drivers/media/i2c/ad5820.c - linux - Git at Google

 /*
  * drivers/media/i2c/ad5820.c
  *
  * AD5820 DAC driver for camera voice coil focus.
  *
  * Copyright (C) 2008 Nokia Corporation
  * Copyright (C) 2007 Texas Instruments
  * Copyright (C) 2016 Pavel Machek <pavel@ucw.cz>
  *
  * Contact: Tuukka Toivonen <tuukkat76@gmail.com>
  *	    Sakari Ailus <sakari.ailus@iki.fi>
  *
  * Based on af_d88.c by Texas Instruments.
  *
  * 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/errno.h>
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>

 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-subdev.h>

 #define AD5820_NAME		"ad5820"

 /* Register definitions */
 #define AD5820_POWER_DOWN		(1 << 15)
 #define AD5820_DAC_SHIFT		4
 #define AD5820_RAMP_MODE_LINEAR		(0 << 3)
 #define AD5820_RAMP_MODE_64_16		(1 << 3)

 #define CODE_TO_RAMP_US(s)	((s) == 0 ? 0 : (1 << ((s) - 1)) * 50)
 #define RAMP_US_TO_CODE(c)	fls(((c) + ((c)>>1)) / 50)

 #define to_ad5820_device(sd)	container_of(sd, struct ad5820_device, subdev)

 struct ad5820_device {
 	struct v4l2_subdev subdev;
 	struct ad5820_platform_data *platform_data;
 	struct regulator *vana;

 	struct v4l2_ctrl_handler ctrls;
 	u32 focus_absolute;
 	u32 focus_ramp_time;
 	u32 focus_ramp_mode;

 	struct mutex power_lock;
 	int power_count;

 	bool standby;
 };

 static int ad5820_write(struct ad5820_device *coil, u16 data)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev);
 	struct i2c_msg msg;
 	__be16 be_data;
 	int r;

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

 	be_data = cpu_to_be16(data);
 	msg.addr  = client->addr;
 	msg.flags = 0;
 	msg.len   = 2;
 	msg.buf   = (u8 *)&be_data;

 	r = i2c_transfer(client->adapter, &msg, 1);
 	if (r < 0) {
 		dev_err(&client->dev, "write failed, error %d\n", r);
 		return r;
 	}

 	return 0;
 }

 /*
  * Calculate status word and write it to the device based on current
  * values of V4L2 controls. It is assumed that the stored V4L2 control
  * values are properly limited and rounded.
  */
 static int ad5820_update_hw(struct ad5820_device *coil)
 {
 	u16 status;

 	status = RAMP_US_TO_CODE(coil->focus_ramp_time);
 	status |= coil->focus_ramp_mode
 		? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR;
 	status |= coil->focus_absolute << AD5820_DAC_SHIFT;

 	if (coil->standby)
 		status |= AD5820_POWER_DOWN;

 	return ad5820_write(coil, status);
 }

 /*
  * Power handling
  */
 static int ad5820_power_off(struct ad5820_device *coil, bool standby)
 {
 	int ret = 0, ret2;

 	/*
 	 * Go to standby first as real power off my be denied by the hardware
 	 * (single power line control for both coil and sensor).
 	 */
 	if (standby) {
 		coil->standby = true;
 		ret = ad5820_update_hw(coil);
 	}

 	ret2 = regulator_disable(coil->vana);
 	if (ret)
 		return ret;
 	return ret2;
 }

 static int ad5820_power_on(struct ad5820_device *coil, bool restore)
 {
 	int ret;

 	ret = regulator_enable(coil->vana);
 	if (ret < 0)
 		return ret;

 	if (restore) {
 		/* Restore the hardware settings. */
 		coil->standby = false;
 		ret = ad5820_update_hw(coil);
 		if (ret)
 			goto fail;
 	}
 	return 0;

 fail:
 	coil->standby = true;
 	regulator_disable(coil->vana);

 	return ret;
 }

 /*
  * V4L2 controls
  */
 static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct ad5820_device *coil =
 		container_of(ctrl->handler, struct ad5820_device, ctrls);

 	switch (ctrl->id) {
 	case V4L2_CID_FOCUS_ABSOLUTE:
 		coil->focus_absolute = ctrl->val;
 		return ad5820_update_hw(coil);
 	}

 	return 0;
 }

 static const struct v4l2_ctrl_ops ad5820_ctrl_ops = {
 	.s_ctrl = ad5820_set_ctrl,
 };


 static int ad5820_init_controls(struct ad5820_device *coil)
 {
 	v4l2_ctrl_handler_init(&coil->ctrls, 1);

 	/*
 	 * V4L2_CID_FOCUS_ABSOLUTE
 	 *
 	 * Minimum current is 0 mA, maximum is 100 mA. Thus, 1 code is
 	 * equivalent to 100/1023 = 0.0978 mA. Nevertheless, we do not use [mA]
 	 * for focus position, because it is meaningless for user. Meaningful
 	 * would be to use focus distance or even its inverse, but since the
 	 * driver doesn't have sufficiently knowledge to do the conversion, we
 	 * will just use abstract codes here. In any case, smaller value = focus
 	 * position farther from camera. The default zero value means focus at
 	 * infinity, and also least current consumption.
 	 */
 	v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
 			  V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);

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

 	coil->focus_absolute = 0;
 	coil->focus_ramp_time = 0;
 	coil->focus_ramp_mode = 0;

 	coil->subdev.ctrl_handler = &coil->ctrls;

 	return 0;
 }

 /*
  * V4L2 subdev operations
  */
 static int ad5820_registered(struct v4l2_subdev *subdev)
 {
 	struct ad5820_device *coil = to_ad5820_device(subdev);

 	return ad5820_init_controls(coil);
 }

 static int
 ad5820_set_power(struct v4l2_subdev *subdev, int on)
 {
 	struct ad5820_device *coil = to_ad5820_device(subdev);
 	int ret = 0;

 	mutex_lock(&coil->power_lock);

 	/*
 	 * If the power count is modified from 0 to != 0 or from != 0 to 0,
 	 * update the power state.
 	 */
 	if (coil->power_count == !on) {
 		ret = on ? ad5820_power_on(coil, true) :
 			ad5820_power_off(coil, true);
 		if (ret < 0)
 			goto done;
 	}

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

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

 static int ad5820_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 {
 	return ad5820_set_power(sd, 1);
 }

 static int ad5820_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 {
 	return ad5820_set_power(sd, 0);
 }

 static const struct v4l2_subdev_core_ops ad5820_core_ops = {
 	.s_power = ad5820_set_power,
 };

 static const struct v4l2_subdev_ops ad5820_ops = {
 	.core = &ad5820_core_ops,
 };

 static const struct v4l2_subdev_internal_ops ad5820_internal_ops = {
 	.registered = ad5820_registered,
 	.open = ad5820_open,
 	.close = ad5820_close,
 };

 /*
  * I2C driver
  */
 static int __maybe_unused ad5820_suspend(struct device *dev)
 {
 	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 	struct ad5820_device *coil = to_ad5820_device(subdev);

 	if (!coil->power_count)
 		return 0;

 	return ad5820_power_off(coil, false);
 }

 static int __maybe_unused ad5820_resume(struct device *dev)
 {
 	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 	struct ad5820_device *coil = to_ad5820_device(subdev);

 	if (!coil->power_count)
 		return 0;

 	return ad5820_power_on(coil, true);
 }

 static int ad5820_probe(struct i2c_client *client,
 			const struct i2c_device_id *devid)
 {
 	struct ad5820_device *coil;
 	int ret;

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

 	coil->vana = devm_regulator_get(&client->dev, "VANA");
 	if (IS_ERR(coil->vana)) {
 		ret = PTR_ERR(coil->vana);
 		if (ret != -EPROBE_DEFER)
 			dev_err(&client->dev, "could not get regulator for vana\n");
 		return ret;
 	}

 	mutex_init(&coil->power_lock);

 	v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
 	coil->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 	coil->subdev.internal_ops = &ad5820_internal_ops;
 	strcpy(coil->subdev.name, "ad5820 focus");

 	ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL);
 	if (ret < 0)
 		goto cleanup2;

 	ret = v4l2_async_register_subdev(&coil->subdev);
 	if (ret < 0)
 		goto cleanup;

 	return ret;

 cleanup2:
 	mutex_destroy(&coil->power_lock);
 cleanup:
 	media_entity_cleanup(&coil->subdev.entity);
 	return ret;
 }

 static int ad5820_remove(struct i2c_client *client)
 {
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 	struct ad5820_device *coil = to_ad5820_device(subdev);

 	v4l2_async_unregister_subdev(&coil->subdev);
 	v4l2_ctrl_handler_free(&coil->ctrls);
 	media_entity_cleanup(&coil->subdev.entity);
 	mutex_destroy(&coil->power_lock);
 	return 0;
 }

 static const struct i2c_device_id ad5820_id_table[] = {
 	{ AD5820_NAME, 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ad5820_id_table);

 static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume);

 static struct i2c_driver ad5820_i2c_driver = {
 	.driver		= {
 		.name	= AD5820_NAME,
 		.pm	= &ad5820_pm,
 	},
 	.probe		= ad5820_probe,
 	.remove		= ad5820_remove,
 	.id_table	= ad5820_id_table,
 };

 module_i2c_driver(ad5820_i2c_driver);

 MODULE_AUTHOR("Tuukka Toivonen");
 MODULE_DESCRIPTION("AD5820 camera lens driver");
 MODULE_LICENSE("GPL");
	/*
	* drivers/media/i2c/ad5820.c
	*
	* AD5820 DAC driver for camera voice coil focus.
	*
	* Copyright (C) 2008 Nokia Corporation
	* Copyright (C) 2007 Texas Instruments
	* Copyright (C) 2016 Pavel Machek <pavel@ucw.cz>
	*
	* Contact: Tuukka Toivonen <tuukkat76@gmail.com>
	* Sakari Ailus <sakari.ailus@iki.fi>
	*
	* Based on af_d88.c by Texas Instruments.
	*
	* 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/errno.h>
	#include <linux/i2c.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/regulator/consumer.h>

	#include <media/v4l2-ctrls.h>
	#include <media/v4l2-device.h>
	#include <media/v4l2-subdev.h>

	#define AD5820_NAME "ad5820"

	/* Register definitions */
	#define AD5820_POWER_DOWN (1 << 15)
	#define AD5820_DAC_SHIFT 4
	#define AD5820_RAMP_MODE_LINEAR (0 << 3)
	#define AD5820_RAMP_MODE_64_16 (1 << 3)

	#define CODE_TO_RAMP_US(s) ((s) == 0 ? 0 : (1 << ((s) - 1)) * 50)
	#define RAMP_US_TO_CODE(c) fls(((c) + ((c)>>1)) / 50)

	#define to_ad5820_device(sd) container_of(sd, struct ad5820_device, subdev)

	struct ad5820_device {
	struct v4l2_subdev subdev;
	struct ad5820_platform_data *platform_data;
	struct regulator *vana;

	struct v4l2_ctrl_handler ctrls;
	u32 focus_absolute;
	u32 focus_ramp_time;
	u32 focus_ramp_mode;

	struct mutex power_lock;
	int power_count;

	bool standby;
	};

	static int ad5820_write(struct ad5820_device *coil, u16 data)
	{
	struct i2c_client *client = v4l2_get_subdevdata(&coil->subdev);
	struct i2c_msg msg;
	__be16 be_data;
	int r;

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

	be_data = cpu_to_be16(data);
	msg.addr = client->addr;
	msg.flags = 0;
	msg.len = 2;
	msg.buf = (u8 *)&be_data;

	r = i2c_transfer(client->adapter, &msg, 1);
	if (r < 0) {
	dev_err(&client->dev, "write failed, error %d\n", r);
	return r;
	}

	return 0;
	}

	/*
	* Calculate status word and write it to the device based on current
	* values of V4L2 controls. It is assumed that the stored V4L2 control
	* values are properly limited and rounded.
	*/
	static int ad5820_update_hw(struct ad5820_device *coil)
	{
	u16 status;

	status = RAMP_US_TO_CODE(coil->focus_ramp_time);
	status \|= coil->focus_ramp_mode
	? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR;
	status \|= coil->focus_absolute << AD5820_DAC_SHIFT;

	if (coil->standby)
	status \|= AD5820_POWER_DOWN;

	return ad5820_write(coil, status);
	}

	/*
	* Power handling
	*/
	static int ad5820_power_off(struct ad5820_device *coil, bool standby)
	{
	int ret = 0, ret2;

	/*
	* Go to standby first as real power off my be denied by the hardware
	* (single power line control for both coil and sensor).
	*/
	if (standby) {
	coil->standby = true;
	ret = ad5820_update_hw(coil);
	}

	ret2 = regulator_disable(coil->vana);
	if (ret)
	return ret;
	return ret2;
	}

	static int ad5820_power_on(struct ad5820_device *coil, bool restore)
	{
	int ret;

	ret = regulator_enable(coil->vana);
	if (ret < 0)
	return ret;

	if (restore) {
	/* Restore the hardware settings. */
	coil->standby = false;
	ret = ad5820_update_hw(coil);
	if (ret)
	goto fail;
	}
	return 0;

	fail:
	coil->standby = true;
	regulator_disable(coil->vana);

	return ret;
	}

	/*
	* V4L2 controls
	*/
	static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct ad5820_device *coil =
	container_of(ctrl->handler, struct ad5820_device, ctrls);

	switch (ctrl->id) {
	case V4L2_CID_FOCUS_ABSOLUTE:
	coil->focus_absolute = ctrl->val;
	return ad5820_update_hw(coil);
	}

	return 0;
	}

	static const struct v4l2_ctrl_ops ad5820_ctrl_ops = {
	.s_ctrl = ad5820_set_ctrl,
	};


	static int ad5820_init_controls(struct ad5820_device *coil)
	{
	v4l2_ctrl_handler_init(&coil->ctrls, 1);

	/*
	* V4L2_CID_FOCUS_ABSOLUTE
	*
	* Minimum current is 0 mA, maximum is 100 mA. Thus, 1 code is
	* equivalent to 100/1023 = 0.0978 mA. Nevertheless, we do not use [mA]
	* for focus position, because it is meaningless for user. Meaningful
	* would be to use focus distance or even its inverse, but since the
	* driver doesn't have sufficiently knowledge to do the conversion, we
	* will just use abstract codes here. In any case, smaller value = focus
	* position farther from camera. The default zero value means focus at
	* infinity, and also least current consumption.
	*/
	v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
	V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);

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

	coil->focus_absolute = 0;
	coil->focus_ramp_time = 0;
	coil->focus_ramp_mode = 0;

	coil->subdev.ctrl_handler = &coil->ctrls;

	return 0;
	}

	/*
	* V4L2 subdev operations
	*/
	static int ad5820_registered(struct v4l2_subdev *subdev)
	{
	struct ad5820_device *coil = to_ad5820_device(subdev);

	return ad5820_init_controls(coil);
	}

	static int
	ad5820_set_power(struct v4l2_subdev *subdev, int on)
	{
	struct ad5820_device *coil = to_ad5820_device(subdev);
	int ret = 0;

	mutex_lock(&coil->power_lock);

	/*
	* If the power count is modified from 0 to != 0 or from != 0 to 0,
	* update the power state.
	*/
	if (coil->power_count == !on) {
	ret = on ? ad5820_power_on(coil, true) :
	ad5820_power_off(coil, true);
	if (ret < 0)
	goto done;
	}

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

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

	static int ad5820_open(struct v4l2_subdev sd, struct v4l2_subdev_fh fh)
	{
	return ad5820_set_power(sd, 1);
	}

	static int ad5820_close(struct v4l2_subdev sd, struct v4l2_subdev_fh fh)
	{
	return ad5820_set_power(sd, 0);
	}

	static const struct v4l2_subdev_core_ops ad5820_core_ops = {
	.s_power = ad5820_set_power,
	};

	static const struct v4l2_subdev_ops ad5820_ops = {
	.core = &ad5820_core_ops,
	};

	static const struct v4l2_subdev_internal_ops ad5820_internal_ops = {
	.registered = ad5820_registered,
	.open = ad5820_open,
	.close = ad5820_close,
	};

	/*
	* I2C driver
	*/
	static int __maybe_unused ad5820_suspend(struct device *dev)
	{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct ad5820_device *coil = to_ad5820_device(subdev);

	if (!coil->power_count)
	return 0;

	return ad5820_power_off(coil, false);
	}

	static int __maybe_unused ad5820_resume(struct device *dev)
	{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct ad5820_device *coil = to_ad5820_device(subdev);

	if (!coil->power_count)
	return 0;

	return ad5820_power_on(coil, true);
	}

	static int ad5820_probe(struct i2c_client *client,
	const struct i2c_device_id *devid)
	{
	struct ad5820_device *coil;
	int ret;

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

	coil->vana = devm_regulator_get(&client->dev, "VANA");
	if (IS_ERR(coil->vana)) {
	ret = PTR_ERR(coil->vana);
	if (ret != -EPROBE_DEFER)
	dev_err(&client->dev, "could not get regulator for vana\n");
	return ret;
	}

	mutex_init(&coil->power_lock);

	v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);
	coil->subdev.flags \|= V4L2_SUBDEV_FL_HAS_DEVNODE;
	coil->subdev.internal_ops = &ad5820_internal_ops;
	strcpy(coil->subdev.name, "ad5820 focus");

	ret = media_entity_pads_init(&coil->subdev.entity, 0, NULL);
	if (ret < 0)
	goto cleanup2;

	ret = v4l2_async_register_subdev(&coil->subdev);
	if (ret < 0)
	goto cleanup;

	return ret;

	cleanup2:
	mutex_destroy(&coil->power_lock);
	cleanup:
	media_entity_cleanup(&coil->subdev.entity);
	return ret;
	}

	static int ad5820_remove(struct i2c_client *client)
	{
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct ad5820_device *coil = to_ad5820_device(subdev);

	v4l2_async_unregister_subdev(&coil->subdev);
	v4l2_ctrl_handler_free(&coil->ctrls);
	media_entity_cleanup(&coil->subdev.entity);
	mutex_destroy(&coil->power_lock);
	return 0;
	}

	static const struct i2c_device_id ad5820_id_table[] = {
	{ AD5820_NAME, 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, ad5820_id_table);

	static SIMPLE_DEV_PM_OPS(ad5820_pm, ad5820_suspend, ad5820_resume);

	static struct i2c_driver ad5820_i2c_driver = {
	.driver = {
	.name = AD5820_NAME,
	.pm = &ad5820_pm,
	},
	.probe = ad5820_probe,
	.remove = ad5820_remove,
	.id_table = ad5820_id_table,
	};

	module_i2c_driver(ad5820_i2c_driver);

	MODULE_AUTHOR("Tuukka Toivonen");
	MODULE_DESCRIPTION("AD5820 camera lens driver");
	MODULE_LICENSE("GPL");