Re: [PATCH v5 3/5] RTC: RK808: add RTC driver for RK808

From: Chris Zhong
Date: Tue Aug 26 2014 - 05:47:37 EST

On 08/26/2014 11:22 AM, Doug Anderson wrote:
+ int ret;
>+ /* Has the RTC been programmed? */
>+ ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
Can you explain what you're doing here? The comment seems wrong since
it implies that you're checking something.

>From what I can tell from the manual you're setting "RTC_READSEL" to 0
which means "Read access directly to dynamic registers.". That's not
clear here, and RTC_V_OPT_M makes no sense to me.

RK808 has a shadowed register for saving a "frozen" RTC time.
When user setting "RTC_READSEL" to 1, the time will save in this shadowed register.
In this case, user read rtc time register, actually get the time of that moment.
So, I move it to probe, this bit needn't clear every time
>+ tm->tm_min = bcd2bin(rtc_data[1]) & MINUTES_REG_MAK;
>+ tm->tm_hour = bcd2bin(rtc_data[2]) & HOURS_REG_MSK;
>+ tm->tm_mday = bcd2bin(rtc_data[3]) & DAYS_REG_MSK;
>+ tm->tm_mon = (bcd2bin(rtc_data[4]) & MONTHS_REG_MSK) - 1;
>+ tm->tm_year = (bcd2bin(rtc_data[5]) & YEARS_REG_MSK) + 100;
>+ tm->tm_wday = bcd2bin(rtc_data[6]) & WEEKS_REG_MSK;
>+ dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
>+ 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
>+ tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);
>+ return 0;
>+ * Set current time and date in RTC
>+ */
>+static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
Make this "const struct rtc_time *tm"
It will be a warning if add const.
It should be match
int (*set_time)(struct device *, struct rtc_time *);
in rtc.h

+ rk808_rtc_set_time(&pdev->dev, &tm_def);
>+ }
>+ device_init_wakeup(&pdev->dev, 1);
You can skip this. We'll set "wakeup-source" in the device tree.
That will set I2C_CLIENT_WAKE. That will cause the i2c core to call
device_init_wakeup() for you.
If I remove it, wakealarm is disappear, even though I add "wakeup-source" in device tree.
So, I keep it temporarily

+ if (IS_ERR(rk808_rtc->rtc)) {
>+ ret = PTR_ERR(rk808_rtc->rtc);
>+ return ret;
>+ }
>+ alm_irq = platform_get_irq(pdev, 0);
Are you sure that platform_get_irq() works in this case? In Javier's
in-flight max77802 driver he use regmap_irq_get_virq().

...oh, maybe your way does work! You've got the rtc_resources to
specify things, so that looks good...

...but I tried testing it by doing:

cd /sys/class/rtc/rtc0
echo +2 > wakealarm
sleep 5
grep 808 /proc/interrupts

...and I didn't see an interrupt go off. Any idea why?
It works well.

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