[U-Boot] [PATCH 2/5] i2c: omap24xx: Fix waitdelay value for I2C HS

[Heiko Schocher]

Hello Christophe,

Am 17.01.2016 um 12:09 schrieb Christophe Ricard:
> After several testings and experiment, it appears that waitdelay calculation
> formula was giving different behavior on the i2c status registers.
>
> Experiment shows waitdelay needs to be extended at least 4 times to get
> proper results.
>
> Signed-off-by: Christophe Ricard <christophe-h.ricard at st.com>
> ---
>
>   drivers/i2c/omap24xx_i2c.c | 18 ++++++++++++------
>   1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
> index f3a4d96..d6e5fe9 100644
> --- a/drivers/i2c/omap24xx_i2c.c
> +++ b/drivers/i2c/omap24xx_i2c.c
> @@ -168,6 +168,13 @@ static int omap24_i2c_setspeed(struct udevice *adap, unsigned int speed)
>   		scll = (unsigned int)hsscll << 8 | (unsigned int)fsscll;
>   		sclh = (unsigned int)hssclh << 8 | (unsigned int)fssclh;
>
> +#ifdef CONFIG_SYS_I2C
> +		adap->speed	= speed;
> +		adap->waitdelay = (10000000 / speed) * 8; /* wait for 20 clkperiods */
> +#else
> +		i2c_bus->clock_frequency = speed;
> +		i2c_bus->waitdelay = (10000000 / speed) * 8; /* wait for 20 clkperiods */
> +#endif
>   	} else {
>   		/* Standard and fast speed */
>   		psc = omap24_i2c_findpsc(&scll, &sclh, speed);
> @@ -175,15 +182,15 @@ static int omap24_i2c_setspeed(struct udevice *adap, unsigned int speed)
>   			puts("Error : I2C initializing clock\n");
>   			return -1;
>   		}
> -	}
>
>   #ifdef CONFIG_SYS_I2C
> -	adap->speed	= speed;
> -	adap->waitdelay = (10000000 / speed) * 2; /* wait for 20 clkperiods */
> +		adap->speed	= speed;
> +		adap->waitdelay = (10000000 / speed) * 2; /* wait for 20 clkperiods */
>   #else
> -	i2c_bus->clock_frequency = speed;
> -	i2c_bus->waitdelay = (10000000 / speed) * 2; /* wait for 20 clkperiods */
> +		i2c_bus->clock_frequency = speed;
> +		i2c_bus->waitdelay = (10000000 / speed) * 2; /* wait for 20 clkperiods */
>   #endif
> +	}

You change here only the "speed >= OMAP_I2C_HIGH_SPEED" case ... Is this your intention?

If so, please add this info in your commit message.

Beside of this nitpick:

Acked-by: Heiko Schocher <hs at denx.de>

bye,
Heiko
>
>   	writew(0, &i2c_base->con);
>   	writew(psc, &i2c_base->psc);
> @@ -467,7 +474,6 @@ static int omap24_i2c_read(struct udevice *adap, uchar chip, uint addr,
>   	i2c_bus = dev_get_priv(adap);
>   	i2c_base = i2c_bus->i2c_base;
>   #endif
> -
>   	if (alen < 0) {
>   		puts("I2C read: addr len < 0\n");
>   		return 1;
>

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