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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 01:40:40 -07:00
menuconfig PWM
bool "Pulse-Width Modulation (PWM) Support"
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 01:40:40 -07:00
help
Generic Pulse-Width Modulation (PWM) support.
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 01:40:40 -07:00
In Pulse-Width Modulation, a variation of the width of pulses
in a rectangular pulse signal is used as a means to alter the
average power of the signal. Applications include efficient
power delivery and voltage regulation. In computer systems,
PWMs are commonly used to control fans or the brightness of
display backlights.
This framework provides a generic interface to PWM devices
within the Linux kernel. On the driver side it provides an API
to register and unregister a PWM chip, an abstraction of a PWM
controller, that supports one or more PWM devices. Client
drivers can request PWM devices and use the generic framework
to configure as well as enable and disable them.
This generic framework replaces the legacy PWM framework which
allows only a single driver implementing the required API. Not
all legacy implementations have been ported to the framework
yet. The framework provides an API that is backward compatible
with the legacy framework so that existing client drivers
continue to work as expected.
If unsure, say no.
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 01:40:40 -07:00
if PWM
config PWM_SYSFS
bool
default y if SYSFS
config PWM_AB8500
tristate "AB8500 PWM support"
depends on AB8500_CORE && ARCH_U8500
help
Generic PWM framework driver for Analog Baseband AB8500.
To compile this driver as a module, choose M here: the module
will be called pwm-ab8500.
config PWM_ATMEL_TCB
tristate "Atmel TC Block PWM support"
depends on ATMEL_TCLIB && OF
help
Generic PWM framework driver for Atmel Timer Counter Block.
A Timer Counter Block provides 6 PWM devices grouped by 2.
Devices in a given group must have the same period.
To compile this driver as a module, choose M here: the module
will be called pwm-atmel-tcb.
config PWM_BFIN
tristate "Blackfin PWM support"
depends on BFIN_GPTIMERS
help
Generic PWM framework driver for Blackfin.
To compile this driver as a module, choose M here: the module
will be called pwm-bfin.
config PWM_EP93XX
tristate "Cirrus Logic EP93xx PWM support"
depends on ARCH_EP93XX
help
Generic PWM framework driver for Cirrus Logic EP93xx.
To compile this driver as a module, choose M here: the module
will be called pwm-ep93xx.
config PWM_IMX
tristate "i.MX PWM support"
depends on ARCH_MXC
help
Generic PWM framework driver for i.MX.
To compile this driver as a module, choose M here: the module
will be called pwm-imx.
config PWM_JZ4740
tristate "Ingenic JZ4740 PWM support"
depends on MACH_JZ4740
help
Generic PWM framework driver for Ingenic JZ4740 based
machines.
To compile this driver as a module, choose M here: the module
will be called pwm-jz4740.
config PWM_LPC32XX
tristate "LPC32XX PWM support"
depends on ARCH_LPC32XX
help
Generic PWM framework driver for LPC32XX. The LPC32XX SOC has two
PWM controllers.
To compile this driver as a module, choose M here: the module
will be called pwm-lpc32xx.
config PWM_MXS
tristate "Freescale MXS PWM support"
depends on ARCH_MXS && OF
select STMP_DEVICE
help
Generic PWM framework driver for Freescale MXS.
To compile this driver as a module, choose M here: the module
will be called pwm-mxs.
config PWM_PCA9685
tristate "NXP PCA9685 PWM driver"
depends on OF && REGMAP_I2C
help
Generic PWM framework driver for NXP PCA9685 LED controller.
To compile this driver as a module, choose M here: the module
will be called pwm-pca9685.
config PWM_PUV3
tristate "PKUnity NetBook-0916 PWM support"
depends on ARCH_PUV3
help
Generic PWM framework driver for PKUnity NetBook-0916.
To compile this driver as a module, choose M here: the module
will be called pwm-puv3.
config PWM_PXA
tristate "PXA PWM support"
depends on ARCH_PXA
help
Generic PWM framework driver for PXA.
To compile this driver as a module, choose M here: the module
will be called pwm-pxa.
config PWM_RENESAS_TPU
tristate "Renesas TPU PWM support"
depends on ARCH_SHMOBILE || COMPILE_TEST
help
This driver exposes the Timer Pulse Unit (TPU) PWM controller found
in Renesas chips through the PWM API.
To compile this driver as a module, choose M here: the module
will be called pwm-renesas-tpu.
config PWM_SAMSUNG
tristate "Samsung PWM support"
depends on PLAT_SAMSUNG
help
Generic PWM framework driver for Samsung.
To compile this driver as a module, choose M here: the module
will be called pwm-samsung.
config PWM_SPEAR
tristate "STMicroelectronics SPEAr PWM support"
depends on PLAT_SPEAR
depends on OF
help
Generic PWM framework driver for the PWM controller on ST
SPEAr SoCs.
To compile this driver as a module, choose M here: the module
will be called pwm-spear.
config PWM_TEGRA
tristate "NVIDIA Tegra PWM support"
depends on ARCH_TEGRA
help
Generic PWM framework driver for the PWFM controller found on NVIDIA
Tegra SoCs.
To compile this driver as a module, choose M here: the module
will be called pwm-tegra.
config PWM_TIECAP
tristate "ECAP PWM support"
depends on SOC_AM33XX || ARCH_DAVINCI_DA8XX
help
PWM driver support for the ECAP APWM controller found on AM33XX
TI SOC
To compile this driver as a module, choose M here: the module
will be called pwm-tiecap.
config PWM_TIEHRPWM
tristate "EHRPWM PWM support"
depends on SOC_AM33XX || ARCH_DAVINCI_DA8XX
help
PWM driver support for the EHRPWM controller found on AM33XX
TI SOC
To compile this driver as a module, choose M here: the module
will be called pwm-tiehrpwm.
config PWM_TIPWMSS
bool
default y if SOC_AM33XX && (PWM_TIECAP || PWM_TIEHRPWM)
help
PWM Subsystem driver support for AM33xx SOC.
PWM submodules require PWM config space access from submodule
drivers and require common parent driver support.
config PWM_TWL
tristate "TWL4030/6030 PWM support"
depends on TWL4030_CORE
help
Generic PWM framework driver for TWL4030/6030.
To compile this driver as a module, choose M here: the module
will be called pwm-twl.
config PWM_TWL_LED
tristate "TWL4030/6030 PWM support for LED drivers"
depends on TWL4030_CORE
help
Generic PWM framework driver for TWL4030/6030 LED terminals.
To compile this driver as a module, choose M here: the module
will be called pwm-twl-led.
config PWM_VT8500
tristate "vt8500 PWM support"
depends on ARCH_VT8500
help
Generic PWM framework driver for vt8500.
To compile this driver as a module, choose M here: the module
will be called pwm-vt8500.
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 01:40:40 -07:00
endif