From 0c2498f1660878339350bea8d18550b1b87ca055 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Fri, 28 Jan 2011 09:40:40 +0100 Subject: 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 Acked-by: Kurt Van Dijck Reviewed-by: Arnd Bergmann Reviewed-by: Matthias Kaehlcke Reviewed-by: Mark Brown Reviewed-by: Shawn Guo [thierry.reding@avionic-design.de: fixup typos, kerneldoc comments] Signed-off-by: Thierry Reding --- drivers/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/Makefile') diff --git a/drivers/Makefile b/drivers/Makefile index 2ba29ffef2cb..bd36f09f2246 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -8,6 +8,7 @@ # GPIO must come after pinctrl as gpios may need to mux pins etc obj-y += pinctrl/ obj-y += gpio/ +obj-y += pwm/ obj-$(CONFIG_PCI) += pci/ obj-$(CONFIG_PARISC) += parisc/ obj-$(CONFIG_RAPIDIO) += rapidio/ -- cgit v1.2.3