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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;
pwm: Allow chips to support multiple PWMs Many PWM controllers provide access to more than a single PWM output and may even share some resource among them. Allowing a PWM chip to provide multiple PWM devices enables better sharing of those resources. As a side-effect this change allows easy integration with the device tree where a given PWM can be looked up based on the PWM chip's phandle and a corresponding index. This commit modifies the PWM core to support multiple PWMs per struct pwm_chip. It achieves this in a similar way to how gpiolib works, by allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or starting at a given offset (pwm_chip.base >= 0). A chip specifies how many PWMs it controls using the npwm member. Each of the functions in the pwm_ops structure gets an additional argument that specified the PWM number (it can be converted to a per-chip index by subtracting the chip's base). The total maximum number of PWM devices is currently fixed to 1024 while the data is actually stored in a radix tree, thus saving resources if not all of them are used. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [eric@eukrea.com: fix error handling in pwmchip_add] Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2011-12-14 18:12:23 +08:00
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: 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
/**
* 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 {
pwm: Allow chips to support multiple PWMs Many PWM controllers provide access to more than a single PWM output and may even share some resource among them. Allowing a PWM chip to provide multiple PWM devices enables better sharing of those resources. As a side-effect this change allows easy integration with the device tree where a given PWM can be looked up based on the PWM chip's phandle and a corresponding index. This commit modifies the PWM core to support multiple PWMs per struct pwm_chip. It achieves this in a similar way to how gpiolib works, by allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or starting at a given offset (pwm_chip.base >= 0). A chip specifies how many PWMs it controls using the npwm member. Each of the functions in the pwm_ops structure gets an additional argument that specified the PWM number (it can be converted to a per-chip index by subtracting the chip's base). The total maximum number of PWM devices is currently fixed to 1024 while the data is actually stored in a radix tree, thus saving resources if not all of them are used. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [eric@eukrea.com: fix error handling in pwmchip_add] Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2011-12-14 18:12:23 +08:00
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 (*enable)(struct pwm_chip *chip,
struct pwm_device *pwm);
void (*disable)(struct pwm_chip *chip,
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
struct module *owner;
};
/**
pwm: Allow chips to support multiple PWMs Many PWM controllers provide access to more than a single PWM output and may even share some resource among them. Allowing a PWM chip to provide multiple PWM devices enables better sharing of those resources. As a side-effect this change allows easy integration with the device tree where a given PWM can be looked up based on the PWM chip's phandle and a corresponding index. This commit modifies the PWM core to support multiple PWMs per struct pwm_chip. It achieves this in a similar way to how gpiolib works, by allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or starting at a given offset (pwm_chip.base >= 0). A chip specifies how many PWMs it controls using the npwm member. Each of the functions in the pwm_ops structure gets an additional argument that specified the PWM number (it can be converted to a per-chip index by subtracting the chip's base). The total maximum number of PWM devices is currently fixed to 1024 while the data is actually stored in a radix tree, thus saving resources if not all of them are used. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [eric@eukrea.com: fix error handling in pwmchip_add] Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2011-12-14 18:12:23 +08:00
* struct pwm_chip - abstract a PWM controller
* @dev: device providing the PWMs
* @list: list node for internal use
* @ops: callbacks for this PWM controller
* @base: number of first PWM controlled by this chip
* @npwm: number of PWMs controlled by this chip
* @pwms: array of PWM devices allocated by the framework
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
*/
struct pwm_chip {
pwm: Allow chips to support multiple PWMs Many PWM controllers provide access to more than a single PWM output and may even share some resource among them. Allowing a PWM chip to provide multiple PWM devices enables better sharing of those resources. As a side-effect this change allows easy integration with the device tree where a given PWM can be looked up based on the PWM chip's phandle and a corresponding index. This commit modifies the PWM core to support multiple PWMs per struct pwm_chip. It achieves this in a similar way to how gpiolib works, by allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or starting at a given offset (pwm_chip.base >= 0). A chip specifies how many PWMs it controls using the npwm member. Each of the functions in the pwm_ops structure gets an additional argument that specified the PWM number (it can be converted to a per-chip index by subtracting the chip's base). The total maximum number of PWM devices is currently fixed to 1024 while the data is actually stored in a radix tree, thus saving resources if not all of them are used. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [eric@eukrea.com: fix error handling in pwmchip_add] Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2011-12-14 18:12:23 +08:00
struct device *dev;
struct list_head list;
const struct pwm_ops *ops;
int base;
unsigned int npwm;
struct pwm_device *pwms;
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
};
pwm: Allow chips to support multiple PWMs Many PWM controllers provide access to more than a single PWM output and may even share some resource among them. Allowing a PWM chip to provide multiple PWM devices enables better sharing of those resources. As a side-effect this change allows easy integration with the device tree where a given PWM can be looked up based on the PWM chip's phandle and a corresponding index. This commit modifies the PWM core to support multiple PWMs per struct pwm_chip. It achieves this in a similar way to how gpiolib works, by allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or starting at a given offset (pwm_chip.base >= 0). A chip specifies how many PWMs it controls using the npwm member. Each of the functions in the pwm_ops structure gets an additional argument that specified the PWM number (it can be converted to a per-chip index by subtracting the chip's base). The total maximum number of PWM devices is currently fixed to 1024 while the data is actually stored in a radix tree, thus saving resources if not all of them are used. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [eric@eukrea.com: fix error handling in pwmchip_add] Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2011-12-14 18:12:23 +08:00
int pwm_set_chip_data(struct pwm_device *pwm, void *data);
void *pwm_get_chip_data(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
int pwmchip_add(struct pwm_chip *chip);
int pwmchip_remove(struct pwm_chip *chip);
pwm: Allow chips to support multiple PWMs Many PWM controllers provide access to more than a single PWM output and may even share some resource among them. Allowing a PWM chip to provide multiple PWM devices enables better sharing of those resources. As a side-effect this change allows easy integration with the device tree where a given PWM can be looked up based on the PWM chip's phandle and a corresponding index. This commit modifies the PWM core to support multiple PWMs per struct pwm_chip. It achieves this in a similar way to how gpiolib works, by allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or starting at a given offset (pwm_chip.base >= 0). A chip specifies how many PWMs it controls using the npwm member. Each of the functions in the pwm_ops structure gets an additional argument that specified the PWM number (it can be converted to a per-chip index by subtracting the chip's base). The total maximum number of PWM devices is currently fixed to 1024 while the data is actually stored in a radix tree, thus saving resources if not all of them are used. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [eric@eukrea.com: fix error handling in pwmchip_add] Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2011-12-14 18:12:23 +08:00
struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
unsigned int index,
const char *label);
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
#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 */