i2c警示訊息

Chip Platform Rockchip
1

<4>[15811.846689] rockchip_i2c 20056000.i2c: Warning: addr[0x0008] msg[0].scl_rate( = 3037725Khz) is too high!

請教大神, 何解??

2

i2c通信的时候，把scl_rate配置上

3

我用下面的func去讀i2c1的device reg內容,

static int get_i2c_register(int file,
unsigned char addr,
unsigned char reg,
unsigned char *val) {
unsigned char inbuf, outbuf = 0x01;
struct i2c_rdwr_ioctl_data packets;
struct i2c_msg messages[2];

/*
 * In order to read a register, we first do a "dummy write" by writing
 * 0 bytes to the register we want to read from.  This is similar to
 * the packet in set_i2c_register, except it's 1 byte rather than 2.
 */
outbuf = reg;
messages[0].addr  = addr;
messages[0].flags = 0;
messages[0].len   = sizeof(outbuf);
messages[0].buf   = &outbuf;

/* The data will get returned in this structure */
messages[1].addr  = addr;
messages[1].flags = I2C_M_RD/* | I2C_M_NOSTART*/;
messages[1].len   = sizeof(inbuf);
messages[1].buf   = &inbuf;

/* Send the request to the kernel and get the result back */
packets.msgs      = messages;
packets.nmsgs     = 2;
if(ioctl(file, I2C_RDWR, &packets) < 0) {
    perror("Unable to send data");
    return 1;
}
*val = inbuf;

return 0;

}
就會印
<4>[15811.846689] rockchip_i2c 20056000.i2c: Warning: addr[0x0008] msg[0].scl_rate( = 3037725Khz) is too high!
或是
<4>[ 463.032272] rockchip_i2c 20056000.i2c: Warning: addr[0x0008] msg[0].scl_rate( = 0Khz) is too low!
==========================分隔線===============================
但是, 用 read 就不會印訊息
if (read(i2c1_fd, &dat, 1) != 1)
{
/* ERROR HANDLING: i2c transaction failed */
printf(“%s %d FAIL @ i2c-1 read\n”, func, LINE);
}

請教大神, 何解??

4

參考 i2c-tools-3.1.2/tools/i2cget.c

int res = i2c_smbus_read_byte_data(file, reg);

用這個也是可以的

持續不解@@

5

rk i2c msg 添加了 变量scl_rate ，来设置速率！ 执行i2c写不会有问题；读操作2个msg，在应该是结构体cp出问题了