[PATCH] i2c: correct I2C deblock logic

[Bough Chen]

> -----Original Message-----
> From: Bough Chen <haibo.chen at nxp.com>
> Sent: 2023年2月10日 17:27
> To: hs at denx.de; al.kochet at gmail.com; marex at denx.de
> Cc: u-boot at lists.denx.de; dl-uboot-imx <uboot-imx at nxp.com>;
> xypron.glpk at gmx.de; Bough Chen <haibo.chen at nxp.com>
> Subject: [PATCH] i2c: correct I2C deblock logic
> 
> 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.
>

Hi, 

Any comments for this patch, just a reminder in case you miss it.

Best Regards
Haibo Chen
 
> 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