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 };
  80
  81 struct pwm_device {
  82         const char              *label;
  83         unsigned long           flags;
  84         unsigned int            hwpwm;
  85         unsigned int            pwm;
  86         struct pwm_chip         *chip;
  87         void                    *chip_data;
  88
  89         unsigned int            period; /* in nanoseconds */
  90 };
  91
  92 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
  93 {
  94         if (pwm)
  95                 pwm->period = period;
  96 }
  97
  98 static inline unsigned int pwm_get_period(struct pwm_device *pwm)
  99 {
 100         return pwm ? pwm->period : 0;
 101 }
 102
 103 /*
 104  * pwm_set_polarity - configure the polarity of a PWM signal
 105  */
 106 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
 107
 108 /**
 109  * struct pwm_ops - PWM controller operations
 110  * @request: optional hook for requesting a PWM
 111  * @free: optional hook for freeing a PWM
 112  * @config: configure duty cycles and period length for this PWM
 113  * @set_polarity: configure the polarity of this PWM
 114  * @enable: enable PWM output toggling
 115  * @disable: disable PWM output toggling
 116  * @dbg_show: optional routine to show contents in debugfs
 117  * @owner: helps prevent removal of modules exporting active PWMs
 118  */
 119 struct pwm_ops {
 120         int                     (*request)(struct pwm_chip *chip,
 121                                            struct pwm_device *pwm);
 122         void                    (*free)(struct pwm_chip *chip,
 123                                         struct pwm_device *pwm);
 124         int                     (*config)(struct pwm_chip *chip,
 125                                           struct pwm_device *pwm,
 126                                           int duty_ns, int period_ns);
 127         int                     (*set_polarity)(struct pwm_chip *chip,
 128                                           struct pwm_device *pwm,
 129                                           enum pwm_polarity polarity);
 130         int                     (*enable)(struct pwm_chip *chip,
 131                                           struct pwm_device *pwm);
 132         void                    (*disable)(struct pwm_chip *chip,
 133                                            struct pwm_device *pwm);
 134 #ifdef CONFIG_DEBUG_FS
 135         void                    (*dbg_show)(struct pwm_chip *chip,
 136                                             struct seq_file *s);
 137 #endif
 138         struct module           *owner;
 139 };
 140
 141 /**
 142  * struct pwm_chip - abstract a PWM controller
 143  * @dev: device providing the PWMs
 144  * @list: list node for internal use
 145  * @ops: callbacks for this PWM controller
 146  * @base: number of first PWM controlled by this chip
 147  * @npwm: number of PWMs controlled by this chip
 148  * @pwms: array of PWM devices allocated by the framework
 149  */
 150 struct pwm_chip {
 151         struct device           *dev;
 152         struct list_head        list;
 153         const struct pwm_ops    *ops;
 154         int                     base;
 155         unsigned int            npwm;
 156
 157         struct pwm_device       *pwms;
 158
 159         struct pwm_device *     (*of_xlate)(struct pwm_chip *pc,
 160                                             const struct of_phandle_args *args);
 161         unsigned int            of_pwm_n_cells;
 162 };
 163
 164 #if IS_ENABLED(CONFIG_PWM)
 165 int pwm_set_chip_data(struct pwm_device *pwm, void *data);
 166 void *pwm_get_chip_data(struct pwm_device *pwm);
 167
 168 int pwmchip_add(struct pwm_chip *chip);
 169 int pwmchip_remove(struct pwm_chip *chip);
 170 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 171                                          unsigned int index,
 172                                          const char *label);
 173
 174 struct pwm_device *pwm_get(struct device *dev, const char *consumer);
 175 void pwm_put(struct pwm_device *pwm);
 176
 177 struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer);
 178 void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
 179 #else
 180 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
 181 {
 182         return -EINVAL;
 183 }
 184
 185 static inline void *pwm_get_chip_data(struct pwm_device *pwm)
 186 {
 187         return NULL;
 188 }
 189
 190 static inline int pwmchip_add(struct pwm_chip *chip)
 191 {
 192         return -EINVAL;
 193 }
 194
 195 static inline int pwmchip_remove(struct pwm_chip *chip)
 196 {
 197         return -EINVAL;
 198 }
 199
 200 static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 201                                                        unsigned int index,
 202                                                        const char *label)
 203 {
 204         return ERR_PTR(-ENODEV);
 205 }
 206
 207 static inline struct pwm_device *pwm_get(struct device *dev,
 208                                          const char *consumer)
 209 {
 210         return ERR_PTR(-ENODEV);
 211 }
 212
 213 static inline void pwm_put(struct pwm_device *pwm)
 214 {
 215 }
 216
 217 static inline struct pwm_device *devm_pwm_get(struct device *dev,
 218                                               const char *consumer)
 219 {
 220         return ERR_PTR(-ENODEV);
 221 }
 222
 223 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
 224 {
 225 }
 226 #endif
 227
 228 struct pwm_lookup {
 229         struct list_head list;
 230         const char *provider;
 231         unsigned int index;
 232         const char *dev_id;
 233         const char *con_id;
 234 };
 235
 236 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id) \
 237         {                                               \
 238                 .provider = _provider,                  \
 239                 .index = _index,                        \
 240                 .dev_id = _dev_id,                      \
 241                 .con_id = _con_id,                      \
 242         }
 243
 244 #if IS_ENABLED(CONFIG_PWM)
 245 void pwm_add_table(struct pwm_lookup *table, size_t num);
 246 #else
 247 static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
 248 {
 249 }
 250 #endif
 251
 252 #endif /* __LINUX_PWM_H */