Linux kernel mirror (for testing)
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tjh.dev
kernel
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linux
1#ifndef __LINUX_PWM_H
2#define __LINUX_PWM_H
3
4#include <linux/err.h>
5#include <linux/of.h>
6
7struct pwm_device;
8struct seq_file;
9
10#if IS_ENABLED(CONFIG_PWM)
11/*
12 * pwm_request - request a PWM device
13 */
14struct pwm_device *pwm_request(int pwm_id, const char *label);
15
16/*
17 * pwm_free - free a PWM device
18 */
19void pwm_free(struct pwm_device *pwm);
20
21/*
22 * pwm_config - change a PWM device configuration
23 */
24int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
25
26/*
27 * pwm_enable - start a PWM output toggling
28 */
29int pwm_enable(struct pwm_device *pwm);
30
31/*
32 * pwm_disable - stop a PWM output toggling
33 */
34void pwm_disable(struct pwm_device *pwm);
35#else
36static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
37{
38 return ERR_PTR(-ENODEV);
39}
40
41static inline void pwm_free(struct pwm_device *pwm)
42{
43}
44
45static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
46{
47 return -EINVAL;
48}
49
50static inline int pwm_enable(struct pwm_device *pwm)
51{
52 return -EINVAL;
53}
54
55static inline void pwm_disable(struct pwm_device *pwm)
56{
57}
58#endif
59
60struct pwm_chip;
61
62/**
63 * enum pwm_polarity - polarity of a PWM signal
64 * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty-
65 * cycle, followed by a low signal for the remainder of the pulse
66 * period
67 * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
68 * cycle, followed by a high signal for the remainder of the pulse
69 * period
70 */
71enum pwm_polarity {
72 PWM_POLARITY_NORMAL,
73 PWM_POLARITY_INVERSED,
74};
75
76enum {
77 PWMF_REQUESTED = 1 << 0,
78 PWMF_ENABLED = 1 << 1,
79 PWMF_EXPORTED = 1 << 2,
80};
81
82/**
83 * struct pwm_device - PWM channel object
84 * @label: name of the PWM device
85 * @flags: flags associated with the PWM device
86 * @hwpwm: per-chip relative index of the PWM device
87 * @pwm: global index of the PWM device
88 * @chip: PWM chip providing this PWM device
89 * @chip_data: chip-private data associated with the PWM device
90 * @period: period of the PWM signal (in nanoseconds)
91 * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
92 * @polarity: polarity of the PWM signal
93 */
94struct pwm_device {
95 const char *label;
96 unsigned long flags;
97 unsigned int hwpwm;
98 unsigned int pwm;
99 struct pwm_chip *chip;
100 void *chip_data;
101
102 unsigned int period;
103 unsigned int duty_cycle;
104 enum pwm_polarity polarity;
105};
106
107static inline bool pwm_is_enabled(const struct pwm_device *pwm)
108{
109 return test_bit(PWMF_ENABLED, &pwm->flags);
110}
111
112static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
113{
114 if (pwm)
115 pwm->period = period;
116}
117
118static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
119{
120 return pwm ? pwm->period : 0;
121}
122
123static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
124{
125 if (pwm)
126 pwm->duty_cycle = duty;
127}
128
129static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
130{
131 return pwm ? pwm->duty_cycle : 0;
132}
133
134/*
135 * pwm_set_polarity - configure the polarity of a PWM signal
136 */
137int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
138
139static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
140{
141 return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
142}
143
144/**
145 * struct pwm_ops - PWM controller operations
146 * @request: optional hook for requesting a PWM
147 * @free: optional hook for freeing a PWM
148 * @config: configure duty cycles and period length for this PWM
149 * @set_polarity: configure the polarity of this PWM
150 * @enable: enable PWM output toggling
151 * @disable: disable PWM output toggling
152 * @dbg_show: optional routine to show contents in debugfs
153 * @owner: helps prevent removal of modules exporting active PWMs
154 */
155struct pwm_ops {
156 int (*request)(struct pwm_chip *chip, struct pwm_device *pwm);
157 void (*free)(struct pwm_chip *chip, struct pwm_device *pwm);
158 int (*config)(struct pwm_chip *chip, struct pwm_device *pwm,
159 int duty_ns, int period_ns);
160 int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm,
161 enum pwm_polarity polarity);
162 int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
163 void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
164#ifdef CONFIG_DEBUG_FS
165 void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s);
166#endif
167 struct module *owner;
168};
169
170/**
171 * struct pwm_chip - abstract a PWM controller
172 * @dev: device providing the PWMs
173 * @list: list node for internal use
174 * @ops: callbacks for this PWM controller
175 * @base: number of first PWM controlled by this chip
176 * @npwm: number of PWMs controlled by this chip
177 * @pwms: array of PWM devices allocated by the framework
178 * @of_xlate: request a PWM device given a device tree PWM specifier
179 * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier
180 * @can_sleep: must be true if the .config(), .enable() or .disable()
181 * operations may sleep
182 */
183struct pwm_chip {
184 struct device *dev;
185 struct list_head list;
186 const struct pwm_ops *ops;
187 int base;
188 unsigned int npwm;
189
190 struct pwm_device *pwms;
191
192 struct pwm_device * (*of_xlate)(struct pwm_chip *pc,
193 const struct of_phandle_args *args);
194 unsigned int of_pwm_n_cells;
195 bool can_sleep;
196};
197
198#if IS_ENABLED(CONFIG_PWM)
199int pwm_set_chip_data(struct pwm_device *pwm, void *data);
200void *pwm_get_chip_data(struct pwm_device *pwm);
201
202int pwmchip_add_with_polarity(struct pwm_chip *chip,
203 enum pwm_polarity polarity);
204int pwmchip_add(struct pwm_chip *chip);
205int pwmchip_remove(struct pwm_chip *chip);
206struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
207 unsigned int index,
208 const char *label);
209
210struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
211 const struct of_phandle_args *args);
212
213struct pwm_device *pwm_get(struct device *dev, const char *con_id);
214struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
215void pwm_put(struct pwm_device *pwm);
216
217struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
218struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
219 const char *con_id);
220void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
221
222bool pwm_can_sleep(struct pwm_device *pwm);
223#else
224static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
225{
226 return -EINVAL;
227}
228
229static inline void *pwm_get_chip_data(struct pwm_device *pwm)
230{
231 return NULL;
232}
233
234static inline int pwmchip_add(struct pwm_chip *chip)
235{
236 return -EINVAL;
237}
238
239static inline int pwmchip_add_inversed(struct pwm_chip *chip)
240{
241 return -EINVAL;
242}
243
244static inline int pwmchip_remove(struct pwm_chip *chip)
245{
246 return -EINVAL;
247}
248
249static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
250 unsigned int index,
251 const char *label)
252{
253 return ERR_PTR(-ENODEV);
254}
255
256static inline struct pwm_device *pwm_get(struct device *dev,
257 const char *consumer)
258{
259 return ERR_PTR(-ENODEV);
260}
261
262static inline struct pwm_device *of_pwm_get(struct device_node *np,
263 const char *con_id)
264{
265 return ERR_PTR(-ENODEV);
266}
267
268static inline void pwm_put(struct pwm_device *pwm)
269{
270}
271
272static inline struct pwm_device *devm_pwm_get(struct device *dev,
273 const char *consumer)
274{
275 return ERR_PTR(-ENODEV);
276}
277
278static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
279 struct device_node *np,
280 const char *con_id)
281{
282 return ERR_PTR(-ENODEV);
283}
284
285static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
286{
287}
288
289static inline bool pwm_can_sleep(struct pwm_device *pwm)
290{
291 return false;
292}
293#endif
294
295struct pwm_lookup {
296 struct list_head list;
297 const char *provider;
298 unsigned int index;
299 const char *dev_id;
300 const char *con_id;
301 unsigned int period;
302 enum pwm_polarity polarity;
303};
304
305#define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \
306 { \
307 .provider = _provider, \
308 .index = _index, \
309 .dev_id = _dev_id, \
310 .con_id = _con_id, \
311 .period = _period, \
312 .polarity = _polarity \
313 }
314
315#if IS_ENABLED(CONFIG_PWM)
316void pwm_add_table(struct pwm_lookup *table, size_t num);
317void pwm_remove_table(struct pwm_lookup *table, size_t num);
318#else
319static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
320{
321}
322
323static inline void pwm_remove_table(struct pwm_lookup *table, size_t num)
324{
325}
326#endif
327
328#ifdef CONFIG_PWM_SYSFS
329void pwmchip_sysfs_export(struct pwm_chip *chip);
330void pwmchip_sysfs_unexport(struct pwm_chip *chip);
331#else
332static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
333{
334}
335
336static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
337{
338}
339#endif /* CONFIG_PWM_SYSFS */
340
341#endif /* __LINUX_PWM_H */