Re: [PATCH v4 22/37] dt-bindings: host1x: Document new interconnect properties

From: Dmitry Osipenko
Date: Wed Jun 17 2020 - 17:44:52 EST


18.06.2020 00:37, Rob Herring ÐÐÑÐÑ:
> On Tue, Jun 09, 2020 at 04:13:49PM +0300, Dmitry Osipenko wrote:
>> Most of Host1x devices have at least one memory client. These clients
>> are directly connected to the memory controller. The new interconnect
>> properties represent the memory client's connection to the memory
>> controller.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>> ---
>> .../display/tegra/nvidia,tegra20-host1x.txt | 68 +++++++++++++++++++
>> 1 file changed, 68 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt
>> index 47319214b5f6..ab4fbee7bccf 100644
>> --- a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt
>> +++ b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt
>> @@ -20,6 +20,10 @@ Required properties:
>> - reset-names: Must include the following entries:
>> - host1x
>>
>> +Each host1x client module having to perform DMA through the Memory Controller
>> +should have the interconnect endpoints set to the Memory Client and External
>> +Memory respectively.
>> +
>> The host1x top-level node defines a number of children, each representing one
>> of the following host1x client modules:
>>
>> @@ -36,6 +40,12 @@ of the following host1x client modules:
>> - reset-names: Must include the following entries:
>> - mpe
>>
>> + Optional properties:
>> + - interconnects: Must contain entry for the MPE memory clients.
>> + - interconnect-names: Must include name of the interconnect path for each
>> + interconnect entry. Consult TRM documentation for information about
>> + available memory clients, see MEMORY CONTROLLER section.
>> +
>> - vi: video input
>>
>> Required properties:
>> @@ -65,6 +75,12 @@ of the following host1x client modules:
>> - power-domains: Must include sor powergate node as csicil is in
>> SOR partition.
>>
>> + Optional properties:
>> + - interconnects: Must contain entry for the VI memory clients.
>> + - interconnect-names: Must include name of the interconnect path for each
>> + interconnect entry. Consult TRM documentation for information about
>> + available memory clients, see MEMORY CONTROLLER section.
>> +
>> - epp: encoder pre-processor
>>
>> Required properties:
>> @@ -78,6 +94,12 @@ of the following host1x client modules:
>> - reset-names: Must include the following entries:
>> - epp
>>
>> + Optional properties:
>> + - interconnects: Must contain entry for the EPP memory clients.
>> + - interconnect-names: Must include name of the interconnect path for each
>> + interconnect entry. Consult TRM documentation for information about
>> + available memory clients, see MEMORY CONTROLLER section.
>> +
>> - isp: image signal processor
>>
>> Required properties:
>> @@ -91,6 +113,12 @@ of the following host1x client modules:
>> - reset-names: Must include the following entries:
>> - isp
>>
>> + Optional properties:
>> + - interconnects: Must contain entry for the ISP memory clients.
>> + - interconnect-names: Must include name of the interconnect path for each
>> + interconnect entry. Consult TRM documentation for information about
>> + available memory clients, see MEMORY CONTROLLER section.
>> +
>> - gr2d: 2D graphics engine
>>
>> Required properties:
>> @@ -104,6 +132,12 @@ of the following host1x client modules:
>> - reset-names: Must include the following entries:
>> - 2d
>>
>> + Optional properties:
>> + - interconnects: Must contain entry for the GR2D memory clients.
>> + - interconnect-names: Must include name of the interconnect path for each
>> + interconnect entry. Consult TRM documentation for information about
>> + available memory clients, see MEMORY CONTROLLER section.
>> +
>> - gr3d: 3D graphics engine
>>
>> Required properties:
>> @@ -122,6 +156,12 @@ of the following host1x client modules:
>> - 3d
>> - 3d2 (Only required on SoCs with two 3D clocks)
>>
>> + Optional properties:
>> + - interconnects: Must contain entry for the GR3D memory clients.
>> + - interconnect-names: Must include name of the interconnect path for each
>> + interconnect entry. Consult TRM documentation for information about
>> + available memory clients, see MEMORY CONTROLLER section.
>> +
>> - dc: display controller
>>
>> Required properties:
>> @@ -149,6 +189,10 @@ of the following host1x client modules:
>> - nvidia,hpd-gpio: specifies a GPIO used for hotplug detection
>> - nvidia,edid: supplies a binary EDID blob
>> - nvidia,panel: phandle of a display panel
>> + - interconnects: Must contain entry for the DC memory clients.
>> + - interconnect-names: Must include name of the interconnect path for each
>> + interconnect entry. Consult TRM documentation for information about
>> + available memory clients, see MEMORY CONTROLLER section.
>>
>> - hdmi: High Definition Multimedia Interface
>>
>> @@ -297,6 +341,12 @@ of the following host1x client modules:
>> - reset-names: Must include the following entries:
>> - vic
>>
>> + Optional properties:
>> + - interconnects: Must contain entry for the VIC memory clients.
>> + - interconnect-names: Must include name of the interconnect path for each
>> + interconnect entry. Consult TRM documentation for information about
>> + available memory clients, see MEMORY CONTROLLER section.
>> +
>> Example:
>>
>> / {
>> @@ -410,6 +460,15 @@ Example:
>> resets = <&tegra_car 27>;
>> reset-names = "dc";
>>
>> + interconnects = <&mc TEGRA20_MC_DISPLAY0A &emc>,
>> + <&mc TEGRA20_MC_DISPLAY0B &emc>,
>> + <&mc TEGRA20_MC_DISPLAY0C &emc>,
>> + <&mc TEGRA20_MC_DISPLAY1B &emc>;
>
> This looks odd or wrong. Each entry has 2 phandles?

Each entry defines interconnect path, where MC is the start of the path
and EMC is the end. So yes, 2 phandles for each path.

Please see arm/boot/dts/qcom-msm8974.dtsi for another example [1].

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/qcom-msm8974.dtsi?h=v5.8-rc1#n1448