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How to carry out rk3288 MIPI DSI mode, I believe that many inexperienced people do not know what to do. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

MIPI DSI uses the Config to configure the Q

Add configuration in arch/arm/configs/firefly_defconfig:

CONFIG_LCD_MIPI=yCONFIG_MIPI_DSI=yCONFIG_RK32_MIPI_DSI=yLCD pin configuration

The pin configuration is placed in the lcdc0 child node power_ctr in the arch/arm/boot/dts/firefly-rk3288.dts, there are power enable pin lcd_en, chip selection pin lcd_cs, reset pin lcd_rst, which can be modified and deleted according to the display screen. Such as:

Power_ctr: power_ctr {rockchip,debug =; lcd_en:lcd_en {rockchip,power_type =; gpios =; rockchip,delay =;}; lcd_cs:lcd_cs {rockchip,power_type =; gpios =; rockchip,delay =;}; / * lcd_rst:lcd_rst {rockchip,power_type =; gpios = Rockchip,delay =;}; * /} create a new DTS profile for the driver configuration

Create a new dst configuration file, such as lcd-xxx-mipi.dtsi, in the arch/arm/boot/dts/ directory.

Add DTS File Q

Add # include "lcd-xxx-mipi.dtsi" to arch/arm/boot/dts/sunychip-rk3288.dts, and comment out other screens' DTS configurations if they were originally include.

Add backlight node information

Add backlight node information to lcd-xxx-mipi.dtsi.

Backlight {compatible = "pwm-backlight"; pwms =; rockchip,pwm_id=; / * | dark (255221) | light scale (220,0) |, scale_div=255*/ brightness-levels =

< /*255 254 253 252 251 250 249 248 247 246 245 244 243 242 241 240 239 238 237 236 235 234 233 232 231 230 229 228 227 226 225224 223 222 221 */220 219 218 217 216 215 214 213 212 211 210 209 208 207 206 205 204 203 202 201 200 199 198 197 196 195 194 193 192 191 190 189 188 187186 185 184 183 182 181 180 179 178 177 176 175 174 173 172 171 170 169 168 167 166 165 164 163 162 161 160 159 158 157 156 155 154 153 152 151 150 149148 147 146 145 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111110 109 108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 6463 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 1312 11 10 9 8 7 6 5 4 3 2 1 0>

; default-brightness-level =; enable-gpios =;}

Attributes:

Pwms attribute: configure PWM,sunychip-RK3288 to use pwm1, and 10000 in the example is the PWM frequency.

Brightness-levels attribute: configure the backlight luminance array, with a maximum of 255. configure dark and bright areas, and adjust the bright area array to a ratio of 255s. For example, in the example, the dark area is 255-221 and the bright area is 220-0.

Default-brightness-level attribute: the default backlight brightness at power on, in the range of 0-255.

Enable-gpios attribute: configure backlight enable pins.

For details, please refer to the instruction document in kernel: Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt

Configure MIPI related information: disp_mipi_init: mipi_dsi_init {compatible = "rockchip,mipi_dsi_init"; rockchip,screen_init =; rockchip,dsi_lane =; rockchip,dsi_hs_clk =; rockchip,mipi_dsi_num =;}

Attributes:

The rockchip,screen_init attribute: 0 indicates that no special instruction is required to initialize the display, and 1 indicates that the instruction is required to initialize.

Rockchip,dsi_lane attribute: the number of data lane.

Rockchip,dsi_hs_clk attribute: configure hsclk.

Rockchip,mipi_dsi_num: configure the number of only DSI interfaces, that is, 1 for single-channel MIPI screen and 2 for dual-channel MIPI screen.

For details, please refer to the instruction document in kernel: Documentation/devicetree/bindings/video/rockchip_mipidsi_lcd.txt

Configure initialization command server

When rockchip,screen_init is 1, you need to configure the initialization command of the display screen, and the initialization command is configured in the node disp_mipi_init_cmds.

Rockchip,cmd_debug property: open to output instruction debugging information.

Rockchip,on-cmdsXX child node: configure information for each instruction.

Rockchip,cmd_type: data transfer mode, LPDT or HSDT.

Rockchip,dsi_id: the DSI interface for instruction transmission. 0 is to send instructions to DSI0 (left half screen for dual-channel MIPI screen), 1 is to send instructions to DSI1 (right half screen for dual-channel MIPI screen), and 2 is to send data to two DSI at the same time.

Rockchip,cmd: instruction sequence. The first byte is the DSI data type, the second byte is REG, and the next byte is the instruction content.

Rockchip,cmd_delay: the delay after sending an instruction, in ms.

Configure the display time series

Timing in the node disp_timings configuration.

Screen-type attribute: display type, SCREEN_MIPI for single-channel MIPI screen and SCREEN_DUAL_MIPI for dual-channel MIPI screen.

Lvds-format attribute: irrelevant options.

Out-face attribute: configure the color, which can be OUT_P888 (24 bits), OUT_P666 (18 bits), or OUT_P565 (16 bits).

Clock-frequency attribute: screen clock, unit Hz.

For other timing attributes, refer to the following figure:

Dsihost configuration Factor

For dual MIPI screens, you need to enable dsihost0 and dsihost1, such as:

& dsihost0 {status = "okay";}; & dsihost1 {status = "okay";}

If it is a single MIPI screen, just enable dsihost0, such as:

& dsihost0 {status = "okay";}; after reading the above, have you mastered the method of how to do the rk3288 MIPI DSI mode? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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