[PATCH 1/4] i2c: rockchip: fix i2c stop condition

[Gerald Loacker]

The i2c bus gets disabled without sending a stop condition. This violates
i2c timing on the clock line. Fix this and include all related functions
(rk_i2c_send_start_bit, rk_i2c_send_stop_bit, rk_i2c_disable) onto the same
level.

Signed-off-by: Gerald Loacker <gerald.loacker at wolfvision.net>
---
 drivers/i2c/busses/i2c-rockchip.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rockchip.c b/drivers/i2c/busses/i2c-rockchip.c
index 23bf4a55d7..1bca3e9913 100644
--- a/drivers/i2c/busses/i2c-rockchip.c
+++ b/drivers/i2c/busses/i2c-rockchip.c
@@ -222,10 +222,6 @@ static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
 	dev_dbg(dev, "rk_i2c_read: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
 	      chip, reg, r_len, b_len);
 
-	err = rk_i2c_send_start_bit(i2c);
-	if (err)
-		return err;
-
 	writel(I2C_MRXADDR_SET(1, chip << 1 | 1), &regs->mrxaddr);
 	if (r_len == 0) {
 		writel(0, &regs->mrxraddr);
@@ -294,8 +290,6 @@ static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
 i2c_exit:
 	if (err)
 		rk_i2c_show_regs(i2c);
-	rk_i2c_disable(i2c);
-
 	return err;
 }
 
@@ -315,9 +309,6 @@ static int rk_i2c_write(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
 
 	dev_dbg(dev, "rk_i2c_write: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
 	      chip, reg, r_len, b_len);
-	err = rk_i2c_send_start_bit(i2c);
-	if (err)
-		return err;
 
 	while (bytes_remain_len) {
 		if (bytes_remain_len > RK_I2C_FIFO_SIZE)
@@ -370,8 +361,6 @@ static int rk_i2c_write(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
 i2c_exit:
 	if (err)
 		rk_i2c_show_regs(i2c);
-	rk_i2c_disable(i2c);
-
 	return err;
 }
 
@@ -387,6 +376,11 @@ static int rockchip_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 		struct i2c_msg *msg = &msgs[i];
 
 		dev_dbg(dev, "i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
+
+		ret = rk_i2c_send_start_bit(i2c);
+		if (ret)
+			break;
+
 		if (msg->flags & I2C_M_RD) {
 			ret = rk_i2c_read(i2c, msg->addr, 0, 0, msg->buf,
 					  msg->len);
@@ -394,6 +388,9 @@ static int rockchip_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 			ret = rk_i2c_write(i2c, msg->addr, 0, 0, msg->buf,
 					   msg->len);
 		}
+
+		rk_i2c_send_stop_bit(i2c);
+
 		if (ret) {
 			dev_dbg(dev, "i2c_write: error sending: %pe\n",
 				ERR_PTR(ret));
@@ -402,9 +399,7 @@ static int rockchip_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 		}
 	}
 
-	rk_i2c_send_stop_bit(i2c);
 	rk_i2c_disable(i2c);
-
 	return ret < 0 ? ret : nmsgs;
 }
 

-- 
2.37.2