Re: [PATCH v7 3/5] RTC: RK808: add RTC driver for RK808

[Chris Zhong <zyw@rock-chips.com>]

On 09/02/2014 11:58 AM, Doug Anderson wrote:
>> +static int rk808_rtc_probe(struct platform_device *pdev)
>> >+{
>> >+       struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
>> >+       struct rk808_rtc *rk808_rtc;
>> >+       struct rtc_time tm;
>> >+       int ret;
>> >+
>> >+       rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);
>> >+       if (rk808_rtc == NULL)
>> >+               return -ENOMEM;
>> >+
>> >+       platform_set_drvdata(pdev, rk808_rtc);
>> >+       rk808_rtc->rk808 = rk808;
>> >+
>> >+       /* start rtc running by default, and use shadowed timer. */
>> >+       ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
>> >+                                BIT_RTC_CTRL_REG_STOP_RTC_M |
>> >+                                BIT_RTC_CTRL_REG_RTC_READSEL_M,
>> >+                                BIT_RTC_CTRL_REG_RTC_READSEL_M);
> I think this should still be setting to 0, not to
> BIT_RTC_CTRL_REG_RTC_READSEL_M.  Otherwise the first read of the time
> will return that time that was frozen at probe time, right?  AKA: if
> probe happens at 11:00:00 and then we read the time at 11:00:05 we'll
> still read 11:00:00 the first time.
>
  Sorry, I did not describe correctly, in the previous mail.
  Actually, RK808 has a "GET_TIME" switch bit. When "GET_TIME" bit rising thansiton to 1,
  the current time will save in a shadowed register.
  If "READSEL" = 1, read rtc time register, return the frozen time.
  If we need the real time, clr this "READSEL" bit.