[PATCH v4 00/10] Add PWM framework and device tree support.

[H Hartley Sweeten]

On Wednesday, March 14, 2012 8:56 AM, Thierry Reding wrote:
> 
> This patch series adds very rudimentary device-tree support for PWM
> devices. With all of these patches applied (plus one board-specific
> patch that is not included), I'm able to control the backlight on the
> device I'm working on using the sysfs interface provided by the pwm-bl
> driver and the backlight class.

Hello Thierry,

Are you planning on adding a sysfs interface for generic userspace access
to the PWM devices?

I have tested your patches (with a couple fixes already mentioned) on a
ep93xx board and have converted the drivers/misc/ep93xx_pwm.c driver
to use the framework.  Everything "seems" to work but my use for the
PWM is from userspace so I can't really test anything.

I have hacked in the sysfs interface from the ep93xx_pwm driver but it
is a hack... It's not really using the framework to control the PWM since
all the sysfs knobs are directly accessing the pwm registers.

Anyway, I would be happy to convert the current driver to the new framework
and get it out of drivers/misc and into a proper location. But, before I can do
that, I need to be able to control the PWM from userspace somehow.

Maybe an interface similar to the one gpiolib provides with CONFIG_GPIO_SYSFS?

Regards,
Hartley