Re: [RFC] arm64: dts: imx8mm: add imx8mm-venice-gw73xx-0x-imx219 overlay

From: Laurent Pinchart
Date: Mon Nov 15 2021 - 04:46:58 EST


Hi Tim,

Thank you for the patch.

On Fri, Nov 12, 2021 at 10:33:11AM -0800, Tim Harvey wrote:
> Add support for the RaspberryPi Camera v2 module attached to an
> imx8mm-venice-gw73xx-0x.
>
> This camera is an IMX219 8MP module:
> - https://datasheets.raspberrypi.com/camera/camera-v2-schematics.pdf
> - has its own on-board 24MHz osc so no clock required from baseboard
> - pin 11 enables 1.8V and 2.8V LDO which is connected to
> GW73xx MIPI_GPIO4 (IMX8MM GPIO1_IO1). The imx219 driver does not
> support powerdown-gpios therefore we use gpio1 via reset-gpios

How about modeling this with a GPIO-controlled regulator, and connecting
it to the IMX219 through the *-supply properties ?

> Support is added via a device-tree overlay.
>
> The IMX219 supports RAW8/RAW10 image formats.
>
> Example usage:
> media-ctl --links "'imx219 2-0010':0->'imx7-mipi-csis.0':0[1]"
> media-ctl -v -V "'imx219 2-0010':0 [fmt:SRGGB8/640x480 field:none]"
> media-ctl -v -V "'csi':0 [fmt:SRGGB8/640x480 field:none]"
> gst-launch-1.0 -v v4l2src num-buffers=1 ! \
> video/x-bayer,format=rggb,width=640,height=480,framerate=30/1 ! \
> bayer2rgb ! jpegenc ! filesink location=test.jpg
> gst-launch-1.0 -v v4l2src num-buffers=300 ! \
> video/x-bayer,format=rggb,width=640,height=480,framerate=30/1 ! \
> bayer2rgb ! jpegenc ! avimux ! filesink location=test.avi
>
> This patch depends on 'arm64: dts: imx8mm: Add CSI nodes' at:
> https://lore.kernel.org/all/20211106155427.753197-2-aford173@xxxxxxxxx/
>
> This is an RFC as I am not aware of other dt fragments/overlays being
> added to the kernel yet. I do get a few warnings but I believe they are
> because this is a fragment:

I like the idea of centralizing DT overlays. I'm not sure where to best
store them, and I don't know if this has been discussed already, but the
kernel supports compilation of DT overlays, so I assume it's meant to be
used. Rob may have an opinion on this.

What we're really missing is a way to parametrize DT overlays, so that a
single overlay file could be used with different hosts. Discussions
about DT connectors have died out as far as I know, but they were aiming
at overlays being applied at runtime. I'm not aware of a similar effort
to standardize connectors when applying overlays in the boot loader. The
Raspberry Pi boot loader has a proprietary implementation of this
feature, which is very handy.

> $ make DTC_FLAGS="-@" dtbs W=1
> DTC
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtb
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dts:33.3-16:
> Warning (reg_format): /fragment@2/__overlay__/sensor@10:reg: property
> has invalid length (4 bytes) (#address-cells == 2, #size-cells == 1)
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dts:52.10-57.5:
> Warning (unit_address_vs_reg): /fragment@3/__overlay__/ports/port@0:
> node has a unit name, but no reg or ranges property
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtb:
> Warning (pci_device_reg): Failed prerequisite 'reg_format'
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtb:
> Warning (pci_device_bus_num): Failed prerequisite 'reg_format'
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtb:
> Warning (simple_bus_reg): Failed prerequisite 'reg_format'
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtb:
> Warning (i2c_bus_reg): Failed prerequisite 'reg_format'
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtb:
> Warning (spi_bus_reg): Failed prerequisite 'reg_format'
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dts:29.20-46.4:
> Warning (avoid_default_addr_size): /fragment@2/__overlay__/sensor@10:
> Relying on default #address-cells value
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dts:29.20-46.4:
> Warning (avoid_default_addr_size): /fragment@2/__overlay__/sensor@10:
> Relying on default #size-cells value
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtb:
> Warning (avoid_unnecessary_addr_size): Failed prerequisite
> 'avoid_default_addr_size'
> arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dtb:
> Warning (unique_unit_address): Failed prerequisite
> 'avoid_default_addr_size'
>
> The intended use of a dt fragement like this is to apply it in boot
> firmware before booting the kernel such as:
>
> u-boot=> load mmc 0:1 $fdt_addr_r imx8mm-venice-gw73xx-0x.dtb
> u-boot=> fdt addr $fdt_addr_r
> u-boot=> fdt resize
> u-boot=> load mmc 0:1 $loadaddr imx8mm-venice-gw73xx-0x-imx219.dtb
> u-boot=> fdt appply $loadaddr
> u-boot=> load mmc 0:1 $kernel_addr_r Image
> u-boot=> booti $kernel_addr_r - $fdt_addr_r
>
> Signed-off-by: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> ---
> arch/arm64/boot/dts/freescale/Makefile | 1 +
> .../imx8mm-venice-gw73xx-0x-imx219.dts | 67 +++++++++++++++++++
> 2 files changed, 68 insertions(+)
> create mode 100644 arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dts
>
> diff --git a/arch/arm64/boot/dts/freescale/Makefile b/arch/arm64/boot/dts/freescale/Makefile
> index db9e36ebe932..cc00ac78dbc6 100644
> --- a/arch/arm64/boot/dts/freescale/Makefile
> +++ b/arch/arm64/boot/dts/freescale/Makefile
> @@ -42,6 +42,7 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mm-var-som-symphony.dtb
> dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw71xx-0x.dtb
> dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw72xx-0x.dtb
> dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x.dtb
> +dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x-imx219.dtb
> dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7901.dtb
> dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7902.dtb
> dtb-$(CONFIG_ARCH_MXC) += imx8mn-beacon-kit.dtb
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dts
> new file mode 100644
> index 000000000000..6f692ba24a31
> --- /dev/null
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx-0x-imx219.dts
> @@ -0,0 +1,67 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright 2021 Gateworks Corporation
> + */
> +
> +#include <dt-bindings/gpio/gpio.h>
> +
> +#include "imx8mm-pinfunc.h"
> +
> +/dts-v1/;
> +/plugin/;
> +
> +&{/} {
> + compatible = "gw,imx8mm-gw73xx-0x", "fsl,imx8mm";
> +
> + cam24m: cam24m {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <24000000>;
> + clock-output-names = "cam24m";
> + };
> +};
> +
> +&csi {
> + status = "okay";
> +};
> +
> +&i2c3 {
> + imx219: sensor@10 {
> + compatible = "sony,imx219";
> + pinctrl-names = "default";
> + pinctrl-0 = <&pinctrl_imx219>;
> + reg = <0x10>;
> + clocks = <&cam24m>;
> + reset-gpios = <&gpio1 1 GPIO_ACTIVE_HIGH>;
> +
> + port {
> + /* MIPI CSI-2 bus endpoint */
> + imx219_to_mipi_csi2: endpoint {
> + remote-endpoint = <&imx8mm_mipi_csi_in>;
> + clock-lanes = <0>;
> + data-lanes = <1 2>;
> + link-frequencies = /bits/ 64 <456000000>;
> + };
> + };
> + };
> +};
> +
> +&mipi_csi {
> + status = "okay";
> + ports {
> + port@0 {
> + imx8mm_mipi_csi_in: endpoint {
> + remote-endpoint = <&imx219_to_mipi_csi2>;
> + data-lanes = <1 2>;
> + };
> + };
> + };
> +};
> +
> +&iomuxc {
> + pinctrl_imx219: imx219grp {
> + fsl,pins = <
> + MX8MM_IOMUXC_GPIO1_IO01_GPIO1_IO1 0x41
> + >;
> + };
> +};

--
Regards,

Laurent Pinchart