summaryrefslogtreecommitdiffstats
path: root/include/linux/pwm.h
blob: f0feafd184a0d655fff326bc979eebd21a7a28ab (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
#ifndef __LINUX_PWM_H
#define __LINUX_PWM_H

#include <linux/err.h>
#include <linux/of.h>

struct pwm_device;
struct seq_file;

#if IS_ENABLED(CONFIG_PWM) || IS_ENABLED(CONFIG_HAVE_PWM)
/*
 * pwm_request - request a PWM device
 */
struct pwm_device *pwm_request(int pwm_id, const char *label);

/*
 * pwm_free - free a PWM device
 */
void pwm_free(struct pwm_device *pwm);

/*
 * pwm_config - change a PWM device configuration
 */
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);

/*
 * pwm_enable - start a PWM output toggling
 */
int pwm_enable(struct pwm_device *pwm);

/*
 * pwm_disable - stop a PWM output toggling
 */
void pwm_disable(struct pwm_device *pwm);
#else
static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
{
	return ERR_PTR(-ENODEV);
}

static inline void pwm_free(struct pwm_device *pwm)
{
}

static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
	return -EINVAL;
}

static inline int pwm_enable(struct pwm_device *pwm)
{
	return -EINVAL;
}

static inline void pwm_disable(struct pwm_device *pwm)
{
}
#endif

struct pwm_chip;

/**
 * enum pwm_polarity - polarity of a PWM signal
 * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty-
 * cycle, followed by a low signal for the remainder of the pulse
 * period
 * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
 * cycle, followed by a high signal for the remainder of the pulse
 * period
 */
enum pwm_polarity {
	PWM_POLARITY_NORMAL,
	PWM_POLARITY_INVERSED,
};

enum {
	PWMF_REQUESTED = 1 << 0,
	PWMF_ENABLED = 1 << 1,
	PWMF_EXPORTED = 1 << 2,
};

struct pwm_device {
	const char		*label;
	unsigned long		flags;
	unsigned int		hwpwm;
	unsigned int		pwm;
	struct pwm_chip		*chip;
	void			*chip_data;

	unsigned int		period; 	/* in nanoseconds */
	unsigned int		duty_cycle;	/* in nanoseconds */
	enum pwm_polarity	polarity;
};

static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
{
	if (pwm)
		pwm->period = period;
}

static inline unsigned int pwm_get_period(struct pwm_device *pwm)
{
	return pwm ? pwm->period : 0;
}

static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
{
	if (pwm)
		pwm->duty_cycle = duty;
}

static inline unsigned int pwm_get_duty_cycle(struct pwm_device *pwm)
{
	return pwm ? pwm->duty_cycle : 0;
}

/*
 * pwm_set_polarity - configure the polarity of a PWM signal
 */
int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);

/**
 * struct pwm_ops - PWM controller operations
 * @request: optional hook for requesting a PWM
 * @free: optional hook for freeing a PWM
 * @config: configure duty cycles and period length for this PWM
 * @set_polarity: configure the polarity of this PWM
 * @enable: enable PWM output toggling
 * @disable: disable PWM output toggling
 * @dbg_show: optional routine to show contents in debugfs
 * @owner: helps prevent removal of modules exporting active PWMs
 */
struct pwm_ops {
	int			(*request)(struct pwm_chip *chip,
					   struct pwm_device *pwm);
	void			(*free)(struct pwm_chip *chip,
					struct pwm_device *pwm);
	int			(*config)(struct pwm_chip *chip,
					  struct pwm_device *pwm,
					  int duty_ns, int period_ns);
	int			(*set_polarity)(struct pwm_chip *chip,
					  struct pwm_device *pwm,
					  enum pwm_polarity polarity);
	int			(*enable)(struct pwm_chip *chip,
					  struct pwm_device *pwm);
	void			(*disable)(struct pwm_chip *chip,
					   struct pwm_device *pwm);
#ifdef CONFIG_DEBUG_FS
	void			(*dbg_show)(struct pwm_chip *chip,
					    struct seq_file *s);
#endif
	struct module		*owner;
};

/**
 * struct pwm_chip - abstract a PWM controller
 * @dev: device providing the PWMs
 * @list: list node for internal use
 * @ops: callbacks for this PWM controller
 * @base: number of first PWM controlled by this chip
 * @npwm: number of PWMs controlled by this chip
 * @pwms: array of PWM devices allocated by the framework
 * @can_sleep: must be true if the .config(), .enable() or .disable()
 *             operations may sleep
 */
struct pwm_chip {
	struct device		*dev;
	struct list_head	list;
	const struct pwm_ops	*ops;
	int			base;
	unsigned int		npwm;

	struct pwm_device	*pwms;

	struct pwm_device *	(*of_xlate)(struct pwm_chip *pc,
					    const struct of_phandle_args *args);
	unsigned int		of_pwm_n_cells;
	bool			can_sleep;
};

#if IS_ENABLED(CONFIG_PWM)
int pwm_set_chip_data(struct pwm_device *pwm, void *data);
void *pwm_get_chip_data(struct pwm_device *pwm);

int pwmchip_add(struct pwm_chip *chip);
int pwmchip_remove(struct pwm_chip *chip);
struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
					 unsigned int index,
					 const char *label);

struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
		const struct of_phandle_args *args);

struct pwm_device *pwm_get(struct device *dev, const char *con_id);
struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
void pwm_put(struct pwm_device *pwm);

struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
				   const char *con_id);
void devm_pwm_put(struct device *dev, struct pwm_device *pwm);

bool pwm_can_sleep(struct pwm_device *pwm);
#else
static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
{
	return -EINVAL;
}

static inline void *pwm_get_chip_data(struct pwm_device *pwm)
{
	return NULL;
}

static inline int pwmchip_add(struct pwm_chip *chip)
{
	return -EINVAL;
}

static inline int pwmchip_remove(struct pwm_chip *chip)
{
	return -EINVAL;
}

static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
						       unsigned int index,
						       const char *label)
{
	return ERR_PTR(-ENODEV);
}

static inline struct pwm_device *pwm_get(struct device *dev,
					 const char *consumer)
{
	return ERR_PTR(-ENODEV);
}

static inline struct pwm_device *of_pwm_get(struct device_node *np,
					    const char *con_id)
{
	return ERR_PTR(-ENODEV);
}

static inline void pwm_put(struct pwm_device *pwm)
{
}

static inline struct pwm_device *devm_pwm_get(struct device *dev,
					      const char *consumer)
{
	return ERR_PTR(-ENODEV);
}

static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
						 struct device_node *np,
						 const char *con_id)
{
	return ERR_PTR(-ENODEV);
}

static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
{
}

static inline bool pwm_can_sleep(struct pwm_device *pwm)
{
	return false;
}
#endif

struct pwm_lookup {
	struct list_head list;
	const char *provider;
	unsigned int index;
	const char *dev_id;
	const char *con_id;
};

#define PWM_LOOKUP(_provider, _index, _dev_id, _con_id)	\
	{						\
		.provider = _provider,			\
		.index = _index,			\
		.dev_id = _dev_id,			\
		.con_id = _con_id,			\
	}

#if IS_ENABLED(CONFIG_PWM)
void pwm_add_table(struct pwm_lookup *table, size_t num);
#else
static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
{
}
#endif

#ifdef CONFIG_PWM_SYSFS
void pwmchip_sysfs_export(struct pwm_chip *chip);
void pwmchip_sysfs_unexport(struct pwm_chip *chip);
#else
static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
{
}

static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
{
}
#endif /* CONFIG_PWM_SYSFS */

#endif /* __LINUX_PWM_H */
OpenPOWER on IntegriCloud