5.常见i2c地址_修改i2c速率

一、 如何修改i2c 速率
    1. 在设备驱动代码中i2c_probe()，添加:
        spin_lock(&kdsensor_drv_lock);
        g_pstI2Cclient->timing = i2cSpeed;    // 遇到过摄像头读不到id: 300 -> 100
        spin_unlock(&kdsensor_drv_lock);

    2. 直接修改默认值:
        dtsi:
        i2c2:i2c@11009000 {
            compatible = "mediatek,mt6735m-i2c";
            cell-index = <2>;
            reg = <0x11009000 0x1000>;
            interrupts = ,
                        ;
            def_speed = <100>;        // 修改为300khz -> 没有生效
        };

        如果大于400,需要修改出错判断条件:
        kernel/driver/i2c/busses/i2c-qup.c
        qup_i2c_probe()
            of_property_read_u32(node, "clock-frequency", &clk_freq);
            if (!clk_freq || clk_freq > 400000) {    /* We support frequencies up to FAST Mode (400KHz) */
                dev_err(qup->dev, "clock frequency not supported %d\n",
                    clk_freq);
            }

1. tp
    GT5668        0x5d    (0xba>>1)
    GT9XX        0x5d    (0xba>>1)
    ft6xx6_ges    0x38    (0x70>>1)
    gsl915        0x40
    hxchipset    0x48
    icn85xx        0x48    (0x90>>1)
    mstar_22xx    0x26    (0x4c>>1)
    mstar_2256    0x26    (0x4c>>1)

2. gsensor
    mxc4005        0x15
    mxc6255        0x15
    mc3433        0x4c
    qma6981        0x12
    bmc156        0x10
    icm-20608d(mpu6050) 0x69

3. alsps
    ap3426        0x1e
    epl259x        0x49
    stk3x1x        0x48

4. magnetometer
    bmc156        0x12
    mmc3524x    0x0d
    mmc5603x    0x30

5. gyroscope
    bmg160        0x69
 icm-20608d(mpu6050) 0x69