On Mon, 16 Nov 2009, Kuninori Morimoto wrote: > > Dear Guennadi > > Thank you > > > Oh, indeed. Ok, but can you add proper support for both high and low > > polarities? > > I think your order will be added in next patch. > "Add polarities support" > I will send it > OK ? Ok, we can do that too. > By the way. > Maybe I should ask you about it. > > My question is that who select ACTIVE HI / LOW ? > > --------------------- > unsigned long flags = SOCAM_PCLK_SAMPLE_RISING | SOCAM_MASTER | > SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_HSYNC_ACTIVE_HIGH | > + SOCAM_VSYNC_ACTIVE_LOW | SOCAM_HSYNC_ACTIVE_LOW | > SOCAM_DATA_ACTIVE_HIGH | priv->info->buswidth; > --------------------- > > If I add above, and (for example) CEU - tw9910 case, > tw9910_query_bus_param will be used in > sh_mobile_ceu_set_bus_param. > > Then, the answer from soc_camera_bus_param_compatible > have both xSYNC_ACTIVE_HIGH/LOW. > In this case, CEU behavior will be LOW, > though it have HIGH. > Please check it. > > In my opinion, the answer from soc_camera_bus_param_compatible > should not have both ACTIVE HIGH/LOW. > This value will be used in tw9910_set_bus_param too. Right, sh_mobile_ceu_camera.c support for clients, that support both high and low polarities of various signals is incorrect. Here's what should happen: 1. the host supports both high and low polarity of a specific signal 2. the client also supports both of them 3. the host then should choose one of them, preferably according to platform configuration 4. the host should use the chosen polarity to configure the client and itself This is how the pxa_camera.c driver does it in pxa_camera_set_bus_param(). What actually happens in sh_mobile_ceu_camera.c, is that it keeps both polarities in its call to the client, so, the client picks up randomly one of them, then the host does the same. So, with a probability of 1/2 they will choose opposite polarities:-) > I guess, to add your order, we needs more than 2 patches. > > "modify soc_camera_bus_param_compatible behavior" No. We should fix the sh-CEU driver. > "tw9910: Add polarities support" Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
