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1 /* $Id: etraxi2c.h,v 1.1 2001/01/18 15:49:57 bjornw Exp $ */
2 
3 #ifndef _LINUX_ETRAXI2C_H
4 #define _LINUX_ETRAXI2C_H
5 
6 /* etraxi2c _IOC_TYPE, bits 8 to 15 in ioctl cmd */
7 
8 #define ETRAXI2C_IOCTYPE 44
9 
10 /* supported ioctl _IOC_NR's */
11 
12 /* in write operations, the argument contains both i2c
13  * slave, register and value.
14  */
15 
16 #define I2C_WRITEARG(slave, reg, value) (((slave) << 16) | ((reg) << 8) | (value))
17 #define I2C_READARG(slave, reg) (((slave) << 16) | ((reg) << 8))
18 
19 #define I2C_ARGSLAVE(arg) ((arg) >> 16)
20 #define I2C_ARGREG(arg) (((arg) >> 8) & 0xff)
21 #define I2C_ARGVALUE(arg) ((arg) & 0xff)
22 
23 #define I2C_WRITEREG 0x1   /* write to an i2c register */
24 #define I2C_READREG  0x2   /* read from an i2c register */
25 
26 /*
27 EXAMPLE usage:
28 
29     i2c_arg = I2C_WRITEARG(STA013_WRITE_ADDR, reg, val);
30     ioctl(fd, _IO(ETRAXI2C_IOCTYPE, I2C_WRITEREG), i2c_arg);
31 
32     i2c_arg = I2C_READARG(STA013_READ_ADDR, reg);
33     val = ioctl(fd, _IO(ETRAXI2C_IOCTYPE, I2C_READREG), i2c_arg);
34 
35 */
36 #endif
37