Hi Guennadi, Thanks for your response! On Wed, Jan 2, 2013 at 3:49 PM, Guennadi Liakhovetski <g.liakhovetski@xxxxxx> wrote: > Hi Prabhakar > > On Wed, 2 Jan 2013, Prabhakar Lad wrote: > >> Hi, >> >> This is my first step towards DT support for media, Question might be >> bit amateur :) > > No worries, we're all doing our first steps in this direction right at the > moment. These two recent threads should give you an idea as to where we > stand atm: > > http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/58646 > > and (optionally, to a lesser extent) > > http://www.spinics.net/lists/linux-media/index.html#57836 > Thanks for the links. >> In the video pipeline there will be external devices (decoders/camera) >> connected via >> i2c, spi, csi. This sub-devices take platform data. So question is >> moving ahead and >> adding DT support for this subdevices how should this platform data be >> passed through. >> Should it be different properties for different devices. > > Mostly, yes. > Ok >> For example the mt9t001 sensor takes following platform data: >> struct mt9t001_platform_data { >> unsigned int clk_pol:1; > > This would presumably be the standard "pclk-sample" property from the > first of the above two quoted threads > >> unsigned int ext_clk; > > Is this the frequency? This should be replaced by a phandle, linking to a Yes its the external clock frequency. > clock device-tree node, assuming, your platform is implementing the > generic clock API. If it isn't yet, not a problem either:-) In either case > your sensor driver shall be using the v4l2_clk API to retrieve the clock > rate and your camera host driver should be providing a matching v4l2_clk > instance and implementing its methods, including retrieving the frequency. > Ok. >> }; >> similarly mt9p031 takes following platform data: >> >> struct mt9p031_platform_data { >> int (*set_xclk)(struct v4l2_subdev *subdev, int hz); > > Not sure what the xclk is, but, presumable, this should be ported to > v4l2_clk too. > >> int reset; > > This is a GPIO number, used to reset the chip. You should use a property, > probably, calling it "reset-gpios", specifying the desired GPIO. > >> int ext_freq; >> int target_freq; > > Presumably, ext_freq should be retrieved, using v4l2_clk_get_rate() and > target_freq could be a proprietary property of your device. > Ok. Regards, --Prabhakar > Thanks > Guennadi > >> }; >> >> should this all be individual properties ? >> >> Regards, >> --Prabhakar > > --- > 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
