pwm.h

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#ifndef __LINUX_PWM_H
#define __LINUX_PWM_H

#include <linux/err.h>
#include <linux/of.h>

struct pwm_device;
struct seq_file;

#if IS_ENABLED(CONFIG_PWM) || IS_ENABLED(CONFIG_HAVE_PWM)
/*
 * pwm_request - request a PWM device
 */
struct pwm_device *pwm_request(int pwm_id, const char *label);

/*
 * pwm_free - free a PWM device
 */
void pwm_free(struct pwm_device *pwm);

/*
 * pwm_config - change a PWM device configuration
 */
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);

/*
 * pwm_enable - start a PWM output toggling
 */
int pwm_enable(struct pwm_device *pwm);

/*
 * pwm_disable - stop a PWM output toggling
 */
void pwm_disable(struct pwm_device *pwm);
#else
static inline struct pwm_device *pwm_request(int pwm_id, const char *label)
{
    return ERR_PTR(-ENODEV);
}

static inline void pwm_free(struct pwm_device *pwm)
{
}

static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
    return -EINVAL;
}

static inline int pwm_enable(struct pwm_device *pwm)
{
    return -EINVAL;
}

static inline void pwm_disable(struct pwm_device *pwm)
{
}
#endif

struct pwm_chip;

enum pwm_polarity {
    PWM_POLARITY_NORMAL,
    PWM_POLARITY_INVERSED,
};

enum {
    PWMF_REQUESTED = 1 << 0,
    PWMF_ENABLED = 1 << 1,
};

struct pwm_device {
    const char      *label;
    unsigned long       flags;
    unsigned int        hwpwm;
    unsigned int        pwm;
    struct pwm_chip     *chip;
    void            *chip_data;

    unsigned int        period; /* in nanoseconds */
};

static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
{
    if (pwm)
        pwm->period = period;
}

static inline unsigned int pwm_get_period(struct pwm_device *pwm)
{
    return pwm ? pwm->period : 0;
}

/*
 * pwm_set_polarity - configure the polarity of a PWM signal
 */
int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);

struct pwm_ops {
    int         (*request)(struct pwm_chip *chip,
                       struct pwm_device *pwm);
    void            (*free)(struct pwm_chip *chip,
                    struct pwm_device *pwm);
    int         (*config)(struct pwm_chip *chip,
                      struct pwm_device *pwm,
                      int duty_ns, int period_ns);
    int         (*set_polarity)(struct pwm_chip *chip,
                      struct pwm_device *pwm,
                      enum pwm_polarity polarity);
    int         (*enable)(struct pwm_chip *chip,
                      struct pwm_device *pwm);
    void            (*disable)(struct pwm_chip *chip,
                       struct pwm_device *pwm);
#ifdef CONFIG_DEBUG_FS
    void            (*dbg_show)(struct pwm_chip *chip,
                        struct seq_file *s);
#endif
    struct module       *owner;
};

struct pwm_chip {
    struct device       *dev;
    struct list_head    list;
    const struct pwm_ops    *ops;
    int         base;
    unsigned int        npwm;

    struct pwm_device   *pwms;

    struct pwm_device * (*of_xlate)(struct pwm_chip *pc,
                        const struct of_phandle_args *args);
    unsigned int        of_pwm_n_cells;
};

#if IS_ENABLED(CONFIG_PWM)
int pwm_set_chip_data(struct pwm_device *pwm, void *data);
void *pwm_get_chip_data(struct pwm_device *pwm);

int pwmchip_add(struct pwm_chip *chip);
int pwmchip_remove(struct pwm_chip *chip);
struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
                     unsigned int index,
                     const char *label);

struct pwm_device *pwm_get(struct device *dev, const char *consumer);
void pwm_put(struct pwm_device *pwm);

struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer);
void devm_pwm_put(struct device *dev, struct pwm_device *pwm);
#else
static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data)
{
    return -EINVAL;
}

static inline void *pwm_get_chip_data(struct pwm_device *pwm)
{
    return NULL;
}

static inline int pwmchip_add(struct pwm_chip *chip)
{
    return -EINVAL;
}

static inline int pwmchip_remove(struct pwm_chip *chip)
{
    return -EINVAL;
}

static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
                               unsigned int index,
                               const char *label)
{
    return ERR_PTR(-ENODEV);
}

static inline struct pwm_device *pwm_get(struct device *dev,
                     const char *consumer)
{
    return ERR_PTR(-ENODEV);
}

static inline void pwm_put(struct pwm_device *pwm)
{
}

static inline struct pwm_device *devm_pwm_get(struct device *dev,
                          const char *consumer)
{
    return ERR_PTR(-ENODEV);
}

static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
{
}
#endif

struct pwm_lookup {
    struct list_head list;
    const char *provider;
    unsigned int index;
    const char *dev_id;
    const char *con_id;
};

#define PWM_LOOKUP(_provider, _index, _dev_id, _con_id) \
    {                       \
        .provider = _provider,          \
        .index = _index,            \
        .dev_id = _dev_id,          \
        .con_id = _con_id,          \
    }

#if IS_ENABLED(CONFIG_PWM)
void pwm_add_table(struct pwm_lookup *table, size_t num);
#else
static inline void pwm_add_table(struct pwm_lookup *table, size_t num)
{
}
#endif

#endif /* __LINUX_PWM_H */