[PATCH v1] dt-bindings: display: Add support for Intel KeemBay Display

[Chrisanthus, Anitha]

Hi Rob,
Thanks for the your prompt review. Please see my comments/questions inline.
For everything else, I can incorporate the changes in v2.
Anitha

> -----Original Message-----
> From: Rob Herring <robh at kernel.org>
> Sent: Tuesday, October 6, 2020 2:08 PM
> To: Chrisanthus, Anitha <anitha.chrisanthus at intel.com>
> Cc: devicetree at vger.kernel.org; Paauwe, Bob J <bob.j.paauwe at intel.com>;
> Dea, Edmund J <edmund.j.dea at intel.com>; sam at ravnborg.org;
> narmstrong at baylibre.com
> Subject: Re: [PATCH v1] dt-bindings: display: Add support for Intel KeemBay
> Display
> 
> On Fri, Oct 02, 2020 at 07:21:02PM -0700, Anitha Chrisanthus wrote:
> > This patch adds bindings for Intel KeemBay Display
> >
> > Signed-off-by: Anitha Chrisanthus <anitha.chrisanthus at intel.com>
> > ---
> >  .../bindings/display/intel,kmb_display.yaml        | 106
> +++++++++++++++++++++
> >  1 file changed, 106 insertions(+)
> >  create mode 100644
> Documentation/devicetree/bindings/display/intel,kmb_display.yaml
> >
> > diff --git
> a/Documentation/devicetree/bindings/display/intel,kmb_display.yaml
> b/Documentation/devicetree/bindings/display/intel,kmb_display.yaml
> > new file mode 100644
> > index 0000000..65835cb
> > --- /dev/null
> > +++
> b/Documentation/devicetree/bindings/display/intel,kmb_display.yaml
> > @@ -0,0 +1,106 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> 
> check checkpatch.pl
> 
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/display/intel,kmb_display.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Devicetree bindings for Intel Keem Bay display controller
> > +
> > +maintainers:
> > +  - Anitha Chrisanthus <anitha.chrisanthus at intel.com>
> > +  - Edmond J Dea <edmund.j.dea at intel.com>
> > +
> > +properties:
> > +  compatible:
> > +    const: intel,kmb_display
> 
> 'keembay' was used elsewhere. Please be consistent.
> 
> Don't use '_' either.
Please note that I cannot change the name at this point as there is a dependency on the u-boot firmware which loads the device tree. I can change the name to kmb-drm or keembay-display when updated firmware becomes available.
> 
> > +
> > +  reg:
> > +    maxItems: 3
> 
> Can drop, implied.
> 
> > +    items:
> > +      - description: Lcd registers range
> > +      - description: Mipi registers range
> > +      - description: Msscam registers range
> 
> Is this really 1 h/w block? Don't really seem like it given addresses
> aren't adjacent, separate clocks, and MIPI blocks are often licensed IP.
Yes, these are part of the camera subsystem block of Intel Movidius Keembay SOC.
Please see  https://lwn.net/Articles/833540/

> 
> > +
> > +  reg-names:
> > +    items:
> > +      - const: lcd_regs
> > +      - const: mipi_regs
> > +      - const: msscam_regs
> 
> '_regs' is redundant.
> 
> > +
> > +  clocks:
> > +    items:
> > +      - description: LCD controller clock
> > +      - description: Mipi DSI clock
> > +      - description: Mipi DSI econfig clock
> > +      - description: Mipi DSI config clock
> > +      - description: System clock or pll0 clock
> > +
> > +  clock-names:
> > +    items:
> > +      - const: clk_lcd
> > +      - const: clk_mipi
> > +      - const: clk_mipi_ecfg
> > +      - const: clk_mipi_cfg
> > +      - const: clk_pll0
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  interrupt-names:
> > +    items:
> > +      - const: irq_lcd
> 
> You don't really need *-names when there's only 1 entry.
> 
> > +
> > +  encoder-slave:
> > +    description: bridge node entry for mipi to hdmi converter
> 
> No, this is what 'port' is for.
Driver calls this
encoder_node = of_parse_phandle(dev->of_node, "encoder-slave", 0)
And  bridge = of_drm_find_bridge(encoder_node); to locate the bridge driver.
How do I do this without this entry? Please advise.
This was tested and it works.
> 
> > +
> > +  port:
> > +    type: object
> > +    description: >
> > +          Port node with one endpoint connected to mipi to hdmi converter
> node.
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - reg-names
> > +  - clocks
> > +  - clock-names
> > +  - interrupts
> > +  - interrupt-names
> > +  - encoder-slave
> > +  - port
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    #define GIC_SPI
> 
> There's a header for this.
> 
> > +    #define MOVISOC_KMB_MSS_AUX_LCD
> > +    #define MOVISOC_KMB_MSS_AUX_MIPI_TX0
> > +    #define MOVISOC_KMB_MSS_AUX_MIPI_ECFG
> > +    #define MOVISOC_KMB_MSS_AUX_MIPI_CFG
> > +    #define MOVISOC_KMB_A53_PLL_0_OUT_0
> > +    display: display at 20900000 {
> 
> Drop unused labels.
> 
> > +      compatible = "intel,kmb_display";
> > +      reg = <0x20930000 0x3000>,
> > +            <0x20900000 0x4000>,
> > +            <0x20910000 0x30>;
> > +      reg-names = "lcd_regs", "mipi_regs", "msscam_regs";
> > +      interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>;
> > +      interrupt-names = "irq_lcd";
> > +      clocks = <&scmi_clk MOVISOC_KMB_MSS_AUX_LCD>,
> > +               <&scmi_clk MOVISOC_KMB_MSS_AUX_MIPI_TX0>,
> > +               <&scmi_clk MOVISOC_KMB_MSS_AUX_MIPI_ECFG>,
> > +               <&scmi_clk MOVISOC_KMB_MSS_AUX_MIPI_CFG>,
> > +               <&scmi_clk MOVISOC_KMB_A53_PLL_0_OUT_0>;
> > +      clock-names = "clk_lcd", "clk_mipi", "clk_mipi_ecfg",
> > +                    "clk_mipi_cfg", "clk_pll0";
> > +
> > +      encoder-slave = <&adv7535>;
> > +
> > +      port {
> > +            dsi_output: endpoint {
> > +                remote-endpoint = <&adv7535_input>;
> > +            };
> > +      };
> > +    };
> > --
> > 2.7.4
> >