openwrt/target/linux/bcm27xx/patches-5.15/950-0796-overlays-Add-overlay-for-MIPI-DBI-displays.patch

From bf5020c3cbf3e799379c661e2f653ac572175d67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
Date: Mon, 7 Mar 2022 17:05:49 +0100
Subject: [PATCH] overlays: Add overlay for MIPI DBI displays
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Add an overlay that can be used with all displays that have a
MIPI DBI compatible controller (pixels over SPI).

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---
 arch/arm/boot/dts/overlays/Makefile           |   1 +
 arch/arm/boot/dts/overlays/README             |  67 +++++++
 .../dts/overlays/mipi-dbi-spi-overlay.dts     | 172 ++++++++++++++++++
 3 files changed, 240 insertions(+)
 create mode 100644 arch/arm/boot/dts/overlays/mipi-dbi-spi-overlay.dts

--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -135,6 +135,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
 	midi-uart5.dtbo \
 	minipitft13.dtbo \
 	miniuart-bt.dtbo \
+	mipi-dbi-spi.dtbo \
 	mlx90640.dtbo \
 	mmc.dtbo \
 	mpu6050.dtbo \
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -2386,6 +2386,73 @@ Params: krnbt                   Set to "
                                 driver without need of hciattach/btattach
 
 
+Name:   mipi-dbi-spi
+Info:   Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
+        driver. The driver will load a file /lib/firmware/panel.bin containing
+        the initialisation commands.
+
+        Example:
+          dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
+          dtparam=width=320,height=240
+          dtparam=reset-gpio=23,dc-gpio=24
+          dtparam=backlight-gpio=18
+
+        Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
+        and init commands at 10MHz. This makes it possible to push the envelope
+        without messing up the controller configuration due to command
+        transmission errors.
+
+        For devices on spi1 or spi2, the interfaces should be enabled
+        with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
+
+        See https://github.com/notro/panel-mipi-dbi/wiki for more info.
+
+Load:   dtoverlay=mipi-dbi-spi,<param>=<val>
+Params:
+        compatible              Set the compatible string to load a different
+                                firmware file. Both the panel compatible value
+                                used to load the firmware file and the value
+                                used to load the driver has to be set having a
+                                NUL (\0) separator between them.
+                                Example:
+                                dtparam=compatible=mypanel\0panel-mipi-dbi-spi
+        spi<n>-<m>              Configure device at spi<n>, cs<m>
+                                (boolean, required)
+        speed                   SPI bus speed in Hz (default 32000000)
+        cpha                    Shifted SPI clock phase (CPHA) mode
+        cpol                    Inverse SPI clock polarity (CPOL) mode
+        write-only              Controller is not readable
+                                (ie. MISO is not wired up).
+
+        width                   Panel width in pixels (required)
+        height                  Panel height in pixels (required)
+        width-mm                Panel width in mm
+        height-mm               Panel height in mm
+        x-offset                Panel x-offset in controller RAM
+        y-offset                Panel y-offset in controller RAM
+
+        clock-frequency         Panel clock frequency in Hz
+                                (optional, just informational).
+
+        reset-gpio              GPIO pin to be used for RESET
+        dc-gpio                 GPIO pin to be used for D/C
+
+        backlight-gpio          GPIO pin to be used for backlight control
+                                (default of none).
+        backlight-pwm           PWM channel to be used for backlight control
+                                (default of none). NB Disables audio headphone
+                                output as that also uses PWM.
+        backlight-pwm-chan      Choose channel on &pwm node for backlight
+                                control (default 0).
+        backlight-pwm-gpio      GPIO pin to be used for the PWM backlight. See
+                                pwm-2chan for valid options (default 18).
+        backlight-pwm-func      Pin function of GPIO used for the PWM backlight.
+                                See pwm-2chan for valid options (default 2).
+        backlight-def-brightness
+                                Set the default brightness. Normal range 1-16.
+                                (default 16).
+
+
 Name:   mlx90640
 Info:   Overlay for i2c connected mlx90640 thermal camera
 Load:   dtoverlay=mlx90640
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/mipi-dbi-spi-overlay.dts
@@ -0,0 +1,172 @@
+/*
+ * mipi-dbi-spi-overlay.dts
+ */
+
+#include <dt-bindings/gpio/gpio.h>
+
+/dts-v1/;
+/plugin/;
+
+/ {
+	compatible = "brcm,bcm2835";
+
+	spidev_fragment: fragment@0 {
+		target-path = "spi0/spidev@0";
+		__overlay__ {
+			status = "disabled";
+		};
+	};
+
+	panel_fragment: fragment@1 {
+		target = <&spi0>;
+		__overlay__ {
+			/* needed to avoid dtc warning */
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			status = "okay";
+
+			panel: panel@0 {
+				compatible = "panel", "panel-mipi-dbi-spi";
+				reg = <0>;
+				spi-max-frequency = <32000000>;
+
+				timing: panel-timing {
+					hactive = <320>;
+					vactive = <240>;
+					hback-porch = <0>;
+					vback-porch = <0>;
+
+					clock-frequency = <0>;
+					hfront-porch = <0>;
+					hsync-len = <0>;
+					vfront-porch = <0>;
+					vsync-len = <0>;
+				};
+			};
+		};
+	};
+
+	fragment@10 {
+		target = <&panel>;
+		__dormant__  {
+			backlight = <&backlight_gpio>;
+		};
+	};
+
+	fragment@11 {
+		target-path = "/";
+		__dormant__  {
+			backlight_gpio: backlight_gpio {
+				compatible = "gpio-backlight";
+				gpios = <&gpio 255 GPIO_ACTIVE_HIGH>;
+			};
+		};
+	};
+
+	fragment@20 {
+		target = <&panel>;
+		__dormant__  {
+			backlight = <&backlight_pwm>;
+		};
+	};
+
+	fragment@21 {
+		target-path = "/";
+		__dormant__  {
+			backlight_pwm: backlight_pwm {
+				compatible = "pwm-backlight";
+				brightness-levels = <0 6 8 12 16 24 32 40 48 64 96 128 160 192 224 255>;
+				default-brightness-level = <16>;
+				pwms = <&pwm 0 200000>;
+			};
+		};
+	};
+
+	fragment@22 {
+		target = <&pwm>;
+		__dormant__ {
+			pinctrl-names = "default";
+			pinctrl-0 = <&pwm_pins>;
+			assigned-clock-rates = <1000000>;
+			status = "okay";
+		};
+	};
+
+	fragment@23 {
+		target = <&gpio>;
+		__dormant__ {
+			pwm_pins: pwm_pins {
+				brcm,pins = <18>;
+				brcm,function = <2>; /* Alt5 */
+			};
+		};
+	};
+
+	fragment@24 {
+		target = <&audio>;
+		__dormant__  {
+		    brcm,disable-headphones;
+		};
+	};
+
+	__overrides__ {
+		compatible    = <&panel>, "compatible";
+
+		spi0-0        = <&panel_fragment>, "target:0=",<&spi0>,
+				<&spidev_fragment>, "target-path=spi0/spidev@0",
+				<&panel>, "reg:0=0";
+		spi0-1        = <&panel_fragment>, "target:0=",<&spi0>,
+				<&spidev_fragment>, "target-path=spi0/spidev@1",
+				<&panel>, "reg:0=1";
+		spi1-0        = <&panel_fragment>, "target:0=",<&spi1>,
+				<&spidev_fragment>, "target-path=spi1/spidev@0",
+				<&panel>, "reg:0=0";
+		spi1-1        = <&panel_fragment>, "target:0=",<&spi1>,
+				<&spidev_fragment>, "target-path=spi1/spidev@1",
+				<&panel>, "reg:0=1";
+		spi1-2        = <&panel_fragment>, "target:0=",<&spi1>,
+				<&spidev_fragment>, "target-path=spi1/spidev@2",
+				<&panel>, "reg:0=2";
+		spi2-0        = <&panel_fragment>, "target:0=",<&spi2>,
+				<&spidev_fragment>, "target-path=spi2/spidev@0",
+				<&panel>, "reg:0=0";
+		spi2-1        = <&panel_fragment>, "target:0=",<&spi2>,
+				<&spidev_fragment>, "target-path=spi2/spidev@1",
+				<&panel>, "reg:0=1";
+		spi2-2        = <&panel_fragment>, "target:0=",<&spi2>,
+				<&spidev_fragment>, "target-path=spi2/spidev@2",
+				<&panel>, "reg:0=2";
+
+		speed         = <&panel>, "spi-max-frequency:0";
+		cpha          = <&panel>, "spi-cpha?";
+		cpol          = <&panel>, "spi-cpol?";
+
+		write-only    = <&panel>, "write-only?";
+
+		width         = <&timing>, "hactive:0";
+		height        = <&timing>, "vactive:0";
+		x-offset      = <&timing>, "hback-porch:0";
+		y-offset      = <&timing>, "vback-porch:0";
+		clock-frequency = <&timing>, "clock-frequency:0";
+
+		width-mm      = <&panel>, "width-mm:0";
+		height-mm     = <&panel>, "height-mm:0";
+
+		/* optional gpios */
+		reset-gpio    = <&panel>, "reset-gpios:0=", <&gpio>,
+				<&panel>, "reset-gpios:4",
+				<&panel>, "reset-gpios:8=0"; /* GPIO_ACTIVE_HIGH */
+		dc-gpio       = <&panel>, "dc-gpios:0=", <&gpio>,
+				<&panel>, "dc-gpios:4",
+				<&panel>, "dc-gpios:8=0"; /* GPIO_ACTIVE_HIGH */
+
+		backlight-gpio        = <0>, "+10+11",
+					<&backlight_gpio>, "gpios:4";
+		backlight-pwm         = <0>, "+20+21+22+23+24";
+		backlight-pwm-chan    = <&backlight_pwm>, "pwms:4";
+		backlight-pwm-gpio    = <&pwm_pins>, "brcm,pins:0";
+		backlight-pwm-func    = <&pwm_pins>, "brcm,function:0";
+		backlight-def-brightness = <&backlight_pwm>, "default-brightness-level:0";
+	};
+};