On Fri, Jun 03, 2005 at 02:36:06PM -0700, Randy Vinson wrote:
> Greetings,
> I've put together a small I2C client for the Maxim/Dallas DS1374 RTC
> chip and tested it on a Freescale MPC8349ADS board that uses the chip.
> The attached patch adds support for the chip itself and a follow-up patch
> will add support to the Freescale board.
[snip]
> + down(&ds1374_mutex);
> +
> + /*
> + * Since the reads are being performed one byte at a time using
> + * the SMBus vs a 4-byte i2c transfer, there is a chance that a
> + * carry will occur during the read. To detect this, 2 reads are
> + * performed and compared.
> + */
> + do {
> + t1 = ds1374_read_rtc();
> + t2 = ds1374_read_rtc();
> + } while (t1 != t2 && limit--);
I wonder, why you chose to use those 1-byte SMBus transfers instead of
i2c transfer.
I wrote similar DS1374 driver some time ago which used those transfers
and they worked just fine.
--
Eugene
