include/linux/pwm.h

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