[linux.git] / drivers / pwm / sysfs.c

/*
 * A simple sysfs interface for the generic PWM framework
 *
 * Copyright (C) 2013 H Hartley Sweeten <[email protected]>
 *
 * Based on previous work by Lars Poeschel <[email protected]>
 *
 * 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, 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/device.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/kdev_t.h>
#include <linux/pwm.h>

struct pwm_export {
	struct device child;
	struct pwm_device *pwm;
};

static struct pwm_export *child_to_pwm_export(struct device *child)
{
	return container_of(child, struct pwm_export, child);
}

static struct pwm_device *child_to_pwm_device(struct device *child)
{
	struct pwm_export *export = child_to_pwm_export(child);

	return export->pwm;
}

static ssize_t pwm_period_show(struct device *child,
			       struct device_attribute *attr,
			       char *buf)
{
	const struct pwm_device *pwm = child_to_pwm_device(child);

	return sprintf(buf, "%u\n", pwm->period);
}

static ssize_t pwm_period_store(struct device *child,
				struct device_attribute *attr,
				const char *buf, size_t size)
{
	struct pwm_device *pwm = child_to_pwm_device(child);
	unsigned int val;
	int ret;

	ret = kstrtouint(buf, 0, &val);
	if (ret)
		return ret;

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

	return ret ? : size;
}

static ssize_t pwm_duty_cycle_show(struct device *child,
				   struct device_attribute *attr,
				   char *buf)
{
	const struct pwm_device *pwm = child_to_pwm_device(child);

	return sprintf(buf, "%u\n", pwm->duty_cycle);
}

static ssize_t pwm_duty_cycle_store(struct device *child,
				    struct device_attribute *attr,
				    const char *buf, size_t size)
{
	struct pwm_device *pwm = child_to_pwm_device(child);
	unsigned int val;
	int ret;

	ret = kstrtouint(buf, 0, &val);
	if (ret)
		return ret;

	ret = pwm_config(pwm, val, pwm->period);

	return ret ? : size;
}

static ssize_t pwm_enable_show(struct device *child,
			       struct device_attribute *attr,
			       char *buf)
{
	const struct pwm_device *pwm = child_to_pwm_device(child);
	int enabled = test_bit(PWMF_ENABLED, &pwm->flags);

	return sprintf(buf, "%d\n", enabled);
}

static ssize_t pwm_enable_store(struct device *child,
				struct device_attribute *attr,
				const char *buf, size_t size)
{
	struct pwm_device *pwm = child_to_pwm_device(child);
	int val, ret;

	ret = kstrtoint(buf, 0, &val);
	if (ret)
		return ret;

	switch (val) {
	case 0:
		pwm_disable(pwm);
		break;
	case 1:
		ret = pwm_enable(pwm);
		break;
	default:
		ret = -EINVAL;
		break;
	}

	return ret ? : size;
}

static ssize_t pwm_polarity_show(struct device *child,
				 struct device_attribute *attr,
				 char *buf)
{
	const struct pwm_device *pwm = child_to_pwm_device(child);

	return sprintf(buf, "%s\n", pwm->polarity ? "inversed" : "normal");
}

static ssize_t pwm_polarity_store(struct device *child,
				  struct device_attribute *attr,
				  const char *buf, size_t size)
{
	struct pwm_device *pwm = child_to_pwm_device(child);
	enum pwm_polarity polarity;
	int ret;

	if (sysfs_streq(buf, "normal"))
		polarity = PWM_POLARITY_NORMAL;
	else if (sysfs_streq(buf, "inversed"))
		polarity = PWM_POLARITY_INVERSED;
	else
		return -EINVAL;

	ret = pwm_set_polarity(pwm, polarity);

	return ret ? : size;
}

static DEVICE_ATTR(period, 0644, pwm_period_show, pwm_period_store);
static DEVICE_ATTR(duty_cycle, 0644, pwm_duty_cycle_show, pwm_duty_cycle_store);
static DEVICE_ATTR(enable, 0644, pwm_enable_show, pwm_enable_store);
static DEVICE_ATTR(polarity, 0644, pwm_polarity_show, pwm_polarity_store);

static struct attribute *pwm_attrs[] = {
	&dev_attr_period.attr,
	&dev_attr_duty_cycle.attr,
	&dev_attr_enable.attr,
	&dev_attr_polarity.attr,
	NULL
};
ATTRIBUTE_GROUPS(pwm);

static void pwm_export_release(struct device *child)
{
	struct pwm_export *export = child_to_pwm_export(child);

	kfree(export);
}

static int pwm_export_child(struct device *parent, struct pwm_device *pwm)
{
	struct pwm_export *export;
	int ret;

	if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
		return -EBUSY;

	export = kzalloc(sizeof(*export), GFP_KERNEL);
	if (!export) {
		clear_bit(PWMF_EXPORTED, &pwm->flags);
		return -ENOMEM;
	}

	export->pwm = pwm;

	export->child.release = pwm_export_release;
	export->child.parent = parent;
	export->child.devt = MKDEV(0, 0);
	export->child.groups = pwm_groups;
	dev_set_name(&export->child, "pwm%u", pwm->hwpwm);

	ret = device_register(&export->child);
	if (ret) {
		clear_bit(PWMF_EXPORTED, &pwm->flags);
		kfree(export);
		return ret;
	}

	return 0;
}

static int pwm_unexport_match(struct device *child, void *data)
{
	return child_to_pwm_device(child) == data;
}

static int pwm_unexport_child(struct device *parent, struct pwm_device *pwm)
{
	struct device *child;

	if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
		return -ENODEV;

	child = device_find_child(parent, pwm, pwm_unexport_match);
	if (!child)
		return -ENODEV;

	/* for device_find_child() */
	put_device(child);
	device_unregister(child);
	pwm_put(pwm);

	return 0;
}

static ssize_t pwm_export_store(struct device *parent,
				struct device_attribute *attr,
				const char *buf, size_t len)
{
	struct pwm_chip *chip = dev_get_drvdata(parent);
	struct pwm_device *pwm;
	unsigned int hwpwm;
	int ret;

	ret = kstrtouint(buf, 0, &hwpwm);
	if (ret < 0)
		return ret;

	if (hwpwm >= chip->npwm)
		return -ENODEV;

	pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
	if (IS_ERR(pwm))
		return PTR_ERR(pwm);

	ret = pwm_export_child(parent, pwm);
	if (ret < 0)
		pwm_put(pwm);

	return ret ? : len;
}
static DEVICE_ATTR(export, 0200, NULL, pwm_export_store);

static ssize_t pwm_unexport_store(struct device *parent,
				  struct device_attribute *attr,
				  const char *buf, size_t len)
{
	struct pwm_chip *chip = dev_get_drvdata(parent);
	unsigned int hwpwm;
	int ret;

	ret = kstrtouint(buf, 0, &hwpwm);
	if (ret < 0)
		return ret;

	if (hwpwm >= chip->npwm)
		return -ENODEV;

	ret = pwm_unexport_child(parent, &chip->pwms[hwpwm]);

	return ret ? : len;
}
static DEVICE_ATTR(unexport, 0200, NULL, pwm_unexport_store);

static ssize_t npwm_show(struct device *parent, struct device_attribute *attr,
			 char *buf)
{
	const struct pwm_chip *chip = dev_get_drvdata(parent);

	return sprintf(buf, "%u\n", chip->npwm);
}
static DEVICE_ATTR_RO(npwm);

static struct attribute *pwm_chip_attrs[] = {
	&dev_attr_export.attr,
	&dev_attr_unexport.attr,
	&dev_attr_npwm.attr,
	NULL,
};
ATTRIBUTE_GROUPS(pwm_chip);

static struct class pwm_class = {
	.name		= "pwm",
	.owner		= THIS_MODULE,
	.dev_groups	= pwm_chip_groups,
};

static int pwmchip_sysfs_match(struct device *parent, const void *data)
{
	return dev_get_drvdata(parent) == data;
}

void pwmchip_sysfs_export(struct pwm_chip *chip)
{
	struct device *parent;

	/*
	 * If device_create() fails the pwm_chip is still usable by
	 * the kernel its just not exported.
	 */
	parent = device_create(&pwm_class, chip->dev, MKDEV(0, 0), chip,
			       "pwmchip%d", chip->base);
	if (IS_ERR(parent)) {
		dev_warn(chip->dev,
			 "device_create failed for pwm_chip sysfs export\n");
	}
}

void pwmchip_sysfs_unexport(struct pwm_chip *chip)
{
	struct device *parent;

	parent = class_find_device(&pwm_class, NULL, chip,
				   pwmchip_sysfs_match);
	if (parent) {
		/* for class_find_device() */
		put_device(parent);
		device_unregister(parent);
	}
}

static int __init pwm_sysfs_init(void)
{
	return class_register(&pwm_class);
}
subsys_initcall(pwm_sysfs_init);
Commit	Line	Data
76abbdde HS	1	/*
	2	* A simple sysfs interface for the generic PWM framework
	3	*
	4	* Copyright (C) 2013 H Hartley Sweeten <[email protected]>
	5	*
	6	* Based on previous work by Lars Poeschel <[email protected]>
	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, or (at your option)
	11	* 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/device.h>
	20	#include <linux/mutex.h>
	21	#include <linux/err.h>
	22	#include <linux/slab.h>
	23	#include <linux/kdev_t.h>
	24	#include <linux/pwm.h>
	25
	26	struct pwm_export {
	27	struct device child;
	28	struct pwm_device *pwm;
	29	};
	30
	31	static struct pwm_export child_to_pwm_export(struct device child)
	32	{
	33	return container_of(child, struct pwm_export, child);
	34	}
	35
	36	static struct pwm_device child_to_pwm_device(struct device child)
	37	{
	38	struct pwm_export *export = child_to_pwm_export(child);
	39
	40	return export->pwm;
	41	}
	42
	43	static ssize_t pwm_period_show(struct device *child,
	44	struct device_attribute *attr,
	45	char *buf)
	46	{
	47	const struct pwm_device *pwm = child_to_pwm_device(child);
	48
	49	return sprintf(buf, "%u\n", pwm->period);
	50	}
	51
	52	static ssize_t pwm_period_store(struct device *child,
	53	struct device_attribute *attr,
	54	const char *buf, size_t size)
	55	{
	56	struct pwm_device *pwm = child_to_pwm_device(child);
	57	unsigned int val;
	58	int ret;
	59
	60	ret = kstrtouint(buf, 0, &val);
	61	if (ret)
	62	return ret;
	63
	64	ret = pwm_config(pwm, pwm->duty_cycle, val);
65
66	return ret ? : size;
67	}
68
69	static ssize_t pwm_duty_cycle_show(struct device *child,
70	struct device_attribute *attr,
71	char *buf)
72	{
73	const struct pwm_device *pwm = child_to_pwm_device(child);
74
75	return sprintf(buf, "%u\n", pwm->duty_cycle);
76	}
77
78	static ssize_t pwm_duty_cycle_store(struct device *child,
79	struct device_attribute *attr,
80	const char *buf, size_t size)
81	{
82	struct pwm_device *pwm = child_to_pwm_device(child);
83	unsigned int val;
84	int ret;
85
86	ret = kstrtouint(buf, 0, &val);
87	if (ret)
88	return ret;
89
90	ret = pwm_config(pwm, val, pwm->period);
91
92	return ret ? : size;
93	}
94
95	static ssize_t pwm_enable_show(struct device *child,
96	struct device_attribute *attr,
97	char *buf)
98	{
99	const struct pwm_device *pwm = child_to_pwm_device(child);
100	int enabled = test_bit(PWMF_ENABLED, &pwm->flags);
101
102	return sprintf(buf, "%d\n", enabled);
103	}
104
105	static ssize_t pwm_enable_store(struct device *child,
106	struct device_attribute *attr,
107	const char *buf, size_t size)
108	{
109	struct pwm_device *pwm = child_to_pwm_device(child);
110	int val, ret;
111
112	ret = kstrtoint(buf, 0, &val);
113	if (ret)
114	return ret;
115
116	switch (val) {
117	case 0:
118	pwm_disable(pwm);
119	break;
120	case 1:
121	ret = pwm_enable(pwm);
122	break;
123	default:
124	ret = -EINVAL;
125	break;
126	}
127
128	return ret ? : size;
129	}
130
131	static ssize_t pwm_polarity_show(struct device *child,
132	struct device_attribute *attr,
133	char *buf)
134	{
135	const struct pwm_device *pwm = child_to_pwm_device(child);
136
137	return sprintf(buf, "%s\n", pwm->polarity ? "inversed" : "normal");
138	}
139
140	static ssize_t pwm_polarity_store(struct device *child,
141	struct device_attribute *attr,
142	const char *buf, size_t size)
143	{
144	struct pwm_device *pwm = child_to_pwm_device(child);
145	enum pwm_polarity polarity;
146	int ret;
147
148	if (sysfs_streq(buf, "normal"))
149	polarity = PWM_POLARITY_NORMAL;
150	else if (sysfs_streq(buf, "inversed"))
151	polarity = PWM_POLARITY_INVERSED;
152	else
153	return -EINVAL;
154
155	ret = pwm_set_polarity(pwm, polarity);
156
157	return ret ? : size;
158	}
159
160	static DEVICE_ATTR(period, 0644, pwm_period_show, pwm_period_store);
161	static DEVICE_ATTR(duty_cycle, 0644, pwm_duty_cycle_show, pwm_duty_cycle_store);
162	static DEVICE_ATTR(enable, 0644, pwm_enable_show, pwm_enable_store);
163	static DEVICE_ATTR(polarity, 0644, pwm_polarity_show, pwm_polarity_store);
164
165	static struct attribute *pwm_attrs[] = {
166	&dev_attr_period.attr,
167	&dev_attr_duty_cycle.attr,
168	&dev_attr_enable.attr,
169	&dev_attr_polarity.attr,
170	NULL
171	};
6ca142ad	172	ATTRIBUTE_GROUPS(pwm);
76abbdde HS	173
	174	static void pwm_export_release(struct device *child)
	175	{
	176	struct pwm_export *export = child_to_pwm_export(child);
	177
	178	kfree(export);
	179	}
	180
	181	static int pwm_export_child(struct device parent, struct pwm_device pwm)
	182	{
	183	struct pwm_export *export;
	184	int ret;
	185
	186	if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
	187	return -EBUSY;
	188
	189	export = kzalloc(sizeof(*export), GFP_KERNEL);
	190	if (!export) {
	191	clear_bit(PWMF_EXPORTED, &pwm->flags);
	192	return -ENOMEM;
	193	}
	194
	195	export->pwm = pwm;
	196
	197	export->child.release = pwm_export_release;
	198	export->child.parent = parent;
	199	export->child.devt = MKDEV(0, 0);
6ca142ad	200	export->child.groups = pwm_groups;
76abbdde HS	201	dev_set_name(&export->child, "pwm%u", pwm->hwpwm);
	202
	203	ret = device_register(&export->child);
	204	if (ret) {
	205	clear_bit(PWMF_EXPORTED, &pwm->flags);
	206	kfree(export);
	207	return ret;
	208	}
	209
	210	return 0;
	211	}
	212
	213	static int pwm_unexport_match(struct device child, void data)
	214	{
	215	return child_to_pwm_device(child) == data;
	216	}
	217
	218	static int pwm_unexport_child(struct device parent, struct pwm_device pwm)
	219	{
	220	struct device *child;
	221
	222	if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
	223	return -ENODEV;
	224
	225	child = device_find_child(parent, pwm, pwm_unexport_match);
	226	if (!child)
	227	return -ENODEV;
	228
	229	/* for device_find_child() */
	230	put_device(child);
	231	device_unregister(child);
	232	pwm_put(pwm);
	233
	234	return 0;
	235	}
	236
	237	static ssize_t pwm_export_store(struct device *parent,
	238	struct device_attribute *attr,
	239	const char *buf, size_t len)
	240	{
	241	struct pwm_chip *chip = dev_get_drvdata(parent);
	242	struct pwm_device *pwm;
	243	unsigned int hwpwm;
	244	int ret;
	245
	246	ret = kstrtouint(buf, 0, &hwpwm);
	247	if (ret < 0)
	248	return ret;
	249
	250	if (hwpwm >= chip->npwm)
	251	return -ENODEV;
	252
	253	pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
	254	if (IS_ERR(pwm))
	255	return PTR_ERR(pwm);
	256
	257	ret = pwm_export_child(parent, pwm);
	258	if (ret < 0)
	259	pwm_put(pwm);
	260
	261	return ret ? : len;
	262	}
9da01759	263	static DEVICE_ATTR(export, 0200, NULL, pwm_export_store);
76abbdde HS	264
	265	static ssize_t pwm_unexport_store(struct device *parent,
	266	struct device_attribute *attr,
	267	const char *buf, size_t len)
	268	{
	269	struct pwm_chip *chip = dev_get_drvdata(parent);
	270	unsigned int hwpwm;
	271	int ret;
	272
	273	ret = kstrtouint(buf, 0, &hwpwm);
	274	if (ret < 0)
	275	return ret;
	276
	277	if (hwpwm >= chip->npwm)
	278	return -ENODEV;
	279
	280	ret = pwm_unexport_child(parent, &chip->pwms[hwpwm]);
	281
	282	return ret ? : len;
	283	}
9da01759	284	static DEVICE_ATTR(unexport, 0200, NULL, pwm_unexport_store);
76abbdde	285
9da01759 GKH	286	static ssize_t npwm_show(struct device parent, struct device_attribute attr,
9da01759 GKH	287	char *buf)
76abbdde HS	288	{
	289	const struct pwm_chip *chip = dev_get_drvdata(parent);
	290
	291	return sprintf(buf, "%u\n", chip->npwm);
	292	}
9da01759	293	static DEVICE_ATTR_RO(npwm);
76abbdde	294
9da01759 GKH	295	static struct attribute *pwm_chip_attrs[] = {
	296	&dev_attr_export.attr,
	297	&dev_attr_unexport.attr,
	298	&dev_attr_npwm.attr,
	299	NULL,
76abbdde	300	};
9da01759	301	ATTRIBUTE_GROUPS(pwm_chip);
76abbdde HS	302
	303	static struct class pwm_class = {
	304	.name = "pwm",
	305	.owner = THIS_MODULE,
9da01759	306	.dev_groups = pwm_chip_groups,
76abbdde HS	307	};
	308
	309	static int pwmchip_sysfs_match(struct device parent, const void data)
	310	{
	311	return dev_get_drvdata(parent) == data;
	312	}
	313
	314	void pwmchip_sysfs_export(struct pwm_chip *chip)
	315	{
	316	struct device *parent;
	317
	318	/*
	319	* If device_create() fails the pwm_chip is still usable by
	320	* the kernel its just not exported.
	321	*/
	322	parent = device_create(&pwm_class, chip->dev, MKDEV(0, 0), chip,
	323	"pwmchip%d", chip->base);
	324	if (IS_ERR(parent)) {
	325	dev_warn(chip->dev,
	326	"device_create failed for pwm_chip sysfs export\n");
	327	}
	328	}
	329
	330	void pwmchip_sysfs_unexport(struct pwm_chip *chip)
	331	{
	332	struct device *parent;
	333
	334	parent = class_find_device(&pwm_class, NULL, chip,
	335	pwmchip_sysfs_match);
	336	if (parent) {
	337	/* for class_find_device() */
	338	put_device(parent);
	339	device_unregister(parent);
	340	}
	341	}
	342
	343	static int __init pwm_sysfs_init(void)
	344	{
	345	return class_register(&pwm_class);
	346	}
	347	subsys_initcall(pwm_sysfs_init);