入门linux之全志H3 nanopi 点亮ST7789VW IPS屏

• NanoPi-NEO-Air 入门
• • Nnaopi的IO
  • 设备树（sun8i-h3-nanopi-neo-air.dts）中禁用其他SPI节点和使能ST7789VW节点：
  • 修改初始化函数
  • 使用1.14（135*240）ips屏幕的注意修改函数set_addr_win
  • 把驱动编译进内核
  • 编译内核 设备树 下载重启看效果
  • 实际效果
  • 播放视频
  • 运行QT

NanoPi-NEO-Air 入门

记录一下第一次尝试用linux点亮spi屏幕的过程，一共尝试了0.96 ST7735S(80160) \1.8 st7735R(128160) \1.14 st7789v(135240) \1.3 st7789vw (240240)这几个屏幕，有个奇怪的现象就是必须要接SPI0的CS引脚到显示屏上才能正常显示。

Nnaopi的IO

设备树（sun8i-h3-nanopi-neo-air.dts）中禁用其他SPI节点和使能ST7789VW节点：

在最后加上以下代码，st7735r和st7735s也调试过可用，7735超过48M显示的颜色就不正常了，7789vw可以96M正常显示,原始的IO口是
DC PA1 RESET PG11 BL PA0
我改成了
DC PA1 RESET PA2 BL PA0
同时禁用hdmi，防止开机从hdmi显示

&spi0{
	spidev0:spi@0{
	  status="disable";
	};
	st7789vw: st7789vw@0{
	compatible = "sitronix,st7789vw";
	reg = <0>;
	status = "okay";
	spi-max-frequency = <96000000>;
	buswidth = <8>;   
	rotate = <0>;
	fps = <60>;
	rgb;
	dc-gpios = <&pio 0 1 GPIO_ACTIVE_HIGH>;  
	reset-gpios = <&pio 0 2 GPIO_ACTIVE_HIGH>; 
	led-gpios = <&pio 0 0 GPIO_ACTIVE_LOW>;  
	debug = <0x00>;
	};

	// st7735r: st7735r@0{
	// 	compatible = "sitronix,st7735r";
	// 	reg = <0>;
	// 	status = "okay";
	// 	spi-max-frequency = <36000000>;
	// 	spi-cpol;
	// 	spi-cpha;
	// 	rotate = <90>;
	// 	fps = <60>;
	// 	buswidth = <8>;
	// 	dc-gpios = <&pio 0 1 GPIO_ACTIVE_HIGH>;  
	// 	reset-gpios = <&pio 0 2 GPIO_ACTIVE_HIGH>; 
	// 	led-gpios = <&pio 0 0 GPIO_ACTIVE_LOW>;  
	// 	debug = <0x0>;
	// 	};
	// st7735s: st7735s@0{
	// 		compatible = "sitronix,st7735s";
	// 		reg = <0>;
	// 		status = "okay";
	// 		spi-max-frequency = <36000000>;
	// 		spi-cpol;
	// 		spi-cpha;
	// 		rotate = <0>;
	// 		fps = <60>;
	// 		buswidth = <8>;
	// 		dc-gpios = <&pio 0 1 GPIO_ACTIVE_HIGH>;  
	// 		reset-gpios = <&pio 0 2 GPIO_ACTIVE_HIGH>; 
	// 		led-gpios = <&pio 0 0 GPIO_ACTIVE_LOW>;  
	// 		debug = <0x0>;
	// 		};
};

&hdmi {
  status = "disable";
};

修改初始化函数

原始的初始化没有复位显示屏，在初始化中添加

par->fbtftops.reset(par);
write_reg(par, PVGAMCTRL, 0xD0, 0x04, 0x0D, 0x11, 0x13, 0x2B, 0x3F, 0x54, 0x4C, 0x18, 0x0D, 0x0B, 0x1F, 0x23);
write_reg(par, NVGAMCTRL, 0xD0, 0x04, 0x0C, 0x11, 0x13, 0x2C, 0x3F, 0x44, 0x51, 0x2F, 0x1F, 0x1F, 0x20, 0x23);

static int init_display(struct fbtft_par *par)
{
	par->fbtftops.reset(par);

	// 
	write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE);
	mdelay(120);

	write_reg(par, MIPI_DCS_SET_ADDRESS_MODE, 0x0);
	write_reg(par, MIPI_DCS_SET_PIXEL_FORMAT, MIPI_DCS_PIXEL_FMT_16BIT);
	write_reg(par, PORCTRL, 0x0C, 0x0C, 0x00, 0x33, 0x33);
	write_reg(par, GCTRL, 0x35);
	write_reg(par, VCOMS, 0x19);
	write_reg(par, LCMCTRL, 0x2C);
	write_reg(par, VDVVRHEN, 0x01);
	write_reg(par, VRHS, 0x12);
	write_reg(par, VDVS, 0x20);
	write_reg(par, FRCTRL2, 0x0F);
	write_reg(par, PWCTRL1, 0xA4, 0xA1);
	write_reg(par, PVGAMCTRL, 0xD0, 0x04, 0x0D, 0x11, 0x13, 0x2B, 0x3F, 0x54, 0x4C, 0x18, 0x0D, 0x0B, 0x1F, 0x23);
	write_reg(par, NVGAMCTRL, 0xD0, 0x04, 0x0C, 0x11, 0x13, 0x2C, 0x3F, 0x44, 0x51, 0x2F, 0x1F, 0x1F, 0x20, 0x23);
	write_reg(par, MIPI_DCS_ENTER_INVERT_MODE);
	write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
	mdelay(120);
     return 0;

}

使用1.14（135*240）ips屏幕的注意修改函数set_addr_win

原始的函数没有纠正偏移量，增加以下代码（只有135*240的需要增加，其他的屏不需要）：

switch(par->info->var.rotate)
	{
		case   0: xs+=53;xe+=53;ys+=40;ye+=40;
				 break;
		case  90: xs+=40;xe+=40;ys+=53;ye+=53;
				 break;
		case 180: xs+=53;xe+=53;ys+=40;ye+=40;
				 break;
		case 270: xs+=40;xe+=40;ys+=53;ye+=53;
				 break;
		default :
				 break;
	}

把驱动编译进内核

最原始的内核没有ST7789VW，只有ST7789V，所以把st7789v.c复制粘贴改名为st7789vw.c，相应驱动做一下修改,并且修改fbtft目录下的Kconfig和Makefile，这里我增加了ST7789VW和ST7735S的驱动

config FB_TFT_ST7789VW
	tristate "FB driver for the ST7789VW LCD Controller"
	depends on FB_TFT
	help
	  This enables generic framebuffer support for the Sitronix ST7789VW
	  display controller. The controller is intended for small color
	  displays with a resolution of up to 240x240 pixels.

	  Say Y if you have such a display that utilizes this controller.

Makefile:

Kconfig:

再到menuconfig使能此驱动，

make menuconfig ARCH=arm CROSS_COMPILE=arm-linux- -j80

Device Drivers  --->　　
	[*] Staging drivers  --->　　
		<*>   Support for small TFT LCD display modules  --->
			<*>   FB driver for the ST7789VW LCD Controller 

编译内核 设备树 下载重启看效果

make zImage dtbs ARCH=arm CROSS_COMPILE=arm-linux- -j80
网络更新内核
scp arch/arm/boot/zImage root@192.168.137.83:/boot
网络更新设备树
scp arch/arm/boot/dts/sun8i-h3-nanopi-neo-air.dtb root@192.168.137.83:/boot

实际效果

1.3寸 240*240 IPS效果：

播放视频

mplayer badapple_320_240_15fps.avi -vo fbdev

运行QT

apt-get update && apt-get install git
git clone https://github.com/friendlyarm/matrix.git
cd matrix/demo/nanopi-status
./build.sh
./run.sh /dev/fb_st7789vw