include/linux/pwm.h

   1 #ifndef __LINUX_PWM_H
   2 #define __LINUX_PWM_H
   3
   4 #include <linux/err.h>
   5 #include <linux/of.h>
   6
   7 struct pwm_device;
   8 struct seq_file;
   9
  10 #if IS_ENABLED(CONFIG_PWM)
  11 /*
  12  * pwm_request - request a PWM device
  13  */
  14 struct pwm_device *pwm_request(int pwm_id, const char *label);
  15
  16 /*
  17  * pwm_free - free a PWM device
  18  */
  19 void pwm_free(struct pwm_device *pwm);
  20
  21 /*
  22  * pwm_config - change a PWM device configuration
  23  */
  24 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
  25
  26 /*
  27  * pwm_enable - start a PWM output toggling
  28  */
  29 int pwm_enable(struct pwm_device *pwm);
  30
  31 /*
  32  * pwm_disable - stop a PWM output toggling
  33  */
  34 void pwm_disable(struct pwm_device *pwm);
  35 #else
  36 static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
  37 {
  38         return ERR_PTR(-ENODEV);
  39 }
  40
  41 static inline void pwm_free(struct pwm_device *pwm)
  42 {
  43 }
  44
  45 static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
  46 {
  47         return -EINVAL;
  48 }
  49
  50 static inline int pwm_enable(struct pwm_device *pwm)
  51 {
  52         return -EINVAL;
  53 }
  54
  55 static inline void pwm_disable(struct pwm_device *pwm)
  56 {
  57 }
  58 #endif
  59
  60 struct 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  */
  71 enum pwm_polarity {
  72         PWM_POLARITY_NORMAL,
  73         PWM_POLARITY_INVERSED,
  74 };
  75
  76 enum {
  77         PWMF_REQUESTED = 1 << 0,
  78         PWMF_ENABLED = 1 << 1,
  79         PWMF_EXPORTED = 1 << 2,
  80 };
  81
  82 struct 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
  95 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
  96 {
  97         if (pwm)
  98                 pwm->period = period;
  99 }
 100
 101 static inline unsigned int pwm_get_period(struct pwm_device *pwm)
 102 {
 103         return pwm ? pwm->period : 0;
 104 }
 105
 106 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
 107 {
 108         if (pwm)
 109                 pwm->duty_cycle = duty;
 110 }
 111
 112 static 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  */
 120 int 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  */
 133 struct 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  */
 166 struct 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)
 182 int pwm_set_chip_data(struct pwm_device *pwm, void *data);
 183 void *pwm_get_chip_data(struct pwm_device *pwm);
 184
 185 int pwmchip_add_with_polarity(struct pwm_chip *chip,
 186                               enum pwm_polarity polarity);
 187 int pwmchip_add(struct pwm_chip *chip);
 188 int pwmchip_remove(struct pwm_chip *chip);
 189 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 190                                          unsigned int index,
 191                                          const char *label);
 192
 193 struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
 194                 const struct of_phandle_args *args);
 195
 196 struct pwm_device *pwm_get(struct device *dev, const char *con_id);
 197 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
 198 void pwm_put(struct pwm_device *pwm);
 199
 200 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
 201 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
 202                                    const char *con_id);
 203 void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
 204
 205 bool pwm_can_sleep(struct pwm_device *pwm);
 206 #else
 207 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
 208 {
 209         return -EINVAL;
 210 }
 211
 212 static inline void *pwm_get_chip_data(struct pwm_device *pwm)
 213 {
 214         return NULL;
 215 }
 216
 217 static inline int pwmchip_add(struct pwm_chip *chip)
 218 {
 219         return -EINVAL;
 220 }
 221
 222 static inline int pwmchip_add_inversed(struct pwm_chip *chip)
 223 {
 224         return -EINVAL;
 225 }
 226
 227 static inline int pwmchip_remove(struct pwm_chip *chip)
 228 {
 229         return -EINVAL;
 230 }
 231
 232 static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 233                                                        unsigned int index,
 234                                                        const char *label)
 235 {
 236         return ERR_PTR(-ENODEV);
 237 }
 238
 239 static inline struct pwm_device *pwm_get(struct device *dev,
 240                                          const char *consumer)
 241 {
 242         return ERR_PTR(-ENODEV);
 243 }
 244
 245 static inline struct pwm_device *of_pwm_get(struct device_node *np,
 246                                             const char *con_id)
 247 {
 248         return ERR_PTR(-ENODEV);
 249 }
 250
 251 static inline void pwm_put(struct pwm_device *pwm)
 252 {
 253 }
 254
 255 static inline struct pwm_device *devm_pwm_get(struct device *dev,
 256                                               const char *consumer)
 257 {
 258         return ERR_PTR(-ENODEV);
 259 }
 260
 261 static inline struct pwm_device *devm_of_pwm_get(struct device *dev,
 262                                                  struct device_node *np,
 263                                                  const char *con_id)
 264 {
 265         return ERR_PTR(-ENODEV);
 266 }
 267
 268 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
 269 {
 270 }
 271
 272 static inline bool pwm_can_sleep(struct pwm_device *pwm)
 273 {
 274         return false;
 275 }
 276 #endif
 277
 278 struct pwm_lookup {
 279         struct list_head list;
 280         const char *provider;
 281         unsigned int index;
 282         const char *dev_id;
 283         const char *con_id;
 284         unsigned int period;
 285         enum pwm_polarity polarity;
 286 };
 287
 288 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \
 289         {                                               \
 290                 .provider = _provider,                  \
 291                 .index = _index,                        \
 292                 .dev_id = _dev_id,                      \
 293                 .con_id = _con_id,                      \
 294                 .period = _period,                      \
 295                 .polarity = _polarity                   \
 296         }
 297
 298 #if IS_ENABLED(CONFIG_PWM)
 299 void pwm_add_table(struct pwm_lookup *table, size_t num);
 300 void pwm_remove_table(struct pwm_lookup *table, size_t num);
 301 #else
 302 static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
 303 {
 304 }
 305
 306 static inline void pwm_remove_table(struct pwm_lookup *table, size_t num)
 307 {
 308 }
 309 #endif
 310
 311 #ifdef CONFIG_PWM_SYSFS
 312 void pwmchip_sysfs_export(struct pwm_chip *chip);
 313 void pwmchip_sysfs_unexport(struct pwm_chip *chip);
 314 #else
 315 static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
 316 {
 317 }
 318
 319 static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
 320 {
 321 }
 322 #endif /* CONFIG_PWM_SYSFS */
 323
 324 #endif /* __LINUX_PWM_H */