blob: 2b2984d950b1c41797c1397a68211e16872c41b4 [file] [log] [blame]
Tony Lee6c595012019-06-19 10:54:59 +08001#include <linux/i2c-dev.h>
2#include <linux/i2c.h>
3#include <linux/types.h>
4#include <sys/ioctl.h>
5
6#define I2C_DATA_MAX 256
7
8static inline __s32 i2c_read_after_write(int file, __u8 slave_addr, __u8 tx_len,
9 __u8* tx_buf, int rx_len, __u8* rx_buf)
10{
11 struct i2c_rdwr_ioctl_data msgst;
12 struct i2c_msg msg[2];
13 int ret;
14
15 msg[0].addr = slave_addr & 0xFF;
16 msg[0].flags = 0;
17 msg[0].buf = (__u8*)tx_buf;
18 msg[0].len = tx_len;
19
20 msg[1].addr = slave_addr & 0xFF;
21 msg[1].flags = I2C_M_RD | I2C_M_RECV_LEN;
22 msg[1].buf = (__u8*)rx_buf;
23 msg[1].len = rx_len;
24
25 msgst.msgs = msg;
26 msgst.nmsgs = 2;
27
28 ret = ioctl(file, I2C_RDWR, &msgst);
29
30 if (ret < 0)
31 return ret;
32
33 return ret;
34}