diff mbox series

[v6,1/5] dt-bindings: msm/dp: add bindings of DP/DP-PLL driver for Snapdragon

Message ID 20200609033818.9028-1-tanmay@codeaurora.org (mailing list archive)
State New, archived
Headers show
Series [v6,1/5] dt-bindings: msm/dp: add bindings of DP/DP-PLL driver for Snapdragon | expand

Commit Message

Tanmay Shah June 9, 2020, 3:38 a.m. UTC
From: Chandan Uddaraju <chandanu@codeaurora.org>

Add bindings for Snapdragon DisplayPort controller driver.

Changes in V2:
Provide details about sel-gpio

Changes in V4:
Provide details about max dp lanes
Change the commit text

Changes in V5:
moved dp.txt to yaml file

Changes in v6:
- Squash all AUX LUT properties into one pattern Property
- Make aux-cfg[0-9]-settings properties optional
- Remove PLL/PHY bindings from DP controller dts
- Add DP clocks description
- Remove _clk suffix from clock names
- Rename pixel clock to stream_pixel
- Remove redundant bindings (GPIO, PHY, HDCP clock, etc..)
- Fix indentation
- Add Display Port as interface of DPU in DPU bindings
  and add port mapping accordingly.

Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org>
Signed-off-by: Vara Reddy <varar@codeaurora.org>
Signed-off-by: Tanmay Shah <tanmay@codeaurora.org>
---
 .../devicetree/bindings/display/msm/dp-sc7180.yaml | 142 +++++++++++++++++++++
 .../devicetree/bindings/display/msm/dpu.txt        |   8 ++
 2 files changed, 150 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml

Comments

Stephen Boyd June 10, 2020, 2:15 a.m. UTC | #1
Quoting Tanmay Shah (2020-06-08 20:38:18)
> diff --git a/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
> new file mode 100644
> index 0000000..5fdb915
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml

Typically the file name matches the compatible string. But the
compatible string is just qcom,dp-display. Maybe the compatible string
should be qcom,sc7180-dp? Notice that the SoC number comes first as is
preferred.


> @@ -0,0 +1,142 @@
> +# SPDX-License-Identifier: (GPL-2.0-only  OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/msm/dp-sc7180.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm Display Port Controller.
> +
> +maintainers:
> +  - Chandan Uddaraju <chandanu@codeaurora.org>
> +  - Vara Reddy <varar@codeaurora.org>
> +  - Tanmay Shah <tanmay@codeaurora.org>
> +
> +description: |
> +  Device tree bindings for MSM Display Port which supports DP host controllers
> +  that are compatible with VESA Display Port interface specification.
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: qcom,dp-display
> +
> +  cell-index:
> +    description: Specifies the controller instance.
> +
> +  reg:
> +    items:
> +      - description: DP controller registers
> +
> +  interrupts:
> +    description: The interrupt signal from the DP block.
> +
> +  clocks:
> +    description: List of clock specifiers for clocks needed by the device.
> +    items:
> +      - description: Display Port AUX clock
> +      - description: Display Port Link clock
> +      - description: Link interface clock between DP and PHY
> +      - description: Display Port Pixel clock
> +      - description: Root clock generator for pixel clock
> +
> +  clock-names:
> +    description: |
> +      Device clock names in the same order as mentioned in clocks property.
> +      The required clocks are mentioned below.
> +    items:
> +      - const: core_aux
> +      - const: ctrl_link
> +      - const: ctrl_link_iface
> +      - const: stream_pixel
> +      - const: pixel_rcg

Why not just 'pixel'? And why is the root clk generator important? It
looks like this binding should be using the assigned clock parents
property instead so that it doesn't have to call clk_set_parent()
explicitly.

> +  "#clock-cells":
> +    const: 1
> +
> +  vdda-1p2-supply:
> +    description: phandle to vdda 1.2V regulator node.
> +
> +  vdda-0p9-supply:
> +    description: phandle to vdda 0.9V regulator node.
> +
> +  data-lanes = <0 1>:

Is this correct? We can have = <value> in the property name? Also feels
generic and possibly should come from the phy binding instead of from
the controller binding.

> +    type: object
> +    description: Maximum number of lanes that can be used for Display port.
> +
> +  ports:
> +    description: |
> +       Contains display port controller endpoint subnode.
> +       remote-endpoint: |
> +         For port@0, set to phandle of the connected panel/bridge's
> +         input endpoint. For port@1, set to the DPU interface output.
> +         Documentation/devicetree/bindings/graph.txt and
> +         Documentation/devicetree/bindings/media/video-interfaces.txt.
> +
> +patternProperties:
> +  "^aux-cfg([0-9])-settings$":
> +    type: object
> +    description: |
> +      Specifies the DP AUX configuration [0-9] settings.
> +      The first entry in this array corresponds to the register offset
> +      within DP AUX, while the remaining entries indicate the
> +      programmable values.

I'd prefer this was removed from the binding and hardcoded in the driver
until we can understand what the values are. If they're not
understandable then they most likely don't change and should be done in
the driver.

> +
> +required:
> +  - compatible
> +  - cell-index
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - vdda-1p2-supply
> +  - vdda-0p9-supply
> +  - data-lanes
> +  - ports
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/clock/qcom,dispcc-sdm845.h>
> +    #include <dt-bindings/clock/qcom,gcc-sdm845.h>
> +    msm_dp: displayport-controller@ae90000{
> +        compatible = "qcom,dp-display";
> +        cell-index = <0>;
> +        reg = <0 0xae90000 0 0x1400>;
> +        reg-names = "dp_controller";
> +
> +        interrupt-parent = <&display_subsystem>;
> +        interrupts = <12 0>;
> +
> +        clocks = <&dispcc DISP_CC_MDSS_DP_AUX_CLK>,
> +                 <&dispcc DISP_CC_MDSS_DP_LINK_CLK>,
> +                 <&dispcc DISP_CC_MDSS_DP_LINK_INTF_CLK>,
> +                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK>,
> +                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK_SRC>;
> +        clock-names = "core_aux",
> +                      "ctrl_link",
> +                      "ctrl_link_iface", "stream_pixel",
> +                      "pixel_rcg";
> +        #clock-cells = <1>;
> +
> +        vdda-1p2-supply = <&vreg_l3c_1p2>;
> +        vdda-0p9-supply = <&vreg_l4a_0p8>;
> +
> +        data-lanes = <0 1>;
> +
> +        ports {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            port@0 {
> +                reg = <0>;
> +                dp_in: endpoint {
> +                    remote-endpoint = <&dpu_intf0_out>;
> +                };
> +            };
> +
> +            port@1 {
> +                reg = <1>;
> +                dp_out: endpoint {
> +                };
> +            };
> +        };
> +    };

I believe there should be a '...' here.
Tanmay Shah June 11, 2020, 8:07 p.m. UTC | #2
On 2020-06-09 19:15, Stephen Boyd wrote:
> Quoting Tanmay Shah (2020-06-08 20:38:18)
>> diff --git 
>> a/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml 
>> b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
>> new file mode 100644
>> index 0000000..5fdb915
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
> 
> Typically the file name matches the compatible string. But the
> compatible string is just qcom,dp-display. Maybe the compatible string
> should be qcom,sc7180-dp? Notice that the SoC number comes first as is
> preferred.
> 
These bindings will be similar for upcoming SOC as well.
So just for understanding, when we add new SOC do we create new file 
with same bidings
with SOC number in new file name?
Instead we can keep this file's name as qcom,dp-display.yaml (same as 
compatible const) and we can include SOC number in compatible enum ?
some examples:
https://patchwork.kernel.org/patch/11448357/
https://patchwork.kernel.org/patch/11164619/
> 
>> @@ -0,0 +1,142 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only  OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/display/msm/dp-sc7180.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Qualcomm Display Port Controller.
>> +
>> +maintainers:
>> +  - Chandan Uddaraju <chandanu@codeaurora.org>
>> +  - Vara Reddy <varar@codeaurora.org>
>> +  - Tanmay Shah <tanmay@codeaurora.org>
>> +
>> +description: |
>> +  Device tree bindings for MSM Display Port which supports DP host 
>> controllers
>> +  that are compatible with VESA Display Port interface specification.
>> +
>> +properties:
>> +  compatible:
>> +    items:
>> +      - const: qcom,dp-display
>> +
>> +  cell-index:
>> +    description: Specifies the controller instance.
>> +
>> +  reg:
>> +    items:
>> +      - description: DP controller registers
>> +
>> +  interrupts:
>> +    description: The interrupt signal from the DP block.
>> +
>> +  clocks:
>> +    description: List of clock specifiers for clocks needed by the 
>> device.
>> +    items:
>> +      - description: Display Port AUX clock
>> +      - description: Display Port Link clock
>> +      - description: Link interface clock between DP and PHY
>> +      - description: Display Port Pixel clock
>> +      - description: Root clock generator for pixel clock
>> +
>> +  clock-names:
>> +    description: |
>> +      Device clock names in the same order as mentioned in clocks 
>> property.
>> +      The required clocks are mentioned below.
>> +    items:
>> +      - const: core_aux
>> +      - const: ctrl_link
>> +      - const: ctrl_link_iface
>> +      - const: stream_pixel
>> +      - const: pixel_rcg
> 
> Why not just 'pixel'? And why is the root clk generator important? It
> looks like this binding should be using the assigned clock parents
> property instead so that it doesn't have to call clk_set_parent()
> explicitly.
> 
Are we talking about renaming stream_pixel to pixel only?
We divide clocks in categories: core, control and stream clock.
Similar terminology will be used in subsequent driver patches as well.

We can remove pixel_rcg use assigned clock parents property and remove 
clk_set_parent
from driver.

>> +  "#clock-cells":
>> +    const: 1
>> +
>> +  vdda-1p2-supply:
>> +    description: phandle to vdda 1.2V regulator node.
>> +
>> +  vdda-0p9-supply:
>> +    description: phandle to vdda 0.9V regulator node.
>> +
>> +  data-lanes = <0 1>:
> 
> Is this correct? We can have = <value> in the property name? Also feels
> generic and possibly should come from the phy binding instead of from
> the controller binding.
> 
We are using this property in DP controller programming sequence such as 
link training.
So I think we can keep this here.
You are right about <value>. <0 1> part should be in example only. It 
was passing through dt_binding_check though.
Here it should be like:
data-lanes:
minItems:1
maxItems:4

>> +    type: object
>> +    description: Maximum number of lanes that can be used for Display 
>> port.
>> +
>> +  ports:
>> +    description: |
>> +       Contains display port controller endpoint subnode.
>> +       remote-endpoint: |
>> +         For port@0, set to phandle of the connected panel/bridge's
>> +         input endpoint. For port@1, set to the DPU interface output.
>> +         Documentation/devicetree/bindings/graph.txt and
>> +         
>> Documentation/devicetree/bindings/media/video-interfaces.txt.
>> +
>> +patternProperties:
>> +  "^aux-cfg([0-9])-settings$":
>> +    type: object
>> +    description: |
>> +      Specifies the DP AUX configuration [0-9] settings.
>> +      The first entry in this array corresponds to the register 
>> offset
>> +      within DP AUX, while the remaining entries indicate the
>> +      programmable values.
> 
> I'd prefer this was removed from the binding and hardcoded in the 
> driver
> until we can understand what the values are. If they're not
> understandable then they most likely don't change and should be done in
> the driver.
> 
Typically customers tune these values by working with vendor. So for 
different boards it can be different. Even though it is hard for 
customers to do this themselves, these are still board specific and 
belong to dts. As requested earlier, we have added default values 
already and made these properties optional but, we would like to keep it 
in bindings so we can have option to tune them as required.
>> +
>> +required:
>> +  - compatible
>> +  - cell-index
>> +  - reg
>> +  - interrupts
>> +  - clocks
>> +  - clock-names
>> +  - vdda-1p2-supply
>> +  - vdda-0p9-supply
>> +  - data-lanes
>> +  - ports
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/clock/qcom,dispcc-sdm845.h>
>> +    #include <dt-bindings/clock/qcom,gcc-sdm845.h>
>> +    msm_dp: displayport-controller@ae90000{
>> +        compatible = "qcom,dp-display";
>> +        cell-index = <0>;
>> +        reg = <0 0xae90000 0 0x1400>;
>> +        reg-names = "dp_controller";
>> +
>> +        interrupt-parent = <&display_subsystem>;
>> +        interrupts = <12 0>;
>> +
>> +        clocks = <&dispcc DISP_CC_MDSS_DP_AUX_CLK>,
>> +                 <&dispcc DISP_CC_MDSS_DP_LINK_CLK>,
>> +                 <&dispcc DISP_CC_MDSS_DP_LINK_INTF_CLK>,
>> +                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK>,
>> +                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK_SRC>;
>> +        clock-names = "core_aux",
>> +                      "ctrl_link",
>> +                      "ctrl_link_iface", "stream_pixel",
>> +                      "pixel_rcg";
>> +        #clock-cells = <1>;
>> +
>> +        vdda-1p2-supply = <&vreg_l3c_1p2>;
>> +        vdda-0p9-supply = <&vreg_l4a_0p8>;
>> +
>> +        data-lanes = <0 1>;
>> +
>> +        ports {
>> +            #address-cells = <1>;
>> +            #size-cells = <0>;
>> +
>> +            port@0 {
>> +                reg = <0>;
>> +                dp_in: endpoint {
>> +                    remote-endpoint = <&dpu_intf0_out>;
>> +                };
>> +            };
>> +
>> +            port@1 {
>> +                reg = <1>;
>> +                dp_out: endpoint {
>> +                };
>> +            };
>> +        };
>> +    };
> 
> I believe there should be a '...' here.
I think you mean signature is missing? If not could you please explain?
Stephen Boyd June 16, 2020, 10:55 a.m. UTC | #3
Quoting tanmay@codeaurora.org (2020-06-11 13:07:09)
> On 2020-06-09 19:15, Stephen Boyd wrote:
> > Quoting Tanmay Shah (2020-06-08 20:38:18)
> >> diff --git 
> >> a/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml 
> >> b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
> >> new file mode 100644
> >> index 0000000..5fdb915
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
> > 
> > Typically the file name matches the compatible string. But the
> > compatible string is just qcom,dp-display. Maybe the compatible string
> > should be qcom,sc7180-dp? Notice that the SoC number comes first as is
> > preferred.
> > 
> These bindings will be similar for upcoming SOC as well.
> So just for understanding, when we add new SOC do we create new file 
> with same bidings
> with SOC number in new file name?
> Instead we can keep this file's name as qcom,dp-display.yaml (same as 
> compatible const) and we can include SOC number in compatible enum ?
> some examples:
> https://patchwork.kernel.org/patch/11448357/
> https://patchwork.kernel.org/patch/11164619/

Yes that works too. It's really up to robh here.

> > 
> >> @@ -0,0 +1,142 @@
> >> +# SPDX-License-Identifier: (GPL-2.0-only  OR BSD-2-Clause)
> >> +%YAML 1.2
> >> +---
> >> +$id: http://devicetree.org/schemas/display/msm/dp-sc7180.yaml#
> >> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> >> +
> >> +title: Qualcomm Display Port Controller.
> >> +
> >> +maintainers:
> >> +  - Chandan Uddaraju <chandanu@codeaurora.org>
> >> +  - Vara Reddy <varar@codeaurora.org>
> >> +  - Tanmay Shah <tanmay@codeaurora.org>
> >> +
> >> +description: |
> >> +  Device tree bindings for MSM Display Port which supports DP host 
> >> controllers
> >> +  that are compatible with VESA Display Port interface specification.
> >> +
> >> +properties:
> >> +  compatible:
> >> +    items:
> >> +      - const: qcom,dp-display
> >> +
> >> +  cell-index:
> >> +    description: Specifies the controller instance.
> >> +
> >> +  reg:
> >> +    items:
> >> +      - description: DP controller registers
> >> +
> >> +  interrupts:
> >> +    description: The interrupt signal from the DP block.
> >> +
> >> +  clocks:
> >> +    description: List of clock specifiers for clocks needed by the 
> >> device.
> >> +    items:
> >> +      - description: Display Port AUX clock
> >> +      - description: Display Port Link clock
> >> +      - description: Link interface clock between DP and PHY
> >> +      - description: Display Port Pixel clock
> >> +      - description: Root clock generator for pixel clock
> >> +
> >> +  clock-names:
> >> +    description: |
> >> +      Device clock names in the same order as mentioned in clocks 
> >> property.
> >> +      The required clocks are mentioned below.
> >> +    items:
> >> +      - const: core_aux
> >> +      - const: ctrl_link
> >> +      - const: ctrl_link_iface
> >> +      - const: stream_pixel
> >> +      - const: pixel_rcg
> > 
> > Why not just 'pixel'? And why is the root clk generator important? It
> > looks like this binding should be using the assigned clock parents
> > property instead so that it doesn't have to call clk_set_parent()
> > explicitly.
> > 
> Are we talking about renaming stream_pixel to pixel only?
> We divide clocks in categories: core, control and stream clock.
> Similar terminology will be used in subsequent driver patches as well.
> 
> We can remove pixel_rcg use assigned clock parents property and remove 
> clk_set_parent
> from driver.

Cool. Using assigned clock parents is good.

> 
> >> +  "#clock-cells":
> >> +    const: 1
> >> +
> >> +  vdda-1p2-supply:
> >> +    description: phandle to vdda 1.2V regulator node.
> >> +
> >> +  vdda-0p9-supply:
> >> +    description: phandle to vdda 0.9V regulator node.
> >> +
> >> +  data-lanes = <0 1>:
> > 
> > Is this correct? We can have = <value> in the property name? Also feels
> > generic and possibly should come from the phy binding instead of from
> > the controller binding.
> > 
> We are using this property in DP controller programming sequence such as 
> link training.
> So I think we can keep this here.
> You are right about <value>. <0 1> part should be in example only. It 
> was passing through dt_binding_check though.
> Here it should be like:
> data-lanes:
> minItems:1
> maxItems:4

Ok.

> 
> >> +    type: object
> >> +    description: Maximum number of lanes that can be used for Display 
> >> port.
> >> +
> >> +  ports:
> >> +    description: |
> >> +       Contains display port controller endpoint subnode.
> >> +       remote-endpoint: |
> >> +         For port@0, set to phandle of the connected panel/bridge's
> >> +         input endpoint. For port@1, set to the DPU interface output.
> >> +         Documentation/devicetree/bindings/graph.txt and
> >> +         
> >> Documentation/devicetree/bindings/media/video-interfaces.txt.
> >> +
> >> +patternProperties:
> >> +  "^aux-cfg([0-9])-settings$":
> >> +    type: object
> >> +    description: |
> >> +      Specifies the DP AUX configuration [0-9] settings.
> >> +      The first entry in this array corresponds to the register 
> >> offset
> >> +      within DP AUX, while the remaining entries indicate the
> >> +      programmable values.
> > 
> > I'd prefer this was removed from the binding and hardcoded in the 
> > driver
> > until we can understand what the values are. If they're not
> > understandable then they most likely don't change and should be done in
> > the driver.
> > 
> Typically customers tune these values by working with vendor. So for 
> different boards it can be different. Even though it is hard for 
> customers to do this themselves, these are still board specific and 
> belong to dts. As requested earlier, we have added default values 
> already and made these properties optional but, we would like to keep it 
> in bindings so we can have option to tune them as required.

If they're in the binding then they should make sense instead of just
being random values. So please move the defaults to the driver and
have human understandable DT properties to tune these settings. This has
been done for the qcom USB phy already (see things like
qcom,hstx-trim-value for example).

> >> +
> >> +required:
> >> +  - compatible
> >> +  - cell-index
> >> +  - reg
> >> +  - interrupts
> >> +  - clocks
> >> +  - clock-names
> >> +  - vdda-1p2-supply
> >> +  - vdda-0p9-supply
> >> +  - data-lanes
> >> +  - ports
> >> +
> >> +examples:
> >> +  - |
> >> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> >> +    #include <dt-bindings/clock/qcom,dispcc-sdm845.h>
> >> +    #include <dt-bindings/clock/qcom,gcc-sdm845.h>
> >> +    msm_dp: displayport-controller@ae90000{
> >> +        compatible = "qcom,dp-display";
> >> +        cell-index = <0>;
> >> +        reg = <0 0xae90000 0 0x1400>;
> >> +        reg-names = "dp_controller";
> >> +
> >> +        interrupt-parent = <&display_subsystem>;
> >> +        interrupts = <12 0>;
> >> +
> >> +        clocks = <&dispcc DISP_CC_MDSS_DP_AUX_CLK>,
> >> +                 <&dispcc DISP_CC_MDSS_DP_LINK_CLK>,
> >> +                 <&dispcc DISP_CC_MDSS_DP_LINK_INTF_CLK>,
> >> +                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK>,
> >> +                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK_SRC>;
> >> +        clock-names = "core_aux",
> >> +                      "ctrl_link",
> >> +                      "ctrl_link_iface", "stream_pixel",
> >> +                      "pixel_rcg";
> >> +        #clock-cells = <1>;
> >> +
> >> +        vdda-1p2-supply = <&vreg_l3c_1p2>;
> >> +        vdda-0p9-supply = <&vreg_l4a_0p8>;
> >> +
> >> +        data-lanes = <0 1>;
> >> +
> >> +        ports {
> >> +            #address-cells = <1>;
> >> +            #size-cells = <0>;
> >> +
> >> +            port@0 {
> >> +                reg = <0>;
> >> +                dp_in: endpoint {
> >> +                    remote-endpoint = <&dpu_intf0_out>;
> >> +                };
> >> +            };
> >> +
> >> +            port@1 {
> >> +                reg = <1>;
> >> +                dp_out: endpoint {
> >> +                };
> >> +            };
> >> +        };
> >> +    };
> > 
> > I believe there should be a '...' here.
> I think you mean signature is missing? If not could you please explain?

No I mean there should be a triple dot at the end.
Tanmay Shah June 16, 2020, 10:30 p.m. UTC | #4
Thanks Stephen for your answers.

On 2020-06-16 03:55, Stephen Boyd wrote:
> Quoting tanmay@codeaurora.org (2020-06-11 13:07:09)
>> On 2020-06-09 19:15, Stephen Boyd wrote:
>> > Quoting Tanmay Shah (2020-06-08 20:38:18)
>> >> diff --git
>> >> a/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
>> >> b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
>> >> new file mode 100644
>> >> index 0000000..5fdb915
>> >> --- /dev/null
>> >> +++ b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
>> >
>> > Typically the file name matches the compatible string. But the
>> > compatible string is just qcom,dp-display. Maybe the compatible string
>> > should be qcom,sc7180-dp? Notice that the SoC number comes first as is
>> > preferred.
>> >
>> These bindings will be similar for upcoming SOC as well.
>> So just for understanding, when we add new SOC do we create new file
>> with same bidings
>> with SOC number in new file name?
>> Instead we can keep this file's name as qcom,dp-display.yaml (same as
>> compatible const) and we can include SOC number in compatible enum ?
>> some examples:
>> https://patchwork.kernel.org/patch/11448357/
>> https://patchwork.kernel.org/patch/11164619/
> 
> Yes that works too. It's really up to robh here.
> 
>> >
>> >> @@ -0,0 +1,142 @@
>> >> +# SPDX-License-Identifier: (GPL-2.0-only  OR BSD-2-Clause)
>> >> +%YAML 1.2
>> >> +---
>> >> +$id: http://devicetree.org/schemas/display/msm/dp-sc7180.yaml#
>> >> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> >> +
>> >> +title: Qualcomm Display Port Controller.
>> >> +
>> >> +maintainers:
>> >> +  - Chandan Uddaraju <chandanu@codeaurora.org>
>> >> +  - Vara Reddy <varar@codeaurora.org>
>> >> +  - Tanmay Shah <tanmay@codeaurora.org>
>> >> +
>> >> +description: |
>> >> +  Device tree bindings for MSM Display Port which supports DP host
>> >> controllers
>> >> +  that are compatible with VESA Display Port interface specification.
>> >> +
>> >> +properties:
>> >> +  compatible:
>> >> +    items:
>> >> +      - const: qcom,dp-display
>> >> +
>> >> +  cell-index:
>> >> +    description: Specifies the controller instance.
>> >> +
>> >> +  reg:
>> >> +    items:
>> >> +      - description: DP controller registers
>> >> +
>> >> +  interrupts:
>> >> +    description: The interrupt signal from the DP block.
>> >> +
>> >> +  clocks:
>> >> +    description: List of clock specifiers for clocks needed by the
>> >> device.
>> >> +    items:
>> >> +      - description: Display Port AUX clock
>> >> +      - description: Display Port Link clock
>> >> +      - description: Link interface clock between DP and PHY
>> >> +      - description: Display Port Pixel clock
>> >> +      - description: Root clock generator for pixel clock
>> >> +
>> >> +  clock-names:
>> >> +    description: |
>> >> +      Device clock names in the same order as mentioned in clocks
>> >> property.
>> >> +      The required clocks are mentioned below.
>> >> +    items:
>> >> +      - const: core_aux
>> >> +      - const: ctrl_link
>> >> +      - const: ctrl_link_iface
>> >> +      - const: stream_pixel
>> >> +      - const: pixel_rcg
>> >
>> > Why not just 'pixel'? And why is the root clk generator important? It
>> > looks like this binding should be using the assigned clock parents
>> > property instead so that it doesn't have to call clk_set_parent()
>> > explicitly.
>> >
>> Are we talking about renaming stream_pixel to pixel only?
>> We divide clocks in categories: core, control and stream clock.
>> Similar terminology will be used in subsequent driver patches as well.
>> 
>> We can remove pixel_rcg use assigned clock parents property and remove
>> clk_set_parent
>> from driver.
> 
> Cool. Using assigned clock parents is good.
> 
>> 
>> >> +  "#clock-cells":
>> >> +    const: 1
>> >> +
>> >> +  vdda-1p2-supply:
>> >> +    description: phandle to vdda 1.2V regulator node.
>> >> +
>> >> +  vdda-0p9-supply:
>> >> +    description: phandle to vdda 0.9V regulator node.
>> >> +
>> >> +  data-lanes = <0 1>:
>> >
>> > Is this correct? We can have = <value> in the property name? Also feels
>> > generic and possibly should come from the phy binding instead of from
>> > the controller binding.
>> >
>> We are using this property in DP controller programming sequence such 
>> as
>> link training.
>> So I think we can keep this here.
>> You are right about <value>. <0 1> part should be in example only. It
>> was passing through dt_binding_check though.
>> Here it should be like:
>> data-lanes:
>> minItems:1
>> maxItems:4
> 
> Ok.
> 
>> 
>> >> +    type: object
>> >> +    description: Maximum number of lanes that can be used for Display
>> >> port.
>> >> +
>> >> +  ports:
>> >> +    description: |
>> >> +       Contains display port controller endpoint subnode.
>> >> +       remote-endpoint: |
>> >> +         For port@0, set to phandle of the connected panel/bridge's
>> >> +         input endpoint. For port@1, set to the DPU interface output.
>> >> +         Documentation/devicetree/bindings/graph.txt and
>> >> +
>> >> Documentation/devicetree/bindings/media/video-interfaces.txt.
>> >> +
>> >> +patternProperties:
>> >> +  "^aux-cfg([0-9])-settings$":
>> >> +    type: object
>> >> +    description: |
>> >> +      Specifies the DP AUX configuration [0-9] settings.
>> >> +      The first entry in this array corresponds to the register
>> >> offset
>> >> +      within DP AUX, while the remaining entries indicate the
>> >> +      programmable values.
>> >
>> > I'd prefer this was removed from the binding and hardcoded in the
>> > driver
>> > until we can understand what the values are. If they're not
>> > understandable then they most likely don't change and should be done in
>> > the driver.
>> >
>> Typically customers tune these values by working with vendor. So for
>> different boards it can be different. Even though it is hard for
>> customers to do this themselves, these are still board specific and
>> belong to dts. As requested earlier, we have added default values
>> already and made these properties optional but, we would like to keep 
>> it
>> in bindings so we can have option to tune them as required.
> 
> If they're in the binding then they should make sense instead of just
> being random values. So please move the defaults to the driver and
> have human understandable DT properties to tune these settings. This 
> has
> been done for the qcom USB phy already (see things like
> qcom,hstx-trim-value for example).
> 
Ok. For now I will move these values to driver and later we will add dt 
properties as required.

>> >> +
>> >> +required:
>> >> +  - compatible
>> >> +  - cell-index
>> >> +  - reg
>> >> +  - interrupts
>> >> +  - clocks
>> >> +  - clock-names
>> >> +  - vdda-1p2-supply
>> >> +  - vdda-0p9-supply
>> >> +  - data-lanes
>> >> +  - ports
>> >> +
>> >> +examples:
>> >> +  - |
>> >> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> >> +    #include <dt-bindings/clock/qcom,dispcc-sdm845.h>
>> >> +    #include <dt-bindings/clock/qcom,gcc-sdm845.h>
>> >> +    msm_dp: displayport-controller@ae90000{
>> >> +        compatible = "qcom,dp-display";
>> >> +        cell-index = <0>;
>> >> +        reg = <0 0xae90000 0 0x1400>;
>> >> +        reg-names = "dp_controller";
>> >> +
>> >> +        interrupt-parent = <&display_subsystem>;
>> >> +        interrupts = <12 0>;
>> >> +
>> >> +        clocks = <&dispcc DISP_CC_MDSS_DP_AUX_CLK>,
>> >> +                 <&dispcc DISP_CC_MDSS_DP_LINK_CLK>,
>> >> +                 <&dispcc DISP_CC_MDSS_DP_LINK_INTF_CLK>,
>> >> +                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK>,
>> >> +                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK_SRC>;
>> >> +        clock-names = "core_aux",
>> >> +                      "ctrl_link",
>> >> +                      "ctrl_link_iface", "stream_pixel",
>> >> +                      "pixel_rcg";
>> >> +        #clock-cells = <1>;
>> >> +
>> >> +        vdda-1p2-supply = <&vreg_l3c_1p2>;
>> >> +        vdda-0p9-supply = <&vreg_l4a_0p8>;
>> >> +
>> >> +        data-lanes = <0 1>;
>> >> +
>> >> +        ports {
>> >> +            #address-cells = <1>;
>> >> +            #size-cells = <0>;
>> >> +
>> >> +            port@0 {
>> >> +                reg = <0>;
>> >> +                dp_in: endpoint {
>> >> +                    remote-endpoint = <&dpu_intf0_out>;
>> >> +                };
>> >> +            };
>> >> +
>> >> +            port@1 {
>> >> +                reg = <1>;
>> >> +                dp_out: endpoint {
>> >> +                };
>> >> +            };
>> >> +        };
>> >> +    };
>> >
>> > I believe there should be a '...' here.
>> I think you mean signature is missing? If not could you please 
>> explain?
> 
> No I mean there should be a triple dot at the end.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
new file mode 100644
index 0000000..5fdb915
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/msm/dp-sc7180.yaml
@@ -0,0 +1,142 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only  OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/msm/dp-sc7180.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Display Port Controller.
+
+maintainers:
+  - Chandan Uddaraju <chandanu@codeaurora.org>
+  - Vara Reddy <varar@codeaurora.org>
+  - Tanmay Shah <tanmay@codeaurora.org>
+
+description: |
+  Device tree bindings for MSM Display Port which supports DP host controllers
+  that are compatible with VESA Display Port interface specification.
+
+properties:
+  compatible:
+    items:
+      - const: qcom,dp-display
+
+  cell-index:
+    description: Specifies the controller instance.
+
+  reg:
+    items:
+      - description: DP controller registers
+
+  interrupts:
+    description: The interrupt signal from the DP block.
+
+  clocks:
+    description: List of clock specifiers for clocks needed by the device.
+    items:
+      - description: Display Port AUX clock
+      - description: Display Port Link clock
+      - description: Link interface clock between DP and PHY
+      - description: Display Port Pixel clock
+      - description: Root clock generator for pixel clock
+
+  clock-names:
+    description: |
+      Device clock names in the same order as mentioned in clocks property.
+      The required clocks are mentioned below.
+    items:
+      - const: core_aux
+      - const: ctrl_link
+      - const: ctrl_link_iface
+      - const: stream_pixel
+      - const: pixel_rcg
+  "#clock-cells":
+    const: 1
+
+  vdda-1p2-supply:
+    description: phandle to vdda 1.2V regulator node.
+
+  vdda-0p9-supply:
+    description: phandle to vdda 0.9V regulator node.
+
+  data-lanes = <0 1>:
+    type: object
+    description: Maximum number of lanes that can be used for Display port.
+
+  ports:
+    description: |
+       Contains display port controller endpoint subnode.
+       remote-endpoint: |
+         For port@0, set to phandle of the connected panel/bridge's
+         input endpoint. For port@1, set to the DPU interface output.
+         Documentation/devicetree/bindings/graph.txt and
+         Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+patternProperties:
+  "^aux-cfg([0-9])-settings$":
+    type: object
+    description: |
+      Specifies the DP AUX configuration [0-9] settings.
+      The first entry in this array corresponds to the register offset
+      within DP AUX, while the remaining entries indicate the
+      programmable values.
+
+required:
+  - compatible
+  - cell-index
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+  - vdda-1p2-supply
+  - vdda-0p9-supply
+  - data-lanes
+  - ports
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/qcom,dispcc-sdm845.h>
+    #include <dt-bindings/clock/qcom,gcc-sdm845.h>
+    msm_dp: displayport-controller@ae90000{
+        compatible = "qcom,dp-display";
+        cell-index = <0>;
+        reg = <0 0xae90000 0 0x1400>;
+        reg-names = "dp_controller";
+
+        interrupt-parent = <&display_subsystem>;
+        interrupts = <12 0>;
+
+        clocks = <&dispcc DISP_CC_MDSS_DP_AUX_CLK>,
+                 <&dispcc DISP_CC_MDSS_DP_LINK_CLK>,
+                 <&dispcc DISP_CC_MDSS_DP_LINK_INTF_CLK>,
+                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK>,
+                 <&dispcc DISP_CC_MDSS_DP_PIXEL_CLK_SRC>;
+        clock-names = "core_aux",
+                      "ctrl_link",
+                      "ctrl_link_iface", "stream_pixel",
+                      "pixel_rcg";
+        #clock-cells = <1>;
+
+        vdda-1p2-supply = <&vreg_l3c_1p2>;
+        vdda-0p9-supply = <&vreg_l4a_0p8>;
+
+        data-lanes = <0 1>;
+
+        ports {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            port@0 {
+                reg = <0>;
+                dp_in: endpoint {
+                    remote-endpoint = <&dpu_intf0_out>;
+                };
+            };
+
+            port@1 {
+                reg = <1>;
+                dp_out: endpoint {
+                };
+            };
+        };
+    };
diff --git a/Documentation/devicetree/bindings/display/msm/dpu.txt b/Documentation/devicetree/bindings/display/msm/dpu.txt
index 551ae26..30c8ab4 100644
--- a/Documentation/devicetree/bindings/display/msm/dpu.txt
+++ b/Documentation/devicetree/bindings/display/msm/dpu.txt
@@ -65,6 +65,7 @@  Required properties:
 
 	Port 0 -> DPU_INTF1 (DSI1)
 	Port 1 -> DPU_INTF2 (DSI2)
+	Port 2 -> DPU_INTF0 (DP)
 
 Optional properties:
 - assigned-clocks: list of clock specifiers for clocks needing rate assignment
@@ -136,6 +137,13 @@  Example:
 						remote-endpoint = <&dsi1_in>;
 					};
 				};
+
+				port@2 {
+					reg = <2>;
+					dpu_intf0_out: endpoint {
+						remote-endpoint = <&dp_in>;
+					};
+				};
 			};
 		};
 	};