On Thu, Jan 16, 2014 at 3:04 PM, Guennadi Liakhovetski <g.liakhovetski@xxxxxx> wrote: > Hi Bryan, > > On Wed, 15 Jan 2014, Bryan Wu wrote: > >> Hi Guennadi, >> >> I'm working on upstream our Tegra soc_camera host driver. But found >> the soc_camera framework is not fully supporting Device Tree probing, >> am I wrong about that? > > Mostly correct, yes, currently soc-camera doesn't support device-tree > probing. > >> While in upstream Tegra kernel, we only support >> DT probing and there is no board files. >> >> Current soc_camera framework needs to put soc_camera_link information >> in a board file and build up soc-camera-pdrv platform_device, then >> finally register this soc-camera-pdrv platform_device. >> >> For the host driver, we can do DT probing but for i2c soc_camera >> sensor driver I failed to find any DT probing in upstream kernel. So >> how to do that without an board file but use DT for this whole thing? >> >> Can we use DT like this? >> DTB file will pass those I2C, clock, regulator, GPIO information to >> host driver. During host driver DT probing, we dynamically create >> soc-camera-pdrv platform_device and soc_camera_link then register >> them. Then the rest of the thing should be the same as None-DT >> probing. > > I've worked on soc-camera DT in the past, this might be the last published > version > > http://marc.info/?l=linux-sh&m=134875489304837&w=1 > > As you see, it's quite old. Since then a few things happened. Device tree > support has been added to V4L2 (see > Documentation/devicetree/bindings/media/video-interfaces.txt and other > files in that directory for examples), it is based on asynchronous > probing, which is also supported by the soc-camera core and some its > host drivers (e.g. > > commit 4dbfd040757b8bf22f4ac17e80b39c068061a16c > Author: Guennadi Liakhovetski <g.liakhovetski@xxxxxx> > Date: Tue Jul 30 02:59:49 2013 -0300 > > [media] V4L2: mx3_camera: add support for asynchronous subdevice registration > > ). So, what you should do, is add asynchronous probing support to your > driver, add DT support to the soc-camera core, add it to your drivers. > Also see drivers/media/v4l2-core/v4l2-of.c for helper functions, you > should be using. > Great, Guennadi. I will start to help to add DT for soc-camera. But one more question is how to add DT support for soc-camera sensor driver? For sensor driver, we need pass those regulator/gpio/clock information for power on/off operations. If we add I2C device node in DTS file to pass those settings to driver, driver will be automatically loaded and start to probing. But I think loading soc_camera sensor driver should be done by soc_camera core code during host driver registering. Any suggestions to solve this problem? Thanks, -Bryan -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
