[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;
	struct mutex lock;
};

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 period_show(struct device *child,
			   struct device_attribute *attr,
			   char *buf)
{
	const struct pwm_device *pwm = child_to_pwm_device(child);
	struct pwm_state state;

	pwm_get_state(pwm, &state);

	return sprintf(buf, "%u\n", state.period);
}

static ssize_t period_store(struct device *child,
			    struct device_attribute *attr,
			    const char *buf, size_t size)
{
	struct pwm_export *export = child_to_pwm_export(child);
	struct pwm_device *pwm = export->pwm;
	struct pwm_state state;
	unsigned int val;
	int ret;

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

	mutex_lock(&export->lock);
	pwm_get_state(pwm, &state);
	state.period = val;
	ret = pwm_apply_state(pwm, &state);
	mutex_unlock(&export->lock);

	return ret ? : size;
}

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

	pwm_get_state(pwm, &state);

	return sprintf(buf, "%u\n", state.duty_cycle);
}

static ssize_t duty_cycle_store(struct device *child,
				struct device_attribute *attr,
				const char *buf, size_t size)
{
	struct pwm_export *export = child_to_pwm_export(child);
	struct pwm_device *pwm = export->pwm;
	struct pwm_state state;
	unsigned int val;
	int ret;

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

	mutex_lock(&export->lock);
	pwm_get_state(pwm, &state);
	state.duty_cycle = val;
	ret = pwm_apply_state(pwm, &state);
	mutex_unlock(&export->lock);

	return ret ? : size;
}

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

	pwm_get_state(pwm, &state);

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

static ssize_t enable_store(struct device *child,
			    struct device_attribute *attr,
			    const char *buf, size_t size)
{
	struct pwm_export *export = child_to_pwm_export(child);
	struct pwm_device *pwm = export->pwm;
	struct pwm_state state;
	int val, ret;

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

	mutex_lock(&export->lock);

	pwm_get_state(pwm, &state);

	switch (val) {
	case 0:
		state.enabled = false;
		break;
	case 1:
		state.enabled = true;
		break;
	default:
		ret = -EINVAL;
		goto unlock;
	}

	ret = pwm_apply_state(pwm, &state);

unlock:
	mutex_unlock(&export->lock);
	return ret ? : size;
}

static ssize_t polarity_show(struct device *child,
			     struct device_attribute *attr,
			     char *buf)
{
	const struct pwm_device *pwm = child_to_pwm_device(child);
	const char *polarity = "unknown";
	struct pwm_state state;

	pwm_get_state(pwm, &state);

	switch (state.polarity) {
	case PWM_POLARITY_NORMAL:
		polarity = "normal";
		break;

	case PWM_POLARITY_INVERSED:
		polarity = "inversed";
		break;
	}

	return sprintf(buf, "%s\n", polarity);
}

static ssize_t polarity_store(struct device *child,
			      struct device_attribute *attr,
			      const char *buf, size_t size)
{
	struct pwm_export *export = child_to_pwm_export(child);
	struct pwm_device *pwm = export->pwm;
	enum pwm_polarity polarity;
	struct pwm_state state;
	int ret;

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

	mutex_lock(&export->lock);
	pwm_get_state(pwm, &state);
	state.polarity = polarity;
	ret = pwm_apply_state(pwm, &state);
	mutex_unlock(&export->lock);

	return ret ? : size;
}

static ssize_t capture_show(struct device *child,
			    struct device_attribute *attr,
			    char *buf)
{
	struct pwm_device *pwm = child_to_pwm_device(child);
	struct pwm_capture result;
	int ret;

	ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
	if (ret)
		return ret;

	return sprintf(buf, "%u %u\n", result.period, result.duty_cycle);
}

static DEVICE_ATTR_RW(period);
static DEVICE_ATTR_RW(duty_cycle);
static DEVICE_ATTR_RW(enable);
static DEVICE_ATTR_RW(polarity);
static DEVICE_ATTR_RO(capture);

static struct attribute *pwm_attrs[] = {
	&dev_attr_period.attr,
	&dev_attr_duty_cycle.attr,
	&dev_attr_enable.attr,
	&dev_attr_polarity.attr,
	&dev_attr_capture.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;
	char *pwm_prop[2];
	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;
	mutex_init(&export->lock);

	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);
		put_device(&export->child);
		export = NULL;
		return ret;
	}
	pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm);
	pwm_prop[1] = NULL;
	kobject_uevent_env(&parent->kobj, KOBJ_CHANGE, pwm_prop);
	kfree(pwm_prop[0]);

	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;
	char *pwm_prop[2];

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

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

	pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm);
	pwm_prop[1] = NULL;
	kobject_uevent_env(&parent->kobj, KOBJ_CHANGE, pwm_prop);
	kfree(pwm_prop[0]);

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

	return 0;
}

static ssize_t 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_WO(export);

static ssize_t 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_WO(unexport);

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);
	}
}

void pwmchip_sysfs_unexport_children(struct pwm_chip *chip)
{
	struct device *parent;
	unsigned int i;

	parent = class_find_device(&pwm_class, NULL, chip,
				   pwmchip_sysfs_match);
	if (!parent)
		return;

	for (i = 0; i < chip->npwm; i++) {
		struct pwm_device *pwm = &chip->pwms[i];

		if (test_bit(PWMF_EXPORTED, &pwm->flags))
			pwm_unexport_child(parent, pwm);
	}

	put_device(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;
459a25af	29	struct mutex lock;
76abbdde HS	30	};
	31
	32	static struct pwm_export child_to_pwm_export(struct device child)
	33	{
	34	return container_of(child, struct pwm_export, child);
	35	}
	36
	37	static struct pwm_device child_to_pwm_device(struct device child)
	38	{
	39	struct pwm_export *export = child_to_pwm_export(child);
	40
	41	return export->pwm;
	42	}
	43
65cdc691 OS	44	static ssize_t period_show(struct device *child,
	45	struct device_attribute *attr,
	46	char *buf)
76abbdde HS	47	{
76abbdde HS	48	const struct pwm_device *pwm = child_to_pwm_device(child);
39100cee	49	struct pwm_state state;
76abbdde	50
39100cee BB	51	pwm_get_state(pwm, &state);
	52
	53	return sprintf(buf, "%u\n", state.period);
76abbdde HS	54	}
76abbdde HS	55
65cdc691 OS	56	static ssize_t period_store(struct device *child,
	57	struct device_attribute *attr,
	58	const char *buf, size_t size)
76abbdde	59	{
459a25af BB	60	struct pwm_export *export = child_to_pwm_export(child);
459a25af BB	61	struct pwm_device *pwm = export->pwm;
39100cee	62	struct pwm_state state;
76abbdde HS	63	unsigned int val;
	64	int ret;
	65
	66	ret = kstrtouint(buf, 0, &val);
	67	if (ret)
	68	return ret;
	69
459a25af	70	mutex_lock(&export->lock);
39100cee BB	71	pwm_get_state(pwm, &state);
	72	state.period = val;
	73	ret = pwm_apply_state(pwm, &state);
459a25af	74	mutex_unlock(&export->lock);
76abbdde HS	75
	76	return ret ? : size;
	77	}
	78
65cdc691 OS	79	static ssize_t duty_cycle_show(struct device *child,
	80	struct device_attribute *attr,
	81	char *buf)
76abbdde HS	82	{
76abbdde HS	83	const struct pwm_device *pwm = child_to_pwm_device(child);
39100cee BB	84	struct pwm_state state;
	85
	86	pwm_get_state(pwm, &state);
76abbdde	87
39100cee	88	return sprintf(buf, "%u\n", state.duty_cycle);
76abbdde HS	89	}
76abbdde HS	90
65cdc691 OS	91	static ssize_t duty_cycle_store(struct device *child,
	92	struct device_attribute *attr,
	93	const char *buf, size_t size)
76abbdde	94	{
459a25af BB	95	struct pwm_export *export = child_to_pwm_export(child);
459a25af BB	96	struct pwm_device *pwm = export->pwm;
39100cee	97	struct pwm_state state;
76abbdde HS	98	unsigned int val;
	99	int ret;
	100
	101	ret = kstrtouint(buf, 0, &val);
	102	if (ret)
	103	return ret;
	104
459a25af	105	mutex_lock(&export->lock);
39100cee BB	106	pwm_get_state(pwm, &state);
	107	state.duty_cycle = val;
	108	ret = pwm_apply_state(pwm, &state);
459a25af	109	mutex_unlock(&export->lock);
76abbdde HS	110
	111	return ret ? : size;
	112	}
	113
65cdc691 OS	114	static ssize_t enable_show(struct device *child,
	115	struct device_attribute *attr,
	116	char *buf)
76abbdde HS	117	{
76abbdde HS	118	const struct pwm_device *pwm = child_to_pwm_device(child);
39100cee	119	struct pwm_state state;
76abbdde	120
39100cee BB	121	pwm_get_state(pwm, &state);
	122
	123	return sprintf(buf, "%d\n", state.enabled);
76abbdde HS	124	}
76abbdde HS	125
65cdc691 OS	126	static ssize_t enable_store(struct device *child,
	127	struct device_attribute *attr,
	128	const char *buf, size_t size)
76abbdde	129	{
459a25af BB	130	struct pwm_export *export = child_to_pwm_export(child);
459a25af BB	131	struct pwm_device *pwm = export->pwm;
39100cee	132	struct pwm_state state;
76abbdde HS	133	int val, ret;
	134
	135	ret = kstrtoint(buf, 0, &val);
	136	if (ret)
	137	return ret;
	138
459a25af BB	139	mutex_lock(&export->lock);
459a25af BB	140
39100cee BB	141	pwm_get_state(pwm, &state);
39100cee BB	142
76abbdde HS	143	switch (val) {
76abbdde HS	144	case 0:
39100cee	145	state.enabled = false;
76abbdde HS	146	break;
76abbdde HS	147	case 1:
39100cee	148	state.enabled = true;
76abbdde HS	149	break;
	150	default:
	151	ret = -EINVAL;
39100cee	152	goto unlock;
76abbdde HS	153	}
76abbdde HS	154
fe5aa34d	155	ret = pwm_apply_state(pwm, &state);
459a25af	156
39100cee BB	157	unlock:
39100cee BB	158	mutex_unlock(&export->lock);
76abbdde HS	159	return ret ? : size;
	160	}
	161
65cdc691 OS	162	static ssize_t polarity_show(struct device *child,
	163	struct device_attribute *attr,
	164	char *buf)
76abbdde HS	165	{
76abbdde HS	166	const struct pwm_device *pwm = child_to_pwm_device(child);
5a063d87	167	const char *polarity = "unknown";
39100cee BB	168	struct pwm_state state;
	169
	170	pwm_get_state(pwm, &state);
76abbdde	171
39100cee	172	switch (state.polarity) {
5a063d87 TR	173	case PWM_POLARITY_NORMAL:
	174	polarity = "normal";
	175	break;
	176
	177	case PWM_POLARITY_INVERSED:
	178	polarity = "inversed";
	179	break;
	180	}
	181
	182	return sprintf(buf, "%s\n", polarity);
76abbdde HS	183	}
76abbdde HS	184
65cdc691 OS	185	static ssize_t polarity_store(struct device *child,
	186	struct device_attribute *attr,
	187	const char *buf, size_t size)
76abbdde	188	{
459a25af BB	189	struct pwm_export *export = child_to_pwm_export(child);
459a25af BB	190	struct pwm_device *pwm = export->pwm;
76abbdde	191	enum pwm_polarity polarity;
39100cee	192	struct pwm_state state;
76abbdde HS	193	int ret;
	194
	195	if (sysfs_streq(buf, "normal"))
	196	polarity = PWM_POLARITY_NORMAL;
	197	else if (sysfs_streq(buf, "inversed"))
	198	polarity = PWM_POLARITY_INVERSED;
	199	else
	200	return -EINVAL;
	201
459a25af	202	mutex_lock(&export->lock);
39100cee BB	203	pwm_get_state(pwm, &state);
	204	state.polarity = polarity;
	205	ret = pwm_apply_state(pwm, &state);
459a25af	206	mutex_unlock(&export->lock);
76abbdde HS	207
	208	return ret ? : size;
	209	}
	210
1a366fe9 LJ	211	static ssize_t capture_show(struct device *child,
	212	struct device_attribute *attr,
	213	char *buf)
	214	{
	215	struct pwm_device *pwm = child_to_pwm_device(child);
	216	struct pwm_capture result;
	217	int ret;
	218
	219	ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
	220	if (ret)
	221	return ret;
	222
	223	return sprintf(buf, "%u %u\n", result.period, result.duty_cycle);
	224	}
	225
65cdc691 OS	226	static DEVICE_ATTR_RW(period);
	227	static DEVICE_ATTR_RW(duty_cycle);
	228	static DEVICE_ATTR_RW(enable);
	229	static DEVICE_ATTR_RW(polarity);
1a366fe9	230	static DEVICE_ATTR_RO(capture);
76abbdde HS	231
	232	static struct attribute *pwm_attrs[] = {
	233	&dev_attr_period.attr,
	234	&dev_attr_duty_cycle.attr,
	235	&dev_attr_enable.attr,
	236	&dev_attr_polarity.attr,
1a366fe9	237	&dev_attr_capture.attr,
76abbdde HS	238	NULL
76abbdde HS	239	};
6ca142ad	240	ATTRIBUTE_GROUPS(pwm);
76abbdde HS	241
	242	static void pwm_export_release(struct device *child)
	243	{
	244	struct pwm_export *export = child_to_pwm_export(child);
	245
	246	kfree(export);
	247	}
	248
	249	static int pwm_export_child(struct device parent, struct pwm_device pwm)
	250	{
	251	struct pwm_export *export;
552c02e3	252	char *pwm_prop[2];
76abbdde HS	253	int ret;
	254
	255	if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
	256	return -EBUSY;
	257
	258	export = kzalloc(sizeof(*export), GFP_KERNEL);
	259	if (!export) {
	260	clear_bit(PWMF_EXPORTED, &pwm->flags);
	261	return -ENOMEM;
	262	}
	263
	264	export->pwm = pwm;
459a25af	265	mutex_init(&export->lock);
76abbdde HS	266
	267	export->child.release = pwm_export_release;
	268	export->child.parent = parent;
	269	export->child.devt = MKDEV(0, 0);
6ca142ad	270	export->child.groups = pwm_groups;
76abbdde HS	271	dev_set_name(&export->child, "pwm%u", pwm->hwpwm);
	272
	273	ret = device_register(&export->child);
	274	if (ret) {
	275	clear_bit(PWMF_EXPORTED, &pwm->flags);
8bbf5b42 AY	276	put_device(&export->child);
8bbf5b42 AY	277	export = NULL;
76abbdde HS	278	return ret;
76abbdde HS	279	}
552c02e3 FG	280	pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm);
	281	pwm_prop[1] = NULL;
	282	kobject_uevent_env(&parent->kobj, KOBJ_CHANGE, pwm_prop);
	283	kfree(pwm_prop[0]);
76abbdde HS	284
	285	return 0;
	286	}
	287
	288	static int pwm_unexport_match(struct device child, void data)
	289	{
	290	return child_to_pwm_device(child) == data;
	291	}
	292
	293	static int pwm_unexport_child(struct device parent, struct pwm_device pwm)
	294	{
	295	struct device *child;
552c02e3	296	char *pwm_prop[2];
76abbdde HS	297
	298	if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
	299	return -ENODEV;
	300
	301	child = device_find_child(parent, pwm, pwm_unexport_match);
	302	if (!child)
	303	return -ENODEV;
	304
552c02e3 FG	305	pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm);
	306	pwm_prop[1] = NULL;
	307	kobject_uevent_env(&parent->kobj, KOBJ_CHANGE, pwm_prop);
	308	kfree(pwm_prop[0]);
	309
76abbdde HS	310	/* for device_find_child() */
	311	put_device(child);
	312	device_unregister(child);
	313	pwm_put(pwm);
	314
	315	return 0;
	316	}
	317
65cdc691 OS	318	static ssize_t export_store(struct device *parent,
	319	struct device_attribute *attr,
	320	const char *buf, size_t len)
76abbdde HS	321	{
	322	struct pwm_chip *chip = dev_get_drvdata(parent);
	323	struct pwm_device *pwm;
	324	unsigned int hwpwm;
	325	int ret;
	326
	327	ret = kstrtouint(buf, 0, &hwpwm);
	328	if (ret < 0)
	329	return ret;
	330
	331	if (hwpwm >= chip->npwm)
	332	return -ENODEV;
	333
	334	pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
	335	if (IS_ERR(pwm))
	336	return PTR_ERR(pwm);
	337
	338	ret = pwm_export_child(parent, pwm);
	339	if (ret < 0)
	340	pwm_put(pwm);
	341
	342	return ret ? : len;
	343	}
65cdc691	344	static DEVICE_ATTR_WO(export);
76abbdde	345
65cdc691 OS	346	static ssize_t unexport_store(struct device *parent,
	347	struct device_attribute *attr,
	348	const char *buf, size_t len)
76abbdde HS	349	{
	350	struct pwm_chip *chip = dev_get_drvdata(parent);
	351	unsigned int hwpwm;
	352	int ret;
	353
	354	ret = kstrtouint(buf, 0, &hwpwm);
	355	if (ret < 0)
	356	return ret;
	357
	358	if (hwpwm >= chip->npwm)
	359	return -ENODEV;
	360
	361	ret = pwm_unexport_child(parent, &chip->pwms[hwpwm]);
	362
	363	return ret ? : len;
	364	}
65cdc691	365	static DEVICE_ATTR_WO(unexport);
76abbdde	366
9da01759 GKH	367	static ssize_t npwm_show(struct device parent, struct device_attribute attr,
9da01759 GKH	368	char *buf)
76abbdde HS	369	{
	370	const struct pwm_chip *chip = dev_get_drvdata(parent);
	371
	372	return sprintf(buf, "%u\n", chip->npwm);
	373	}
9da01759	374	static DEVICE_ATTR_RO(npwm);
76abbdde	375
9da01759 GKH	376	static struct attribute *pwm_chip_attrs[] = {
	377	&dev_attr_export.attr,
	378	&dev_attr_unexport.attr,
	379	&dev_attr_npwm.attr,
	380	NULL,
76abbdde	381	};
9da01759	382	ATTRIBUTE_GROUPS(pwm_chip);
76abbdde HS	383
76abbdde HS	384	static struct class pwm_class = {
412820dd TR	385	.name = "pwm",
	386	.owner = THIS_MODULE,
	387	.dev_groups = pwm_chip_groups,
76abbdde HS	388	};
	389
	390	static int pwmchip_sysfs_match(struct device parent, const void data)
	391	{
	392	return dev_get_drvdata(parent) == data;
	393	}
	394
	395	void pwmchip_sysfs_export(struct pwm_chip *chip)
	396	{
	397	struct device *parent;
	398
	399	/*
	400	* If device_create() fails the pwm_chip is still usable by
	401	* the kernel its just not exported.
	402	*/
	403	parent = device_create(&pwm_class, chip->dev, MKDEV(0, 0), chip,
	404	"pwmchip%d", chip->base);
	405	if (IS_ERR(parent)) {
	406	dev_warn(chip->dev,
	407	"device_create failed for pwm_chip sysfs export\n");
	408	}
	409	}
	410
	411	void pwmchip_sysfs_unexport(struct pwm_chip *chip)
	412	{
	413	struct device *parent;
	414
	415	parent = class_find_device(&pwm_class, NULL, chip,
	416	pwmchip_sysfs_match);
	417	if (parent) {
	418	/* for class_find_device() */
	419	put_device(parent);
	420	device_unregister(parent);
	421	}
	422	}
	423
0733424c DH	424	void pwmchip_sysfs_unexport_children(struct pwm_chip *chip)
	425	{
	426	struct device *parent;
	427	unsigned int i;
	428
	429	parent = class_find_device(&pwm_class, NULL, chip,
	430	pwmchip_sysfs_match);
	431	if (!parent)
	432	return;
	433
	434	for (i = 0; i < chip->npwm; i++) {
	435	struct pwm_device *pwm = &chip->pwms[i];
	436
	437	if (test_bit(PWMF_EXPORTED, &pwm->flags))
	438	pwm_unexport_child(parent, pwm);
	439	}
0e1614ac JH	440
0e1614ac JH	441	put_device(parent);
0733424c DH	442	}
0733424c DH	443
76abbdde HS	444	static int __init pwm_sysfs_init(void)
	445	{
	446	return class_register(&pwm_class);
	447	}
	448	subsys_initcall(pwm_sysfs_init);