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SubjectRe: [PATCH] rtc: add Abracon ABx80x driver
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On Sat, 2015-02-28 at 21:52 +0100, Alexandre Belloni wrote:
> > > diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
> > []
> > > +static int ab08xx_get_datetime(struct i2c_client *client, struct rtc_time *tm)
[]
> > > + tm->tm_sec = bcd2bin(date[AB08XX_REG_SC] & 0x7F);
> > > + tm->tm_min = bcd2bin(date[AB08XX_REG_MN] & 0x7F);
> > > + tm->tm_hour = bcd2bin(date[AB08XX_REG_HR] & 0x3F);
> > > + tm->tm_wday = date[AB08XX_REG_WD] & 0x7;
> > > + tm->tm_mday = bcd2bin(date[AB08XX_REG_DA] & 0x3F);
> > > + tm->tm_mon = bcd2bin(date[AB08XX_REG_MO] & 0x1F) - 1;
> > > + tm->tm_year = bcd2bin(date[AB08XX_REG_YR]);
> > > + if (tm->tm_year < 70)
> > > + tm->tm_year += 100;
> > > +
> > > + err = rtc_valid_tm(tm);
> > > + if (err < 0)
> > > + dev_err(&client->dev, "retrieved date/time is not valid.\n");
> >
> > Is setting the date to a known bad value really the desired thing?
>
> I'm not sure what you mean here, isn't that what is done in almost all
> the rtc drivers?

Dunno.

> A lot of those are simply using return
> rtc_valid_tm(tm); My guess is that a userspace program must not try to
> use tm when errno is not 0.

My thought was that it might be better to
use a local struct rtc_time r like

r.tm_sec = bcd2bin(date[AB08XX_REG_SC] & 0x7F);
r.tm_min = bcd2bin(date[AB08XX_REG_MN] & 0x7F);
r.tm_hour = bcd2bin(date[AB08XX_REG_HR] & 0x3F);
r.tm_wday = date[AB08XX_REG_WD] & 0x7;
r.tm_mday = bcd2bin(date[AB08XX_REG_DA] & 0x3F);
r.tm_mon = bcd2bin(date[AB08XX_REG_MO] & 0x1F) - 1;
r.tm_year = bcd2bin(date[AB08XX_REG_YR]);
if (r.tm_year < 70)
r.tm_year += 100;

err = rtc_valid_tm(&r);
if (!err)
*tm = r;
else
dev_err(&client->dev, "retrieved date/time is not valid\n");

return err;




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