[PATCH v2] i2c: mt76xx: add I2C_FUNC_NOSTART and I2C_M_REV_DIR_ADDR

[zhaojh329 at gmail.com]

This patch adds I2C_FUNC_NOSTART and I2C_M_REV_DIR_ADDR support for
MediaTek MT7621/7628/7688. This is useful for some I2C slave chips,
such as 'drivers/input/joystick/as5011.c'.

Signed-off-by: Jianhui Zhao <zhaojh329 at gmail.com>
Reviewed-by: Stefan Roese <sr at denx.de>
---
Changes v1 -> v2:
- Fix code style
---
 drivers/i2c/busses/i2c-mt7621.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt7621.c b/drivers/i2c/busses/i2c-mt7621.c
index 45fe4a7fe0c0..a7acab78ef9d 100644
--- a/drivers/i2c/busses/i2c-mt7621.c
+++ b/drivers/i2c/busses/i2c-mt7621.c
@@ -150,6 +150,9 @@ static int mtk_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	for (i = 0; i < num; i++) {
 		pmsg = &msgs[i];
 
+		if (pmsg->flags & I2C_M_NOSTART)
+			goto nostart;
+
 		/* wait hardware idle */
 		ret = mtk_i2c_wait_idle(i2c);
 		if (ret)
@@ -174,6 +177,8 @@ static int mtk_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 		} else {
 			/* 7 bits address */
 			addr = i2c_8bit_addr_from_msg(pmsg);
+			if (pmsg->flags & I2C_M_REV_DIR_ADDR)
+				addr ^= 1;
 			iowrite32(addr, i2c->base + REG_SM0D0_REG);
 			ret = mtk_i2c_master_cmd(i2c, SM0CTL1_WRITE, 1);
 			if (ret)
@@ -187,6 +192,7 @@ static int mtk_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 				goto err_ack;
 		}
 
+nostart:
 		/* transfer data */
 		for (len = pmsg->len, j = 0; len > 0; len -= 8, j += 8) {
 			page_len = (len >= 8) ? 8 : len;
@@ -242,7 +248,8 @@ static int mtk_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 
 static u32 mtk_i2c_func(struct i2c_adapter *a)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
+		I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART;
 }
 
 static const struct i2c_algorithm mtk_i2c_algo = {
-- 
2.25.1