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) || IS_ENABLED(CONFIG_HAVE_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(struct pwm_chip *chip);
 186 int pwmchip_remove(struct pwm_chip *chip);
 187 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 188                                          unsigned int index,
 189                                          const char *label);
 190
 191 struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
 192                 const struct of_phandle_args *args);
 193
 194 struct pwm_device *pwm_get(struct device *dev, const char *con_id);
 195 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id);
 196 void pwm_put(struct pwm_device *pwm);
 197
 198 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id);
 199 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
 200                                    const char *con_id);
 201 void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
 202
 203 bool pwm_can_sleep(struct pwm_device *pwm);
 204 #else
 205 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
 206 {
 207         return -EINVAL;
 208 }
 209
 210 static inline void *pwm_get_chip_data(struct pwm_device *pwm)
 211 {
 212         return NULL;
 213 }
 214
 215 static inline int pwmchip_add(struct pwm_chip *chip)
 216 {
 217         return -EINVAL;
 218 }
 219
 220 static inline int pwmchip_remove(struct pwm_chip *chip)
 221 {
 222         return -EINVAL;
 223 }
 224
 225 static 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
 232 static inline struct pwm_device *pwm_get(struct device *dev,
 233                                          const char *consumer)
 234 {
 235         return ERR_PTR(-ENODEV);
 236 }
 237
 238 static inline struct pwm_device *of_pwm_get(struct device_node *np,
 239                                             const char *con_id)
 240 {
 241         return ERR_PTR(-ENODEV);
 242 }
 243
 244 static inline void pwm_put(struct pwm_device *pwm)
 245 {
 246 }
 247
 248 static inline struct pwm_device *devm_pwm_get(struct device *dev,
 249                                               const char *consumer)
 250 {
 251         return ERR_PTR(-ENODEV);
 252 }
 253
 254 static 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
 261 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
 262 {
 263 }
 264
 265 static inline bool pwm_can_sleep(struct pwm_device *pwm)
 266 {
 267         return false;
 268 }
 269 #endif
 270
 271 struct 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 };
 278
 279 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id) \
 280         {                                               \
 281                 .provider = _provider,                  \
 282                 .index = _index,                        \
 283                 .dev_id = _dev_id,                      \
 284                 .con_id = _con_id,                      \
 285         }
 286
 287 #if IS_ENABLED(CONFIG_PWM)
 288 void pwm_add_table(struct pwm_lookup *table, size_t num);
 289 #else
 290 static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
 291 {
 292 }
 293 #endif
 294
 295 #ifdef CONFIG_PWM_SYSFS
 296 void pwmchip_sysfs_export(struct pwm_chip *chip);
 297 void pwmchip_sysfs_unexport(struct pwm_chip *chip);
 298 #else
 299 static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
 300 {
 301 }
 302
 303 static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
 304 {
 305 }
 306 #endif /* CONFIG_PWM_SYSFS */
 307
 308 #endif /* __LINUX_PWM_H */