[PATCH] i2c: ast_i2c: Remove SCL direct drive mode

[Joel Stanley]

On Wed, 11 May 2022 at 20:52, Eddie James <eajames at linux.ibm.com> wrote:
>
> SCL direct drive mode prevents communication with devices that
> do clock stretching, so disable. The Linux driver doesn't use
> this mode, and the engine can handle clock stretching.
>
> Signed-off-by: Eddie James <eajames at linux.ibm.com>

Reviewed-by: Joel Stanley <joel at jms.id.au>

I have added the aspeed team to cc for their review.

Ryan, we discovered this fix when testing the tpm i2c driver on the ast2600.

> ---
>  drivers/i2c/ast_i2c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/ast_i2c.c b/drivers/i2c/ast_i2c.c
> index 2d3fecaa14..8b24a260c0 100644
> --- a/drivers/i2c/ast_i2c.c
> +++ b/drivers/i2c/ast_i2c.c
> @@ -76,7 +76,7 @@ static void ast_i2c_init_bus(struct udevice *dev)
>         /* Enable Master Mode. Assuming single-master */
>         writel(I2CD_MASTER_EN
>                | I2CD_M_SDA_LOCK_EN
> -              | I2CD_MULTI_MASTER_DIS | I2CD_M_SCL_DRIVE_EN,
> +              | I2CD_MULTI_MASTER_DIS,
>                &priv->regs->fcr);
>         /* Enable Interrupts */
>         writel(I2CD_INTR_TX_ACK
> --
> 2.27.0
>