[mirror_ubuntu-bionic-kernel.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 period;
	int ret = 0;
	struct pwm_state state = { };

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

	pwm_init_state(ctx->pwm, &state);
	period = ctx->pwm->args.period;
	state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
	state.enabled = pwm ? true : false;

	ret = pwm_apply_state(ctx->pwm, &state);
	if (!ret)
		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 ret;
	struct pwm_state state = { };

	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);

	ctx->pwm_value = MAX_PWM;

	/* Set duty cycle to maximum allowed and enable PWM output */
	pwm_init_state(ctx->pwm, &state);
	state.duty_cycle = ctx->pwm->args.period - 1;
	state.enabled = true;

	ret = pwm_apply_state(ctx->pwm, &state);
	if (ret) {
		dev_err(&pdev->dev, "Failed to configure 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");
		ret = PTR_ERR(hwmon);
		goto err_pwm_disable;
	}

	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");
			ret = PTR_ERR(cdev);
			goto err_pwm_disable;
		}
		ctx->cdev = cdev;
		thermal_cdev_update(cdev);
	}

	return 0;

err_pwm_disable:
	state.enabled = false;
	pwm_apply_state(ctx->pwm, &state);

	return ret;
}

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);
	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");
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	{
677252a1	43	unsigned long period;
cb85ca33	44	int ret = 0;
677252a1	45	struct pwm_state state = { };
2289711c	46
d82d5776	47	mutex_lock(&ctx->lock);
d82d5776	48	if (ctx->pwm_value == pwm)
cb85ca33	49	goto exit_set_pwm_err;
d82d5776	50
677252a1 BZ	51	pwm_init_state(ctx->pwm, &state);
	52	period = ctx->pwm->args.period;
	53	state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
	54	state.enabled = pwm ? true : false;
f354169e	55
677252a1 BZ	56	ret = pwm_apply_state(ctx->pwm, &state);
	57	if (!ret)
	58	ctx->pwm_value = pwm;
d82d5776 KD	59	exit_set_pwm_err:
	60	mutex_unlock(&ctx->lock);
	61	return ret;
	62	}
	63
b6bddec0 LM	64	static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
	65	{
	66	int i;
	67
	68	for (i = 0; i < ctx->pwm_fan_max_state; ++i)
	69	if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
	70	break;
	71
	72	ctx->pwm_fan_state = i;
	73	}
	74
cb85ca33 LM	75	static ssize_t set_pwm(struct device dev, struct device_attribute attr,
	76	const char *buf, size_t count)
	77	{
	78	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	79	unsigned long pwm;
	80	int ret;
	81
	82	if (kstrtoul(buf, 10, &pwm) \|\| pwm > MAX_PWM)
	83	return -EINVAL;
	84
	85	ret = __set_pwm(ctx, pwm);
	86	if (ret)
	87	return ret;
	88
b6bddec0	89	pwm_fan_update_state(ctx, pwm);
cb85ca33 LM	90	return count;
	91	}
	92
d82d5776 KD	93	static ssize_t show_pwm(struct device *dev,
	94	struct device_attribute attr, char buf)
	95	{
	96	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	97
	98	return sprintf(buf, "%u\n", ctx->pwm_value);
	99	}
	100
	101
	102	static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO \| S_IWUSR, show_pwm, set_pwm, 0);
	103
	104	static struct attribute *pwm_fan_attrs[] = {
	105	&sensor_dev_attr_pwm1.dev_attr.attr,
	106	NULL,
	107	};
	108
	109	ATTRIBUTE_GROUPS(pwm_fan);
	110
b6bddec0 LM	111	/* thermal cooling device callbacks */
	112	static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
	113	unsigned long *state)
	114	{
	115	struct pwm_fan_ctx *ctx = cdev->devdata;
	116
	117	if (!ctx)
	118	return -EINVAL;
	119
	120	*state = ctx->pwm_fan_max_state;
	121
	122	return 0;
	123	}
	124
	125	static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
	126	unsigned long *state)
	127	{
	128	struct pwm_fan_ctx *ctx = cdev->devdata;
	129
	130	if (!ctx)
	131	return -EINVAL;
	132
	133	*state = ctx->pwm_fan_state;
	134
	135	return 0;
	136	}
	137
	138	static int
	139	pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
	140	{
	141	struct pwm_fan_ctx *ctx = cdev->devdata;
	142	int ret;
	143
	144	if (!ctx \|\| (state > ctx->pwm_fan_max_state))
	145	return -EINVAL;
	146
	147	if (state == ctx->pwm_fan_state)
	148	return 0;
	149
	150	ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
	151	if (ret) {
	152	dev_err(&cdev->device, "Cannot set pwm!\n");
	153	return ret;
	154	}
	155
	156	ctx->pwm_fan_state = state;
	157
	158	return ret;
	159	}
	160
	161	static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
	162	.get_max_state = pwm_fan_get_max_state,
	163	.get_cur_state = pwm_fan_get_cur_state,
	164	.set_cur_state = pwm_fan_set_cur_state,
	165	};
	166
de52b049 GR	167	static int pwm_fan_of_get_cooling_data(struct device *dev,
de52b049 GR	168	struct pwm_fan_ctx *ctx)
2e5219c7 LM	169	{
	170	struct device_node *np = dev->of_node;
	171	int num, i, ret;
	172
	173	if (!of_find_property(np, "cooling-levels", NULL))
	174	return 0;
	175
	176	ret = of_property_count_u32_elems(np, "cooling-levels");
	177	if (ret <= 0) {
	178	dev_err(dev, "Wrong data!\n");
	179	return ret ? : -EINVAL;
	180	}
	181
	182	num = ret;
	183	ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
	184	GFP_KERNEL);
	185	if (!ctx->pwm_fan_cooling_levels)
	186	return -ENOMEM;
	187
	188	ret = of_property_read_u32_array(np, "cooling-levels",
	189	ctx->pwm_fan_cooling_levels, num);
	190	if (ret) {
	191	dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
	192	return ret;
	193	}
	194
	195	for (i = 0; i < num; i++) {
	196	if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
	197	dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
	198	ctx->pwm_fan_cooling_levels[i], MAX_PWM);
	199	return -EINVAL;
	200	}
	201	}
	202
	203	ctx->pwm_fan_max_state = num - 1;
	204
	205	return 0;
	206	}
	207
d82d5776 KD	208	static int pwm_fan_probe(struct platform_device *pdev)
d82d5776 KD	209	{
b6bddec0	210	struct thermal_cooling_device *cdev;
d82d5776	211	struct pwm_fan_ctx *ctx;
b6bddec0	212	struct device *hwmon;
d82d5776	213	int ret;
677252a1	214	struct pwm_state state = { };
d82d5776 KD	215
	216	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
	217	if (!ctx)
	218	return -ENOMEM;
	219
	220	mutex_init(&ctx->lock);
	221
	222	ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
	223	if (IS_ERR(ctx->pwm)) {
	224	dev_err(&pdev->dev, "Could not get PWM\n");
	225	return PTR_ERR(ctx->pwm);
	226	}
	227
d82d5776 KD	228	platform_set_drvdata(pdev, ctx);
d82d5776 KD	229
d82d5776 KD	230	ctx->pwm_value = MAX_PWM;
d82d5776 KD	231
677252a1 BZ	232	/* Set duty cycle to maximum allowed and enable PWM output */
	233	pwm_init_state(ctx->pwm, &state);
	234	state.duty_cycle = ctx->pwm->args.period - 1;
	235	state.enabled = true;
d82d5776	236
677252a1	237	ret = pwm_apply_state(ctx->pwm, &state);
d82d5776	238	if (ret) {
677252a1	239	dev_err(&pdev->dev, "Failed to configure PWM\n");
d82d5776 KD	240	return ret;
	241	}
	242
	243	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
	244	ctx, pwm_fan_groups);
	245	if (IS_ERR(hwmon)) {
	246	dev_err(&pdev->dev, "Failed to register hwmon device\n");
677252a1 BZ	247	ret = PTR_ERR(hwmon);
677252a1 BZ	248	goto err_pwm_disable;
d82d5776	249	}
2e5219c7 LM	250
	251	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
	252	if (ret)
	253	return ret;
	254
b6bddec0 LM	255	ctx->pwm_fan_state = ctx->pwm_fan_max_state;
	256	if (IS_ENABLED(CONFIG_THERMAL)) {
	257	cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
	258	"pwm-fan", ctx,
	259	&pwm_fan_cooling_ops);
	260	if (IS_ERR(cdev)) {
	261	dev_err(&pdev->dev,
	262	"Failed to register pwm-fan as cooling device");
677252a1 BZ	263	ret = PTR_ERR(cdev);
677252a1 BZ	264	goto err_pwm_disable;
b6bddec0 LM	265	}
	266	ctx->cdev = cdev;
	267	thermal_cdev_update(cdev);
	268	}
	269
d82d5776	270	return 0;
677252a1 BZ	271
	272	err_pwm_disable:
	273	state.enabled = false;
	274	pwm_apply_state(ctx->pwm, &state);
	275
	276	return ret;
d82d5776 KD	277	}
	278
	279	static int pwm_fan_remove(struct platform_device *pdev)
	280	{
	281	struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
	282
b6bddec0	283	thermal_cooling_device_unregister(ctx->cdev);
d82d5776 KD	284	if (ctx->pwm_value)
	285	pwm_disable(ctx->pwm);
	286	return 0;
	287	}
	288
	289	#ifdef CONFIG_PM_SLEEP
	290	static int pwm_fan_suspend(struct device *dev)
	291	{
	292	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
	293
	294	if (ctx->pwm_value)
	295	pwm_disable(ctx->pwm);
	296	return 0;
	297	}
	298
	299	static int pwm_fan_resume(struct device *dev)
	300	{
	301	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
2289711c	302	struct pwm_args pargs;
48b9d5b4 KD	303	unsigned long duty;
48b9d5b4 KD	304	int ret;
d82d5776	305
48b9d5b4 KD	306	if (ctx->pwm_value == 0)
	307	return 0;
	308
2289711c BB	309	pwm_get_args(ctx->pwm, &pargs);
	310	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
	311	ret = pwm_config(ctx->pwm, duty, pargs.period);
48b9d5b4 KD	312	if (ret)
	313	return ret;
	314	return pwm_enable(ctx->pwm);
d82d5776 KD	315	}
	316	#endif
	317
	318	static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
	319
d720acac	320	static const struct of_device_id of_pwm_fan_match[] = {
d82d5776 KD	321	{ .compatible = "pwm-fan", },
	322	{},
	323	};
f491e70c	324	MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
d82d5776 KD	325
	326	static struct platform_driver pwm_fan_driver = {
	327	.probe = pwm_fan_probe,
	328	.remove = pwm_fan_remove,
	329	.driver = {
	330	.name = "pwm-fan",
	331	.pm = &pwm_fan_pm,
	332	.of_match_table = of_pwm_fan_match,
	333	},
	334	};
	335
	336	module_platform_driver(pwm_fan_driver);
	337
	338	MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
	339	MODULE_ALIAS("platform:pwm-fan");
	340	MODULE_DESCRIPTION("PWM FAN driver");
	341	MODULE_LICENSE("GPL");