source: src/linux/universal/linux-3.18/include/linux/pwm.h @ 31869

Last change on this file since 31869 was 31869, checked in by brainslayer, 3 months ago

update

File size: 7.4 KB
Line 
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
82struct pwm_device {
83        const char              *label;
84        unsigned long           flags;
85        unsigned int            hwpwm;
86        unsigned int            pwm;
87        struct pwm_chip         *chip;
88        void                    *chip_data;
89
90        unsigned int            period;         /* in nanoseconds */
91        unsigned int            duty_cycle;     /* in nanoseconds */
92        enum pwm_polarity       polarity;
93};
94
95static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
96{
97        if (pwm)
98                pwm->period = period;
99}
100
101static inline unsigned int pwm_get_period(struct pwm_device *pwm)
102{
103        return pwm ? pwm->period : 0;
104}
105
106static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
107{
108        if (pwm)
109                pwm->duty_cycle = duty;
110}
111
112static inline unsigned int pwm_get_duty_cycle(struct pwm_device *pwm)
113{
114        return pwm ? pwm->duty_cycle : 0;
115}
116
117/*
118 * pwm_set_polarity - configure the polarity of a PWM signal
119 */
120int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
121
122/**
123 * struct pwm_ops - PWM controller operations
124 * @request: optional hook for requesting a PWM
125 * @free: optional hook for freeing a PWM
126 * @config: configure duty cycles and period length for this PWM
127 * @set_polarity: configure the polarity of this PWM
128 * @enable: enable PWM output toggling
129 * @disable: disable PWM output toggling
130 * @dbg_show: optional routine to show contents in debugfs
131 * @owner: helps prevent removal of modules exporting active PWMs
132 */
133struct pwm_ops {
134        int                     (*request)(struct pwm_chip *chip,
135                                           struct pwm_device *pwm);
136        void                    (*free)(struct pwm_chip *chip,
137                                        struct pwm_device *pwm);
138        int                     (*config)(struct pwm_chip *chip,
139                                          struct pwm_device *pwm,
140                                          int duty_ns, int period_ns);
141        int                     (*set_polarity)(struct pwm_chip *chip,
142                                          struct pwm_device *pwm,
143                                          enum pwm_polarity polarity);
144        int                     (*enable)(struct pwm_chip *chip,
145                                          struct pwm_device *pwm);
146        void                    (*disable)(struct pwm_chip *chip,
147                                           struct pwm_device *pwm);
148#ifdef CONFIG_DEBUG_FS
149        void                    (*dbg_show)(struct pwm_chip *chip,
150                                            struct seq_file *s);
151#endif
152        struct module           *owner;
153};
154
155/**
156 * struct pwm_chip - abstract a PWM controller
157 * @dev: device providing the PWMs
158 * @list: list node for internal use
159 * @ops: callbacks for this PWM controller
160 * @base: number of first PWM controlled by this chip
161 * @npwm: number of PWMs controlled by this chip
162 * @pwms: array of PWM devices allocated by the framework
163 * @can_sleep: must be true if the .config(), .enable() or .disable()
164 *             operations may sleep
165 */
166struct pwm_chip {
167        struct device           *dev;
168        struct list_head        list;
169        const struct pwm_ops    *ops;
170        int                     base;
171        unsigned int            npwm;
172
173        struct pwm_device       *pwms;
174
175        struct pwm_device *     (*of_xlate)(struct pwm_chip *pc,
176                                            const struct of_phandle_args *args);
177        unsigned int            of_pwm_n_cells;
178        bool                    can_sleep;
179};
180
181#if IS_ENABLED(CONFIG_PWM)
182int pwm_set_chip_data(struct pwm_device *pwm, void *data);
183void *pwm_get_chip_data(struct pwm_device *pwm);
184
185int pwmchip_add(struct pwm_chip *chip);
186int pwmchip_remove(struct pwm_chip *chip);
187struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
188                                         unsigned int index,
189                                         const char *label);
190
191struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
192                const struct of_phandle_args *args);
193
194struct pwm_device *pwm_get(struct device *dev, const char *con_id);
195struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
196void pwm_put(struct pwm_device *pwm);
197
198struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
199struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
200                                   const char *con_id);
201void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
202
203bool pwm_can_sleep(struct pwm_device *pwm);
204#else
205static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
206{
207        return -EINVAL;
208}
209
210static inline void *pwm_get_chip_data(struct pwm_device *pwm)
211{
212        return NULL;
213}
214
215static inline int pwmchip_add(struct pwm_chip *chip)
216{
217        return -EINVAL;
218}
219
220static inline int pwmchip_remove(struct pwm_chip *chip)
221{
222        return -EINVAL;
223}
224
225static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
226                                                       unsigned int index,
227                                                       const char *label)
228{
229        return ERR_PTR(-ENODEV);
230}
231
232static inline struct pwm_device *pwm_get(struct device *dev,
233                                         const char *consumer)
234{
235        return ERR_PTR(-ENODEV);
236}
237
238static inline struct pwm_device *of_pwm_get(struct device_node *np,
239                                            const char *con_id)
240{
241        return ERR_PTR(-ENODEV);
242}
243
244static inline void pwm_put(struct pwm_device *pwm)
245{
246}
247
248static inline struct pwm_device *devm_pwm_get(struct device *dev,
249                                              const char *consumer)
250{
251        return ERR_PTR(-ENODEV);
252}
253
254static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
255                                                 struct device_node *np,
256                                                 const char *con_id)
257{
258        return ERR_PTR(-ENODEV);
259}
260
261static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
262{
263}
264
265static inline bool pwm_can_sleep(struct pwm_device *pwm)
266{
267        return false;
268}
269#endif
270
271struct pwm_lookup {
272        struct list_head list;
273        const char *provider;
274        unsigned int index;
275        const char *dev_id;
276        const char *con_id;
277        unsigned int period;
278        enum pwm_polarity polarity;
279};
280
281#define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \
282        {                                               \
283                .provider = _provider,                  \
284                .index = _index,                        \
285                .dev_id = _dev_id,                      \
286                .con_id = _con_id,                      \
287                .period = _period,                      \
288                .polarity = _polarity                   \
289        }
290
291#if IS_ENABLED(CONFIG_PWM)
292void pwm_add_table(struct pwm_lookup *table, size_t num);
293#else
294static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
295{
296}
297#endif
298
299#ifdef CONFIG_PWM_SYSFS
300void pwmchip_sysfs_export(struct pwm_chip *chip);
301void pwmchip_sysfs_unexport(struct pwm_chip *chip);
302void pwmchip_sysfs_unexport_children(struct pwm_chip *chip);
303#else
304static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
305{
306}
307
308static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
309{
310}
311
312static inline void pwmchip_sysfs_unexport_children(struct pwm_chip *chip)
313{
314}
315#endif /* CONFIG_PWM_SYSFS */
316
317#endif /* __LINUX_PWM_H */
Note: See TracBrowser for help on using the repository browser.