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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.

             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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