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 > 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. > 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 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. > }; > 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. 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
