On Fri, Oct 07, 2011 at 10:47:34PM +0200, Gregory CLEMENT wrote: > On 10/07/2011 03:15 PM, Sascha Hauer wrote: > > Hi Gregory, > > > Hi Sasha, > > thanks to have taken some time to have a look on my series. > > > On Thu, Oct 06, 2011 at 10:05:07AM +0200, Gregory CLEMENT wrote: > >> This patch set is a RFC about a backlight framework. The purpose of > >> this framework is mainly to allow to add easily a support for a > >> backlight with the possibility of setting brightness directly from the > >> barebox shell using the brightness parameter. > >> > >> An implementation is provided for i.MX23 by using the PWM. It was > >> tested on a custom i.MX23 base board. > > > > Two things that bother me in this series. > > > > First thing is that I wonder if it would be better to not > > register a seperate device for backlight. How about a call > > like this: > > > > fb_register_backlight(const char *fb, > > void (*set_brightness)(int brightness, void *priv)); > > > > The core would only need a function to find the struct device_d > > by the corresponding "fbx" string. This way we could add the > > brightness variable to the framebuffer and not a seperate device, > > so fb0.brightness=50. > > > > I wasn't entirely convinced by having a driver with a single > function. I came to this by several iterations and it didn't lead me > in the best direction. That's why I called this series a RFC. I will > take in account your idea and propose a new version. > > > The second thing is that the pwm you use for the mxs backlight > > is a generic pwm which not necessarily drives a backlight. We > > should have a generic pwm api for this. Otherwise we end up > > with different drivers for the same pwm. > > As I didn't see any pwm framework or API I wasn't sure it was planned > or needed to have it in barebox. But I volunteer to work on it. So how > do you see it: as an API or as complete driver ? Maybe you can use https://lkml.org/lkml/2011/6/30/163 as a template. It should be easy to convert to barebox and also gives us the chance that we can easily adopt drivers from the kernel. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
