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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* $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/*
27EXAMPLE 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