include/linux/pwm.h

   1 #ifndef __LINUX_PWM_H
   2 #define __LINUX_PWM_H
   3
   4 #include <linux/of.h>
   5
   6 struct pwm_device;
   7 struct seq_file;
   8
   9 /*
  10  * pwm_request - request a PWM device
  11  */
  12 struct pwm_device *pwm_request(int pwm_id, const char *label);
  13
  14 /*
  15  * pwm_free - free a PWM device
  16  */
  17 void pwm_free(struct pwm_device *pwm);
  18
  19 /*
  20  * pwm_config - change a PWM device configuration
  21  */
  22 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
  23
  24 /*
  25  * pwm_enable - start a PWM output toggling
  26  */
  27 int pwm_enable(struct pwm_device *pwm);
  28
  29 /*
  30  * pwm_disable - stop a PWM output toggling
  31  */
  32 void pwm_disable(struct pwm_device *pwm);
  33
  34 #ifdef CONFIG_PWM
  35 struct pwm_chip;
  36
  37 enum {
  38         PWMF_REQUESTED = 1 << 0,
  39         PWMF_ENABLED = 1 << 1,
  40 };
  41
  42 struct pwm_device {
  43         const char              *label;
  44         unsigned long           flags;
  45         unsigned int            hwpwm;
  46         unsigned int            pwm;
  47         struct pwm_chip         *chip;
  48         void                    *chip_data;
  49
  50         unsigned int            period; /* in nanoseconds */
  51 };
  52
  53 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
  54 {
  55         if (pwm)
  56                 pwm->period = period;
  57 }
  58
  59 static inline unsigned int pwm_get_period(struct pwm_device *pwm)
  60 {
  61         return pwm ? pwm->period : 0;
  62 }
  63
  64 /**
  65  * struct pwm_ops - PWM controller operations
  66  * @request: optional hook for requesting a PWM
  67  * @free: optional hook for freeing a PWM
  68  * @config: configure duty cycles and period length for this PWM
  69  * @enable: enable PWM output toggling
  70  * @disable: disable PWM output toggling
  71  * @dbg_show: optional routine to show contents in debugfs
  72  * @owner: helps prevent removal of modules exporting active PWMs
  73  */
  74 struct pwm_ops {
  75         int                     (*request)(struct pwm_chip *chip,
  76                                            struct pwm_device *pwm);
  77         void                    (*free)(struct pwm_chip *chip,
  78                                         struct pwm_device *pwm);
  79         int                     (*config)(struct pwm_chip *chip,
  80                                           struct pwm_device *pwm,
  81                                           int duty_ns, int period_ns);
  82         int                     (*enable)(struct pwm_chip *chip,
  83                                           struct pwm_device *pwm);
  84         void                    (*disable)(struct pwm_chip *chip,
  85                                            struct pwm_device *pwm);
  86 #ifdef CONFIG_DEBUG_FS
  87         void                    (*dbg_show)(struct pwm_chip *chip,
  88                                             struct seq_file *s);
  89 #endif
  90         struct module           *owner;
  91 };
  92
  93 /**
  94  * struct pwm_chip - abstract a PWM controller
  95  * @dev: device providing the PWMs
  96  * @list: list node for internal use
  97  * @ops: callbacks for this PWM controller
  98  * @base: number of first PWM controlled by this chip
  99  * @npwm: number of PWMs controlled by this chip
 100  * @pwms: array of PWM devices allocated by the framework
 101  */
 102 struct pwm_chip {
 103         struct device           *dev;
 104         struct list_head        list;
 105         const struct pwm_ops    *ops;
 106         int                     base;
 107         unsigned int            npwm;
 108
 109         struct pwm_device       *pwms;
 110
 111         struct pwm_device *     (*of_xlate)(struct pwm_chip *pc,
 112                                             const struct of_phandle_args *args);
 113         unsigned int            of_pwm_n_cells;
 114 };
 115
 116 int pwm_set_chip_data(struct pwm_device *pwm, void *data);
 117 void *pwm_get_chip_data(struct pwm_device *pwm);
 118
 119 int pwmchip_add(struct pwm_chip *chip);
 120 int pwmchip_remove(struct pwm_chip *chip);
 121 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 122                                          unsigned int index,
 123                                          const char *label);
 124
 125 struct pwm_device *pwm_get(struct device *dev, const char *consumer);
 126 void pwm_put(struct pwm_device *pwm);
 127
 128 struct pwm_lookup {
 129         struct list_head list;
 130         const char *provider;
 131         unsigned int index;
 132         const char *dev_id;
 133         const char *con_id;
 134 };
 135
 136 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id) \
 137         {                                               \
 138                 .provider = _provider,                  \
 139                 .index = _index,                        \
 140                 .dev_id = _dev_id,                      \
 141                 .con_id = _con_id,                      \
 142         }
 143
 144 void pwm_add_table(struct pwm_lookup *table, size_t num);
 145
 146 #endif
 147
 148 #endif /* __LINUX_PWM_H */