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 /**
  38  * enum pwm_polarity - polarity of a PWM signal
  39  * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty-
  40  * cycle, followed by a low signal for the remainder of the pulse
  41  * period
  42  * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty-
  43  * cycle, followed by a high signal for the remainder of the pulse
  44  * period
  45  */
  46 enum pwm_polarity {
  47         PWM_POLARITY_NORMAL,
  48         PWM_POLARITY_INVERSED,
  49 };
  50
  51 enum {
  52         PWMF_REQUESTED = 1 << 0,
  53         PWMF_ENABLED = 1 << 1,
  54 };
  55
  56 struct pwm_device {
  57         const char              *label;
  58         unsigned long           flags;
  59         unsigned int            hwpwm;
  60         unsigned int            pwm;
  61         struct pwm_chip         *chip;
  62         void                    *chip_data;
  63
  64         unsigned int            period; /* in nanoseconds */
  65 };
  66
  67 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
  68 {
  69         if (pwm)
  70                 pwm->period = period;
  71 }
  72
  73 static inline unsigned int pwm_get_period(struct pwm_device *pwm)
  74 {
  75         return pwm ? pwm->period : 0;
  76 }
  77
  78 /*
  79  * pwm_set_polarity - configure the polarity of a PWM signal
  80  */
  81 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
  82
  83 /**
  84  * struct pwm_ops - PWM controller operations
  85  * @request: optional hook for requesting a PWM
  86  * @free: optional hook for freeing a PWM
  87  * @config: configure duty cycles and period length for this PWM
  88  * @set_polarity: configure the polarity of this PWM
  89  * @enable: enable PWM output toggling
  90  * @disable: disable PWM output toggling
  91  * @dbg_show: optional routine to show contents in debugfs
  92  * @owner: helps prevent removal of modules exporting active PWMs
  93  */
  94 struct pwm_ops {
  95         int                     (*request)(struct pwm_chip *chip,
  96                                            struct pwm_device *pwm);
  97         void                    (*free)(struct pwm_chip *chip,
  98                                         struct pwm_device *pwm);
  99         int                     (*config)(struct pwm_chip *chip,
 100                                           struct pwm_device *pwm,
 101                                           int duty_ns, int period_ns);
 102         int                     (*set_polarity)(struct pwm_chip *chip,
 103                                           struct pwm_device *pwm,
 104                                           enum pwm_polarity polarity);
 105         int                     (*enable)(struct pwm_chip *chip,
 106                                           struct pwm_device *pwm);
 107         void                    (*disable)(struct pwm_chip *chip,
 108                                            struct pwm_device *pwm);
 109 #ifdef CONFIG_DEBUG_FS
 110         void                    (*dbg_show)(struct pwm_chip *chip,
 111                                             struct seq_file *s);
 112 #endif
 113         struct module           *owner;
 114 };
 115
 116 /**
 117  * struct pwm_chip - abstract a PWM controller
 118  * @dev: device providing the PWMs
 119  * @list: list node for internal use
 120  * @ops: callbacks for this PWM controller
 121  * @base: number of first PWM controlled by this chip
 122  * @npwm: number of PWMs controlled by this chip
 123  * @pwms: array of PWM devices allocated by the framework
 124  */
 125 struct pwm_chip {
 126         struct device           *dev;
 127         struct list_head        list;
 128         const struct pwm_ops    *ops;
 129         int                     base;
 130         unsigned int            npwm;
 131
 132         struct pwm_device       *pwms;
 133
 134         struct pwm_device *     (*of_xlate)(struct pwm_chip *pc,
 135                                             const struct of_phandle_args *args);
 136         unsigned int            of_pwm_n_cells;
 137 };
 138
 139 int pwm_set_chip_data(struct pwm_device *pwm, void *data);
 140 void *pwm_get_chip_data(struct pwm_device *pwm);
 141
 142 int pwmchip_add(struct pwm_chip *chip);
 143 int pwmchip_remove(struct pwm_chip *chip);
 144 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
 145                                          unsigned int index,
 146                                          const char *label);
 147
 148 struct pwm_device *pwm_get(struct device *dev, const char *consumer);
 149 void pwm_put(struct pwm_device *pwm);
 150
 151 struct pwm_lookup {
 152         struct list_head list;
 153         const char *provider;
 154         unsigned int index;
 155         const char *dev_id;
 156         const char *con_id;
 157 };
 158
 159 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id) \
 160         {                                               \
 161                 .provider = _provider,                  \
 162                 .index = _index,                        \
 163                 .dev_id = _dev_id,                      \
 164                 .con_id = _con_id,                      \
 165         }
 166
 167 void pwm_add_table(struct pwm_lookup *table, size_t num);
 168
 169 #endif
 170
 171 #endif /* __LINUX_PWM_H */