From 28ec38666ca101d18732c1ea529ec3e2bfa00bdb Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Tue, 11 Jun 2013 10:38:59 -0700 Subject: pwm: Add sysfs interface Add a simple sysfs interface to the generic PWM framework. /sys/class/pwm/ `-- pwmchipN/ for each PWM chip |-- export (w/o) ask the kernel to export a PWM channel |-- npwm (r/o) number of PWM channels in this PWM chip |-- pwmX/ for each exported PWM channel | |-- duty_cycle (r/w) duty cycle (in nanoseconds) | |-- enable (r/w) enable/disable PWM | |-- period (r/w) period (in nanoseconds) | `-- polarity (r/w) polarity of PWM (normal/inversed) `-- unexport (w/o) return a PWM channel to the kernel Based on work by Lars Poeschel. Signed-off-by: H Hartley Sweeten Cc: Thierry Reding Cc: Lars Poeschel Cc: Ryan Mallon Cc: Rob Landley Signed-off-by: Thierry Reding --- include/linux/pwm.h | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/pwm.h b/include/linux/pwm.h index a4df2042b79..f0feafd184a 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -76,6 +76,7 @@ enum pwm_polarity { enum { PWMF_REQUESTED = 1 << 0, PWMF_ENABLED = 1 << 1, + PWMF_EXPORTED = 1 << 2, }; struct pwm_device { @@ -86,7 +87,9 @@ struct pwm_device { struct pwm_chip *chip; void *chip_data; - unsigned int period; /* in nanoseconds */ + unsigned int period; /* in nanoseconds */ + unsigned int duty_cycle; /* in nanoseconds */ + enum pwm_polarity polarity; }; static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) @@ -100,6 +103,17 @@ static inline unsigned int pwm_get_period(struct pwm_device *pwm) return pwm ? pwm->period : 0; } +static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty) +{ + if (pwm) + pwm->duty_cycle = duty; +} + +static inline unsigned int pwm_get_duty_cycle(struct pwm_device *pwm) +{ + return pwm ? pwm->duty_cycle : 0; +} + /* * pwm_set_polarity - configure the polarity of a PWM signal */ @@ -278,4 +292,17 @@ static inline void pwm_add_table(struct pwm_lookup *table, size_t num) } #endif +#ifdef CONFIG_PWM_SYSFS +void pwmchip_sysfs_export(struct pwm_chip *chip); +void pwmchip_sysfs_unexport(struct pwm_chip *chip); +#else +static inline void pwmchip_sysfs_export(struct pwm_chip *chip) +{ +} + +static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip) +{ +} +#endif /* CONFIG_PWM_SYSFS */ + #endif /* __LINUX_PWM_H */ -- cgit v1.2.3