海思平台i2c_read命令的简单使用

【海思】通过I2C读取IMX334寄存器的值

摘要：本文是在海思平台上，通过 i2c_read 命令来读取 imx334 寄存器的值，通过和代码设置的寄存器的值来进行比较，根据读到的值和设置的值是否一致，从而来判断设置的是否正确，寄存器是否生效。

已知：imx334 的 I2C 地址是0x34

查看 i2c_read 用法

~ # i2c_read
*** Board tools : ver0.0.1_20121120 ***
[debug]: {source/utils/cmdshell.c:168}cmdstr:i2c_read
usage: i2c_read <i2c_num> <dev_addr> <reg_addr> <reg_addr_end><reg_width> <data_width> <reg_step>. sample:
                0x1 0x56 0x0 0x10 2 2.
                0x1 0x56 0x0 0x10 2 2 2.
                0x1 0x56 0x0 0x10. default reg_width, data_width, reg_step is 1.

do errro
[END]
~ #

设置寄存器值的代码片段：

void imx334_linear_8M30_12bit_init(VI_PIPE ViPipe)
{
    imx334_write_register(ViPipe, 0x3000, 0x01); //standby
    imx334_write_register(ViPipe, 0x3001, 0x00);
    imx334_write_register(ViPipe, 0x3002, 0x01);
    imx334_write_register(ViPipe, 0x3003, 0x00);
    imx334_write_register(ViPipe, 0x300C, 0x3B);
    imx334_write_register(ViPipe, 0x300D, 0x2A);
    imx334_write_register(ViPipe, 0x3018, 0x00);
    imx334_write_register(ViPipe, 0x302C, 0x30);
    imx334_write_register(ViPipe, 0x302D, 0x00);
    imx334_write_register(ViPipe, 0x302E, 0x18);
    imx334_write_register(ViPipe, 0x302F, 0x0F);
    imx334_write_register(ViPipe, 0x3030, 0xCA);
    imx334_write_register(ViPipe, 0x3031, 0x08);
    imx334_write_register(ViPipe, 0x3032, 0x00);
    imx334_write_register(ViPipe, 0x3033, 0x00);
    imx334_write_register(ViPipe, 0x3034, 0x4C);
    imx334_write_register(ViPipe, 0x3035, 0x04);
    imx334_write_register(ViPipe, 0x304C, 0x14);
 ...
    imx334_write_register(ViPipe, 0x3000, 0x00); //Standby Cancel
    delay_ms(18);
    imx334_write_register(ViPipe, 0x3002, 0x00);
    //delay_ms(320);  //wait for image stablization

    printf("===Imx334 8M30fps 12bit LINE Init OK!===\n");
    return;
}

此处通过读取寄存器 0x3000 和寄存器 0x300C 的值来简单验证一下

读寄存器 0x3000 的值：

~ # i2c_read 0x0 0x34 0x3000 0x3000 2 1 1
*** Board tools : ver0.0.1_20121120 ***
[debug]: {source/utils/cmdshell.c:168}cmdstr:i2c_read
i2c_num:0x0, dev_addr:0x34; reg_addr:0x3000; reg_addr_end:0x3000;                       reg_width: 2; data_width: 1; reg_step: 1.

0x3000: 0x0
[END]
~ #

读寄存器 0x300C 的值：

~ # i2c_read 0x0 0x34 0x300c 0x300c 2 1 1
*** Board tools : ver0.0.1_20121120 ***
[debug]: {source/utils/cmdshell.c:168}cmdstr:i2c_read
i2c_num:0x0, dev_addr:0x34; reg_addr:0x300c; reg_addr_end:0x300c;                       reg_width: 2; data_width: 1; reg_step: 1.

0x300c: 0x3b
[END]
~ #

由上可见：通过代码设置下去的给寄存器的值能正确读取，是有效的。