On 10/23/2013 04:00 PM, Thierry Reding wrote: > On Wed, Oct 23, 2013 at 10:16:24AM +0800, Mark Zhang wrote: >> On 10/22/2013 08:49 PM, Thierry Reding wrote: >>> On Tue, Oct 22, 2013 at 04:55:09PM +0800, Mark Zhang wrote: >>>> On 10/22/2013 03:24 PM, Thierry Reding wrote: >>>>> On Fri, Oct 18, 2013 at 12:48:12PM +0800, Mark Zhang wrote: >>>> [...] >>>>>>> >>>>>> >>>>>> Okay, I just want to set the "notify" function pointer in "struct >>>>>> platform_pwm_backlight_data", because I want to tune the brightness >>>>>> value before the pwm-bl sets the brightness to hardware. I don't know >>>>>> how to do that, unless we define the platform data explicitly. >>>>> >>>>> Okay, my question should have been what you need the functions for and >>>>> why you think you need them. >>>>> >>>> >>>> If I understanding you correctly, I suppose I've said that: "because I >>>> want to tune the brightness value before the pwm-bl sets the brightness >>>> to hardware". >>> >>> Why do you want to tune the brightness value? What are you trying to >>> achieve? >>> >> >> Oh, Tegra has a feature named PRISM(aka SmartDimmer). It changes the >> color value to make the display looks bright so that we can reduce the >> backlight brightness to save power. So everytime PRISM is triggered, we >> call "backlight_update_status", then in the "notify" callback, we change >> the brightness value which pwm-bl provides by considering the PRISM >> compensations. > > If you automatically call backlight_update_status() everytime PRISM > gives you new data, can't you just pass the correct value in in the > first place so that you don't have to tweak it in the .notify() > callback? OK, how to do that? -- "pass the correct value in in the first place"? Mark > > Thierry > -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
