include/linux/pwm.h

   1 #ifndef __LINUX_PWM_H
   2 #define __LINUX_PWM_H
   3
   4 #include <linux/err.h>
   5 #include <linux/mutex.h>
   6 #include <linux/of.h>
   7
   8 struct pwm_device;
   9 struct seq_file;
  10
  11 #if IS_ENABLED(CONFIG_PWM)
  12 /*
  13  * pwm_request - request a PWM device
  14  */
  15 struct pwm_device *pwm_request(int pwm_id, const char *label);
  16
  17 /*
  18  * pwm_free - free a PWM device
  19  */
  20 void pwm_free(struct pwm_device *pwm);
  21
  22 /*
  23  * pwm_config - change a PWM device configuration
  24  */
  25 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
  26
  27 /*
  28  * pwm_enable - start a PWM output toggling
  29  */
  30 int pwm_enable(struct pwm_device *pwm);
  31
  32 /*
  33  * pwm_disable - stop a PWM output toggling
  34  */
  35 void pwm_disable(struct pwm_device *pwm);
  36 #else
  37 static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
  38 {
  39         return ERR_PTR(-ENODEV);
  40 }
  41
  42 static inline void pwm_free(struct pwm_device *pwm)
  43 {
  44 }
  45
  46 static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
  47 {
  48         return -EINVAL;
  49 }
  50
  51 static inline int pwm_enable(struct pwm_device *pwm)
  52 {
  53         return -EINVAL;
  54 }
  55
  56 static inline void pwm_disable(struct pwm_device *pwm)
  57 {
  58 }
  59 #endif
  60
  61 struct pwm_chip;
  62
  63 /**
  64  * enum pwm_polarity - polarity of a PWM signal
  65  * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty-
  66  * cycle, followed by a low signal for the remainder of the pulse
  67  * period
  68  * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
  69  * cycle, followed by a high signal for the remainder of the pulse
  70  * period
  71  */
  72 enum pwm_polarity {
  73         PWM_POLARITY_NORMAL,
  74         PWM_POLARITY_INVERSED,
  75 };
  76
  77 enum {
  78         PWMF_REQUESTED = 1 << 0,
  79         PWMF_ENABLED = 1 << 1,
  80         PWMF_EXPORTED = 1 << 2,
  81 };
  82
  83 /**
  84  * struct pwm_device - PWM channel object
  85  * @label: name of the PWM device
  86  * @flags: flags associated with the PWM device
  87  * @hwpwm: per-chip relative index of the PWM device
  88  * @pwm: global index of the PWM device
  89  * @chip: PWM chip providing this PWM device
  90  * @chip_data: chip-private data associated with the PWM device
  91  * @lock: used to serialize accesses to the PWM device where necessary
  92  * @period: period of the PWM signal (in nanoseconds)
  93  * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
  94  * @polarity: polarity of the PWM signal
  95  */
  96 struct pwm_device {
  97         const char *label;
  98         unsigned long flags;
  99         unsigned int hwpwm;
 100         unsigned int pwm;
 101         struct pwm_chip *chip;
 102         void *chip_data;
 103         struct mutex lock;
 104
 105         unsigned int period;
 106         unsigned int duty_cycle;
 107         enum pwm_polarity polarity;
 108 };
 109
 110 static inline bool pwm_is_enabled(const struct pwm_device *pwm)
 111 {
 112         return test_bit(PWMF_ENABLED, &pwm->flags);
 113 }
 114
 115 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
 116 {
 117         if (pwm)
 118                 pwm->period = period;
 119 }
 120
 121 static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
 122 {
 123         return pwm ? pwm->period : 0;
 124 }
 125
 126 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
 127 {
 128         if (pwm)
 129                 pwm->duty_cycle = duty;
 130 }
 131
 132 static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
 133 {
 134         return pwm ? pwm->duty_cycle : 0;
 135 }
 136
 137 /*
 138  * pwm_set_polarity - configure the polarity of a PWM signal
 139  */
 140 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
 141
 142 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
 143 {
 144         return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
 145 }
 146
 147 /**
 148  * struct pwm_ops - PWM controller operations
 149  * @request: optional hook for requesting a PWM
 150  * @free: optional hook for freeing a PWM
 151  * @config: configure duty cycles and period length for this PWM
 152  * @set_polarity: configure the polarity of this PWM
 153  * @enable: enable PWM output toggling
 154  * @disable: disable PWM output toggling
 155  * @dbg_show: optional routine to show contents in debugfs
 156  * @owner: helps prevent removal of modules exporting active PWMs
 157  */
 158 struct pwm_ops {
 159         int (*request)(struct pwm_chip *chip, struct pwm_device *pwm);
 160         void (*free)(struct pwm_chip *chip, struct pwm_device *pwm);
 161         int (*config)(struct pwm_chip *chip, struct pwm_device *pwm,
 162                       int duty_ns, int period_ns);
 163         int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm,
 164                             enum pwm_polarity polarity);
 165         int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
 166         void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
 167 #ifdef CONFIG_DEBUG_FS
 168         void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s);
 169 #endif
 170         struct module *owner;
 171 };
 172
 173 /**
 174  * struct pwm_chip - abstract a PWM controller
 175  * @dev: device providing the PWMs
 176  * @list: list node for internal use
 177  * @ops: callbacks for this PWM controller
 178  * @base: number of first PWM controlled by this chip
 179  * @npwm: number of PWMs controlled by this chip
 180  * @pwms: array of PWM devices allocated by the framework
 181  * @of_xlate: request a PWM device given a device tree PWM specifier
 182  * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier
 183  * @can_sleep: must be true if the .config(), .enable() or .disable()
 184  *             operations may sleep
 185  */
 186 struct pwm_chip {
 187         struct device *dev;
 188         struct list_head list;
 189         const struct pwm_ops *ops;
 190         int base;
 191         unsigned int npwm;
 192
 193         struct pwm_device *pwms;
 194
 195         struct pwm_device * (*of_xlate)(struct pwm_chip *pc,
 196                                         const struct of_phandle_args *args);
 197         unsigned int of_pwm_n_cells;
 198         bool can_sleep;
 199 };
 200
 201 #if IS_ENABLED(CONFIG_PWM)
 202 int pwm_set_chip_data(struct pwm_device *pwm, void *data);
 203 void *pwm_get_chip_data(struct pwm_device *pwm);
 204
 205 int pwmchip_add_with_polarity(struct pwm_chip *chip,
 206                               enum pwm_polarity polarity);
 207 int pwmchip_add(struct pwm_chip *chip);
 208 int pwmchip_remove(struct pwm_chip *chip);
 209 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 210                                          unsigned int index,
 211                                          const char *label);
 212
 213 struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
 214                 const struct of_phandle_args *args);
 215
 216 struct pwm_device *pwm_get(struct device *dev, const char *con_id);
 217 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
 218 void pwm_put(struct pwm_device *pwm);
 219
 220 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
 221 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
 222                                    const char *con_id);
 223 void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
 224
 225 bool pwm_can_sleep(struct pwm_device *pwm);
 226 #else
 227 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
 228 {
 229         return -EINVAL;
 230 }
 231
 232 static inline void *pwm_get_chip_data(struct pwm_device *pwm)
 233 {
 234         return NULL;
 235 }
 236
 237 static inline int pwmchip_add(struct pwm_chip *chip)
 238 {
 239         return -EINVAL;
 240 }
 241
 242 static inline int pwmchip_add_inversed(struct pwm_chip *chip)
 243 {
 244         return -EINVAL;
 245 }
 246
 247 static inline int pwmchip_remove(struct pwm_chip *chip)
 248 {
 249         return -EINVAL;
 250 }
 251
 252 static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 253                                                        unsigned int index,
 254                                                        const char *label)
 255 {
 256         return ERR_PTR(-ENODEV);
 257 }
 258
 259 static inline struct pwm_device *pwm_get(struct device *dev,
 260                                          const char *consumer)
 261 {
 262         return ERR_PTR(-ENODEV);
 263 }
 264
 265 static inline struct pwm_device *of_pwm_get(struct device_node *np,
 266                                             const char *con_id)
 267 {
 268         return ERR_PTR(-ENODEV);
 269 }
 270
 271 static inline void pwm_put(struct pwm_device *pwm)
 272 {
 273 }
 274
 275 static inline struct pwm_device *devm_pwm_get(struct device *dev,
 276                                               const char *consumer)
 277 {
 278         return ERR_PTR(-ENODEV);
 279 }
 280
 281 static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
 282                                                  struct device_node *np,
 283                                                  const char *con_id)
 284 {
 285         return ERR_PTR(-ENODEV);
 286 }
 287
 288 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
 289 {
 290 }
 291
 292 static inline bool pwm_can_sleep(struct pwm_device *pwm)
 293 {
 294         return false;
 295 }
 296 #endif
 297
 298 struct pwm_lookup {
 299         struct list_head list;
 300         const char *provider;
 301         unsigned int index;
 302         const char *dev_id;
 303         const char *con_id;
 304         unsigned int period;
 305         enum pwm_polarity polarity;
 306 };
 307
 308 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \
 309         {                                               \
 310                 .provider = _provider,                  \
 311                 .index = _index,                        \
 312                 .dev_id = _dev_id,                      \
 313                 .con_id = _con_id,                      \
 314                 .period = _period,                      \
 315                 .polarity = _polarity                   \
 316         }
 317
 318 #if IS_ENABLED(CONFIG_PWM)
 319 void pwm_add_table(struct pwm_lookup *table, size_t num);
 320 void pwm_remove_table(struct pwm_lookup *table, size_t num);
 321 #else
 322 static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
 323 {
 324 }
 325
 326 static inline void pwm_remove_table(struct pwm_lookup *table, size_t num)
 327 {
 328 }
 329 #endif
 330
 331 #ifdef CONFIG_PWM_SYSFS
 332 void pwmchip_sysfs_export(struct pwm_chip *chip);
 333 void pwmchip_sysfs_unexport(struct pwm_chip *chip);
 334 #else
 335 static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
 336 {
 337 }
 338
 339 static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
 340 {
 341 }
 342 #endif /* CONFIG_PWM_SYSFS */
 343
 344 #endif /* __LINUX_PWM_H */