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

/*
 * Generic pwmlib implementation
 *
 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
 * Copyright (C) 2011-2012 Avionic Design GmbH
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/pwm.h>
#include <linux/radix-tree.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>

#define MAX_PWMS 1024

static DEFINE_MUTEX(pwm_lock);
static LIST_HEAD(pwm_chips);
static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
static RADIX_TREE(pwm_tree, GFP_KERNEL);

static struct pwm_device *pwm_to_device(unsigned int pwm)
{
	return radix_tree_lookup(&pwm_tree, pwm);
}

static int alloc_pwms(int pwm, unsigned int count)
{
	unsigned int from = 0;
	unsigned int start;

	if (pwm >= MAX_PWMS)
		return -EINVAL;

	if (pwm >= 0)
		from = pwm;

	start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
					   count, 0);

	if (pwm >= 0 && start != pwm)
		return -EEXIST;

	if (start + count > MAX_PWMS)
		return -ENOSPC;

	return start;
}

static void free_pwms(struct pwm_chip *chip)
{
	unsigned int i;

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

	bitmap_clear(allocated_pwms, chip->base, chip->npwm);

	kfree(chip->pwms);
	chip->pwms = NULL;
}

static int pwm_device_request(struct pwm_device *pwm, const char *label)
{
	int err;

	if (test_bit(PWMF_REQUESTED, &pwm->flags))
		return -EBUSY;

	if (!try_module_get(pwm->chip->ops->owner))
		return -ENODEV;

	if (pwm->chip->ops->request) {
		err = pwm->chip->ops->request(pwm->chip, pwm);
		if (err) {
			module_put(pwm->chip->ops->owner);
			return err;
		}
	}

	set_bit(PWMF_REQUESTED, &pwm->flags);
	pwm->label = label;

	return 0;
}

/**
 * pwm_set_chip_data() - set private chip data for a PWM
 * @pwm: PWM device
 * @data: pointer to chip-specific data
 */
int pwm_set_chip_data(struct pwm_device *pwm, void *data)
{
	if (!pwm)
		return -EINVAL;

	pwm->chip_data = data;

	return 0;
}

/**
 * pwm_get_chip_data() - get private chip data for a PWM
 * @pwm: PWM device
 */
void *pwm_get_chip_data(struct pwm_device *pwm)
{
	return pwm ? pwm->chip_data : NULL;
}

/**
 * pwmchip_add() - register a new PWM chip
 * @chip: the PWM chip to add
 *
 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
 * will be used.
 */
int pwmchip_add(struct pwm_chip *chip)
{
	struct pwm_device *pwm;
	unsigned int i;
	int ret;

	if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
	    !chip->ops->enable || !chip->ops->disable)
		return -EINVAL;

	mutex_lock(&pwm_lock);

	ret = alloc_pwms(chip->base, chip->npwm);
	if (ret < 0)
		goto out;

	chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
	if (!chip->pwms) {
		ret = -ENOMEM;
		goto out;
	}

	chip->base = ret;

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

		pwm->chip = chip;
		pwm->pwm = chip->base + i;
		pwm->hwpwm = i;

		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
	}

	bitmap_set(allocated_pwms, chip->base, chip->npwm);

	INIT_LIST_HEAD(&chip->list);
	list_add(&chip->list, &pwm_chips);

	ret = 0;

out:
	mutex_unlock(&pwm_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(pwmchip_add);

/**
 * pwmchip_remove() - remove a PWM chip
 * @chip: the PWM chip to remove
 *
 * Removes a PWM chip. This function may return busy if the PWM chip provides
 * a PWM device that is still requested.
 */
int pwmchip_remove(struct pwm_chip *chip)
{
	unsigned int i;
	int ret = 0;

	mutex_lock(&pwm_lock);

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

		if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
			ret = -EBUSY;
			goto out;
		}
	}

	list_del_init(&chip->list);
	free_pwms(chip);

out:
	mutex_unlock(&pwm_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(pwmchip_remove);

/**
 * pwm_request() - request a PWM device
 * @pwm_id: global PWM device index
 * @label: PWM device label
 */
struct pwm_device *pwm_request(int pwm, const char *label)
{
	struct pwm_device *dev;
	int err;

	if (pwm < 0 || pwm >= MAX_PWMS)
		return ERR_PTR(-EINVAL);

	mutex_lock(&pwm_lock);

	dev = pwm_to_device(pwm);
	if (!dev) {
		dev = ERR_PTR(-EPROBE_DEFER);
		goto out;
	}

	err = pwm_device_request(dev, label);
	if (err < 0)
		dev = ERR_PTR(err);

out:
	mutex_unlock(&pwm_lock);

	return dev;
}
EXPORT_SYMBOL_GPL(pwm_request);

/**
 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
 * @chip: PWM chip
 * @index: per-chip index of the PWM to request
 * @label: a literal description string of this PWM
 *
 * Returns the PWM at the given index of the given PWM chip. A negative error
 * code is returned if the index is not valid for the specified PWM chip or
 * if the PWM device cannot be requested.
 */
struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
					 unsigned int index,
					 const char *label)
{
	struct pwm_device *pwm;
	int err;

	if (!chip || index >= chip->npwm)
		return ERR_PTR(-EINVAL);

	mutex_lock(&pwm_lock);
	pwm = &chip->pwms[index];

	err = pwm_device_request(pwm, label);
	if (err < 0)
		pwm = ERR_PTR(err);

	mutex_unlock(&pwm_lock);
	return pwm;
}
EXPORT_SYMBOL_GPL(pwm_request_from_chip);

/**
 * pwm_free() - free a PWM device
 * @pwm: PWM device
 */
void pwm_free(struct pwm_device *pwm)
{
	mutex_lock(&pwm_lock);

	if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
		pr_warning("PWM device already freed\n");
		goto out;
	}

	if (pwm->chip->ops->free)
		pwm->chip->ops->free(pwm->chip, pwm);

	pwm->label = NULL;

	module_put(pwm->chip->ops->owner);
out:
	mutex_unlock(&pwm_lock);
}
EXPORT_SYMBOL_GPL(pwm_free);

/**
 * pwm_config() - change a PWM device configuration
 * @pwm: PWM device
 * @duty_ns: "on" time (in nanoseconds)
 * @period_ns: duration (in nanoseconds) of one cycle
 */
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
	if (!pwm || period_ns == 0 || duty_ns > period_ns)
		return -EINVAL;

	return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
}
EXPORT_SYMBOL_GPL(pwm_config);

/**
 * pwm_enable() - start a PWM output toggling
 * @pwm: PWM device
 */
int pwm_enable(struct pwm_device *pwm)
{
	if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
		return pwm->chip->ops->enable(pwm->chip, pwm);

	return pwm ? 0 : -EINVAL;
}
EXPORT_SYMBOL_GPL(pwm_enable);

/**
 * pwm_disable() - stop a PWM output toggling
 * @pwm: PWM device
 */
void pwm_disable(struct pwm_device *pwm)
{
	if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
		pwm->chip->ops->disable(pwm->chip, pwm);
}
EXPORT_SYMBOL_GPL(pwm_disable);

#ifdef CONFIG_DEBUG_FS
static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
{
	unsigned int i;

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

		seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);

		if (test_bit(PWMF_REQUESTED, &pwm->flags))
			seq_printf(s, " requested");

		if (test_bit(PWMF_ENABLED, &pwm->flags))
			seq_printf(s, " enabled");

		seq_printf(s, "\n");
	}
}

static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
{
	mutex_lock(&pwm_lock);
	s->private = "";

	return seq_list_start(&pwm_chips, *pos);
}

static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
	s->private = "\n";

	return seq_list_next(v, &pwm_chips, pos);
}

static void pwm_seq_stop(struct seq_file *s, void *v)
{
	mutex_unlock(&pwm_lock);
}

static int pwm_seq_show(struct seq_file *s, void *v)
{
	struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);

	seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
		   chip->dev->bus ? chip->dev->bus->name : "no-bus",
		   dev_name(chip->dev), chip->npwm,
		   (chip->npwm != 1) ? "s" : "");

	if (chip->ops->dbg_show)
		chip->ops->dbg_show(chip, s);
	else
		pwm_dbg_show(chip, s);

	return 0;
}

static const struct seq_operations pwm_seq_ops = {
	.start = pwm_seq_start,
	.next = pwm_seq_next,
	.stop = pwm_seq_stop,
	.show = pwm_seq_show,
};

static int pwm_seq_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &pwm_seq_ops);
}

static const struct file_operations pwm_debugfs_ops = {
	.owner = THIS_MODULE,
	.open = pwm_seq_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
};

static int __init pwm_debugfs_init(void)
{
	debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
			    &pwm_debugfs_ops);

	return 0;
}

subsys_initcall(pwm_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
Commit	Line	Data
0c2498f1 SH	1	/*
	2	* Generic pwmlib implementation
	3	*
	4	* Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
f051c466	5	* Copyright (C) 2011-2012 Avionic Design GmbH
0c2498f1 SH	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2, or (at your option)
	10	* any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; see the file COPYING. If not, write to
	19	* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
	20	*/
	21
	22	#include <linux/module.h>
	23	#include <linux/pwm.h>
f051c466	24	#include <linux/radix-tree.h>
0c2498f1 SH	25	#include <linux/list.h>
	26	#include <linux/mutex.h>
	27	#include <linux/err.h>
	28	#include <linux/slab.h>
	29	#include <linux/device.h>
62099abf TR	30	#include <linux/debugfs.h>
62099abf TR	31	#include <linux/seq_file.h>
0c2498f1	32
f051c466	33	#define MAX_PWMS 1024
0c2498f1 SH	34
0c2498f1 SH	35	static DEFINE_MUTEX(pwm_lock);
f051c466 TR	36	static LIST_HEAD(pwm_chips);
	37	static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
	38	static RADIX_TREE(pwm_tree, GFP_KERNEL);
0c2498f1	39
f051c466	40	static struct pwm_device *pwm_to_device(unsigned int pwm)
0c2498f1	41	{
f051c466 TR	42	return radix_tree_lookup(&pwm_tree, pwm);
	43	}
	44
	45	static int alloc_pwms(int pwm, unsigned int count)
	46	{
	47	unsigned int from = 0;
	48	unsigned int start;
	49
	50	if (pwm >= MAX_PWMS)
	51	return -EINVAL;
	52
	53	if (pwm >= 0)
	54	from = pwm;
0c2498f1	55
f051c466 TR	56	start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
	57	count, 0);
	58
	59	if (pwm >= 0 && start != pwm)
	60	return -EEXIST;
	61
	62	if (start + count > MAX_PWMS)
	63	return -ENOSPC;
	64
	65	return start;
	66	}
	67
	68	static void free_pwms(struct pwm_chip *chip)
	69	{
	70	unsigned int i;
	71
	72	for (i = 0; i < chip->npwm; i++) {
	73	struct pwm_device *pwm = &chip->pwms[i];
	74	radix_tree_delete(&pwm_tree, pwm->pwm);
0c2498f1 SH	75	}
0c2498f1 SH	76
f051c466 TR	77	bitmap_clear(allocated_pwms, chip->base, chip->npwm);
	78
	79	kfree(chip->pwms);
	80	chip->pwms = NULL;
	81	}
	82
	83	static int pwm_device_request(struct pwm_device pwm, const char label)
	84	{
	85	int err;
	86
	87	if (test_bit(PWMF_REQUESTED, &pwm->flags))
	88	return -EBUSY;
	89
	90	if (!try_module_get(pwm->chip->ops->owner))
	91	return -ENODEV;
	92
	93	if (pwm->chip->ops->request) {
	94	err = pwm->chip->ops->request(pwm->chip, pwm);
	95	if (err) {
	96	module_put(pwm->chip->ops->owner);
	97	return err;
	98	}
	99	}
	100
	101	set_bit(PWMF_REQUESTED, &pwm->flags);
	102	pwm->label = label;
	103
	104	return 0;
	105	}
	106
	107	/**
	108	* pwm_set_chip_data() - set private chip data for a PWM
	109	* @pwm: PWM device
	110	* @data: pointer to chip-specific data
	111	*/
	112	int pwm_set_chip_data(struct pwm_device pwm, void data)
	113	{
	114	if (!pwm)
	115	return -EINVAL;
	116
	117	pwm->chip_data = data;
	118
	119	return 0;
	120	}
	121
	122	/**
	123	* pwm_get_chip_data() - get private chip data for a PWM
	124	* @pwm: PWM device
	125	*/
	126	void pwm_get_chip_data(struct pwm_device pwm)
	127	{
	128	return pwm ? pwm->chip_data : NULL;
0c2498f1 SH	129	}
	130
	131	/**
	132	* pwmchip_add() - register a new PWM chip
	133	* @chip: the PWM chip to add
f051c466 TR	134	*
	135	* Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
	136	* will be used.
0c2498f1 SH	137	*/
	138	int pwmchip_add(struct pwm_chip *chip)
	139	{
	140	struct pwm_device *pwm;
f051c466 TR	141	unsigned int i;
f051c466 TR	142	int ret;
0c2498f1	143
f051c466 TR	144	if (!chip \|\| !chip->dev \|\| !chip->ops \|\| !chip->ops->config \|\|
	145	!chip->ops->enable \|\| !chip->ops->disable)
	146	return -EINVAL;
0c2498f1 SH	147
	148	mutex_lock(&pwm_lock);
	149
f051c466 TR	150	ret = alloc_pwms(chip->base, chip->npwm);
	151	if (ret < 0)
	152	goto out;
	153
	154	chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
	155	if (!chip->pwms) {
	156	ret = -ENOMEM;
0c2498f1 SH	157	goto out;
	158	}
	159
f051c466 TR	160	chip->base = ret;
	161
	162	for (i = 0; i < chip->npwm; i++) {
	163	pwm = &chip->pwms[i];
	164
	165	pwm->chip = chip;
	166	pwm->pwm = chip->base + i;
	167	pwm->hwpwm = i;
0c2498f1	168
f051c466 TR	169	radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
	170	}
	171
	172	bitmap_set(allocated_pwms, chip->base, chip->npwm);
	173
	174	INIT_LIST_HEAD(&chip->list);
	175	list_add(&chip->list, &pwm_chips);
0c2498f1	176
f051c466 TR	177	ret = 0;
	178
	179	out:
	180	mutex_unlock(&pwm_lock);
0c2498f1 SH	181	return ret;
	182	}
	183	EXPORT_SYMBOL_GPL(pwmchip_add);
	184
	185	/**
	186	* pwmchip_remove() - remove a PWM chip
	187	* @chip: the PWM chip to remove
	188	*
	189	* Removes a PWM chip. This function may return busy if the PWM chip provides
	190	* a PWM device that is still requested.
	191	*/
	192	int pwmchip_remove(struct pwm_chip *chip)
	193	{
f051c466	194	unsigned int i;
0c2498f1 SH	195	int ret = 0;
	196
	197	mutex_lock(&pwm_lock);
	198
f051c466 TR	199	for (i = 0; i < chip->npwm; i++) {
f051c466 TR	200	struct pwm_device *pwm = &chip->pwms[i];
0c2498f1	201
f051c466 TR	202	if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
	203	ret = -EBUSY;
	204	goto out;
	205	}
0c2498f1 SH	206	}
0c2498f1 SH	207
f051c466 TR	208	list_del_init(&chip->list);
f051c466 TR	209	free_pwms(chip);
0c2498f1	210
0c2498f1 SH	211	out:
0c2498f1 SH	212	mutex_unlock(&pwm_lock);
0c2498f1 SH	213	return ret;
	214	}
	215	EXPORT_SYMBOL_GPL(pwmchip_remove);
	216
	217	/**
	218	* pwm_request() - request a PWM device
	219	* @pwm_id: global PWM device index
	220	* @label: PWM device label
	221	*/
f051c466	222	struct pwm_device pwm_request(int pwm, const char label)
0c2498f1	223	{
f051c466 TR	224	struct pwm_device *dev;
	225	int err;
	226
	227	if (pwm < 0 \|\| pwm >= MAX_PWMS)
	228	return ERR_PTR(-EINVAL);
0c2498f1 SH	229
	230	mutex_lock(&pwm_lock);
	231
f051c466 TR	232	dev = pwm_to_device(pwm);
	233	if (!dev) {
	234	dev = ERR_PTR(-EPROBE_DEFER);
0c2498f1 SH	235	goto out;
	236	}
	237
f051c466 TR	238	err = pwm_device_request(dev, label);
	239	if (err < 0)
	240	dev = ERR_PTR(err);
0c2498f1	241
f051c466 TR	242	out:
f051c466 TR	243	mutex_unlock(&pwm_lock);
0c2498f1	244
f051c466 TR	245	return dev;
	246	}
	247	EXPORT_SYMBOL_GPL(pwm_request);
0c2498f1	248
f051c466 TR	249	/**
	250	* pwm_request_from_chip() - request a PWM device relative to a PWM chip
	251	* @chip: PWM chip
	252	* @index: per-chip index of the PWM to request
	253	* @label: a literal description string of this PWM
	254	*
	255	* Returns the PWM at the given index of the given PWM chip. A negative error
	256	* code is returned if the index is not valid for the specified PWM chip or
	257	* if the PWM device cannot be requested.
	258	*/
	259	struct pwm_device pwm_request_from_chip(struct pwm_chip chip,
	260	unsigned int index,
	261	const char *label)
	262	{
	263	struct pwm_device *pwm;
	264	int err;
0c2498f1	265
f051c466 TR	266	if (!chip \|\| index >= chip->npwm)
f051c466 TR	267	return ERR_PTR(-EINVAL);
0c2498f1	268
f051c466 TR	269	mutex_lock(&pwm_lock);
f051c466 TR	270	pwm = &chip->pwms[index];
0c2498f1	271
f051c466 TR	272	err = pwm_device_request(pwm, label);
	273	if (err < 0)
	274	pwm = ERR_PTR(err);
	275
	276	mutex_unlock(&pwm_lock);
0c2498f1 SH	277	return pwm;
0c2498f1 SH	278	}
f051c466	279	EXPORT_SYMBOL_GPL(pwm_request_from_chip);
0c2498f1 SH	280
	281	/**
	282	* pwm_free() - free a PWM device
	283	* @pwm: PWM device
	284	*/
	285	void pwm_free(struct pwm_device *pwm)
	286	{
	287	mutex_lock(&pwm_lock);
	288
f051c466	289	if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
0c2498f1 SH	290	pr_warning("PWM device already freed\n");
	291	goto out;
	292	}
	293
f051c466 TR	294	if (pwm->chip->ops->free)
	295	pwm->chip->ops->free(pwm->chip, pwm);
	296
0c2498f1 SH	297	pwm->label = NULL;
	298
	299	module_put(pwm->chip->ops->owner);
	300	out:
	301	mutex_unlock(&pwm_lock);
	302	}
	303	EXPORT_SYMBOL_GPL(pwm_free);
	304
	305	/**
	306	* pwm_config() - change a PWM device configuration
	307	* @pwm: PWM device
	308	* @duty_ns: "on" time (in nanoseconds)
	309	* @period_ns: duration (in nanoseconds) of one cycle
	310	*/
	311	int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
	312	{
f051c466 TR	313	if (!pwm \|\| period_ns == 0 \|\| duty_ns > period_ns)
	314	return -EINVAL;
	315
	316	return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
0c2498f1 SH	317	}
	318	EXPORT_SYMBOL_GPL(pwm_config);
	319
	320	/**
	321	* pwm_enable() - start a PWM output toggling
	322	* @pwm: PWM device
	323	*/
	324	int pwm_enable(struct pwm_device *pwm)
	325	{
f051c466 TR	326	if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
f051c466 TR	327	return pwm->chip->ops->enable(pwm->chip, pwm);
0c2498f1	328
f051c466	329	return pwm ? 0 : -EINVAL;
0c2498f1 SH	330	}
	331	EXPORT_SYMBOL_GPL(pwm_enable);
	332
	333	/**
	334	* pwm_disable() - stop a PWM output toggling
	335	* @pwm: PWM device
	336	*/
	337	void pwm_disable(struct pwm_device *pwm)
	338	{
f051c466 TR	339	if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
f051c466 TR	340	pwm->chip->ops->disable(pwm->chip, pwm);
0c2498f1 SH	341	}
0c2498f1 SH	342	EXPORT_SYMBOL_GPL(pwm_disable);
62099abf TR	343
	344	#ifdef CONFIG_DEBUG_FS
	345	static void pwm_dbg_show(struct pwm_chip chip, struct seq_file s)
	346	{
	347	unsigned int i;
	348
	349	for (i = 0; i < chip->npwm; i++) {
	350	struct pwm_device *pwm = &chip->pwms[i];
	351
	352	seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
	353
	354	if (test_bit(PWMF_REQUESTED, &pwm->flags))
	355	seq_printf(s, " requested");
	356
	357	if (test_bit(PWMF_ENABLED, &pwm->flags))
	358	seq_printf(s, " enabled");
	359
	360	seq_printf(s, "\n");
	361	}
	362	}
	363
	364	static void pwm_seq_start(struct seq_file s, loff_t *pos)
	365	{
	366	mutex_lock(&pwm_lock);
	367	s->private = "";
	368
	369	return seq_list_start(&pwm_chips, *pos);
	370	}
	371
	372	static void pwm_seq_next(struct seq_file s, void v, loff_t pos)
	373	{
	374	s->private = "\n";
	375
	376	return seq_list_next(v, &pwm_chips, pos);
	377	}
	378
	379	static void pwm_seq_stop(struct seq_file s, void v)
	380	{
	381	mutex_unlock(&pwm_lock);
	382	}
	383
	384	static int pwm_seq_show(struct seq_file s, void v)
	385	{
	386	struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
	387
	388	seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
	389	chip->dev->bus ? chip->dev->bus->name : "no-bus",
	390	dev_name(chip->dev), chip->npwm,
	391	(chip->npwm != 1) ? "s" : "");
	392
	393	if (chip->ops->dbg_show)
	394	chip->ops->dbg_show(chip, s);
	395	else
	396	pwm_dbg_show(chip, s);
	397
	398	return 0;
	399	}
	400
	401	static const struct seq_operations pwm_seq_ops = {
	402	.start = pwm_seq_start,
	403	.next = pwm_seq_next,
	404	.stop = pwm_seq_stop,
	405	.show = pwm_seq_show,
	406	};
407
408	static int pwm_seq_open(struct inode inode, struct file file)
409	{
410	return seq_open(file, &pwm_seq_ops);
411	}
412
413	static const struct file_operations pwm_debugfs_ops = {
414	.owner = THIS_MODULE,
415	.open = pwm_seq_open,
416	.read = seq_read,
417	.llseek = seq_lseek,
418	.release = seq_release,
419	};
420
421	static int __init pwm_debugfs_init(void)
422	{
423	debugfs_create_file("pwm", S_IFREG \| S_IRUGO, NULL, NULL,
424	&pwm_debugfs_ops);
425
426	return 0;
427	}
428
429	subsys_initcall(pwm_debugfs_init);
430	#endif /* CONFIG_DEBUG_FS */