Re: question: CSI on imx8mq with (any) CSI2 camera / experience with mx6s_capture?
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2021-02-23 11:33:44
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linux-media
Hi Martin, On Tue, Feb 23, 2021 at 10:04:44AM +0100, Martin Kepplinger wrote:
On 22.12.20 16:55, Martin Kepplinger wrote:quoted
On 22.12.20 16:35, Laurent Pinchart wrote:quoted
On Tue, Dec 22, 2020 at 03:06:28PM +0100, Martin Kepplinger wrote:quoted
On 10.12.20 17:04, Laurent Pinchart wrote:quoted
On Thu, Dec 10, 2020 at 02:12:30PM +0100, Martin Kepplinger wrote:quoted
On 10.12.20 13:17, Laurent Pinchart wrote:quoted
On Thu, Dec 10, 2020 at 11:24:00AM +0200, Laurent Pinchart wrote:quoted
On Thu, Dec 10, 2020 at 09:17:48AM +0100, Martin Kepplinger wrote:quoted
hi, TL;DR: did you use the NXP "mx6s_capture" csi bridge driver with other cameras?I've recently worked on camera support for i.MX8MM (whose camera IP cores are, if not identical, very similar to the i.MX8MQ's). The least I can say is that it was painful :-( I'm using an MT9M114 sensor, which can produce RAW8, RAW10 and YUV and has a CSI-2 interface. My first use case is to capture RAW10, which isn't supported by the mx6s_capture driver.so did you successfully use the NXP mx6s_capture driver with that sensor too?I haven't tried. The mx6s_capture driver and the mainline driver share a similar architecture, as they came from the same code base. They have diverged, with the mainline driver receiving bug fixes and new features, and my large no-yet-upstreamed patch series adds lots of fixes that are required for the mt9m114 driver to work with the driver. For that reason, I've considered that porting the mt9m114 driver to the NXP mx6s_capture, and fixing the same issues in the mx6s_capture driver than were present in the mainline driver, would require lots of time for likely very little gain. That being said, I've compared the two drivers, and I haven't seen anything in mx6s_capture that would address the specific issues I'm facing. I've ordered yesterday an i.MX8MM EVK with an OV5640 camera module, and I will test those with the mainline driver. If they don't work, and assuming the NXP kernel driver works on that platform, I'll have two code bases to compare.quoted
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I try to use a CSI2 camera (hi846 I'm writing a driver for) on imx8mq: Using NXP's CSI bridge driver https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/media/platform/mxc/capture/mx6s_capture.c?h=imx_5.4.0_8dxlphantom_er as well as the CSI driver itself: https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/media/platform/imx8/mxc-mipi-csi2_yav.c?h=imx_5.4.0_8dxlphantom_er works fine when using the ov5640 camera with this driver: https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/media/platform/mxc/capture/ov5640_mipi_v2.c?h=imx_5.4.0_8dxlphantom_er (I realize there is a CSI bridge driver in staging, but that need more work to be actually used. Of course after this the goal is to fix and use it; and mainline a CSI phy driver too.)I have lots of patches for this driver, which I've developed on i.MX7D for a separate project. I'd like to mainline them, but this is blocked by one last issue that I haven't been able to solve yet. In a nutshell, the CSI writes two consecutive frames in each buffer, overflowing the allocated memory. The registers that control the buffer size seem to be programmed correctly as far as I can tell. I've reported this issue to NXP but haven't received any feedback yet.that's different from where I am. So you don't get any interrupt (EOF or other) when only *one* frame is written into one buffer?I don't get any FB1_DMA_DONE or FB2_DMA_DONE interrupt at least. I haven't checked other interrupts. I thus get half of the frame rate. If I configure the CSI_CSIIMAG_PARA register with half of the actual image height, buffers then contain a single image and the frame rate goes to the expected value. That gives me a workaround, but without understanding the root cause, I'm worried that just halving the height would introduce other breakages.Hi Laurent, Thanks a lot, exchanging things this way alone is much appreciated. I'll give you detailed feedback on the staging drivers later - I tried running them, they probe but still a (gstreamer) stream would not start. But most all of your addition make a lot of sense. Just so you know, to emphasize that once more: I'm still on the nxp drivers (yes, they are very similar) just because the ov56 cam works with them over here.I've recently bought an i.MX8MM EVK, with the OV5647 camera module, and when I try to capture images, with the NXP kernel, I just don't get any. *sigh* I'll have to debug that.oh you have it already. very good. I guess the nxp kernel directly *should* work, but I use a kernel based on v5.9.X and include the drivers like so: https://source.puri.sm/Librem5/linux-next/-/commit/ed8f567432d776d21cb7160c03e3272826a5f316 https://source.puri.sm/Librem5/linux-next/-/commit/8d93a2cfd485d404741560dcb2f22da548f54ebcquoted
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The main problem I have is that, as soon as I try to use a different pixelformat than V4L2_PIX_FMT_YUYV that basically nothing works anymore. userspace stops to "be interested" pretty soon. If I do (wrongly) use that pixelformat, I do get (only) one frame (dma) completed, the usual way. And when I break the ov56 by using a wrong pixelformat in mx6s_capture (nxp bridge driver), I get equally get only one frame (dma) completed there. How can I make this thing use a different pixelformat (by setting the media bus format in the sensor driver)?All the components have to support the format you want to capture. This includes the CSI driver, the MIPI_CSI driver, and the OV5647 driver. The pixel format only matters in the CSI driver, for the other two it's the media bus format that matters. To capture raw bayer data, you'll first need to extend the OV5640 driver to support the corresponding media bus format (and of course configure the sensor to output that format), then the MIPI_CSI driver to support that media bus format as well, and finally the CSI driver.ok, the sensor I work with outputs raw bayer only, and that sounds like I should pay more attention to the mipi csi driver. that links to my experiments I occasionally update: https://source.puri.sm/martin.kepplinger/linux-next/-/commits/hi846quoted
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thanks again for sharing your code early. have a nice rest of the year,hi Laurent, how are you? Am I right in that you tried to run the ov5640 mainline driver with the CSI bridge staging driver on imx8mq? Which mipi driver would you then use?
I've run it with the staging driver on i.MX8MP, not i.MX8MQ. The MQ seems to have the same CSI bridge, but a different CSI-2 receiver (and PHY). It would be great if you could contribute a driver for that :-)
Did you have progress in that area and in resolving things in order to push some of your changes out?
I've sent a large patch series recently, if you could review it it would speed up integration ;-)
I'm still struggling with the different sensor I want to use on imx8mq (hi846) and I still use the nxp bsp drivers for mipi and csi bridge: I was able to add and fix a few things and get some kind of image at least, but there's still definitely some sizes or timings wrong (in every resolution mode I think). 1280x720 shows it clearly as the image looks "almost" normal only when I resize it to 916 pixel width. Also, it "shifts" with later frames. For a few images of this, see https://source.puri.sm/Librem5/linux-next/-/issues/43#note_143875 I just wanted to describe the above just in case you've seen something like that during your experiments with sensors and can point me to places to look at. I do think that the SoC side should be ok now (but still now 100% sure), but many sensors are similar and maybe you have ideas there too.
I've seen similar (but not identical) issues that were due to incorrect Ths_settle values in the D-PHY. You could start by trying different values there. This seems to be controlled on i.MX8MQ by CSI2_1_S_PRG_RXHS_SETTLE in IOMUXC_GPR_GPR34 or CSI2_2_S_PRG_RXHS_SETTLE in IOMUXC_GPR_GPR41, but the value of the fields are not properly documented :-S The i.MX8MM suffered from the same issue, but a table with register values for different clock frequencies was posted by NXP on their support forum. Maybe the same information could be available there for i.M8XMQ ?
anyways, thanks for looking at this and as soon as I have a satisfying
image with my current setup, I'll switch to the staging csi driver. But
there's no driver for the mipi ("phy") in staging for imx8mq, right?-- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel