[linux-yocto] [PATCH 28/28] i2c: axxia: Add support for 10-bit addressing

[Charlie Paul]

From: Anders Berg <anders.berg at lsi.com>

Add support for I2c transfers using 10-bit address. The upper layer passes the
flag I2C_M_TEN to inform the driver that the msg->addr field is a 10-bit
address. The Axxia I2C controller will transmit a 10-bit address when the 5
most significant bits in address register 1 equals 5'b11110. The least
significant part of the address is then read from address register 2.

Signed-off-by: Anders Berg <anders.berg at lsi.com>
---
 drivers/i2c/busses/i2c-axxia.c |   32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-axxia.c b/drivers/i2c/busses/i2c-axxia.c
index b2cdbba..db1a2d3 100644
--- a/drivers/i2c/busses/i2c-axxia.c
+++ b/drivers/i2c/busses/i2c-axxia.c
@@ -251,6 +251,12 @@ i2c_m_rd(const struct i2c_msg *msg)
 }
 
 static int
+i2c_m_ten(const struct i2c_msg *msg)
+{
+	return (msg->flags & I2C_M_TEN) != 0;
+}
+
+static int
 i2c_m_recv_len(const struct i2c_msg *msg)
 {
 	return (msg->flags & I2C_M_RECV_LEN) != 0;
@@ -376,6 +382,7 @@ static int
 axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
 {
 	u32 int_mask = MST_STATUS_ERR | MST_STATUS_SNS;
+	u32 addr_1, addr_2;
 	int ret;
 
 	if (msg->len == 0 || msg->len > 255)
@@ -391,17 +398,32 @@ axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
 		writel(0, &idev->regs->mst_tx_xfer);
 		/* RX # bytes */
 		writel(msg->len, &idev->regs->mst_rx_xfer);
-		/* Chip address for write */
-		writel(CHIP_READ(msg->addr), &idev->regs->mst_addr_1);
 	} else {
 		/* TX # bytes */
 		writel(msg->len, &idev->regs->mst_tx_xfer);
 		/* RX 0 bytes */
 		writel(0, &idev->regs->mst_rx_xfer);
-		/* Chip address for write */
-		writel(CHIP_WRITE(msg->addr), &idev->regs->mst_addr_1);
 	}
-	writel(msg->addr >> 8, &idev->regs->mst_addr_2);
+
+	if (i2c_m_ten(msg)) {
+		/* 10-bit address
+		 *   addr_1: 5'b11110 | addr[9:8] | (R/W)
+		 *   addr_2: addr[7:0]
+		 */
+		addr_1 = 0xF0 | ((msg->addr >> 7) & 0x06);
+		addr_2 = msg->addr & 0xFF;
+	} else {
+		/* 7-bit address
+		 *   addr_1: addr[6:0] | (R/W)
+		 *   addr_2: dont care
+		 */
+		addr_1 = (msg->addr << 1) & 0xFF;
+		addr_2 = 0;
+	}
+	if (i2c_m_rd(msg))
+		addr_1 |= 1;
+	writel(addr_1, &idev->regs->mst_addr_1);
+	writel(addr_2, &idev->regs->mst_addr_2);
 
 	if (i2c_m_rd(msg)) {
 		int_mask |= MST_STATUS_RFL;
-- 
1.7.9.5