[PATCH v3 1/7] drm/vc4: Add devicetree bindings for VC4.

Rob Herring robh at kernel.org
Tue Oct 13 06:26:27 PDT 2015


On Fri, Oct 9, 2015 at 4:27 PM, Eric Anholt <eric at anholt.net> wrote:
> VC4 is the GPU (display and 3D) subsystem present on the 2835 and some
> other Broadcom SoCs.
>
> This binding follows the model of msm, imx, sti, and others, where
> there is a subsystem node for the whole GPU, with nodes for the

The subsystem node is gone now, right?

> individual HW components within it.
>
> Signed-off-by: Eric Anholt <eric at anholt.net>
> ---
>
> v2: Extend the commit message, fix several nits from Stephen Warren.
> v3: Rename the compatibility strings, clean up node names, drop the
>     unnecessary lists of components.  Use compatibility strings for
>     choosing CRTC HVS channel numbers.  Document the HDMI clock usage.
>
>  .../devicetree/bindings/gpu/brcm,bcm-vc4.txt       | 64 ++++++++++++++++++++++

Can you put this in bindings/display/ instead? Things are moving there in 4.4.


>  1 file changed, 64 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpu/brcm,bcm-vc4.txt
>
> diff --git a/Documentation/devicetree/bindings/gpu/brcm,bcm-vc4.txt b/Documentation/devicetree/bindings/gpu/brcm,bcm-vc4.txt
> new file mode 100644
> index 0000000..175bcde
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpu/brcm,bcm-vc4.txt
> @@ -0,0 +1,64 @@
> +Broadcom VC4 GPU
> +
> +The VC4 device present on the Raspberry Pi includes a display system
> +with HDMI output and the HVS scaler for compositing display planes.
> +
> +Required properties for VC4:
> +- compatible:  Should be "brcm,bcm2835-vc4"

reg property? interrupts? clocks?

> +
> +Required properties for Pixel Valve:
> +- compatible:  Should be one of "brcm,bcm2835-pixelvalve0",
> +               "brcm,bcm2835-pixelvalve1", or "brcm,bcm2835-pixelvalve2"
> +- reg:         Physical base address and length of the PV's registers
> +- interrupts:  The interrupt number
> +                 See bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt
> +
> +Required properties for HVS:
> +- compatible:  Should be "brcm,bcm2835-hvs"
> +- reg:         Physical base address and length of the HVS's registers
> +- interrupts:  The interrupt number
> +                 See bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt
> +
> +Required properties for HDMI

Is HDMI the only output possibility? If not, then you should have OF
graph nodes describing the connection between HDMI block and HVS (or
PV?).

> +- compatible:  Should be "brcm,bcm2835-hdmi"
> +- reg:         Physical base address and length of the two register ranges
> +                 ("HDMI" and "HD", in that order)
> +- interrupts:  The interrupt numbers
> +                 See bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt
> +- ddc:         phandle of the I2C controller used for DDC EDID probing
> +- clocks:      a) hdmi: The HDMI state machine clock
> +               b) pixel: The pixel clock.
> +
> +Optional properties for HDMI:
> +- hpd-gpio:    The GPIO pin for HDMI hotplug detect (if it doesn't appear

*-gpio is deprecated, so "hpd-gpios".

Really, I think this and ddc should be in hdmi-connector binding node.
What has been done for bindings so far is all over the map though.

> +                 as an interrupt/status bit in the HDMI controller
> +                 itself).  See bindings/pinctrl/brcm,bcm2835-gpio.txt
> +
> +Example:
> +pixelvalve at 7e807000 {
> +       compatible = "brcm,bcm2835-pixelvalve2";
> +       reg = <0x7e807000 0x100>;
> +       interrupts = <2 10>; /* pixelvalve */
> +};
> +
> +hvs at 7e400000 {
> +       compatible = "brcm,bcm2835-hvs";
> +       reg = <0x7e400000 0x6000>;
> +       interrupts = <2 1>;
> +};
> +
> +hdmi: hdmi at 7e902000 {
> +       compatible = "brcm,bcm2835-hdmi";
> +       reg = <0x7e902000 0x600>,
> +             <0x7e808000 0x100>;
> +       interrupts = <2 8>, <2 9>;
> +       ddc = <&i2c2>;
> +       hpd-gpio = <&gpio 46 GPIO_ACTIVE_HIGH>;
> +       clocks = <&clocks BCM2835_PLLH_PIX>,
> +                <&clocks BCM2835_CLOCK_HSM>;
> +       clock-names = "pixel", "hdmi";
> +};
> +
> +vc4: gpu at 7e4c0000 {
> +       compatible = "brcm,bcm2835-vc4";
> +};
> --
> 2.1.4
>
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