On 26 September 2012 18:52, Jonathan Corbet <cor...@lwn.net> wrote: > On Wed, 26 Sep 2012 11:47:56 +0200 > Javier Martin <javier.mar...@vista-silicon.com> wrote: > >> >> Signed-off-by: Javier Martin <javier.mar...@vista-silicon.com> > > This one needs a changelog - what does bypassing the PLL do and why might > you want to do it? Otherwise:
As I stated in a previous patch, frame rate depends on the pixclk. Moreover: pixclk = xvclk / clkrc * PLLfactor Bypassing the PLL means that the PLL gets out of the way so, in practice, PLLfactor = 1 pixclk = xvclk / clkrc For a frame rate of 30 fps a pixclk of 24MHz is needed. Since we have a clean clock signal we want pixclk = xvclk. If one applies the formula in ov7670_set_framerate() with PLLfactor = 1 and clock_speed = 24 MHz the resulting clkrc = 1 which means that: pixclk = xvclk which is what we want > Acked-by: Jonathan Corbet <cor...@lwn.net> Thank you. I will add a changelog when I send v2 of the series. Regards. -- Javier Martin Vista Silicon S.L. CDTUC - FASE C - Oficina S-345 Avda de los Castros s/n 39005- Santander. Cantabria. Spain +34 942 25 32 60 www.vista-silicon.com -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
