[PATCH] i2c: correct I2C deblock logic

[haibo.chen at nxp.com]

From: Haibo Chen <haibo.chen at nxp.com>

Current code use dm_gpio_get_value() to get SDA and SCL value, and the
value depends on the flag GPIOD_ACTIVE_LOW. When toggle SCL to wait
slave release SDA, the SDA are config as GPIOD_IS_IN, and whether contain
the GPIOD_ACTIVE_LOW depends on the DTS setting. Usually, for I2C GPIO,
we use GPIOD_ACTIVE_LOW flag in DTS, so if the SDA is in low level, then
dm_gpio_get_value() will return 1, current code logic will stop the SCL
toggle wrongly, cause the I2C deblock not work as expect.

This patch force set the GPIOD_ACTIVE_LOW for both GPIOD_IS_IN and
GPIOD_IS_OUT, and make the return value of i2c_gpio_get_pin() eaqual to
the physical voltage logic level.

Fixes: aa54192d4a87 ("dm: i2c: implement gpio-based I2C deblock")
Signed-off-by: Haibo Chen <haibo.chen at nxp.com>
---
 drivers/i2c/i2c-uclass.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c
index 8d9a89ed89..4dc707c659 100644
--- a/drivers/i2c/i2c-uclass.c
+++ b/drivers/i2c/i2c-uclass.c
@@ -505,7 +505,8 @@ uint i2c_get_chip_addr_offset_mask(struct udevice *dev)
 static void i2c_gpio_set_pin(struct gpio_desc *pin, int bit)
 {
 	if (bit)
-		dm_gpio_set_dir_flags(pin, GPIOD_IS_IN);
+		dm_gpio_set_dir_flags(pin, GPIOD_IS_IN |
+					   GPIOD_ACTIVE_LOW);
 	else
 		dm_gpio_set_dir_flags(pin, GPIOD_IS_OUT |
 					   GPIOD_ACTIVE_LOW |
@@ -514,7 +515,7 @@ static void i2c_gpio_set_pin(struct gpio_desc *pin, int bit)
 
 static int i2c_gpio_get_pin(struct gpio_desc *pin)
 {
-	return dm_gpio_get_value(pin);
+	return !dm_gpio_get_value(pin);
 }
 
 int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin,
-- 
2.34.1