Re: [PATCH 4/6] dt-bindings: display: sitronix,st7735r: Add initialization properties

On Wed, Nov 24, 2021 at 04:07:55PM +0100, Noralf Trønnes wrote:

Add initialization properties that are commonly used to initialize the controller for a specific display panel. It is common for displays to have a datasheet listing the necessary controller settings or some example code doing the same. These settings can be matched directly to the DT properties.

The commands FRMCTR2, FRMCTR3, PWCTR4 and PWCTR5 are usually part of the setup examples but they are skipped here since they deal with partial and idle mode which are powersaving modes for very special use cases.

dc-gpios is made optional because its absence indicates 3-line mode.

Signed-off-by: Noralf Trønnes noralf@tronnes.org

.../bindings/display/sitronix,st7735r.yaml | 118 +++++++++++++++++- 1 file changed, 116 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/sitronix,st7735r.yaml b/Documentation/devicetree/bindings/display/sitronix,st7735r.yaml index 157b1a7b18f9..2db1cfe6ae30 100644 --- a/Documentation/devicetree/bindings/display/sitronix,st7735r.yaml +++ b/Documentation/devicetree/bindings/display/sitronix,st7735r.yaml @@ -19,6 +19,10 @@ allOf: properties: compatible: oneOf:

•  - description:
  

•      Sitronix ST7735R 262K Color Single-Chip TFT Controller/Driver
  

•    items:
  

•      - const: sitronix,st7735r
   - description:
       Adafruit 1.8" 160x128 Color TFT LCD (Product ID 358 or 618)
     items:
  

@@ -32,20 +36,99 @@ properties: - okaya,rh128128t - const: sitronix,st7715r

• width:
• description:

•  Width of display panel in pixels
  

• height:
• description:

•  Height of display panel in pixels
  

We already have width-mm and height-mm for physical size so this might be a bit confusing. There's also panel-timing 'vactive' and 'hactive' which is effectively the same thing you are defining.

• frmctr1:

Are all these standardized by MIPI or otherwise common? If not, they need vendor prefixes.

• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  Frame Rate Control (In normal mode/Full colors) (B1h)
  

• minItems: 3
• maxItems: 3
• invctr:
• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  Display Inversion Control (B4h)
  

• minItems: 1
• maxItems: 1
• pwctr1:
• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  Power Control 1 (C0h)
  

• minItems: 3
• maxItems: 3
• pwctr2:
• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  Power Control 2 (C1h)
  

• minItems: 1
• maxItems: 1
• pwctr3:
• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  Power Control 3 (in Normal mode/Full colors) (C2h)
  

• minItems: 2
• maxItems: 2
• vmctr1:
• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  VCOM Control 1 (C5h)
  

• minItems: 1
• maxItems: 1
• madctl:
• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  Memory Data Access Control (36h)
  

• minItems: 1
• maxItems: 1
• gamctrp1:
• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  Gamma Positive Polarity Correction Characteristics Setting (E0h)
  

• minItems: 16
• maxItems: 16
• gamctrn1:
• $ref: /schemas/types.yaml#definitions/uint8-array
• description:

•  Gamma Negative Polarity Correction Characteristics Setting (E1h)
  

• minItems: 16
• maxItems: 16
• write-only:
• type: boolean
• description:

•  Controller is not readable (ie. MISO is not wired up).
  

• dc-gpios: maxItems: 1

• description: Display data/command selection (D/CX)

• description: |

•  Controller data/command selection (D/CX) in 4-line SPI mode.
  

•  If not set, the controller is in 3-line SPI mode.
  
  

  backlight: true reg: true spi-max-frequency: true reset-gpios: true rotation: true

• width-mm: true

• height-mm: true

required:

• compatible
• reg
• • dc-gpios

additionalProperties: false

@@ -72,5 +155,36 @@ examples: backlight = <&backlight>; }; };

• • |
• #include <dt-bindings/gpio/gpio.h>
• spi {

•        #address-cells = <1>;
  

•        #size-cells = <0>;
  

•        sainsmart18@0{
  

•                compatible = "sitronix,st7735r";
  

•                reg = <0>;
  

•                spi-max-frequency = <40000000>;
  

•                width = <160>;
  

•                height = <128>;
  

•                frmctr1 = [ 01 2C 2D ];
  

•                invctr = [ 07 ];
  

•                pwctr1 = [ A2 02 84 ];
  

•                pwctr2 = [ C5 ];
  

•                pwctr3 = [ 0A 00 ];
  

•                vmctr1 = [ 0E ];
  

•                madctl = [ 60 ];
  

•                gamctrp1 = [ 0F 1A 0F 18 2F 28 20 22 1F 1B 23 37 00 07 02 10 ];
  

•                gamctrn1 = [ 0F 1B 0F 17 33 2C 29 2E 30 30 39 3F 00 07 03 10 ];
  

•                dc-gpios = <&gpio 43 GPIO_ACTIVE_HIGH>;
  

•                reset-gpios = <&gpio 80 GPIO_ACTIVE_HIGH>;
  

•                write-only;
  

•        };
  

• };

...

2.33.0