pdp7/BB-LCD-ADAFRUIT-18-SPI1-00A0.dts

## BB-LCD-ADAFRUIT-18-SPI1-00A0.dts
/*
 * Copyright (C) 2013 CircuitCo
 * Copyright (C) 2018 Drew Fustini <drew@beagleboard.org>
 *
 * Adafruit 1.8" TFT LCD on SPI1 bus using tinydrm st7735r driver
 *
 * LICENSE:
 * --------
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * DOCUMENTATION:
 * --------------
 * This file was copied from src/arm/BB-SPIDEV1-00A0.dts and modified
 * by Drew Fustini based on an exmample from David Lechner.
 *
 * This is the Adafruit 1.8" TFT LCD:
 * https://www.adafruit.com/products/358
 *
 * It should be connected to BeagleBone SPI1 bus:
 *
 *   P9.12 <--> reset
 *   P9.14 <--> lite (pwm)
 *   P9.15 <--> dc
 *   P9.23 <--> lite (gpio)
 *   P9.28 <--> tft_cs
 *   P9.30 <--> mosi
 *   P9.31 <--> clk
 *
 * This overlay will load the mainline tinydrm st7735r driver by David Lechner:
 * https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/tinydrm/st7735r.c
 *
 * Tested with 4.16.0-rc2-bone3 kernel on Debian 9.3 image
 *
 * Run libdrm modetest for colorbar test based on instructions from:
 * https://github.com/notro/tinydrm/wiki/Development#modetest
 *
 * modetest -M "st7735r" -c #this will display connector id
 * modetest -M "st7735r" -s 28:128x160 #connector id and resolution
 * # you should now see a color bar on the LCD
 *
 * Mailing list post with more information:
 * https://groups.google.com/d/msg/beagleboard/GuMQIP_XCW0/b3lxbx_8AwAJ
 *
 * GitHub Gist with testing results:
 * https://gist.github.com/pdp7/aee5664598059c9b9a9020f107957f80
 *
 * Discussion with notro on how to test tinydrm driver:
 * https://github.com/notro/tinydrm/issues/1#issuecomment-367279037
 */

#include <dt-bindings/board/am335x-bbw-bbb-base.h>
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/pinctrl/am33xx.h>

/dts-v1/;
/plugin/;

/ {
	fragment@0 {
		target-path = "/";
		__overlay__ {
			backlight_gpio: backlight_gpio {
				compatible = "gpio-backlight";
				gpios = <&gpio1 17 GPIO_ACTIVE_HIGH>;
				// connect lcd lite pin to P9.23 which is gpio1[17]
				// refer to https://elinux.org/Beagleboard:Cape_Expansion_Headers
			};

			backlight_pwm: backlight_pwm {
				// P9.14 <--> lite (pwm-backlight EHRPWM1A)
				pinctrl-names = "default";
				pinctrl-0 = <&backlight_pwm_pins>;
                                status = "okay";
                                compatible = "pwm-backlight";
                                pwms = <&ehrpwm1 1 500000 0>;
                                brightness-levels = <
                                        0  1  2  3  4  5  6  7  8  9
                                        10 11 12 13 14 15 16 17 18 19
                                        20 21 22 23 24 25 26 27 28 29
                                        30 31 32 33 34 35 36 37 38 39
                                        40 41 42 43 44 45 46 47 48 49
                                        50 51 52 53 54 55 56 57 58 59
                                        60 61 62 63 64 65 66 67 68 69
                                        70 71 72 73 74 75 76 77 78 79
                                        80 81 82 83 84 85 86 87 88 89
                                        90 91 92 93 94 95 96 97 98 99
                                        100
                                >;
                                default-brightness-level = <90>;
                        };
		};
	};

	/*
	 * Free up the pins used by the cape from the pinmux helpers.
	 */
	fragment@1 {
		target = <&ocp>;
		__overlay__ {
			P9_12_pinmux { status = "disabled"; };	/* lcd reset */
			P9_14_pinmux { status = "disabled"; };	/* lcd pwm backlight */
			P9_15_pinmux { status = "disabled"; };	/* lcd dc */
			P9_23_pinmux { status = "disabled"; };	/* lcd gpio backlight */
			P9_28_pinmux { status = "disabled"; };	/* spi1_cs0 */
			P9_29_pinmux { status = "disabled"; };	/* spi1_d0 */
			P9_30_pinmux { status = "disabled"; };	/* spi1_d1 */
			P9_31_pinmux { status = "disabled"; };	/* spi1_sclk */
		};
	};

	fragment@2 {
		target = <&am33xx_pinmux>;
		__overlay__ {
			/* default state has all gpios released and mode set to uart1 */
			bb_spi1_pins: pinmux_bb_spi1_pins {
				pinctrl-single,pins = <
					0x190 0x33	/* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3 */
					0x194 0x33	/* mcasp0_fsx.spi1_d0, INPUT_PULLUP | MODE3 */
					0x198 0x13	/* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP | MODE3 */
					0x19c 0x13	/* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
					// 0x164 0x12	/* eCAP0_in_PWM0_out.spi1_cs1 OUTPUT_PULLUP | MODE2 */
				>;
			};

			backlight_pwm_pins: backlight_pwm_pins {
				pinctrl-single,pins = < AM33XX_IOPAD(0x0848, PIN_OUTPUT_PULLDOWN | INPUT_EN | MUX_MODE6) >;
			};  /* gpmc_a2.ehrpwm1a */
		};
	};

	fragment@3 {
		target = <&ehrpwm1>;
		__overlay__ {
			pinctrl-names = "default";
			pinctrl-0 = <&backlight_pwm_pins>;
			status = "okay";
		};
	};

	fragment@4 {
		target = <&spi1>;
		__overlay__ {
			#address-cells = <1>;
			#size-cells = <0>;

			status = "okay";
			pinctrl-names = "default";
			pinctrl-0 = <&bb_spi1_pins>;

			display@0{
				status = "okay";
				compatible = "jianda,jd-t18003-t01", "sitronix,st7735r";
				reg = <0>;
				spi-max-frequency = <16000000>;
				dc-gpios = <&gpio1 16 0>;      // lcd dc    P9.15 gpio1[16]
				reset-gpios = <&gpio1 28 0>;   // lcd reset P9.12 gpio1[28]
				//backlight = <&backlight_gpio>; // lcd lite  P9.23 gpio1[17]
				backlight = <&backlight_pwm>; // lcd lite  P9.14
				// refer to https://elinux.org/Beagleboard:Cape_Expansion_Headers
				// rotation is optional
				// rotation = <270>;
			};

		};
	};
};
	/*
	* Copyright (C) 2013 CircuitCo
	* Copyright (C) 2018 Drew Fustini <drew@beagleboard.org>
	*
	* Adafruit 1.8" TFT LCD on SPI1 bus using tinydrm st7735r driver
	*
	* LICENSE:
	* --------
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* DOCUMENTATION:
	* --------------
	* This file was copied from src/arm/BB-SPIDEV1-00A0.dts and modified
	* by Drew Fustini based on an exmample from David Lechner.
	*
	* This is the Adafruit 1.8" TFT LCD:
	* https://www.adafruit.com/products/358
	*
	* It should be connected to BeagleBone SPI1 bus:
	*
	* P9.12 <--> reset
	* P9.14 <--> lite (pwm)
	* P9.15 <--> dc
	* P9.23 <--> lite (gpio)
	* P9.28 <--> tft_cs
	* P9.30 <--> mosi
	* P9.31 <--> clk
	*
	* This overlay will load the mainline tinydrm st7735r driver by David Lechner:
	* https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/tinydrm/st7735r.c
	*
	* Tested with 4.16.0-rc2-bone3 kernel on Debian 9.3 image
	*
	* Run libdrm modetest for colorbar test based on instructions from:
	* https://github.com/notro/tinydrm/wiki/Development#modetest
	*
	* modetest -M "st7735r" -c #this will display connector id
	* modetest -M "st7735r" -s 28:128x160 #connector id and resolution
	* # you should now see a color bar on the LCD
	*
	* Mailing list post with more information:
	* https://groups.google.com/d/msg/beagleboard/GuMQIP_XCW0/b3lxbx_8AwAJ
	*
	* GitHub Gist with testing results:
	* https://gist.github.com/pdp7/aee5664598059c9b9a9020f107957f80
	*
	* Discussion with notro on how to test tinydrm driver:
	* https://github.com/notro/tinydrm/issues/1#issuecomment-367279037
	*/

	#include <dt-bindings/board/am335x-bbw-bbb-base.h>
	#include <dt-bindings/gpio/gpio.h>
	#include <dt-bindings/pinctrl/am33xx.h>

	/dts-v1/;
	/plugin/;

	/ {
	fragment@0 {
	target-path = "/";
	__overlay__ {
	backlight_gpio: backlight_gpio {
	compatible = "gpio-backlight";
	gpios = <&gpio1 17 GPIO_ACTIVE_HIGH>;
	// connect lcd lite pin to P9.23 which is gpio1[17]
	// refer to https://elinux.org/Beagleboard:Cape_Expansion_Headers
	};

	backlight_pwm: backlight_pwm {
	// P9.14 <--> lite (pwm-backlight EHRPWM1A)
	pinctrl-names = "default";
	pinctrl-0 = <&backlight_pwm_pins>;
	status = "okay";
	compatible = "pwm-backlight";
	pwms = <&ehrpwm1 1 500000 0>;
	brightness-levels = <
	0 1 2 3 4 5 6 7 8 9
	10 11 12 13 14 15 16 17 18 19
	20 21 22 23 24 25 26 27 28 29
	30 31 32 33 34 35 36 37 38 39
	40 41 42 43 44 45 46 47 48 49
	50 51 52 53 54 55 56 57 58 59
	60 61 62 63 64 65 66 67 68 69
	70 71 72 73 74 75 76 77 78 79
	80 81 82 83 84 85 86 87 88 89
	90 91 92 93 94 95 96 97 98 99
	100
	>;
	default-brightness-level = <90>;
	};
	};
	};

	/*
	* Free up the pins used by the cape from the pinmux helpers.
	*/
	fragment@1 {
	target = <&ocp>;
	__overlay__ {
	P9_12_pinmux { status = "disabled"; }; /* lcd reset */
	P9_14_pinmux { status = "disabled"; }; /* lcd pwm backlight */
	P9_15_pinmux { status = "disabled"; }; /* lcd dc */
	P9_23_pinmux { status = "disabled"; }; /* lcd gpio backlight */
	P9_28_pinmux { status = "disabled"; }; /* spi1_cs0 */
	P9_29_pinmux { status = "disabled"; }; /* spi1_d0 */
	P9_30_pinmux { status = "disabled"; }; /* spi1_d1 */
	P9_31_pinmux { status = "disabled"; }; /* spi1_sclk */
	};
	};

	fragment@2 {
	target = <&am33xx_pinmux>;
	__overlay__ {
	/* default state has all gpios released and mode set to uart1 */
	bb_spi1_pins: pinmux_bb_spi1_pins {
	pinctrl-single,pins = <
	0x190 0x33 /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP \| MODE3 */
	0x194 0x33 /* mcasp0_fsx.spi1_d0, INPUT_PULLUP \| MODE3 */
	0x198 0x13 /* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP \| MODE3 */
	0x19c 0x13 /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP \| MODE3 */
	// 0x164 0x12 /* eCAP0_in_PWM0_out.spi1_cs1 OUTPUT_PULLUP \| MODE2 */
	>;
	};

	backlight_pwm_pins: backlight_pwm_pins {
	pinctrl-single,pins = < AM33XX_IOPAD(0x0848, PIN_OUTPUT_PULLDOWN \| INPUT_EN \| MUX_MODE6) >;
	}; /* gpmc_a2.ehrpwm1a */
	};
	};

	fragment@3 {
	target = <&ehrpwm1>;
	__overlay__ {
	pinctrl-names = "default";
	pinctrl-0 = <&backlight_pwm_pins>;
	status = "okay";
	};
	};

	fragment@4 {
	target = <&spi1>;
	__overlay__ {
	#address-cells = <1>;
	#size-cells = <0>;

	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&bb_spi1_pins>;

	display@0{
	status = "okay";
	compatible = "jianda,jd-t18003-t01", "sitronix,st7735r";
	reg = <0>;
	spi-max-frequency = <16000000>;
	dc-gpios = <&gpio1 16 0>; // lcd dc P9.15 gpio1[16]
	reset-gpios = <&gpio1 28 0>; // lcd reset P9.12 gpio1[28]
	//backlight = <&backlight_gpio>; // lcd lite P9.23 gpio1[17]
	backlight = <&backlight_pwm>; // lcd lite P9.14
	// refer to https://elinux.org/Beagleboard:Cape_Expansion_Headers
	// rotation is optional
	// rotation = <270>;
	};

	};
	};
	};