Commit 3c4bb241 authored by Jean Delvare's avatar Jean Delvare Committed by Jean Delvare
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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: default avatarJean Delvare <khali@linux-fr.org>
parent 209d27c3

drivers/i2c/algos/i2c-algo-bit.c

+17 −0
Original line number Diff line number Diff line
@@ -391,6 +391,21 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) 
		};

		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 @@ bailout: 
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;

}

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