i2c-algo-bit: Emulate SMBus block read
Now that i2c-core lets the i2c bus drivers emulate the SMBus block read
and SMBus block process call transaction types, let's implement that in
the popular i2c bit-banging driver. This will also act as a reference
implementation for other bus drivers which want to do the same.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 28b7e25..fcef6ff 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -391,6 +391,21 @@
};
scllo(adap);
sdahi(adap);
+
+ /* Some SMBus transactions require that we receive the
+ transaction length as the first read byte. */
+ if (rdcount == 1 && (msg->flags & I2C_M_RECV_LEN)) {
+ if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) {
+ printk(KERN_ERR "i2c-algo-bit: readbytes: "
+ "invalid block length (%d)\n", inval);
+ return -EREMOTEIO;
+ }
+ /* The original count value accounts for the extra
+ bytes, that is, either 1 for a regular transaction,
+ or 2 for a PEC transaction. */
+ count += inval;
+ msg->len += inval;
+ }
}
return rdcount;
}
@@ -509,6 +524,8 @@
static u32 bit_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA |
+ I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
}