[linux-2.6-block.git] / drivers / hwmon / pwm-fan.c

/*
 * 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)
{
	unsigned long duty;
	int ret = 0;

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

	duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
	ret = pwm_config(ctx->pwm, duty, ctx->pwm->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 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);

	/* Set duty cycle to maximum allowed */
	duty_cycle = ctx->pwm->period - 1;
	ctx->pwm_value = MAX_PWM;

	ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->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);

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

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

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

	duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
	ret = pwm_config(ctx->pwm, duty, ctx->pwm->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");
Commit	Line	Data
d82d5776 KD	1	/*
	2	* pwm-fan.c - Hwmon driver for fans connected to PWM lines.
	3	*
	4	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
	5	*
	6	* Author: Kamil Debski <k.debski@samsung.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*/
	18
	19	#include <linux/hwmon.h>
	20	#include <linux/hwmon-sysfs.h>
	21	#include <linux/module.h>
	22	#include <linux/mutex.h>
	23	#include <linux/of.h>
	24	#include <linux/platform_device.h>
	25	#include <linux/pwm.h>
	26	#include <linux/sysfs.h>
b6bddec0	27	#include <linux/thermal.h>
d82d5776 KD	28
	29	#define MAX_PWM 255
	30
	31	struct pwm_fan_ctx {
	32	struct mutex lock;
	33	struct pwm_device *pwm;
2e5219c7 LM	34	unsigned int pwm_value;
	35	unsigned int pwm_fan_state;
	36	unsigned int pwm_fan_max_state;
	37	unsigned int *pwm_fan_cooling_levels;
b6bddec0	38	struct thermal_cooling_device *cdev;
d82d5776 KD	39	};
d82d5776 KD	40
cb85ca33	41	static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
d82d5776	42	{
cb85ca33 LM	43	unsigned long duty;
cb85ca33 LM	44	int ret = 0;
d82d5776 KD	45
d82d5776 KD	46	mutex_lock(&ctx->lock);
d82d5776	47	if (ctx->pwm_value == pwm)
cb85ca33	48	goto exit_set_pwm_err;
d82d5776	49
d82d5776 KD	50	duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
	51	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
	52	if (ret)
	53	goto exit_set_pwm_err;
	54
f354169e AM	55	if (pwm == 0)
	56	pwm_disable(ctx->pwm);
	57
d82d5776 KD	58	if (ctx->pwm_value == 0) {
	59	ret = pwm_enable(ctx->pwm);
	60	if (ret)
	61	goto exit_set_pwm_err;
	62	}
	63
d82d5776	64	ctx->pwm_value = pwm;
d82d5776 KD	65	exit_set_pwm_err:
	66	mutex_unlock(&ctx->lock);
	67	return ret;
	68	}
	69
b6bddec0 LM	70	static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
	71	{
	72	int i;
	73
	74	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
	75	if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
	76	break;
	77
	78	ctx->pwm_fan_state = i;
	79	}
	80
cb85ca33 LM	81	static ssize_t set_pwm(struct device dev, struct device_attribute attr,
	82	const char *buf, size_t count)
	83	{
	84	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	85	unsigned long pwm;
	86	int ret;
	87
	88	if (kstrtoul(buf, 10, &pwm) \|\| pwm > MAX_PWM)
	89	return -EINVAL;
	90
	91	ret = __set_pwm(ctx, pwm);
	92	if (ret)
	93	return ret;
	94
b6bddec0	95	pwm_fan_update_state(ctx, pwm);
cb85ca33 LM	96	return count;
	97	}
	98
d82d5776 KD	99	static ssize_t show_pwm(struct device *dev,
	100	struct device_attribute attr, char buf)
	101	{
	102	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	103
	104	return sprintf(buf, "%u\n", ctx->pwm_value);
	105	}
	106
	107
	108	static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO \| S_IWUSR, show_pwm, set_pwm, 0);
	109
	110	static struct attribute *pwm_fan_attrs[] = {
	111	&sensor_dev_attr_pwm1.dev_attr.attr,
	112	NULL,
	113	};
	114
	115	ATTRIBUTE_GROUPS(pwm_fan);
	116
b6bddec0 LM	117	/* thermal cooling device callbacks */
	118	static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
	119	unsigned long *state)
	120	{
	121	struct pwm_fan_ctx *ctx = cdev->devdata;
	122
	123	if (!ctx)
	124	return -EINVAL;
	125
	126	*state = ctx->pwm_fan_max_state;
	127
	128	return 0;
	129	}
	130
	131	static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
	132	unsigned long *state)
	133	{
	134	struct pwm_fan_ctx *ctx = cdev->devdata;
	135
	136	if (!ctx)
	137	return -EINVAL;
	138
	139	*state = ctx->pwm_fan_state;
	140
	141	return 0;
	142	}
	143
	144	static int
	145	pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	146	{
	147	struct pwm_fan_ctx *ctx = cdev->devdata;
	148	int ret;
	149
	150	if (!ctx \|\| (state > ctx->pwm_fan_max_state))
	151	return -EINVAL;
	152
	153	if (state == ctx->pwm_fan_state)
	154	return 0;
	155
	156	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
	157	if (ret) {
	158	dev_err(&cdev->device, "Cannot set pwm!\n");
	159	return ret;
	160	}
	161
	162	ctx->pwm_fan_state = state;
	163
	164	return ret;
	165	}
	166
	167	static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	168	.get_max_state = pwm_fan_get_max_state,
	169	.get_cur_state = pwm_fan_get_cur_state,
	170	.set_cur_state = pwm_fan_set_cur_state,
	171	};
	172
de52b049 GR	173	static int pwm_fan_of_get_cooling_data(struct device *dev,
de52b049 GR	174	struct pwm_fan_ctx *ctx)
2e5219c7 LM	175	{
	176	struct device_node *np = dev->of_node;
	177	int num, i, ret;
	178
	179	if (!of_find_property(np, "cooling-levels", NULL))
	180	return 0;
	181
	182	ret = of_property_count_u32_elems(np, "cooling-levels");
	183	if (ret <= 0) {
	184	dev_err(dev, "Wrong data!\n");
	185	return ret ? : -EINVAL;
	186	}
	187
	188	num = ret;
	189	ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
	190	GFP_KERNEL);
	191	if (!ctx->pwm_fan_cooling_levels)
	192	return -ENOMEM;
	193
	194	ret = of_property_read_u32_array(np, "cooling-levels",
	195	ctx->pwm_fan_cooling_levels, num);
	196	if (ret) {
	197	dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
	198	return ret;
	199	}
	200
	201	for (i = 0; i < num; i++) {
	202	if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
	203	dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
	204	ctx->pwm_fan_cooling_levels[i], MAX_PWM);
	205	return -EINVAL;
	206	}
	207	}
	208
	209	ctx->pwm_fan_max_state = num - 1;
	210
	211	return 0;
	212	}
	213
d82d5776 KD	214	static int pwm_fan_probe(struct platform_device *pdev)
d82d5776 KD	215	{
b6bddec0	216	struct thermal_cooling_device *cdev;
d82d5776	217	struct pwm_fan_ctx *ctx;
b6bddec0	218	struct device *hwmon;
d82d5776 KD	219	int duty_cycle;
	220	int ret;
	221
	222	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
	223	if (!ctx)
	224	return -ENOMEM;
	225
	226	mutex_init(&ctx->lock);
	227
	228	ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
	229	if (IS_ERR(ctx->pwm)) {
	230	dev_err(&pdev->dev, "Could not get PWM\n");
	231	return PTR_ERR(ctx->pwm);
	232	}
	233
d82d5776 KD	234	platform_set_drvdata(pdev, ctx);
	235
	236	/* Set duty cycle to maximum allowed */
	237	duty_cycle = ctx->pwm->period - 1;
	238	ctx->pwm_value = MAX_PWM;
	239
	240	ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period);
	241	if (ret) {
	242	dev_err(&pdev->dev, "Failed to configure PWM\n");
	243	return ret;
	244	}
	245
	246	/* Enbale PWM output */
	247	ret = pwm_enable(ctx->pwm);
	248	if (ret) {
	249	dev_err(&pdev->dev, "Failed to enable PWM\n");
	250	return ret;
	251	}
	252
	253	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
	254	ctx, pwm_fan_groups);
	255	if (IS_ERR(hwmon)) {
	256	dev_err(&pdev->dev, "Failed to register hwmon device\n");
	257	pwm_disable(ctx->pwm);
	258	return PTR_ERR(hwmon);
	259	}
2e5219c7 LM	260
	261	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
	262	if (ret)
	263	return ret;
	264
b6bddec0 LM	265	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
	266	if (IS_ENABLED(CONFIG_THERMAL)) {
	267	cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
	268	"pwm-fan", ctx,
	269	&pwm_fan_cooling_ops);
	270	if (IS_ERR(cdev)) {
	271	dev_err(&pdev->dev,
	272	"Failed to register pwm-fan as cooling device");
	273	pwm_disable(ctx->pwm);
	274	return PTR_ERR(cdev);
	275	}
	276	ctx->cdev = cdev;
	277	thermal_cdev_update(cdev);
	278	}
	279
d82d5776 KD	280	return 0;
	281	}
	282
	283	static int pwm_fan_remove(struct platform_device *pdev)
	284	{
	285	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
	286
b6bddec0	287	thermal_cooling_device_unregister(ctx->cdev);
d82d5776 KD	288	if (ctx->pwm_value)
	289	pwm_disable(ctx->pwm);
	290	return 0;
	291	}
	292
	293	#ifdef CONFIG_PM_SLEEP
	294	static int pwm_fan_suspend(struct device *dev)
	295	{
	296	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	297
	298	if (ctx->pwm_value)
	299	pwm_disable(ctx->pwm);
	300	return 0;
	301	}
	302
	303	static int pwm_fan_resume(struct device *dev)
	304	{
	305	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
48b9d5b4 KD	306	unsigned long duty;
48b9d5b4 KD	307	int ret;
d82d5776	308
48b9d5b4 KD	309	if (ctx->pwm_value == 0)
	310	return 0;
	311
	312	duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
	313	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
	314	if (ret)
	315	return ret;
	316	return pwm_enable(ctx->pwm);
d82d5776 KD	317	}
	318	#endif
	319
	320	static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
	321
d720acac	322	static const struct of_device_id of_pwm_fan_match[] = {
d82d5776 KD	323	{ .compatible = "pwm-fan", },
	324	{},
	325	};
f491e70c	326	MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
d82d5776 KD	327
	328	static struct platform_driver pwm_fan_driver = {
	329	.probe = pwm_fan_probe,
	330	.remove = pwm_fan_remove,
	331	.driver = {
	332	.name = "pwm-fan",
	333	.pm = &pwm_fan_pm,
	334	.of_match_table = of_pwm_fan_match,
	335	},
	336	};
	337
	338	module_platform_driver(pwm_fan_driver);
	339
	340	MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
	341	MODULE_ALIAS("platform:pwm-fan");
	342	MODULE_DESCRIPTION("PWM FAN driver");
	343	MODULE_LICENSE("GPL");