03 野火imxull开发板添加 正点原子lcd 支持

由于手里野火的imx6ull的开发板闲置好几年了，且手里有之前买的stm32f7的lcd，于是决定将两者结合使用

RGB LCD接口 主要由RGB信号线和RGB控制线组成，在设计时会将触摸接口一起放在LCD接口上。

原理图

由于正点原子和野火的lcd的接口不同，所以需要绘制一个转接板，可以薅嘉立创的免费打板服务，fpc接口某多多5块钱10个，成本就五块钱，原理图如下
pcb工程 力创eda

pcb闭着眼睛连同就好，反正是低速信号。

uboot 修改

由于野火的LCD_DISP是板卡直接拉高的3.3V，因此lcd上电就是使能状态，因此屏蔽uboot复位LCD_RST

屏蔽复位pin的pad定义

文件路径board/freescale/mx6ullevk_board/mx6ullevk_board.c

static iomux_v3_cfg_t const lcd_pads[] = {
MX6_PAD_LCD_CLK__LCDIF_CLK | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_ENABLE__LCDIF_ENABLE | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_HSYNC__LCDIF_HSYNC | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_VSYNC__LCDIF_VSYNC | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA00__LCDIF_DATA00 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA01__LCDIF_DATA01 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA02__LCDIF_DATA02 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA03__LCDIF_DATA03 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA04__LCDIF_DATA04 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA05__LCDIF_DATA05 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA06__LCDIF_DATA06 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA07__LCDIF_DATA07 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA08__LCDIF_DATA08 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA09__LCDIF_DATA09 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA10__LCDIF_DATA10 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA11__LCDIF_DATA11 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA12__LCDIF_DATA12 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA13__LCDIF_DATA13 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA14__LCDIF_DATA14 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA15__LCDIF_DATA15 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA16__LCDIF_DATA16 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA17__LCDIF_DATA17 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA18__LCDIF_DATA18 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA19__LCDIF_DATA19 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA20__LCDIF_DATA20 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA21__LCDIF_DATA21 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA22__LCDIF_DATA22 | MUX_PAD_CTRL(LCD_PAD_CTRL),
MX6_PAD_LCD_DATA23__LCDIF_DATA23 | MUX_PAD_CTRL(LCD_PAD_CTRL),

/* LCD_RST */
/*MX6_PAD_SNVS_TAMPER9__GPIO5_IO09 | MUX_PAD_CTRL(NO_PAD_CTRL),*/

/* Use GPIO for Brightness adjustment, duty cycle = period. */
MX6_PAD_GPIO1_IO08__GPIO1_IO08 | MUX_PAD_CTRL(NO_PAD_CTRL),
};
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屏蔽复位代码

void do_enable_parallel_lcd(struct display_info_t const *dev)
{
	enable_lcdif_clock(dev->bus);

	imx_iomux_v3_setup_multiple_pads(lcd_pads, ARRAY_SIZE(lcd_pads));

	/*lcd 复位操作代码
	gpio_direction_output(IMX_GPIO_NR(5, 9) , 0);
	udelay(500);
	gpio_direction_output(IMX_GPIO_NR(5, 9) , 1);
	*/
	/* 设置背光，可以通过lcd背光玻璃的状态来确定lcd 背光开启状态
	lcd背光不亮是看不到内容的。
	 */
	gpio_direction_output(IMX_GPIO_NR(1, 8) , 1);
}
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修改lcd参数

struct display_info_t const displays[] = {{
	.bus = MX6UL_LCDIF1_BASE_ADDR,
	.addr = 0,
	.pixfmt = 24,
	.detect = NULL,
	.enable	= do_enable_parallel_lcd,
	.mode	= {
		.name			= "TFT7016",
		.xres           = 1024,
		.yres           = 600,
		.pixclock       = 19531,
		.left_margin    = 140,
		.right_margin   = 160,
		.upper_margin   = 20,
		.lower_margin   = 12,
		.hsync_len      = 20,
		.vsync_len      = 3,
		.sync           = 0,
		.vmode          = FB_VMODE_NONINTERLACED
} } };
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修改环境变量 lcd 名称

路径include/configs/mx6ullevk_board.h

panel=TFT43AB
1

将其改为：

panel=TFT7016
1

至此，uboot lcd 支持修改完成，编译后lcd就会看到nxp log

linux 修改

使能Linux logo

-> Device Drivers
	 -> Graphics support 
	 -> Bootup logo (LOGO [=y]) 
		-> Standard black and white Linux logo
		-> Standard 16-color Linux logo 
		-> Standard 224-color Linux logo
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设备树修改

屏蔽复位pinctrl 和修改lcd参数
路径 arch/arm/boot/dts/imx6ull-board-emmc.dts

&lcdif {
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_lcdif_dat
		     &pinctrl_lcdif_ctrl>;
		     /*&pinctrl_lcdif_reset>;*/
	display = <&display0>;
	status = "okay";

	display0: display {
		bits-per-pixel = <24>;
		bus-width = <24>;

		display-timings {
			native-mode = <&timing0>;
			timing0: timing0 {
			clock-frequency = <51200000>;
			hactive = <1024>;
			vactive = <600>;
			hfront-porch = <160>;
			hback-porch = <140>;
			hsync-len = <20>;
			vback-porch = <20>;
			vfront-porch = <12>;
			vsync-len = <3>;

			hsync-active = <0>;
			vsync-active = <0>;
			de-active = <1>;
			pixelclk-active = <0>;
			};
		};
	};
};
/*
这里屏蔽掉后面触摸需要使用到这个pin
pinctrl_lcdif_reset: lcdifresetgrp {
                   fsl,pins = <
                           MX6ULL_PAD_SNVS_TAMPER9__GPIO5_IO09  0x79
                   >;
           };
*/
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修改lcd 背光pinctrl 引脚

路径 arch/arm/boot/dts/imx6ull-board-emmc.dts

	pinctrl_pwm1: pwm1grp {
		fsl,pins = <
			MX6UL_PAD_GPIO1_IO08__PWM1_OUT   0x110b0
		>;
	}; 
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确认lcdpwm设置亮度等级不为0

路径 arch/arm/boot/dts/imx6ull-board-emmc.dts

backlight {
	compatible = "pwm-backlight";
	pwms = <&pwm1 0 5000000>;
	brightness-levels = <0 4 8 16 32 64 128 255>;
	default-brightness-level = <6>;
	status = "okay";
};
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修改环境变量

console=tty1 console=ttymxc0打开了两个 console，一个是 LCD，一个是串口

setenv bootargs 'console=tty1 console=ttymxc0,115200 root=/dev/nfs rw nfsroot=192.168.1.26:/home/li/linux/nfs/rootfs ip=192.168.1.25:192.168.1.250:192.168.1.1:255.255.255.0::eth0:off'
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关闭 lcd 休眠

2、关闭 10 分钟熄屏功能

drivers/tty/vt/vt.c 文件 blankinterval 变量控制息屏时间单位为秒， 0 熄屏的功能。

vim drivers/tty/vt/vt.c
---------------------------------------
static int vesa_blank_mode;
static int vesa_off_interval;
static int blankinterval = 0;
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