1 files changed, 61 insertions, 3 deletions

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index cef553f..1902d8a 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -530,6 +530,33 @@ static int qup_i2c_get_data_len(struct qup_i2c_dev *qup)
 	return data_len;
 }
 
+static bool qup_i2c_check_msg_len(struct i2c_msg *msg)
+{
+	return ((msg->flags & I2C_M_RD) && (msg->flags & I2C_M_RECV_LEN));
+}
+
+static int qup_i2c_set_tags_smb(u16 addr, u8 *tags, struct qup_i2c_dev *qup,
+			struct i2c_msg *msg)
+{
+	int len = 0;
+
+	if (msg->len > 1) {
+		tags[len++] = QUP_TAG_V2_DATARD_STOP;
+		tags[len++] = qup_i2c_get_data_len(qup) - 1;
+	} else {
+		tags[len++] = QUP_TAG_V2_START;
+		tags[len++] = addr & 0xff;
+
+		if (msg->flags & I2C_M_TEN)
+			tags[len++] = addr >> 8;
+
+		tags[len++] = QUP_TAG_V2_DATARD;
+		/* Read 1 byte indicating the length of the SMBus message */
+		tags[len++] = 1;
+	}
+	return len;
+}
+
 static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
 			    struct i2c_msg *msg,  int is_dma)
 {
@@ -539,6 +566,10 @@ static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
 
 	int last = (qup->blk.pos == (qup->blk.count - 1)) && (qup->is_last);
 
+	/* Handle tags for SMBus block read */
+	if (qup_i2c_check_msg_len(msg))
+		return qup_i2c_set_tags_smb(addr, tags, qup, msg);
+
 	if (qup->blk.pos == 0) {
 		tags[len++] = QUP_TAG_V2_START;
 		tags[len++] = addr & 0xff;
@@ -1061,9 +1092,17 @@ static int qup_i2c_read_fifo_v2(struct qup_i2c_dev *qup,
 				struct i2c_msg *msg)
 {
 	u32 val;
-	int idx, pos = 0, ret = 0, total;
+	int idx, pos = 0, ret = 0, total, msg_offset = 0;
 
+	/*
+	 * If the message length is already read in
+	 * the first byte of the buffer, account for
+	 * that by setting the offset
+	 */
+	if (qup_i2c_check_msg_len(msg) && (msg->len > 1))
+		msg_offset = 1;
 	total = qup_i2c_get_data_len(qup);
+	total -= msg_offset;
 
 	/* 2 extra bytes for read tags */
 	while (pos < (total + 2)) {
@@ -1083,8 +1122,8 @@ static int qup_i2c_read_fifo_v2(struct qup_i2c_dev *qup,
 
 			if (pos >= (total + 2))
 				goto out;
-
-			msg->buf[qup->pos++] = val & 0xff;
+			msg->buf[qup->pos + msg_offset] = val & 0xff;
+			qup->pos++;
 		}
 	}
 
@@ -1124,6 +1163,20 @@ static int qup_i2c_read_one_v2(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 			goto err;
 
 		qup->blk.pos++;
+
+		/* Handle SMBus block read length */
+		if (qup_i2c_check_msg_len(msg) && (msg->len == 1)) {
+			if (msg->buf[0] > I2C_SMBUS_BLOCK_MAX) {
+				ret = -EPROTO;
+				goto err;
+			}
+			msg->len += msg->buf[0];
+			qup->pos = 0;
+			qup_i2c_set_blk_data(qup, msg);
+			/* set tag length for block read */
+			qup->blk.tx_tag_len = 2;
+			qup_i2c_set_read_mode_v2(qup, msg->buf[0]);
+		}
 	} while (qup->blk.pos < qup->blk.count);
 
 err:
@@ -1209,6 +1262,11 @@ static int qup_i2c_xfer(struct i2c_adapter *adap,
 			goto out;
 		}
 
+		if (qup_i2c_check_msg_len(&msgs[idx])) {
+			ret = -EINVAL;
+			goto out;
+		}
+
 		if (msgs[idx].flags & I2C_M_RD)
 			ret = qup_i2c_read_one(qup, &msgs[idx]);
 		else