diff options
| author | Jean Delvare <khali@linux-fr.org> | 2007-05-01 23:26:29 +0200 |
|---|---|---|
| committer | Jean Delvare <khali@hyperion.delvare> | 2007-05-01 23:26:29 +0200 |
| commit | 209d27c3b1676c0497108f0642c51a08b98a7856 (patch) | |
| tree | 434c063c4bd163ff242ae8a18bf65701bb6d39e6 | |
| parent | 1ecac07abaca1a4084d0259d4a15b55188852a2e (diff) | |
i2c: Emulate SMBus block read over I2C
Let the I2C bus drivers emulate the SMBus Block Read and Block Process
Call transactions if they wish. This requires to define a new message
flag, which i2c-core will use to let the underlying I2C bus driver
know that the first received byte will specify the length of the read
message.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
| -rw-r--r-- | drivers/i2c/i2c-core.c | 34 | ||||
| -rw-r--r-- | include/linux/i2c.h | 1 |
2 files changed, 27 insertions, 8 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index ae07b874a5d7..fd921ce0b75b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -590,8 +590,9 @@ int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num) #ifdef DEBUG for (ret = 0; ret < num; ret++) { dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " - "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ? - 'R' : 'W', msgs[ret].addr, msgs[ret].len); + "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) + ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, + (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); } #endif @@ -1050,9 +1051,9 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, break; case I2C_SMBUS_BLOCK_DATA: if (read_write == I2C_SMBUS_READ) { - dev_err(&adapter->dev, "Block read not supported " - "under I2C emulation!\n"); - return -1; + msg[1].flags |= I2C_M_RECV_LEN; + msg[1].len = 1; /* block length will be added by + the underlying bus driver */ } else { msg[0].len = data->block[0] + 2; if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { @@ -1066,9 +1067,21 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, } break; case I2C_SMBUS_BLOCK_PROC_CALL: - dev_dbg(&adapter->dev, "Block process call not supported " - "under I2C emulation!\n"); - return -1; + num = 2; /* Another special case */ + read_write = I2C_SMBUS_READ; + if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { + dev_err(&adapter->dev, "%s called with invalid " + "block proc call size (%d)\n", __FUNCTION__, + data->block[0]); + return -1; + } + msg[0].len = data->block[0] + 2; + for (i = 1; i < msg[0].len; i++) + msgbuf0[i] = data->block[i-1]; + msg[1].flags |= I2C_M_RECV_LEN; + msg[1].len = 1; /* block length will be added by + the underlying bus driver */ + break; case I2C_SMBUS_I2C_BLOCK_DATA: if (read_write == I2C_SMBUS_READ) { msg[1].len = I2C_SMBUS_BLOCK_MAX; @@ -1132,6 +1145,11 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++) data->block[i+1] = msgbuf1[i]; break; + case I2C_SMBUS_BLOCK_DATA: + case I2C_SMBUS_BLOCK_PROC_CALL: + for (i = 0; i < msgbuf1[0] + 1; i++) + data->block[i] = msgbuf1[i]; + break; } return 0; } diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 568dd1007b53..563c9651dd37 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -366,6 +366,7 @@ struct i2c_msg { #define I2C_M_REV_DIR_ADDR 0x2000 #define I2C_M_IGNORE_NAK 0x1000 #define I2C_M_NO_RD_ACK 0x0800 +#define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ __u16 len; /* msg length */ __u8 *buf; /* pointer to msg data */ }; |