4寸MIPI
评测作者：宁静致远 · 本篇为社区评测文章，来自开发者实测，未经官方逐字校对。
手里有块4寸的MIPI屏幕TFT08006，下面要完成哪吒开发板支持这块屏幕。
驱动
首先是屏幕驱动，LCD的驱动路径： uboot的LCD驱动路径：lichee/brandy-2.0/u-boot-2018/drivers/video/sunxi/disp2/disp/lcd/ 内核的LCD驱动路径：lichee/linux-5.4/drivers/video/fbdev/sunxi/disp2/disp/lcd/
<div style="text-align:center;width:800px;height:600px;">
<p style="font-style:italic;">uboot屏幕驱动</p>
<p style="font-style:italic;">内核屏幕驱动</p>
</div>
可以看到，SDK已经集成了tft08006的驱动源文件。 下面要做的是分别修改uboot和内核的配置，保证tft08006的驱动分别编译到了uboot和内核。
修改uboot配置 执行cboot快捷命令进入uboot根目录，执行make menuconfig → Device Drivers → Graphics support → LCD panels select [*] LCD support TFT08006 panel
<div style="text-align:center;width:800px;height:600px;">
<p style="font-style:italic;">uboot屏幕驱动配置</p>
</div>
修改内核配置 执行croot快捷命令进入SDK根目录，执行make kernel_menuconfig → Device Drivers → Graphics support → Frame buffer Devices → Video support for sunxi → LCD panels select [*] LCD support tft08006 panel
<div style="text-align:center;width:800px;height:600px;">
<p style="font-style:italic;">内核屏幕驱动配置</p>
</div>
设备树
下面要根据哪吒开发板的硬件设计，来修改设备树文件。原理图如下：
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<p style="font-style:italic;">mipi原理图</p>
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uboot设备树文件在device/config/chips/d1-h/configs/nezha/uboot-board.dts vim device/config/chips/d1-h/configs/nezha/uboot-board.dts
修改lcd0节点
&lcd0 { base_config_start = <1>; lcd_used = <1>; lcd_driver_name = "tft08006"; lcd_backlight = <500>; lcd_if = <4>; lcd_x = <480>; lcd_y = <800>; lcd_width = <52>; lcd_height = <52>; lcd_dclk_freq = <25>; lcd_pwm_used = <1>; lcd_pwm_ch = <9>; lcd_pwm_freq = <50000>; lcd_pwm_pol = <1>; lcd_pwm_max_limit = <255>; lcd_hbp = <10>; lcd_ht = <515>; lcd_hspw = <5>; lcd_vbp = <20>; lcd_vt = <830>; lcd_vspw = <5>; lcd_dsi_if = <0>; lcd_dsi_lane = <2>; lcd_dsi_format = <0>; lcd_dsi_te = <0>; lcd_dsi_eotp = <0>; lcd_frm = <0>; lcd_io_phase = <0x0000>; lcd_hv_clk_phase = <0>; lcd_hv_sync_polarity= <0>; lcd_gamma_en= <0>; lcd_bright_curve_en = <0>; lcd_cmap_en= <0>; lcdgamma4iep= <22>; lcd_gpio_0= <&pio PH 0 1 0 3 1>; pinctrl-0 = <&dsi4lane_pins_a>; pinctrl-1= <&dsi4lane_pins_b>; base_config_end = <1>; };
依据硬件原理图，定义管脚 &pio{ dsi4lane_pins_a: dsi4lane@0 { allwinner,pins = "PD1", "PD2", "PD3", "PD4", "PD5", "PD6", "PD7","PD9", "PD10", "PD11"; allwinner,pname = "PD1", "PD2", "PD3", "PD4", "PD5", "PD6","PD7", "PD9", "PD10", "PD11"; allwinner,function = "dsi"; allwinner,muxsel = <5>; allwinner,drive = <3>; allwinner,pull = <0>; };
dsi4lane_pins_b: dsi4lane@1 { allwinner,pins = "PD1", "PD2", "PD3", "PD4", "PD5", "PD6", "PD7","PD9", "PD10", "PD11"; allwinner,pname = "PD1", "PD2", "PD3", "PD4", "PD5", "PD6","PD7", "PD9", "PD10", "DP11"; allwinner,function = "io_disabled"; allwinner,muxsel = <0xf>; allwinner,drive = <1>; allwinner,pull = <0>; }; }
内核设备树文件在device/config/chips/d1-h/configs/nezha/linux-5.4/board.dts vim device/config/chips/d1-h/configs/nezha/linux-5.4/board.dts 修改&lcd0节点 &lcd0 { base_config_start = <1>; lcd_used= <1>; lcd_driver_name = "tft08006"; lcd_backlight= <500>; lcd_if= <4>; lcd_x= <480>; lcd_y= <800>; lcd_width= <52>; lcd_height= <52>; lcd_dclk_freq= <25>; lcd_pwm_used= <1>; lcd_pwm_ch= <9>; lcd_pwm_freq= <50000>; lcd_pwm_pol= <1>; lcd_pwm_max_limit = <255>; lcd_hbp= <10>; lcd_ht= <515>; lcd_hspw= <5>; lcd_vbp= <20>; lcd_vt= <830>; lcd_vspw= <5>; lcd_dsi_if= <0>; lcd_dsi_lane= <2>; lcd_dsi_format = <0>; lcd_dsi_te= <0>; lcd_dsi_eotp= <0>; lcd_frm= <0>; lcd_io_phase= <0x0000>; lcd_hv_clk_phase = <0>; lcd_hv_sync_polarity= <0>; lcd_gamma_en= <0>; lcd_bright_curve_en = <0>; lcd_cmap_en= <0>; lcdgamma4iep= <22>; lcd_gpio_0= <&pio PH 0 1 0 3 1>; pinctrl-0= <&dsi4lane_pins_a>; pinctrl-1= <&dsi4lane_pins_b>; base_config_end = <1>; };
依据硬件原理图，定义管脚
&pio { dsi4lane_pins_a: dsi4lane@0 { allwinner,pins = "PD1", "PD2", "PD3", "PD4", "PD5", "PD6", "PD7","PD9", "PD10", "PD11"; allwinner,pname = "PD1", "PD2", "PD3", "PD4", "PD5", "PD6","PD7", "PD9", "PD10", "PD11"; allwinner,function = "dsi"; allwinner,muxsel = <5>; allwinner,drive = <3>; allwinner,pull = <0>; };
dsi4lane_pins_b: dsi4lane@1 { allwinner,pins = "PD1", "PD2", "PD3", "PD4", "PD5", "PD6", "PD7","PD9", "PD10", "PD11"; allwinner,pname = "PD1", "PD2", "PD3", "PD4", "PD5", "PD6","PD7", "PD9", "PD10", "DP11"; allwinner,function = "io_disabled"; allwinner,muxsel = <0xf>; allwinner,drive = <1>; allwinner,pull = <0>; }; }
编译并打包成镜像
croot make -j4 pack
烧录并测试
将新镜像烧录到开发板后，在串口终端中输入： lv_example 0 启动示例