drivers/hwmon/pwm-fan.c - kernel/msm-4.9 - Gitiles

 /*
  * pwm-fan.c - Hwmon driver for fans connected to PWM lines.
  *
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
  *
  * Author: Kamil Debski <k.debski@samsung.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * 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/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/sysfs.h>
 #include <linux/thermal.h>

 #define MAX_PWM 255

 struct pwm_fan_ctx {
 	struct mutex lock;
 	struct pwm_device *pwm;
 	unsigned int pwm_value;
 	unsigned int pwm_fan_state;
 	unsigned int pwm_fan_max_state;
 	unsigned int *pwm_fan_cooling_levels;
 	struct thermal_cooling_device *cdev;
 };

 static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 {
 	struct pwm_args pargs;
 	unsigned long duty;
 	int ret = 0;

 	pwm_get_args(ctx->pwm, &pargs);

 	mutex_lock(&ctx->lock);
 	if (ctx->pwm_value == pwm)
 		goto exit_set_pwm_err;

 	duty = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM);
 	ret = pwm_config(ctx->pwm, duty, pargs.period);
 	if (ret)
 		goto exit_set_pwm_err;

 	if (pwm == 0)
 		pwm_disable(ctx->pwm);

 	if (ctx->pwm_value == 0) {
 		ret = pwm_enable(ctx->pwm);
 		if (ret)
 			goto exit_set_pwm_err;
 	}

 	ctx->pwm_value = pwm;
 exit_set_pwm_err:
 	mutex_unlock(&ctx->lock);
 	return ret;
 }

 static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
 {
 	int i;

 	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
 		if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
 			break;

 	ctx->pwm_fan_state = i;
 }

 static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
 		       const char *buf, size_t count)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 	unsigned long pwm;
 	int ret;

 	if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
 		return -EINVAL;

 	ret = __set_pwm(ctx, pwm);
 	if (ret)
 		return ret;

 	pwm_fan_update_state(ctx, pwm);
 	return count;
 }

 static ssize_t show_pwm(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);

 	return sprintf(buf, "%u\n", ctx->pwm_value);
 }


 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm, 0);

 static struct attribute *pwm_fan_attrs[] = {
 	&sensor_dev_attr_pwm1.dev_attr.attr,
 	NULL,
 };

 ATTRIBUTE_GROUPS(pwm_fan);

 /* thermal cooling device callbacks */
 static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
 				 unsigned long *state)
 {
 	struct pwm_fan_ctx *ctx = cdev->devdata;

 	if (!ctx)
 		return -EINVAL;

 	*state = ctx->pwm_fan_max_state;

 	return 0;
 }

 static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
 				 unsigned long *state)
 {
 	struct pwm_fan_ctx *ctx = cdev->devdata;

 	if (!ctx)
 		return -EINVAL;

 	*state = ctx->pwm_fan_state;

 	return 0;
 }

 static int
 pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
 {
 	struct pwm_fan_ctx *ctx = cdev->devdata;
 	int ret;

 	if (!ctx || (state > ctx->pwm_fan_max_state))
 		return -EINVAL;

 	if (state == ctx->pwm_fan_state)
 		return 0;

 	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
 	if (ret) {
 		dev_err(&cdev->device, "Cannot set pwm!\n");
 		return ret;
 	}

 	ctx->pwm_fan_state = state;

 	return ret;
 }

 static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
 	.get_max_state = pwm_fan_get_max_state,
 	.get_cur_state = pwm_fan_get_cur_state,
 	.set_cur_state = pwm_fan_set_cur_state,
 };

 static int pwm_fan_of_get_cooling_data(struct device *dev,
 				       struct pwm_fan_ctx *ctx)
 {
 	struct device_node *np = dev->of_node;
 	int num, i, ret;

 	if (!of_find_property(np, "cooling-levels", NULL))
 		return 0;

 	ret = of_property_count_u32_elems(np, "cooling-levels");
 	if (ret <= 0) {
 		dev_err(dev, "Wrong data!\n");
 		return ret ? : -EINVAL;
 	}

 	num = ret;
 	ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
 						   GFP_KERNEL);
 	if (!ctx->pwm_fan_cooling_levels)
 		return -ENOMEM;

 	ret = of_property_read_u32_array(np, "cooling-levels",
 					 ctx->pwm_fan_cooling_levels, num);
 	if (ret) {
 		dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
 		return ret;
 	}

 	for (i = 0; i < num; i++) {
 		if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
 			dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
 				ctx->pwm_fan_cooling_levels[i], MAX_PWM);
 			return -EINVAL;
 		}
 	}

 	ctx->pwm_fan_max_state = num - 1;

 	return 0;
 }

 static int pwm_fan_probe(struct platform_device *pdev)
 {
 	struct thermal_cooling_device *cdev;
 	struct pwm_fan_ctx *ctx;
 	struct pwm_args pargs;
 	struct device *hwmon;
 	int duty_cycle;
 	int ret;

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

 	mutex_init(&ctx->lock);

 	ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
 	if (IS_ERR(ctx->pwm)) {
 		dev_err(&pdev->dev, "Could not get PWM\n");
 		return PTR_ERR(ctx->pwm);
 	}

 	platform_set_drvdata(pdev, ctx);

 	/*
 	 * FIXME: pwm_apply_args() should be removed when switching to the
 	 * atomic PWM API.
 	 */
 	pwm_apply_args(ctx->pwm);

 	/* Set duty cycle to maximum allowed */
 	pwm_get_args(ctx->pwm, &pargs);

 	duty_cycle = pargs.period - 1;
 	ctx->pwm_value = MAX_PWM;

 	ret = pwm_config(ctx->pwm, duty_cycle, pargs.period);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to configure PWM\n");
 		return ret;
 	}

 	/* Enbale PWM output */
 	ret = pwm_enable(ctx->pwm);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to enable PWM\n");
 		return ret;
 	}

 	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
 						       ctx, pwm_fan_groups);
 	if (IS_ERR(hwmon)) {
 		dev_err(&pdev->dev, "Failed to register hwmon device\n");
 		pwm_disable(ctx->pwm);
 		return PTR_ERR(hwmon);
 	}

 	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
 	if (ret)
 		return ret;

 	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
 	if (IS_ENABLED(CONFIG_THERMAL)) {
 		cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
 							  "pwm-fan", ctx,
 							  &pwm_fan_cooling_ops);
 		if (IS_ERR(cdev)) {
 			dev_err(&pdev->dev,
 				"Failed to register pwm-fan as cooling device");
 			pwm_disable(ctx->pwm);
 			return PTR_ERR(cdev);
 		}
 		ctx->cdev = cdev;
 		thermal_cdev_update(cdev);
 	}

 	return 0;
 }

 static int pwm_fan_remove(struct platform_device *pdev)
 {
 	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);

 	thermal_cooling_device_unregister(ctx->cdev);
 	if (ctx->pwm_value)
 		pwm_disable(ctx->pwm);
 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int pwm_fan_suspend(struct device *dev)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 	struct pwm_args args;
 	int ret;

 	pwm_get_args(ctx->pwm, &args);

 	if (ctx->pwm_value) {
 		ret = pwm_config(ctx->pwm, 0, args.period);
 		if (ret < 0)
 			return ret;

 		pwm_disable(ctx->pwm);
 	}

 	return 0;
 }

 static int pwm_fan_resume(struct device *dev)
 {
 	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 	struct pwm_args pargs;
 	unsigned long duty;
 	int ret;

 	if (ctx->pwm_value == 0)
 		return 0;

 	pwm_get_args(ctx->pwm, &pargs);
 	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
 	ret = pwm_config(ctx->pwm, duty, pargs.period);
 	if (ret)
 		return ret;
 	return pwm_enable(ctx->pwm);
 }
 #endif

 static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);

 static const struct of_device_id of_pwm_fan_match[] = {
 	{ .compatible = "pwm-fan", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, of_pwm_fan_match);

 static struct platform_driver pwm_fan_driver = {
 	.probe		= pwm_fan_probe,
 	.remove		= pwm_fan_remove,
 	.driver	= {
 		.name		= "pwm-fan",
 		.pm		= &pwm_fan_pm,
 		.of_match_table	= of_pwm_fan_match,
 	},
 };

 module_platform_driver(pwm_fan_driver);

 MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
 MODULE_ALIAS("platform:pwm-fan");
 MODULE_DESCRIPTION("PWM FAN driver");
 MODULE_LICENSE("GPL");
	/*
	* pwm-fan.c - Hwmon driver for fans connected to PWM lines.
	*
	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
	*
	* Author: Kamil Debski <k.debski@samsung.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* 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/hwmon.h>
	#include <linux/hwmon-sysfs.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/pwm.h>
	#include <linux/sysfs.h>
	#include <linux/thermal.h>

	#define MAX_PWM 255

	struct pwm_fan_ctx {
	struct mutex lock;
	struct pwm_device *pwm;
	unsigned int pwm_value;
	unsigned int pwm_fan_state;
	unsigned int pwm_fan_max_state;
	unsigned int *pwm_fan_cooling_levels;
	struct thermal_cooling_device *cdev;
	};

	static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
	{
	struct pwm_args pargs;
	unsigned long duty;
	int ret = 0;

	pwm_get_args(ctx->pwm, &pargs);

	mutex_lock(&ctx->lock);
	if (ctx->pwm_value == pwm)
	goto exit_set_pwm_err;

	duty = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM);
	ret = pwm_config(ctx->pwm, duty, pargs.period);
	if (ret)
	goto exit_set_pwm_err;

	if (pwm == 0)
	pwm_disable(ctx->pwm);

	if (ctx->pwm_value == 0) {
	ret = pwm_enable(ctx->pwm);
	if (ret)
	goto exit_set_pwm_err;
	}

	ctx->pwm_value = pwm;
	exit_set_pwm_err:
	mutex_unlock(&ctx->lock);
	return ret;
	}

	static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
	{
	int i;

	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
	if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
	break;

	ctx->pwm_fan_state = i;
	}

	static ssize_t set_pwm(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	unsigned long pwm;
	int ret;

	if (kstrtoul(buf, 10, &pwm) \|\| pwm > MAX_PWM)
	return -EINVAL;

	ret = __set_pwm(ctx, pwm);
	if (ret)
	return ret;

	pwm_fan_update_state(ctx, pwm);
	return count;
	}

	static ssize_t show_pwm(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", ctx->pwm_value);
	}


	static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO \| S_IWUSR, show_pwm, set_pwm, 0);

	static struct attribute *pwm_fan_attrs[] = {
	&sensor_dev_attr_pwm1.dev_attr.attr,
	NULL,
	};

	ATTRIBUTE_GROUPS(pwm_fan);

	/* thermal cooling device callbacks */
	static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
	unsigned long *state)
	{
	struct pwm_fan_ctx *ctx = cdev->devdata;

	if (!ctx)
	return -EINVAL;

	*state = ctx->pwm_fan_max_state;

	return 0;
	}

	static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
	unsigned long *state)
	{
	struct pwm_fan_ctx *ctx = cdev->devdata;

	if (!ctx)
	return -EINVAL;

	*state = ctx->pwm_fan_state;

	return 0;
	}

	static int
	pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	{
	struct pwm_fan_ctx *ctx = cdev->devdata;
	int ret;

	if (!ctx \|\| (state > ctx->pwm_fan_max_state))
	return -EINVAL;

	if (state == ctx->pwm_fan_state)
	return 0;

	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
	if (ret) {
	dev_err(&cdev->device, "Cannot set pwm!\n");
	return ret;
	}

	ctx->pwm_fan_state = state;

	return ret;
	}

	static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	.get_max_state = pwm_fan_get_max_state,
	.get_cur_state = pwm_fan_get_cur_state,
	.set_cur_state = pwm_fan_set_cur_state,
	};

	static int pwm_fan_of_get_cooling_data(struct device *dev,
	struct pwm_fan_ctx *ctx)
	{
	struct device_node *np = dev->of_node;
	int num, i, ret;

	if (!of_find_property(np, "cooling-levels", NULL))
	return 0;

	ret = of_property_count_u32_elems(np, "cooling-levels");
	if (ret <= 0) {
	dev_err(dev, "Wrong data!\n");
	return ret ? : -EINVAL;
	}

	num = ret;
	ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
	GFP_KERNEL);
	if (!ctx->pwm_fan_cooling_levels)
	return -ENOMEM;

	ret = of_property_read_u32_array(np, "cooling-levels",
	ctx->pwm_fan_cooling_levels, num);
	if (ret) {
	dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
	return ret;
	}

	for (i = 0; i < num; i++) {
	if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
	dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
	ctx->pwm_fan_cooling_levels[i], MAX_PWM);
	return -EINVAL;
	}
	}

	ctx->pwm_fan_max_state = num - 1;

	return 0;
	}

	static int pwm_fan_probe(struct platform_device *pdev)
	{
	struct thermal_cooling_device *cdev;
	struct pwm_fan_ctx *ctx;
	struct pwm_args pargs;
	struct device *hwmon;
	int duty_cycle;
	int ret;

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

	mutex_init(&ctx->lock);

	ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
	if (IS_ERR(ctx->pwm)) {
	dev_err(&pdev->dev, "Could not get PWM\n");
	return PTR_ERR(ctx->pwm);
	}

	platform_set_drvdata(pdev, ctx);

	/*
	* FIXME: pwm_apply_args() should be removed when switching to the
	* atomic PWM API.
	*/
	pwm_apply_args(ctx->pwm);

	/* Set duty cycle to maximum allowed */
	pwm_get_args(ctx->pwm, &pargs);

	duty_cycle = pargs.period - 1;
	ctx->pwm_value = MAX_PWM;

	ret = pwm_config(ctx->pwm, duty_cycle, pargs.period);
	if (ret) {
	dev_err(&pdev->dev, "Failed to configure PWM\n");
	return ret;
	}

	/* Enbale PWM output */
	ret = pwm_enable(ctx->pwm);
	if (ret) {
	dev_err(&pdev->dev, "Failed to enable PWM\n");
	return ret;
	}

	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
	ctx, pwm_fan_groups);
	if (IS_ERR(hwmon)) {
	dev_err(&pdev->dev, "Failed to register hwmon device\n");
	pwm_disable(ctx->pwm);
	return PTR_ERR(hwmon);
	}

	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
	if (ret)
	return ret;

	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
	if (IS_ENABLED(CONFIG_THERMAL)) {
	cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
	"pwm-fan", ctx,
	&pwm_fan_cooling_ops);
	if (IS_ERR(cdev)) {
	dev_err(&pdev->dev,
	"Failed to register pwm-fan as cooling device");
	pwm_disable(ctx->pwm);
	return PTR_ERR(cdev);
	}
	ctx->cdev = cdev;
	thermal_cdev_update(cdev);
	}

	return 0;
	}

	static int pwm_fan_remove(struct platform_device *pdev)
	{
	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);

	thermal_cooling_device_unregister(ctx->cdev);
	if (ctx->pwm_value)
	pwm_disable(ctx->pwm);
	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int pwm_fan_suspend(struct device *dev)
	{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	struct pwm_args args;
	int ret;

	pwm_get_args(ctx->pwm, &args);

	if (ctx->pwm_value) {
	ret = pwm_config(ctx->pwm, 0, args.period);
	if (ret < 0)
	return ret;

	pwm_disable(ctx->pwm);
	}

	return 0;
	}

	static int pwm_fan_resume(struct device *dev)
	{
	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	struct pwm_args pargs;
	unsigned long duty;
	int ret;

	if (ctx->pwm_value == 0)
	return 0;

	pwm_get_args(ctx->pwm, &pargs);
	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
	ret = pwm_config(ctx->pwm, duty, pargs.period);
	if (ret)
	return ret;
	return pwm_enable(ctx->pwm);
	}
	#endif

	static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);

	static const struct of_device_id of_pwm_fan_match[] = {
	{ .compatible = "pwm-fan", },
	{},
	};
	MODULE_DEVICE_TABLE(of, of_pwm_fan_match);

	static struct platform_driver pwm_fan_driver = {
	.probe = pwm_fan_probe,
	.remove = pwm_fan_remove,
	.driver = {
	.name = "pwm-fan",
	.pm = &pwm_fan_pm,
	.of_match_table = of_pwm_fan_match,
	},
	};

	module_platform_driver(pwm_fan_driver);

	MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
	MODULE_ALIAS("platform:pwm-fan");
	MODULE_DESCRIPTION("PWM FAN driver");
	MODULE_LICENSE("GPL");