i2c-stub: Implement I2C block support

This is required to test some drivers, for example at24.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/busses/i2c-stub.c b/drivers/i2c/busses/i2c-stub.c
index 1b7b2af..52ebeda 100644
--- a/drivers/i2c/busses/i2c-stub.c
+++ b/drivers/i2c/busses/i2c-stub.c
@@ -48,7 +48,7 @@
 	char read_write, u8 command, int size, union i2c_smbus_data * data)
 {
 	s32 ret;
-	int i;
+	int i, len;
 	struct stub_chip *chip = NULL;
 
 	/* Search for the right chip */
@@ -118,6 +118,29 @@
 		ret = 0;
 		break;
 
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		len = data->block[0];
+		if (read_write == I2C_SMBUS_WRITE) {
+			for (i = 0; i < len; i++) {
+				chip->words[command + i] &= 0xff00;
+				chip->words[command + i] |= data->block[1 + i];
+			}
+			dev_dbg(&adap->dev, "i2c block data - addr 0x%02x, "
+					"wrote %d bytes at 0x%02x.\n",
+					addr, len, command);
+		} else {
+			for (i = 0; i < len; i++) {
+				data->block[1 + i] =
+					chip->words[command + i] & 0xff;
+			}
+			dev_dbg(&adap->dev, "i2c block data - addr 0x%02x, "
+					"read  %d bytes at 0x%02x.\n",
+					addr, len, command);
+		}
+
+		ret = 0;
+		break;
+
 	default:
 		dev_dbg(&adap->dev, "Unsupported I2C/SMBus command\n");
 		ret = -EOPNOTSUPP;
@@ -130,7 +153,8 @@
 static u32 stub_func(struct i2c_adapter *adapter)
 {
 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
-		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA;
+		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+		I2C_FUNC_SMBUS_I2C_BLOCK;
 }
 
 static const struct i2c_algorithm smbus_algorithm = {