Input: atmel_mxt_ts - read ID information block in one i2c transaction

Reading the whole info block in one i2c transaction speeds up driver
probe significantly, especially on slower i2c busses.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

drivers/input/touchscreen/atmel_mxt_ts.c

@@ -36,6 +36,7 @@
 #define MXT_FW_NAME		"maxtouch.fw"
 
 /* Registers */
+#define MXT_INFO		0x00
 #define MXT_FAMILY_ID		0x00
 #define MXT_VARIANT_ID		0x01
 #define MXT_VERSION		0x02
@@ -760,32 +761,11 @@ static int mxt_get_info(struct mxt_data *data)
 	struct i2c_client *client = data->client;
 	struct mxt_info *info = &data->info;
 	int error;
-	u8 val;
-
-	error = mxt_read_reg(client, MXT_FAMILY_ID, &val);
-	if (error)
-		return error;
-	info->family_id = val;
-
-	error = mxt_read_reg(client, MXT_VARIANT_ID, &val);
-	if (error)
-		return error;
-	info->variant_id = val;
-
-	error = mxt_read_reg(client, MXT_VERSION, &val);
-	if (error)
-		return error;
-	info->version = val;
-
-	error = mxt_read_reg(client, MXT_BUILD, &val);
-	if (error)
-		return error;
-	info->build = val;
 
-	error = mxt_read_reg(client, MXT_OBJECT_NUM, &val);
+	/* Read 7-byte info block starting at address 0 */
+	error = __mxt_read_reg(client, MXT_INFO, sizeof(*info), info);
 	if (error)
 		return error;
-	info->object_num = val;
 
 	return 0;
 }