte_data(client, ADP1653_REG_FAULT);
 	if (IS_ERR_VALUE(fault))
 		return fault;

 	flash->fault |= fault;

 	if (!flash->fault)
 		return 0;

 	/* Clear faults. */
 	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL, 0);
 	if (IS_ERR_VALUE(rval))
 		return rval;

 	flash->led_mode->val = V4L2_FLASH_LED_MODE_NONE;

 	rval = adp1653_update_hw(flash);
 	if (IS_ERR_VALUE(rval))
 		return rval;

 	return flash->fault;
 }

 static int adp1653_strobe(struct adp1653_flash *flash, int enable)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
 	u8 out_sel = ADP1653_INDICATOR_INTENSITY_uA_TO_REG(
 		flash->indicator_intensity->val)
 		<< ADP1653_REG_OUT_SEL_ILED_SHIFT;
 	int rval;

 	if (flash->led_mode->val != V4L2_FLASH_LED_MODE_FLASH)
 		return -EBUSY;

 	if (!enable)
 		return i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL,
 						 out_sel);

 	out_sel |= ADP1653_FLASH_INTENSITY_mA_TO_REG(
 		flash->flash_intensity->val)
 		<< ADP1653_REG_OUT_SEL_HPLED_SHIFT;
 	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL, out_sel);
 	if (rval)
 		return rval;

 	/* Software strobe using i2c */
 	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_SW_STROBE,
 		ADP1653_REG_SW_STROBE_SW_STROBE);
 	if (rval)
 		return rval;
 	return i2c_smbus_write_byte_data(client, ADP1653_REG_SW_STROBE, 0);
 }

 /* --------------------------------------------------------------------------
  * V4L2 controls
  */

 static int adp1653_get_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct adp1653_flash *flash =
 		container_of(ctrl->handler, struct adp1653_flash, ctrls);
 	int rval;

 	rval = adp1653_get_fault(flash);
 	if (IS_ERR_VALUE(rval))
 		return rval;

 	ctrl->cur.val = 0;

 	if (flash->fault & ADP1653_REG_FAULT_FLT_SCP)
 		ctrl->cur.val |= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
 	if (flash->fault & ADP1653_REG_FAULT_FLT_OT)
 		ctrl->cur.val |= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
 	if (flash->fault & ADP1653_REG_FAULT_FLT_TMR)
 		ctrl->cur.val |= V4L2_FLASH_FAULT_TIMEOUT;
 	if (flash->fault & ADP1653_REG_FAULT_FLT_OV)
 		ctrl->cur.val |= V4L2_FLASH_FAULT_OVER_VOLTAGE;

 	flash->fault = 0;

 	return 0;
 }

 static int adp1653_set_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct adp1653_flash *flash =
 		container_of(ctrl->handler, struct adp1653_flash, ctrls);
 	int rval;

 	rval = adp1653_get_fault(flash);
 	if (IS_ERR_VALUE(rval))
 		return rval;
 	if ((rval & (ADP1653_REG_FAULT_FLT_SCP |
 		     ADP1653_REG_FAULT_FLT_OT |
 		     ADP1653_REG_FAULT_FLT_OV)) &&
 	    (ctrl->id == V4L2_CID_FLASH_STROBE ||
 	     ctrl->id == V4L2_CID_FLASH_TORCH_INTENSITY ||
 	     ctrl->id == V4L2_CID_FLASH_LED_MODE))
 		return -EBUSY;

 	switch (ctrl->id) {
 	case V4L2_CID_FLASH_STROBE:
 		return adp1653_strobe(flash, 1);
 	case V4L2_CID_FLASH_STROBE_STOP:
 		return adp1653_strobe(flash, 0);
 	}

 	return adp1653_update_hw(flash);
 }

 static const struct v4l2_ctrl_ops adp1653_ctrl_ops = {
 	.g_volatile_ctrl = adp1653_get_ctrl,
 	.s_ctrl = adp1653_set_ctrl,
 };

 static int adp1653_init_controls(struct adp1653_flash *flash)
 {
 	struct v4l2_ctrl *fault;

 	v4l2_ctrl_handler_init(&flash->ctrls, 9);

 	flash->led_mode =
 		v4l2_ctrl_new_std_menu(&flash->ctrls, &adp1653_ctrl_ops,
 				       V4L2_CID_FLASH_LED_MODE,
 				       V4L2_FLASH_LED_MODE_TORCH, ~0x7, 0);
 	v4l2_ctrl_new_std_menu(&flash->ctrls, &adp1653_ctrl_ops,
 			       V4L2_CID_FLASH_STROBE_SOURCE,
 			       V4L2_FLASH_STROBE_SOURCE_SOFTWARE, ~0x1, 0);
 	v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
 			  V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
 	v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
 			  V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);
 	flash->flash_timeout =
 		v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
 				  V4L2_CID_FLASH_TIMEOUT, TIMEOUT_MIN,
 				  flash->platform_data->max_flash_timeout,
 				  TIMEOUT_STEP,
 				  flash->platform_data->max_flash_timeout);
 	flash->flash_intensity =
 		v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
 				  V4L2_CID_FLASH_INTENSITY,
 				  ADP1653_FLASH_INTENSITY_MIN,
 				  flash->platform_data->max_flash_intensity,
 				  1, flash->platform_data->max_flash_intensity);
 	flash->torch_intensity =
 		v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
 				  V4L2_CID_FLASH_TORCH_INTENSITY,
 				  ADP1653_TORCH_INTENSITY_MIN,
 				  flash->platform_data->max_torch_intensity,
 				  ADP1653_FLASH_INTENSITY_STEP,
 				  flash->platform_data->max_torch_intensity);
 	flash->indicator_intensity =
 		v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
 				  V4L2_CID_FLASH_INDICATOR_INTENSITY,
 				  ADP1653_INDICATOR_INTENSITY_MIN,
 				  flash->platform_data->max_indicator_intensity,
 				  ADP1653_INDICATOR_INTENSITY_STEP,
 				  ADP1653_INDICATOR_INTENSITY_MIN);
 	fault = v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
 				  V4L2_CID_FLASH_FAULT, 0,
 				  V4L2_FLASH_FAULT_OVER_VOLTAGE
 				  | V4L2_FLASH_FAULT_OVER_TEMPERATURE
 				  | V4L2_FLASH_FAULT_SHORT_CIRCUIT, 0, 0);

 	if (flash->ctrls.error)
 		return flash->ctrls.error;

 	fault->flags |= V4L2_CTRL_FLAG_VOLATILE;

 	flash->subdev.ctrl_handler = &flash->ctrls;
 	return 0;
 }

 /* --------------------------------------------------------------------------
  * V4L2 subdev operations
  */

 static int
 adp1653_init_device(struct adp1653_flash *flash)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
 	int rval;

 	/* Clear FAULT register by writing zero to OUT_SEL */
 	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL, 0);
 	if (rval < 0) {
 		dev_err(&client->dev, "failed writing fault register\n");
 		return -EIO;
 	}

 	mutex_lock(flash->ctrls.lock);
 	/* Reset faults before reading new ones. */
 	flash->fault = 0;
 	rval = adp1653_get_fault(flash);
 	mutex_unlock(flash->ctrls.lock);
 	if (rval > 0) {
 		dev_err(&client->dev, "faults detected: 0x%1.1x\n", rval);
 		return -EIO;
 	}

 	mutex_lock(flash->ctrls.lock);
 	rval = adp1653_update_hw(flash);
 	mutex_unlock(flash->ctrls.lock);
 	if (rval) {
 		dev_err(&client->dev,
 			"adp1653_update_hw failed at %s\n", __func__);
 		return -EIO;
 	}

 	return 0;
 }

 static int
 __adp1653_set_power(struct adp1653_flash *flash, int on)
 {
 	int ret;

 	if (flash->platform_data->power) {
 		ret = flash->platform_data->power(&flash->subdev, on);
 		if (ret < 0)
 			return ret;
 	} else {
 		gpiod_set_value(flash->platform_data->enable_gpio, on);
 		if (on)
 			/* Some delay is apparently required. */
 			udelay(20);
 	}

 	if (!on)
 		return 0;

 	ret = adp1653_init_device(flash);
 	if (ret >= 0)
 		return ret;

 	if (flash->platform_data->power)
 		flash->platform_data->power(&flash->subdev, 0);
 	else
 		gpiod_set_value(flash->platform_data->enable_gpio, 0);

 	return ret;
 }

 static int
 adp1653_set_power(struct v4l2_subdev *subdev, int on)
 {
 	struct adp1653_flash *flash = to_adp1653_flash(subdev);
 	int ret = 0;

 	mutex_lock(&flash->power_lock);

 	/* If the power count is modified from 0 to != 0 or from != 0 to 0,
 	 * update the power state.
 	 */
 	if (flash->power_count == !on) {
 		ret = __adp1653_set_power(flash, !!on);
 		if (ret < 0)
 			goto done;
 	}

 	/* Update the power count. */
 	flash->power_count += on ? 1 : -1;
 	WARN_ON(flash->power_count < 0);

 done:
 	mutex_unlock(&flash->power_lock);
 	return ret;
 }

 static int adp1653_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 {
 	return adp1653_set_power(sd, 1);
 }

 static int adp1653_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 {
 	return adp1653_set_power(sd, 0);
 }

 static const struct v4l2_subdev_core_ops adp1653_core_ops = {
 	.s_power = adp1653_set_power,
 };

 static const struct v4l2_subdev_ops adp1653_ops = {
 	.core = &adp1653_core_ops,
 };

 static const struct v4l2_subdev_internal_ops adp1653_internal_ops = {
 	.open = adp1653_open,
 	.close = adp1653_close,
 };

 /* --------------------------------------------------------------------------
  * I2C driver
  */
 #ifdef CONFIG_PM

 static int adp1653_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 	struct adp1653_flash *flash = to_adp1653_flash(subdev);

 	if (!flash->power_count)
 		return 0;

 	return __adp1653_set_power(flash, 0);
 }

 static int adp1653_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 	struct adp1653_flash *flash = to_adp1653_flash(subdev);

 	if (!flash->power_count)
 		return 0;

 	return __adp1653_set_power(flash, 1);
 }

 #else

 #define adp1653_suspend	NULL
 #define adp1653_resume	NULL

 #endif /* CONFIG_PM */

 static int adp1653_of_init(struct i2c_client *client,
 			   struct adp1653_flash *flash,
 			   struct device_node *node)
 {
 	struct adp1653_platform_data *pd;
 	struct device_node *child;

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

 	child = of_get_child_by_name(node, "flash");
 	if (!child)
 		return -EINVAL;

 	if (of_property_read_u32(child, "flash-timeout-us",
 				 &pd->max_flash_timeout))
 		goto err;

 	if (of_property_read_u32(child, "flash-max-microamp",
 				 &pd->max_flash_intensity))
 		goto err;

 	pd->max_flash_intensity /= 1000;

 	if (of_property_read_u32(child, "led-max-microamp",
 				 &pd->max_torch_intensity))
 		goto err;

 	pd->max_torch_intensity /= 1000;
 	of_node_put(child);

 	child = of_get_child_by_name(node, "indicator");
 	if (!child)
 		return -EINVAL;

 	if (of_property_read_u32(child, "led-max-microamp",
 				 &pd->max_indicator_intensity))
 		goto err;

 	of_node_put(child);

 	pd->enable_gpio = devm_gpiod_get(&client->dev, "enable", GPIOD_OUT_LOW);
 	if (!pd->enable_gpio) {
 		dev_err(&client->dev, "Error getting GPIO\n");
 		return -EINVAL;
 	}

 	return 0;
 err:
 	dev_err(&client->dev, "Required property not found\n");
 	of_node_put(child);
 	return -EINVAL;
 }


 static int adp1653_probe(struct i2c_client *client,
 			 const struct i2c_device_id *devid)
 {
 	struct adp1653_flash *flash;
 	int ret;

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

 	if (client->dev.of_node) {
 		ret = adp1653_of_init(client, flash, client->dev.of_node);
 		if (ret)
 			return ret;
 	} else {
 		if (!client->dev.platform_data) {
 			dev_err(&client->dev,
 				"Neither DT not platform data provided\n");
 			return EINVAL;
 		}
 		flash->platform_data = client->dev.platform_data;
 	}

 	mutex_init(&flash->power_lock);

 	v4l2_i2c_subdev_init(&flash->subdev, client, &adp1653_ops);
 	flash->subdev.internal_ops = &adp1653_internal_ops;
 	flash->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

 	ret = adp1653_init_controls(flash);
 	if (ret)
 		goto free_and_quit;

 	ret = media_entity_pads_init(&flash->subdev.entity, 0, NULL);
 	if (ret < 0)
 		goto free_and_quit;

 	flash->subdev.entity.function = MEDIA_ENT_F_FLASH;

 	return 0;

 free_and_quit:
 	dev_err(&client->dev, "adp1653: failed to register device\n");
 	v4l2_ctrl_handler_free(&flash->ctrls);
 	return ret;
 }

 static int adp1653_remove(struct i2c_client *client)
 {
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 	struct adp1653_flash *flash = to_adp1653_flash(subdev);

 	v4l2_device_unregister_subdev(&flash->subdev);
 	v4l2_ctrl_handler_free(&flash->ctrls);
 	media_entity_cleanup(&flash->subdev.entity);

 	return 0;
 }

 static const struct i2c_device_id adp1653_id_table[] = {
 	{ ADP1653_NAME, 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, adp1653_id_table);

 static const struct dev_pm_ops adp1653_pm_ops = {
 	.suspend	= adp1653_suspend,
 	.resume		= adp1653_resume,
 };

 static struct i2c_driver adp1653_i2c_driver = {
 	.driver		= {
 		.name	= ADP1653_NAME,
 		.pm	= &adp1653_pm_ops,
 	},
 	.probe		= adp1653_probe,
 	.remove		= adp1653_remove,
 	.id_table	= adp1653_id_table,
 };

 module_i2c_driver(adp1653_i2c_driver);

 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@nokia.com>");
 MODULE_DESCRIPTION("Analog Devices ADP1653 LED flash driver");
 MODULE_LICENSE("GPL");
	/*
	* drivers/media/i2c/adp1653.c
	*
	* Copyright (C) 2008--2011 Nokia Corporation
	*
	* Contact: Sakari Ailus <sakari.ailus@iki.fi>
	*
	* Contributors:
	* Sakari Ailus <sakari.ailus@iki.fi>
	* Tuukka Toivonen <tuukkat76@gmail.com>
	* Pavel Machek <pavel@ucw.cz>
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	* 02110-1301 USA
	*
	* TODO:
	* - fault interrupt handling
	* - hardware strobe
	* - power doesn't need to be ON if all lights are off
	*
	*/

	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/slab.h>
	#include <linux/of.h>
	#include <linux/gpio/consumer.h>
	#include <media/i2c/adp1653.h>
	#include <media/v4l2-device.h>

	#define TIMEOUT_MAX 820000
	#define TIMEOUT_STEP 54600
	#define TIMEOUT_MIN (TIMEOUT_MAX - ADP1653_REG_CONFIG_TMR_SET_MAX \
	* TIMEOUT_STEP)
	#define TIMEOUT_US_TO_CODE(t) ((TIMEOUT_MAX + (TIMEOUT_STEP / 2) - (t)) \
	/ TIMEOUT_STEP)
	#define TIMEOUT_CODE_TO_US(c) (TIMEOUT_MAX - (c) * TIMEOUT_STEP)

	/* Write values into ADP1653 registers. */
	static int adp1653_update_hw(struct adp1653_flash *flash)
	{
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	u8 out_sel;
	u8 config = 0;
	int rval;

	out_sel = ADP1653_INDICATOR_INTENSITY_uA_TO_REG(
	flash->indicator_intensity->val)
	<< ADP1653_REG_OUT_SEL_ILED_SHIFT;

	switch (flash->led_mode->val) {
	case V4L2_FLASH_LED_MODE_NONE:
	break;
	case V4L2_FLASH_LED_MODE_FLASH:
	/* Flash mode, light on with strobe, duration from timer */
	config = ADP1653_REG_CONFIG_TMR_CFG;
	config \|= TIMEOUT_US_TO_CODE(flash->flash_timeout->val)
	<< ADP1653_REG_CONFIG_TMR_SET_SHIFT;
	break;
	case V4L2_FLASH_LED_MODE_TORCH:
	/* Torch mode, light immediately on, duration indefinite */
	out_sel \|= ADP1653_FLASH_INTENSITY_mA_TO_REG(
	flash->torch_intensity->val)
	<< ADP1653_REG_OUT_SEL_HPLED_SHIFT;
	break;
	}

	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL, out_sel);
	if (rval < 0)
	return rval;

	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_CONFIG, config);
	if (rval < 0)
	return rval;

	return 0;
	}

	static int adp1653_get_fault(struct adp1653_flash *flash)
	{
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	int fault;
	int rval;

	fault = i2c_smbus_read_byte_data(client, ADP1653_REG_FAULT);
	if (IS_ERR_VALUE(fault))
	return fault;

	flash->fault \|= fault;

	if (!flash->fault)
	return 0;

	/* Clear faults. */
	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL, 0);
	if (IS_ERR_VALUE(rval))
	return rval;

	flash->led_mode->val = V4L2_FLASH_LED_MODE_NONE;

	rval = adp1653_update_hw(flash);
	if (IS_ERR_VALUE(rval))
	return rval;

	return flash->fault;
	}

	static int adp1653_strobe(struct adp1653_flash *flash, int enable)
	{
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	u8 out_sel = ADP1653_INDICATOR_INTENSITY_uA_TO_REG(
	flash->indicator_intensity->val)
	<< ADP1653_REG_OUT_SEL_ILED_SHIFT;
	int rval;

	if (flash->led_mode->val != V4L2_FLASH_LED_MODE_FLASH)
	return -EBUSY;

	if (!enable)
	return i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL,
	out_sel);

	out_sel \|= ADP1653_FLASH_INTENSITY_mA_TO_REG(
	flash->flash_intensity->val)
	<< ADP1653_REG_OUT_SEL_HPLED_SHIFT;
	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL, out_sel);
	if (rval)
	return rval;

	/* Software strobe using i2c */
	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_SW_STROBE,
	ADP1653_REG_SW_STROBE_SW_STROBE);
	if (rval)
	return rval;
	return i2c_smbus_write_byte_data(client, ADP1653_REG_SW_STROBE, 0);
	}

	/* --------------------------------------------------------------------------
	* V4L2 controls
	*/

	static int adp1653_get_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct adp1653_flash *flash =
	container_of(ctrl->handler, struct adp1653_flash, ctrls);
	int rval;

	rval = adp1653_get_fault(flash);
	if (IS_ERR_VALUE(rval))
	return rval;

	ctrl->cur.val = 0;

	if (flash->fault & ADP1653_REG_FAULT_FLT_SCP)
	ctrl->cur.val \|= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
	if (flash->fault & ADP1653_REG_FAULT_FLT_OT)
	ctrl->cur.val \|= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
	if (flash->fault & ADP1653_REG_FAULT_FLT_TMR)
	ctrl->cur.val \|= V4L2_FLASH_FAULT_TIMEOUT;
	if (flash->fault & ADP1653_REG_FAULT_FLT_OV)
	ctrl->cur.val \|= V4L2_FLASH_FAULT_OVER_VOLTAGE;

	flash->fault = 0;

	return 0;
	}

	static int adp1653_set_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct adp1653_flash *flash =
	container_of(ctrl->handler, struct adp1653_flash, ctrls);
	int rval;

	rval = adp1653_get_fault(flash);
	if (IS_ERR_VALUE(rval))
	return rval;
	if ((rval & (ADP1653_REG_FAULT_FLT_SCP \|
	ADP1653_REG_FAULT_FLT_OT \|
	ADP1653_REG_FAULT_FLT_OV)) &&
	(ctrl->id == V4L2_CID_FLASH_STROBE \|\|
	ctrl->id == V4L2_CID_FLASH_TORCH_INTENSITY \|\|
	ctrl->id == V4L2_CID_FLASH_LED_MODE))
	return -EBUSY;

	switch (ctrl->id) {
	case V4L2_CID_FLASH_STROBE:
	return adp1653_strobe(flash, 1);
	case V4L2_CID_FLASH_STROBE_STOP:
	return adp1653_strobe(flash, 0);
	}

	return adp1653_update_hw(flash);
	}

	static const struct v4l2_ctrl_ops adp1653_ctrl_ops = {
	.g_volatile_ctrl = adp1653_get_ctrl,
	.s_ctrl = adp1653_set_ctrl,
	};

	static int adp1653_init_controls(struct adp1653_flash *flash)
	{
	struct v4l2_ctrl *fault;

	v4l2_ctrl_handler_init(&flash->ctrls, 9);

	flash->led_mode =
	v4l2_ctrl_new_std_menu(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_LED_MODE,
	V4L2_FLASH_LED_MODE_TORCH, ~0x7, 0);
	v4l2_ctrl_new_std_menu(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_STROBE_SOURCE,
	V4L2_FLASH_STROBE_SOURCE_SOFTWARE, ~0x1, 0);
	v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
	v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);
	flash->flash_timeout =
	v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_TIMEOUT, TIMEOUT_MIN,
	flash->platform_data->max_flash_timeout,
	TIMEOUT_STEP,
	flash->platform_data->max_flash_timeout);
	flash->flash_intensity =
	v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_INTENSITY,
	ADP1653_FLASH_INTENSITY_MIN,
	flash->platform_data->max_flash_intensity,
	1, flash->platform_data->max_flash_intensity);
	flash->torch_intensity =
	v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_TORCH_INTENSITY,
	ADP1653_TORCH_INTENSITY_MIN,
	flash->platform_data->max_torch_intensity,
	ADP1653_FLASH_INTENSITY_STEP,
	flash->platform_data->max_torch_intensity);
	flash->indicator_intensity =
	v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_INDICATOR_INTENSITY,
	ADP1653_INDICATOR_INTENSITY_MIN,
	flash->platform_data->max_indicator_intensity,
	ADP1653_INDICATOR_INTENSITY_STEP,
	ADP1653_INDICATOR_INTENSITY_MIN);
	fault = v4l2_ctrl_new_std(&flash->ctrls, &adp1653_ctrl_ops,
	V4L2_CID_FLASH_FAULT, 0,
	V4L2_FLASH_FAULT_OVER_VOLTAGE
	\| V4L2_FLASH_FAULT_OVER_TEMPERATURE
	\| V4L2_FLASH_FAULT_SHORT_CIRCUIT, 0, 0);

	if (flash->ctrls.error)
	return flash->ctrls.error;

	fault->flags \|= V4L2_CTRL_FLAG_VOLATILE;

	flash->subdev.ctrl_handler = &flash->ctrls;
	return 0;
	}

	/* --------------------------------------------------------------------------
	* V4L2 subdev operations
	*/

	static int
	adp1653_init_device(struct adp1653_flash *flash)
	{
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	int rval;

	/* Clear FAULT register by writing zero to OUT_SEL */
	rval = i2c_smbus_write_byte_data(client, ADP1653_REG_OUT_SEL, 0);
	if (rval < 0) {
	dev_err(&client->dev, "failed writing fault register\n");
	return -EIO;
	}

	mutex_lock(flash->ctrls.lock);
	/* Reset faults before reading new ones. */
	flash->fault = 0;
	rval = adp1653_get_fault(flash);
	mutex_unlock(flash->ctrls.lock);
	if (rval > 0) {
	dev_err(&client->dev, "faults detected: 0x%1.1x\n", rval);
	return -EIO;
	}

	mutex_lock(flash->ctrls.lock);
	rval = adp1653_update_hw(flash);
	mutex_unlock(flash->ctrls.lock);
	if (rval) {
	dev_err(&client->dev,
	"adp1653_update_hw failed at %s\n", __func__);
	return -EIO;
	}

	return 0;
	}

	static int
	__adp1653_set_power(struct adp1653_flash *flash, int on)
	{
	int ret;

	if (flash->platform_data->power) {
	ret = flash->platform_data->power(&flash->subdev, on);
	if (ret < 0)
	return ret;
	} else {
	gpiod_set_value(flash->platform_data->enable_gpio, on);
	if (on)
	/* Some delay is apparently required. */
	udelay(20);
	}

	if (!on)
	return 0;

	ret = adp1653_init_device(flash);
	if (ret >= 0)
	return ret;

	if (flash->platform_data->power)
	flash->platform_data->power(&flash->subdev, 0);
	else
	gpiod_set_value(flash->platform_data->enable_gpio, 0);

	return ret;
	}

	static int
	adp1653_set_power(struct v4l2_subdev *subdev, int on)
	{
	struct adp1653_flash *flash = to_adp1653_flash(subdev);
	int ret = 0;

	mutex_lock(&flash->power_lock);

	/* If the power count is modified from 0 to != 0 or from != 0 to 0,
	* update the power state.
	*/
	if (flash->power_count == !on) {
	ret = __adp1653_set_power(flash, !!on);
	if (ret < 0)
	goto done;
	}

	/* Update the power count. */
	flash->power_count += on ? 1 : -1;
	WARN_ON(flash->power_count < 0);

	done:
	mutex_unlock(&flash->power_lock);
	return ret;
	}

	static int adp1653_open(struct v4l2_subdev sd, struct v4l2_subdev_fh fh)
	{
	return adp1653_set_power(sd, 1);
	}

	static int adp1653_close(struct v4l2_subdev sd, struct v4l2_subdev_fh fh)
	{
	return adp1653_set_power(sd, 0);
	}

	static const struct v4l2_subdev_core_ops adp1653_core_ops = {
	.s_power = adp1653_set_power,
	};

	static const struct v4l2_subdev_ops adp1653_ops = {
	.core = &adp1653_core_ops,
	};

	static const struct v4l2_subdev_internal_ops adp1653_internal_ops = {
	.open = adp1653_open,
	.close = adp1653_close,
	};

	/* --------------------------------------------------------------------------
	* I2C driver
	*/
	#ifdef CONFIG_PM

	static int adp1653_suspend(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct adp1653_flash *flash = to_adp1653_flash(subdev);

	if (!flash->power_count)
	return 0;

	return __adp1653_set_power(flash, 0);
	}

	static int adp1653_resume(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct adp1653_flash *flash = to_adp1653_flash(subdev);

	if (!flash->power_count)
	return 0;

	return __adp1653_set_power(flash, 1);
	}

	#else

	#define adp1653_suspend NULL
	#define adp1653_resume NULL

	#endif /* CONFIG_PM */

	static int adp1653_of_init(struct i2c_client *client,
	struct adp1653_flash *flash,
	struct device_node *node)
	{
	struct adp1653_platform_data *pd;
	struct device_node *child;

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

	child = of_get_child_by_name(node, "flash");
	if (!child)
	return -EINVAL;

	if (of_property_read_u32(child, "flash-timeout-us",
	&pd->max_flash_timeout))
	goto err;

	if (of_property_read_u32(child, "flash-max-microamp",
	&pd->max_flash_intensity))
	goto err;

	pd->max_flash_intensity /= 1000;

	if (of_property_read_u32(child, "led-max-microamp",
	&pd->max_torch_intensity))
	goto err;

	pd->max_torch_intensity /= 1000;
	of_node_put(child);

	child = of_get_child_by_name(node, "indicator");
	if (!child)
	return -EINVAL;

	if (of_property_read_u32(child, "led-max-microamp",
	&pd->max_indicator_intensity))
	goto err;

	of_node_put(child);

	pd->enable_gpio = devm_gpiod_get(&client->dev, "enable", GPIOD_OUT_LOW);
	if (!pd->enable_gpio) {
	dev_err(&client->dev, "Error getting GPIO\n");
	return -EINVAL;
	}

	return 0;
	err:
	dev_err(&client->dev, "Required property not found\n");
	of_node_put(child);
	return -EINVAL;
	}


	static int adp1653_probe(struct i2c_client *client,
	const struct i2c_device_id *devid)
	{
	struct adp1653_flash *flash;
	int ret;

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

	if (client->dev.of_node) {
	ret = adp1653_of_init(client, flash, client->dev.of_node);
	if (ret)
	return ret;
	} else {
	if (!client->dev.platform_data) {
	dev_err(&client->dev,
	"Neither DT not platform data provided\n");
	return EINVAL;
	}
	flash->platform_data = client->dev.platform_data;
	}

	mutex_init(&flash->power_lock);

	v4l2_i2c_subdev_init(&flash->subdev, client, &adp1653_ops);
	flash->subdev.internal_ops = &adp1653_internal_ops;
	flash->subdev.flags \|= V4L2_SUBDEV_FL_HAS_DEVNODE;

	ret = adp1653_init_controls(flash);
	if (ret)
	goto free_and_quit;

	ret = media_entity_pads_init(&flash->subdev.entity, 0, NULL);
	if (ret < 0)
	goto free_and_quit;

	flash->subdev.entity.function = MEDIA_ENT_F_FLASH;

	return 0;

	free_and_quit:
	dev_err(&client->dev, "adp1653: failed to register device\n");
	v4l2_ctrl_handler_free(&flash->ctrls);
	return ret;
	}

	static int adp1653_remove(struct i2c_client *client)
	{
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct adp1653_flash *flash = to_adp1653_flash(subdev);

	v4l2_device_unregister_subdev(&flash->subdev);
	v4l2_ctrl_handler_free(&flash->ctrls);
	media_entity_cleanup(&flash->subdev.entity);

	return 0;
	}

	static const struct i2c_device_id adp1653_id_table[] = {
	{ ADP1653_NAME, 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, adp1653_id_table);

	static const struct dev_pm_ops adp1653_pm_ops = {
	.suspend = adp1653_suspend,
	.resume = adp1653_resume,
	};

	static struct i2c_driver adp1653_i2c_driver = {
	.driver = {
	.name = ADP1653_NAME,
	.pm = &adp1653_pm_ops,
	},
	.probe = adp1653_probe,
	.remove = adp1653_remove,
	.id_table = adp1653_id_table,
	};

	module_i2c_driver(adp1653_i2c_driver);

	MODULE_AUTHOR("Sakari Ailus <sakari.ailus@nokia.com>");
	MODULE_DESCRIPTION("Analog Devices ADP1653 LED flash driver");
	MODULE_LICENSE("GPL");