On Mon, Feb 05, 2018 at 11:42:11AM +0000, Fabrizio Castro wrote: > Hello Maxime, > > thank you for your feedback. > > > > > +/* > > > > + * configure parallel port control lines polarity > > > > + * > > > > + * POLARITY CTRL0 > > > > + * - [5]:PCLK polarity (0: active low, 1: active high) > > > > + * - [1]:HREF polarity (0: active low, 1: active high) > > > > + * - [0]:VSYNC polarity (mismatch here between > > > > + *datasheet and hardware, 0 is active high > > > > + *and 1 is active low...) > > > > > > I know that yourself and Maxime have both confirmed that VSYNC > > > polarity is inverted, but I am looking at HSYNC and VSYNC with a > > > logic analyser and I am dumping the values written to > > > OV5640_REG_POLARITY_CTRL00 and to me it looks like that HSYNC is > > > active HIGH when hsync_pol == 0, and VSYNC is active HIGH when > > > vsync_pol == 1. > > > > Which mode are you testing this on? > > My testing environment is made of the sensor connected to a SoC with > 8 data lines, vsync, hsync, and pclk, and of course I am specifying > hsync-active, vsync-active, and pclk-sample in the device tree on > both ends so that they configure themselves accordingly to work in > DVP mode (V4L2_MBUS_PARALLEL), with the correct polarities. > > Between the sensor and the SoC there is a noninverting bus > transceiver (voltage translator), for my experiments I have plugged > myself onto the outputs of this transceiver only to be compliant > with the voltage level of my logic analyser. Sorry, my question was more about the resolution, refresh rate, etc. > > The non-active periods are insanely high in most modes (1896 for an > > active horizontal length of 640 in 640x480 for example), especially > > hsync, and it's really easy to invert the two. > > I am looking at all the data lines, so that I don't confuse the > non-active periods with the active periods, and with my setup what I > reported is what I get. I wonder if this difference comes from the > sensor revision at all? Unfortunately I can only test the one camera > I have got. I don't really know then. I've had issues with the polarities on my side, but it was on the receiver side and the sensor part looked like what is documented. Maxime -- Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering http://bootlin.com
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