[U-Boot] [PATCH 13/24] mxc_i2c: check for arbitration lost

Marek Vasut marex at denx.de
Fri Jun 22 19:04:41 CEST 2012


Dear Troy Kisky,

> No need to continue waiting if arbitration lost.
> 
> Signed-off-by: Troy Kisky <troy.kisky at boundarydevices.com>

Acked-by: Marek Vasut <marex at denx.de>

> ---
>  drivers/i2c/mxc_i2c.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
> index 2bff2b8..df033ea 100644
> --- a/drivers/i2c/mxc_i2c.c
> +++ b/drivers/i2c/mxc_i2c.c
> @@ -54,6 +54,7 @@ struct mxc_i2c_regs {
> 
>  #define I2SR_ICF	(1 << 7)
>  #define I2SR_IBB	(1 << 5)
> +#define I2SR_IAL	(1 << 4)
>  #define I2SR_IIF	(1 << 1)
>  #define I2SR_RX_NO_AK	(1 << 0)
> 
> @@ -164,6 +165,12 @@ static unsigned wait_for_sr_state(struct mxc_i2c_regs
> *i2c_regs, unsigned state) ulong start_time = get_timer(0);
>  	for (;;) {
>  		sr = readb(&i2c_regs->i2sr);
> +		if (sr & I2SR_IAL) {
> +			writeb(sr & ~I2SR_IAL, &i2c_regs->i2sr);
> +			printf("%s: Arbitration lost sr=%x cr=%x state=%x\n",
> +				__func__, sr, readb(&i2c_regs->i2cr), state);
> +			return -ERESTART;
> +		}
>  		if ((sr & (state >> 8)) == (unsigned char)state)
>  			return sr;
>  		elapsed = get_timer(start_time);

Best regards,
Marek Vasut


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