[PATCH 0/3] SPEAr320: Add pwm support

[s.hauer@pengutronix.de (Sascha Hauer)]

On Mon, May 30, 2011 at 01:53:20PM +0530, viresh kumar wrote:
> On 05/30/2011 01:15 PM, Arnd Bergmann wrote:
> > No objection to your patch, but I think we need to have
> > a long-term plan for pwm:
> > 
> > arnd at wuerfel:~/linux-2.6$ git ls-files | grep pwm.c
> > arch/arm/mach-exynos4/include/mach/pwm-clock.h
> > arch/arm/mach-mxs/devices/platform-mxs-pwm.c
> > arch/arm/mach-s3c64xx/include/mach/pwm-clock.h
> > arch/arm/mach-s5p64x0/include/mach/pwm-clock.h
> > arch/arm/mach-s5pc100/include/mach/pwm-clock.h
> > arch/arm/mach-s5pv210/include/mach/pwm-clock.h
> > arch/arm/mach-vt8500/pwm.c
> > arch/arm/plat-mxc/devices/platform-mxc_pwm.c
> > arch/arm/plat-mxc/pwm.c
> > arch/arm/plat-pxa/pwm.c
> > arch/arm/plat-s3c24xx/include/mach/pwm-clock.h
> > arch/arm/plat-samsung/dev-pwm.c
> > arch/arm/plat-samsung/pwm-clock.c
> > arch/arm/plat-samsung/pwm.c
> > arch/mips/jz4740/pwm.c
> > arch/unicore32/kernel/pwm.c
> > drivers/leds/leds-atmel-pwm.c
> > drivers/leds/leds-pwm.c
> > drivers/mfd/twl6030-pwm.c
> > drivers/misc/ab8500-pwm.c
> > drivers/misc/atmel_pwm.c
> > drivers/misc/ep93xx_pwm.c
> > 
> > My rough feeling is that what this should look like is a new
> > subsystem that exports a set of operations and has specific
> > drivers, like:
> > 
> > drivers/pwm/Kconfig
> > drivers/pwm/pwm_core.c
> > drivers/pwm/pwm_pxa.c
> > drivers/pwm/pwm_unicore.c
> > drivers/pwm/pwm_st.c
> > drivers/pwm/pwm_...
> > 
> 
> Sascha sent a patchset for something similar earlier.
> But don't know what happened to it.

Nothing yet, unfortunately. It was a straight forward implementation
which basically implements the existing pwm functions and adds
register/unregister functions.
Bill Gatliff posts a pwm framework since 2008. I wasn't aware of his
patches by the time I wrote my pwm layer. Bills patches target more the
motor controller use case and are (in my opinion) too complicated. I
can't agree on his approach, but didn't want to go with competing
patches either.

As Bills patches still didn't make it into the kernel Maybe it's time
to respin my version.

For reference, find my patches here:

https://lkml.org/lkml/2011/1/28/92

Sascha

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