Hi Hans- Thanks for reviewing this again in such detail.
On 27/06/2016 12:26, Hans Verkuil wrote: > On 06/23/2016 12:08 AM, Nick Dyer wrote: >> This is a series of patches to add output of raw touch diagnostic data via >> V4L2 >> to the Atmel maXTouch and Synaptics RMI4 drivers. >> >> It's a rewrite of the previous implementation which output via debugfs: it >> now >> uses a V4L2 device in a similar way to the sur40 driver. >> >> We have a utility which can read the data and display it in a useful format: >> https://github.com/ndyer/heatmap/commits/heatmap-v4l >> >> These patches are also available from >> https://github.com/ndyer/linux/commits/v4l-touch-2016-06-22 >> >> Changes in v5 (Hans Verkuil review): >> - Update v4l2-core: >> - Add VFL_TYPE_TOUCH, V4L2_BUF_TYPE_TOUCH_CAPTURE and V4L2_CAP_TOUCH > > The use of V4L2_CAP_TOUCH and V4L2_BUF_TYPE_TOUCH_CAPTURE is very > inconsistent. > What is the rationale of adding V4L2_BUF_TYPE_TOUCH_CAPTURE? I can't remember > asking for it. I am afraid that I missed updating atmel_mxt_ts from V4L2_BUF_TYPE_VIDEO_CAPTURE to V4L2_BUF_TYPE_TOUCH_CAPTURE, which has confused the situation. Perhaps I read too much into your request that I look at the way that SDR is treated. When I started going through the code paths in v4l2-core and v4l2-compliance, it seemed cleaner to treat touch as completely separate, hence introducing the new BUF_TYPE. I'm happy to try it without this. > And wouldn't the use of V4L2_BUF_TYPE_TOUCH_CAPTURE break userspace for sur40? I think it is likely, yes. And it looks like that would make Florian unhappy. > I'm ambiguous towards having a V4L2_BUF_TYPE_TOUCH_CAPTURE, to be honest. > > I would also recommend renaming V4L2_CAP_TOUCH to V4L2_CAP_TOUCH_CAPTURE. Do you agree with the following changes: - Rename V4L2_CAP_TOUCH to V4L2_CAP_TOUCH_CAPTURE. - Touch devices should register both V4L2_CAP_VIDEO_CAPTURE and V4L2_CAP_TOUCH_CAPTURE. - Get rid of V4L2_BUF_TYPE_TOUCH_CAPTURE and use V4L2_BUF_TYPE_VIDEO_CAPTURE. In v4l2-ioctl.c if we need to force particular pix formats for touch, it will need to look at V4L2_CAP_TOUCH_CAPTURE. Your other review comments look straightforward to address - thanks. I should say, you can see my current changes to v4l2-compliance here: https://github.com/ndyer/v4l-utils/commit/07e00c33 Should I post them along with the kernel patches next time? > > I can imagine an embedded usb gadget device that outputs touch data to a PC. > > Regards, > > Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
