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OpenCloudOS-Kernel/include/linux/pwm.h

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[ARM] pxa: Add bare bones PWM API Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-14 04:41:55 +08:00
#ifndef __LINUX_PWM_H
#define __LINUX_PWM_H
struct pwm_device;
/*
* 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);
pwm: Add PWM framework support This patch adds framework support for PWM (pulse width modulation) devices. The is a barebone PWM API already in the kernel under include/linux/pwm.h, but it does not allow for multiple drivers as each of them implements the pwm_*() functions. There are other PWM framework patches around from Bill Gatliff. Unlike his framework this one does not change the existing API for PWMs so that this framework can act as a drop in replacement for the existing API. Why another framework? Several people argue that there should not be another framework for PWMs but they should be integrated into one of the existing frameworks like led or hwmon. Unlike these frameworks the PWM framework is agnostic to the purpose of the PWM. In fact, a PWM can drive a LED, but this makes the LED framework a user of a PWM, like already done in leds-pwm.c. The gpio framework also is not suitable for PWMs. Every gpio could be turned into a PWM using timer based toggling, but on the other hand not every PWM hardware device can be turned into a gpio due to the lack of hardware capabilities. This patch does not try to improve the PWM API yet, this could be done in subsequent patches. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Matthias Kaehlcke <matthias@kaehlcke.net> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [thierry.reding@avionic-design.de: fixup typos, kerneldoc comments] Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2011-01-28 16:40:40 +08:00
#ifdef CONFIG_PWM
struct pwm_chip;
/**
* struct pwm_ops - PWM controller operations
* @request: optional hook for requesting a PWM
* @free: optional hook for freeing a PWM
* @config: configure duty cycles and period length for this PWM
* @enable: enable PWM output toggling
* @disable: disable PWM output toggling
* @owner: helps prevent removal of modules exporting active PWMs
*/
struct pwm_ops {
int (*request)(struct pwm_chip *chip);
void (*free)(struct pwm_chip *chip);
int (*config)(struct pwm_chip *chip, int duty_ns,
int period_ns);
int (*enable)(struct pwm_chip *chip);
void (*disable)(struct pwm_chip *chip);
struct module *owner;
};
/**
* struct pwm_chip - abstract a PWM
* @pwm_id: global PWM device index
* @label: PWM device label
* @ops: controller operations
*/
struct pwm_chip {
int pwm_id;
const char *label;
struct pwm_ops *ops;
};
int pwmchip_add(struct pwm_chip *chip);
int pwmchip_remove(struct pwm_chip *chip);
#endif
trivial: PWM: fix of #endif comment Signed-off-by: Mark Vels <mark.vels@team-embedded.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-19 01:42:45 +08:00
#endif /* __LINUX_PWM_H */