From: Kassey Lee <kassey1216-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org,
grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org
Subject: static s32 i2c_smbus_xfer_emulated
Date: Tue, 14 Jun 2011 14:39:24 +0800 [thread overview]
Message-ID: <BANLkTinS1RA6iQfjZaVOE-q4qCtbt17LPg@mail.gmail.com> (raw)
hi, Jean:
here is the structur of i2c_msg,
struct i2c_msg {
__u16 addr; /* slave address */
__u16 flags;
#define I2C_M_TEN 0x0010 /* this is a ten bit chip address */
#define I2C_M_RD 0x0001 /* read data, from slave to master */
#define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */
__u16 len; /* msg length */
__u8 *buf; /* pointer to msg data */
};
do you think it is better to use __u8 other than unsigned char here ?
thanks
static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
unsigned short flags,
char read_write, u8 command, int size,
union i2c_smbus_data *data)
{
/* So we need to generate a series of msgs. In the case of writing, we
need to use only one message; when reading, we need two. We initialize
most things with sane defaults, to keep the code below somewhat
simpler. */
unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
int num = read_write == I2C_SMBUS_READ ? 2 : 1;
struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
{ addr, flags | I2C_M_RD, 0, msgbuf1 }
};
--
Best regards
Kassey
Application Processor Systems Engineering, Marvell Technology Group Ltd.
Shanghai, China.
next reply other threads:[~2011-06-14 6:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-14 6:39 Kassey Lee [this message]
[not found] ` <BANLkTinS1RA6iQfjZaVOE-q4qCtbt17LPg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-06-16 16:44 ` static s32 i2c_smbus_xfer_emulated Jean Delvare
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