diff options
| author | H Hartley Sweeten <hartleys@visionengravers.com> | 2013-06-11 10:38:59 -0700 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2013-06-21 11:32:51 +0200 |
| commit | 76abbdde2d95a3807d0dc6bf9f84d03d0dbd4f3d (patch) | |
| tree | 63a5476d6fbf80ec90b813461ec7ec67ff462684 /include/linux/pwm.h | |
| parent | 3dd0a909479c1d372341d749b4ff94cd638b57da (diff) | |
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 <hsweeten@visionengravers.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Lars Poeschel <poeschel@lemonage.de>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'include/linux/pwm.h')
| -rw-r--r-- | include/linux/pwm.h | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/include/linux/pwm.h b/include/linux/pwm.h index a4df2042b79c..f0feafd184a0 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 */ |