[U-Boot] [PATCH 04/24] mxc_i2c: clear i2sr before waiting for bit

[Troy Kisky]

On 6/22/2012 9:59 AM, Marek Vasut wrote:
> Dear Troy Kisky,
>
>> Let's clear the sr register before waiting for
>> bit to be set, instead of clearing it after
>> hardware sets it. No real operational difference here,
>> but allows combining of i2c_imx_trx_complete and
>> i2c_imx_bus_busy in later patches.
>>
>> Signed-off-by: Troy Kisky <troy.kisky at boundarydevices.com>
>> ---
>>   drivers/i2c/mxc_i2c.c |    5 ++---
>>   1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
>> index 0fd508a..bae9335 100644
>> --- a/drivers/i2c/mxc_i2c.c
>> +++ b/drivers/i2c/mxc_i2c.c
>> @@ -200,10 +200,8 @@ int i2c_imx_trx_complete(void)
>>   	int timeout = I2C_MAX_TIMEOUT;
>>
>>   	while (timeout--) {
>> -		if (readb(&i2c_regs->i2sr) & I2SR_IIF) {
>> -			writeb(0, &i2c_regs->i2sr);
>> +		if (readb(&i2c_regs->i2sr) & I2SR_IIF)
>>   			return 0;
>> -		}
>>
>>   		udelay(1);
>>   	}
>> @@ -215,6 +213,7 @@ static int tx_byte(struct mxc_i2c_regs *i2c_regs, u8
>> byte) {
>>   	unsigned ret;
>>
>> +	writeb(0, &i2c_regs->i2sr);
>>   	writeb(byte, &i2c_regs->i2dr);
>>   	ret = i2c_imx_trx_complete();
>>   	if (ret < 0)
> If you could try this on mx51 and mx31, I'd be glad. I recall having some issues
> there.
>
> If it works, add
> Acked-by: Marek Vasut <marex at denx.de>
>
> Best regards,
> Marek Vasut
>
I can't try on a mx31, but will try on a mx51.

Thanks
Troy