Hello Teresa On Thu, 7 Apr 2011, Teresa Gamez wrote: > Hello Guennadi, > > the datasheet also says (see table 3): > > <quote> > Pixel clock out. DOUT is valid on rising edge of this > clock. > </quote> > > There is a difference between DOUT beeing vaild and DOUT beeing set up. > So does SOCAM_PCLK_SAMPLE_RISING mean that the data is valid at rising > edge or > does it mean the data is set up at rising edge? Hm, yeah, looks like a typical example of a copy-paste datasheet to me:-( And now we don't know which of the two is actually supposed to be true. As for "set up" vs. "valid" - not sure, whether there is indeed a difference between them. To me "set up _TO_ the rising edge" is a short way to set "set up to be valid at the rising edge," however, I might be wrong. Can you tell me in more detail what and where (at the sensor board or on the baseboard) you measured and what it looked like? I think, Figure 7 and the description below it are interesting. From that diagram I would indeed say indeed the DOUT pins are valid and should be sampled at the rising edge by default - when bit 4 in 0x74 is not set. SOCAM_PCLK_SAMPLE_RISING means, that the data should be sampled at the rising of pclkm, i.e., it is valid there. So, yes, if your measurements agree with figure 7 from the datasheet, we shall assume, that the driver implements the pclk polarity wrongly. But the fix should be more extensive, than what you've submitted: if we invert driver's behaviour, we should also invert board configuration of all driver users: pcm990 and pcm037. Or we have to test them and verify, that the inverted pclk polarity doesn't megatively affect the image quality, or maybe even improves it. Thanks Guennadi > I have tested this with a pcm038 but I will also make meassurements with > the pcm037. > > Teresa > > Guennadi Liakhovetski <g.liakhovetski@xxxxxx> schrieb am 07.04.2011 > 13:08:11: > > > Von: Guennadi Liakhovetski <g.liakhovetski@xxxxxx> > > An: Teresa Gámez <t.gamez@xxxxxxxxx> > > Kopie: linux-media@xxxxxxxxxxxxxxx > > Datum: 07.04.2011 13:08 > > Betreff: Re: [PATCH 1/2] mt9v022: fix pixel clock > > > > On Wed, 6 Apr 2011, Teresa Gámez wrote: > > > > > Measurements show that the setup of the pixel clock is not correct. > > > The 'Invert Pixel Clock' bit has to be set to 1 for falling edge > > > and not for rising. > > > > Doesn't seem correct to me. The mt9v022 datasheet says: > > > > <quote> > > Invert pixel clock. When set, LINE_VALID, > > FRAME_VALID, and DOUT is set up to the rising edge > > of pixel clock, PIXCLK. When clear, they are set up to > > the falling edge of PIXCLK. > > </quote> > > > > and this works for present mt9v022 configurations, which include at > least > > two boards: PXA270-based arch/arm/mach-pxa/pcm990-baseboard.c and i.MX31 > > > based arch/arm/mach-mx3/mach-pcm037.c. If this is different for your > > board, maybe you have to set the SOCAM_SENSOR_INVERT_PCLK flag in your > > "struct soc_camera_link" instance. > > > > Thanks > > Guennadi > > > > > Signed-off-by: Teresa Gámez <t.gamez@xxxxxxxxx> > > > --- > > > drivers/media/video/mt9v022.c | 2 +- > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > diff --git a/drivers/media/video/mt9v022.c > b/drivers/media/video/mt9v022.c > > > index 6a784c8..dec2a69 100644 > > > --- a/drivers/media/video/mt9v022.c > > > +++ b/drivers/media/video/mt9v022.c > > > @@ -228,7 +228,7 @@ static int mt9v022_set_bus_param(struct > > soc_camera_device *icd, > > > > > > flags = soc_camera_apply_sensor_flags(icl, flags); > > > > > > - if (flags & SOCAM_PCLK_SAMPLE_RISING) > > > + if (flags & SOCAM_PCLK_SAMPLE_FALLING) > > > pixclk |= 0x10; > > > > > > if (!(flags & SOCAM_HSYNC_ACTIVE_HIGH)) > > > -- > > > 1.7.0.4 > > > > > > -- > > > 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 > > > > > > > --- > > Guennadi Liakhovetski, Ph.D. > > Freelance Open-Source Software Developer > > http://www.open-technology.de/ > --- 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
