Hi Paul, I have some comments through the series, I hope this helps. On 10/23/20 2:45 PM, Paul Kocialkowski wrote: > This series introduces support for MIPI CSI-2, with the A31 controller that is > found on most SoCs (A31, V3s and probably V5) as well as the A83T-specific > controller. While the former uses the same MIPI D-PHY that is already supported > for DSI, the latter embeds its own D-PHY. > > In order to distinguish the use of the D-PHY between Rx mode (for MIPI CSI-2) > and Tx mode (for MIPI DSI), a submode is introduced for D-PHY in the PHY API. > This allows adding Rx support in the A31 D-PHY driver. > > A few changes and fixes are applied to the A31 CSI controller driver, in order > to support the MIPI CSI-2 use-case. > > Follows is the V4L2 device topology representing the interactions between > the MIPI CSI-2 sensor, the MIPI CSI-2 controller (which controls the D-PHY) > and the CSI controller: > - entity 1: sun6i-csi (1 pad, 1 link) > type Node subtype V4L flags 0 > device node name /dev/video0 > pad0: Sink > <- "sun6i-mipi-csi2":1 [ENABLED,IMMUTABLE] > > - entity 5: sun6i-mipi-csi2 (2 pads, 2 links) > type V4L2 subdev subtype Unknown flags 0 > pad0: Sink > <- "ov5648 0-0036":0 [ENABLED,IMMUTABLE] > pad1: Source > -> "sun6i-csi":0 [ENABLED,IMMUTABLE] > > - entity 8: ov5648 0-0036 (1 pad, 1 link) > type V4L2 subdev subtype Sensor flags 0 > device node name /dev/v4l-subdev0 Question: I noticed is that sun6i-mipi-csi2 doesn't expose a node under /dev/, but the sensor exposes it. Probably because it uses V4L2_SUBDEV_FL_HAS_DEVNODE and sun6i-csi() calls v4l2_device_register_subdev_nodes(). I find this weird from a userspace pov, since usually we don't mix manual and auto propagation of the configs, so I started wondering if sun6i-csi driver should be calling v4l2_device_register_subdev_nodes() in the first place. Also, sun6i-csi doesn't seem to be used by any board dts (it's declared on the dtsi, but I didn't find any dts enabling it), so I wonder if it would be a bad thing if we update it. > pad0: Source > [fmt:SBGGR8_1X8/640x480@1/30 field:none colorspace:raw xfer:none ycbcr:601 quantization:full-range] > -> "sun6i-mipi-csi2":0 [ENABLED,IMMUTABLE] If I understand correctly, this is very similar to ipu3: sensor->bus->dma_engine in the case of ipu3-cio2: sensor->ipu3-csi2->ipu3-cio2 in this case: ov5648->sun6i-mipi-csi2->sun6i-csi On thing that is confusing me is the name csi2 with csi (that makes me think of csi vesun6i-csirsion one, which is not the case), I would rename it to sun6i-video (or maybe it is just me who gets confused). I know this driver is already upstream and not part of this series, but on the other hand it doesn't seem to be used. On another note, I always wonder if we should expose the bus in the topology, I'm not sure if it provides any useful API or information for userspace, and you could have a cleaner code (maybe code could be under phy subsystem). But at the same time, it seems this is a pattern on v4l2. I'd like to hear what others think on the above. Regards, Helen > > Happy reviewing! > > Paul Kocialkowski (14): > phy: Distinguish between Rx and Tx for MIPI D-PHY with submodes > phy: allwinner: phy-sun6i-mipi-dphy: Support D-PHY Rx mode for MIPI > CSI-2 > media: sun6i-csi: Support an optional dedicated memory pool > media: sun6i-csi: Fix the image storage bpp for 10/12-bit Bayer > formats > media: sun6i-csi: Only configure the interface data width for parallel > media: sun6i-csi: Support feeding from the MIPI CSI-2 controller > dt-bindings: media: i2c: Add A31 MIPI CSI-2 bindings documentation > media: sunxi: Add support for the A31 MIPI CSI-2 controller > ARM: dts: sun8i: v3s: Add CSI0 camera interface node > ARM: dts: sun8i: v3s: Add MIPI D-PHY and MIPI CSI-2 interface nodes > dt-bindings: media: i2c: Add A83T MIPI CSI-2 bindings documentation > media: sunxi: Add support for the A83T MIPI CSI-2 controller > ARM: dts: sun8i: a83t: Add MIPI CSI-2 controller node > media: sunxi: sun8i-a83t-mipi-csi2: Avoid using the (unsolicited) > interrupt > > .../media/allwinner,sun6i-a31-mipi-csi2.yaml | 168 +++++ > .../media/allwinner,sun8i-a83t-mipi-csi2.yaml | 158 +++++ > arch/arm/boot/dts/sun8i-a83t.dtsi | 26 + > arch/arm/boot/dts/sun8i-v3s.dtsi | 62 ++ > drivers/media/platform/sunxi/Kconfig | 2 + > drivers/media/platform/sunxi/Makefile | 2 + > .../platform/sunxi/sun6i-csi/sun6i_csi.c | 54 +- > .../platform/sunxi/sun6i-csi/sun6i_csi.h | 20 +- > .../platform/sunxi/sun6i-mipi-csi2/Kconfig | 11 + > .../platform/sunxi/sun6i-mipi-csi2/Makefile | 4 + > .../sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.c | 635 +++++++++++++++++ > .../sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.h | 116 +++ > .../sunxi/sun8i-a83t-mipi-csi2/Kconfig | 11 + > .../sunxi/sun8i-a83t-mipi-csi2/Makefile | 4 + > .../sun8i-a83t-mipi-csi2/sun8i_a83t_dphy.c | 92 +++ > .../sun8i-a83t-mipi-csi2/sun8i_a83t_dphy.h | 39 ++ > .../sun8i_a83t_mipi_csi2.c | 660 ++++++++++++++++++ > .../sun8i_a83t_mipi_csi2.h | 196 ++++++ > drivers/phy/allwinner/phy-sun6i-mipi-dphy.c | 164 ++++- > drivers/staging/media/rkisp1/rkisp1-isp.c | 3 +- > include/linux/phy/phy-mipi-dphy.h | 13 + > 21 files changed, 2408 insertions(+), 32 deletions(-) > create mode 100644 Documentation/devicetree/bindings/media/allwinner,sun6i-a31-mipi-csi2.yaml > create mode 100644 Documentation/devicetree/bindings/media/allwinner,sun8i-a83t-mipi-csi2.yaml > create mode 100644 drivers/media/platform/sunxi/sun6i-mipi-csi2/Kconfig > create mode 100644 drivers/media/platform/sunxi/sun6i-mipi-csi2/Makefile > create mode 100644 drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.c > create mode 100644 drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.h > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/Kconfig > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/Makefile > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/sun8i_a83t_dphy.c > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/sun8i_a83t_dphy.h > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/sun8i_a83t_mipi_csi2.c > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/sun8i_a83t_mipi_csi2.h >