U-Boot 显示与开机 LOGO
由于内核启动需要一定时间，所以会选择在 U-Boot 中开启显示驱动，提前初始化屏幕显示启动 LOGO，这样可以增强户体验。
下文将以 V821-PERF2B 板级和配套的显示屏模组 T27P06 作为示例，演示如何配置 U-Boot 显示驱动与开机 LOGO。
转换内核驱动到 U-Boot
内核显示驱动与 U-Boot 显示驱动大部分函数都是相同的，仅有部分差异。
修改驱动文件 t27p06.c 将
static void LCD_cfg_panel_info(struct panel_extend_para *info)
修改为
static void LCD_cfg_panel_info(panel_extend_para *info)
修改驱动文件 t27p06.c 将
struct __lcd_panel t27p06_panel
修改为
__lcd_panel_t t27p06_panel
修改驱动头文件 t27p06.h 将
extern struct __lcd_panel t27p06_panel;
修改为
extern __lcd_panel_t t27p06_panel;
U-Boot 驱动配置
驱动功能配置
首先需要确认 U-boot 使用的配置文件，查看板级目录中的 device/config/chips/v821/configs/perf2b/BoardConfig_nor.mk 配置文件的 LICHEE_BRANDY_DEFCONF 配置项，这里是 sun300iw1p1_v821_defconfig
前往 U-Boot 的配置目标文件夹 brandy/brandy-2.0/u-boot-2018/configs 找到配置 sun300iw1p1_v821_defconfig 文件
增加下列配置开启启动 LOGO，DISP 驱动，并且开启 CONFIG_LCD_SUPPORT_T27P06=y 对应的显示驱动。
CONFIG_BOOT_GUI=y
CONFIG_CMD_SUNXI_BMP=y
CONFIG_SUNXI_ADVERT_PICTURE=y
CONFIG_LZMA=y
CONFIG_DISP2_SUNXI=y
CONFIG_LCD_SUPPORT_T27P06=y
设备树配置
配置背光
首先设备树配置背光使用的 PWM 引脚，参考电路图，使用的是 PD13 引脚
PD13 引脚是 PWM3，则配置 PWM3 作为背光功能
&pwm3_pin_a {
allwinner,pins = "PD13";
allwinner,function = "pwm_3";
allwinner,muxsel = <0x4>;
allwinner,drive = <10>;
allwinner,pull = <2>;
};
&pwm3_pin_b {
allwinner,pins = "PD13";
allwinner,function = "io_disabled";
allwinner,muxsel = <0xf>;
allwinner,drive = <3>;
allwinner,pull = <2>;
};
&pwm3 {
pinctrl-names = "active", "sleep";
pinctrl-0 = <&pwm3_pin_a>;
pinctrl-1 = <&pwm3_pin_b>;
status = "okay";
};
配置 DISP 驱动和 LCD
首先配置 DISP 驱动
&disp {
disp_init_enable = <1>;
disp_mode = <0>;
dev0_output_type = <1>;
screen0_to_lcd_index = <0>;
dev0_output_mode = <4>;
dev0_screen_id = <0>;
dev0_do_hpd = <0>;
fb0_format = <0>;
fb0_width = <0>;
fb0_height = <0>;
chn_cfg_mode = <1>;
disp_para_zone = <1>;
};
配置含义
disp init configuration
disp_mode (0:screen0<screen0,fb0>)
screenx_output_type (0:none; 1:lcd; 2:tv; 3:hdmi;5:vdpo)
screenx_output_mode (used for hdmi output, 0:480i 1:576i 2:480p 3:576p 4:720p50 5:720p60 6:1080i50 7:1080i60 8:1080p24 9:1080p50 10:1080p60)
screenx_output_format (for hdmi, 0:RGB 1:yuv444 2:yuv422 3:yuv420)
screenx_output_bits (for hdmi, 0:8bit 1:10bit 2:12bit 2:16bit)
screenx_output_eotf (for hdmi, 0:reserve 4:SDR 16:HDR10 18:HLG)
screenx_output_cs (for hdmi, 0:undefined 257:BT709 260:BT601 263:BT2020)
screenx_output_dvi_hdmi (for hdmi, 0:undefined 1:dvi mode 2:hdmi mode)
screen0_output_range (for hdmi, 0:default 1:full 2:limited)
screen0_output_scan (for hdmi, 0:no data 1:overscan 2:underscan)
screen0_output_aspect_ratio (for hdmi, 8-same as original picture 9-4:3 10-16:9 11-14:9)
fbx format (4:RGB655 5:RGB565 6:RGB556 7:ARGB1555 8:RGBA5551 9:RGB888 10:ARGB8888 12:ARGB4444)
fbx pixel sequence (0:ARGB 1:BGRA 2:ABGR 3:RGBA)
fb0_scaler_mode_enable (scaler mode enable, used FE)
fbx_width,fbx_height (framebuffer horizontal/vertical pixels, fix to output resolution while equal 0)
lcdx_backlight (lcd init backlight,the range:[0,256],default:197
lcdx_yy (lcd init screen bright/contrast/saturation/hue, value:0~100, default:50/50/57/50)
lcd0_contrast (LCD contrast, 0~100)
lcd0_saturation (LCD saturation, 0~100)
lcd0_hue (LCD hue, 0~100)
framebuffer software rotation setting:
disp_rotation_used: (0:disable; 1:enable,you must set fbX_width to lcd_y, set fbX_height to lcd_x)
degreeX: (X:screen index; 0:0 degree; 1:90 degree; 3:270 degree)
degreeX_Y: (X:screen index; Y:layer index 0~15; 0:0 degree; 1:90 degree; 3:270 degree)
devX_output_type : config output type in bootGUI framework in UBOOT-2018.
(0:none; 1:lcd; 2:tv; 4:hdmi;)
devX_output_mode : config output resolution(see include/video/sunxi_display2.h) of bootGUI framework in UBOOT-2018
devX_screen_id : config display index of bootGUI framework in UBOOT-2018
devX_do_hpd : whether do hpd detectation or not in UBOOT-2018
chn_cfg_mode : Hardware DE channel allocation config.
0:single display with 6 channel,
1:dual display with 4 channel in main display and 2 channel in second display,
2:dual display with 3 channel in main display and 3 channel in second in display.
然后需要配置 LCD 驱动
&lcd0 {
lcd_used = <1>;
lcd_driver_name = "t27p06";
lcd_if = <0>;
lcd_hv_if = <8>;
lcd_x = <320>;
lcd_y = <240>;
lcd_width = <108>;
lcd_height = <64>;
lcd_dclk_freq = <27>;
lcd_hbp = <70>;
lcd_ht = <1716>;
lcd_hspw = <1>;
lcd_vbp = <21>;
lcd_vt = <263>;
lcd_vspw = <1>;
lcd_backlight = <50>;
lcd_pwm_used = <1>;
lcd_pwm_ch = <3>;
lcd_pwm_freq = <50000>;
lcd_pwm_pol = <0>;
lcd_pwm_max_limit = <255>;
lcd_bright_curve_en = <1>;
lcd_frm = <0>;
lcd_hv_clk_phase = <1>;
lcd_hv_sync_polarity= <0>;
lcd_hv_srgb_seq = <2>;
lcd_io_phase = <0x0000>;
lcd_gamma_en = <0>;
lcd_cmap_en = <0>;
lcd_rb_swap = <0>;
/* cs */
lcd_gpio_0 = <&pio PD 18 1 1 2 0>;//ID0 : direct(0:in 1:out)/pull(0:disable 1:up 2:down)/driver(0123)/level
/* sda */
lcd_gpio_1 = <&pio PD 19 1 1 2 0>;//ID0 : direct(0:in 1:out)/pull(0:disable 1:up 2:down)/driver(0123)/level
/* sck */
lcd_gpio_2 = <&pio PD 17 1 1 2 0>;//ID0 : direct(0:in 1:out)/pull(0:disable 1:up 2:down)/driver(0123)/level
pinctrl-0 = <&rgb8_pins_a>, <&rgb8_pins_ctl_a>;
pinctrl-1 = <&rgb8_pins_b>, <&rgb8_pins_ctl_b>;
};
内核驱动配置
在内核中，需要开启同样的显示驱动，背光驱动等。
驱动配置
CONFIG_AW_DISP2=y
CONFIG_AW_DISP2_DEBUG=y
CONFIG_LCD_SUPPORT_T27P06=y
CONFIG_BACKLIGHT_CLASS_DEVICE=y
设备树配置
PWM 设备配置
&pio {
pwm3_pins_active: pwm3@0 {
pins = "PD13"; /* lcd-pwm */
function = "pwm0_3";
};
pwm3_pins_sleep: pwm3@1 {
pins = "PD13";
function = "gpio_in";
bias-pull-down;
};
};
&pwm0_3 {
pinctrl-names = "active", "sleep";
pinctrl-0 = <&pwm3_pins_active>;
pinctrl-1 = <&pwm3_pins_sleep>;
status = "okay";
};
DISP 节点配置
&disp {
disp_init_enable = <1>;
disp_mode = <0>;
screen0_output_type = <1>;
screen0_output_mode = <4>;
screen0_to_lcd_index = <0>;
screen1_output_type = <3>;
screen1_output_mode = <10>;
screen1_to_lcd_index = <2>;
screen1_output_format = <0>;
screen1_output_bits = <0>;
screen1_output_eotf = <4>;
screen1_output_cs = <257>;
screen1_output_dvi_hdmi = <2>;
screen1_output_range = <2>;
screen1_output_scan = <0>;
screen1_output_aspect_ratio = <8>;
fb_format = <0>;
fb_num = <1>;
fb_debug = <0>;
/*<disp channel layer zorder>*/
fb0_map = <0 0 0 16>;
fb0_width = <320>;
fb0_height = <240>;
/*<disp channel layer zorder>*/
fb1_map = <0 2 0 16>;
fb1_width = <300>;
fb1_height = <300>;
/*<disp channel layer zorder>*/
fb2_map = <1 0 0 16>;
fb2_width = <1280>;
fb2_height = <720>;
/*<disp channel layer zorder>*/
fb3_map = <1 1 0 16>;
fb3_width = <300>;
fb3_height = <300>;
chn_cfg_mode = <1>;
disp_para_zone = <1>;
};
LCD 节点配置
&lcd0 {
lcd_used = <1>;
lcd_driver_name = "t27p06";
lcd_if = <0>;
lcd_hv_if = <8>;
lcd_x = <320>;
lcd_y = <240>;
lcd_width = <108>;
lcd_height = <64>;
lcd_dclk_freq = <27>;
lcd_hbp = <70>;
lcd_ht = <1716>;
lcd_hspw = <1>;
lcd_vbp = <21>;
lcd_vt = <263>;
lcd_vspw = <1>;
lcd_backlight = <50>;
lcd_pwm_used = <1>;
lcd_pwm_ch = <3>;
lcd_pwm_freq = <50000>;
lcd_pwm_pol = <0>;
lcd_pwm_max_limit = <255>;
/* lcd_bl_en = <&pio PB 1 1 0 3 1>; */
lcd_bright_curve_en = <1>;
lcd_frm = <0>;
lcd_hv_clk_phase = <1>;
lcd_hv_sync_polarity= <0>;
lcd_hv_srgb_seq = <2>;
lcd_io_phase = <0x0000>;
lcd_gamma_en = <0>;
lcd_cmap_en = <0>;
lcd_rb_swap = <0>;
/* cs */
lcd_gpio_0 = <&pio PD 18 GPIO_ACTIVE_LOW>;
/* sda */
lcd_gpio_1 = <&pio PD 19 GPIO_ACTIVE_LOW>;
/* sck */
lcd_gpio_2 = <&pio PD 17 GPIO_ACTIVE_LOW>;
pinctrl-0 = <&rgb8_pins_a>, <&rgb8_pins_ctl_a>;
pinctrl-1 = <&rgb8_pins_b>, <&rgb8_pins_ctl_b>;
};
LOGO 配置
为了显示 LOGO，需要准备一个开机 LOGO 图片，放到路径 openwrt/target/v821/v821-common/boot-resource/boot-resource/bootlogo.bmp
提示
LOGO 图片需要 BMP 格式，24位深
编辑分区表，加入资源文件
[partition]
name = boot-resource
size = 1024
downloadfile = "boot-resource.fex"
user_type = 0x8000
U-Boot 下调试屏幕方法
U-Boot 下可以通过命令 disp 调试屏幕，可以查看当前屏显参数，图层参数
screen 0:
de_rate 150000000 hz, ref_fps:59
mgr0: 320x240 fmt[rgb] cs[0x204] range[full] eotf[0x4] bits[8bits] err[1] force_sync[0] unblank direct_show[false] iommu[0]
lcd output backlight( 50) fps:55.9 320x 240
err:0 skip:1 irq:968 vsync:0 vsync_skip:0
BUF enable ch[1] lyr[0] z[1] prem[N] a[globl 255] fmt[ 0] fb[ 320, 240; 0, 0; 0, 0] crop[ 0, 0, 320, 240] frame[ 0, 0, 320, 240] addr[8390c000, 0, 0] flags[0x 0] trd[0,0]
可以用 colorbar 命令显示彩条
colorbar
