Chapter 15 I2C configuration

Chapter 15 I2C configuration

The SSD20X provides two sets of hardware I2C. According to the SSD201 HW Checklist V6.xlsx[GPIOList] table, we can see which pins I2C0 and I2C1 can reuse:

The data in the following table are summarized:

First configure the DTS I2C node:

 vi arch/arm/boot/dts/infinity2m-ssc011a-s01a-display.dtsi

        i2c0@0{
            compatible = "sstar,i2c";
            reg = <0x1F223000 0x200>,<0x1F203c00 0x200>,<0x1F207000 0x200>;
                #address-cells = <1>;
                #size-cells = <0>;
            clocks = <&CLK_miic0>;
            i2c-group = <0>;
            /*
             * padmux: 1 -> PAD_HDMITX_SCL, PAD_HDMITX_SDA
             *         2 -> PAD_TTL1, PAD_TTL2
             *         3 -> PAD_TTL14, PAD_TTL15
             *         4 -> PAD_GPIO6, PAD_GPIO7
            */
            i2c-padmux = <4>;
           /*
              *  speed: 0 -> HWI2C_HIGH(high speed: 400 KHz)
              *         1 -> HWI2C_NORMAL(normal speed: 300 KHz)
              *         2 -> HWI2C_SLOW(slow speed: 200 KHz)
              *         3 -> HWI2C_VSLOW(very slow: 100 KHz)
              *         4 -> HWI2C_USLOW(ultra slow: 50 KHz)
              *         5 -> HWI2C_UVSLOW(ultra-very slow: 25 KHz)
              */
            i2c-speed = <3>;
            i2c-en-dma = <0>;  // 0: disable; 1: enable;
            status = "ok";
        };

Pay attention to which set of GPIOs is used and assign the value I2C -padmux.Then set the multiplexing mode of this group of GPIO:

vi infinity2m-ssc011a-s01a-padmux-display.dtsi

    <PAD_GPIO6          PINMUX_FOR_I2C0_MODE_4      MDRV_PUSE_I2C0_SCL >,
    <PAD_GPIO7          PINMUX_FOR_I2C0_MODE_4      MDRV_PUSE_I2C0_SDA >,

Once the system is up，You can see /dev/i2C-0，The driver was loaded successfully.