diff mbox series

[v8,05/11] rtc: sun6i: Add support for broken-down alarm registers

Message ID 20210723153838.6785-6-andre.przywara@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: sunxi: Initial Allwinner H616 SoC support | expand

Commit Message

Andre Przywara July 23, 2021, 3:38 p.m. UTC
Newer versions of the Allwinner RTC, for instance as found in the H616
SoC, not only store the current day as a linear number, but also change
the way the alarm is handled: There are now two registers, that
explicitly store the wakeup time, in the same format as the current
time.

Add support for that variant by writing the requested wakeup time
directly into the registers, instead of programming the seconds left, as
the old SoCs required.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/rtc/rtc-sun6i.c | 60 +++++++++++++++++++++++++++++------------
 1 file changed, 43 insertions(+), 17 deletions(-)

Comments

Jernej Skrabec July 25, 2021, 6:11 a.m. UTC | #1
Hi Andre!

Dne petek, 23. julij 2021 ob 17:38:32 CEST je Andre Przywara napisal(a):
> Newer versions of the Allwinner RTC, for instance as found in the H616
> SoC, not only store the current day as a linear number, but also change
> the way the alarm is handled: There are now two registers, that
> explicitly store the wakeup time, in the same format as the current
> time.
> 
> Add support for that variant by writing the requested wakeup time
> directly into the registers, instead of programming the seconds left, as
> the old SoCs required.
> 
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  drivers/rtc/rtc-sun6i.c | 60 +++++++++++++++++++++++++++++------------
>  1 file changed, 43 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
> index a02be8bca6f3..f0ee20bfdccb 100644
> --- a/drivers/rtc/rtc-sun6i.c
> +++ b/drivers/rtc/rtc-sun6i.c
> @@ -48,7 +48,8 @@
>  
>  /* Alarm 0 (counter) */
>  #define SUN6I_ALRM_COUNTER			0x0020
> -#define SUN6I_ALRM_CUR_VAL			0x0024
> +/* This holds the remaining alarm seconds on older SoCs (current value) */
> +#define SUN6I_ALRM_COUNTER_HMS			0x0024
>  #define SUN6I_ALRM_EN				0x0028
>  #define SUN6I_ALRM_EN_CNT_EN			BIT(0)
>  #define SUN6I_ALRM_IRQ_EN			0x002c
> @@ -523,32 +524,57 @@ static int sun6i_rtc_setalarm(struct device *dev, 
struct rtc_wkalrm *wkalrm)
>  	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
>  	struct rtc_time *alrm_tm = &wkalrm->time;
>  	struct rtc_time tm_now;
> -	time64_t time_now, time_set;
> +	time64_t time_set;
> +	u32 counter_val, counter_val_hms;
>  	int ret;
>  
> -	ret = sun6i_rtc_gettime(dev, &tm_now);
> -	if (ret < 0) {
> -		dev_err(dev, "Error in getting time\n");
> -		return -EINVAL;
> -	}
> -
>  	time_set = rtc_tm_to_time64(alrm_tm);
> -	time_now = rtc_tm_to_time64(&tm_now);
> -	if (time_set <= time_now) {
> -		dev_err(dev, "Date to set in the past\n");
> -		return -EINVAL;
> -	}
>  
> -	if ((time_set - time_now) > U32_MAX) {
> -		dev_err(dev, "Date too far in the future\n");
> -		return -EINVAL;
> +	if (chip->flags & RTC_LINEAR_DAY) {
> +		time64_t seconds;
> +
> +		/*
> +		 * The alarm registers hold the actual alarm time, 
encoded
> +		 * in the same way (linear day + HMS) as the current 
time.
> +		 */
> +		counter_val_hms = SUN6I_TIME_SET_SEC_VALUE(alrm_tm-
>tm_sec)  |
> +				  
SUN6I_TIME_SET_MIN_VALUE(alrm_tm->tm_min)  |
> +				  
SUN6I_TIME_SET_HOUR_VALUE(alrm_tm->tm_hour);
> +		seconds = mktime64(alrm_tm->tm_year + 1900, alrm_tm-
>tm_mon,
> +				   alrm_tm->tm_mday, 0, 0, 0);

While above line should work, it's confusing why you're adding 1900 to years. 
In my opinion it would be better to use same trick you used in patch 4 - 
rtc_tm_to_time64() with hours, minutes and seconds set to 0. Or maybe you 
don't even need to do that, since division by SECS_PER_DAY will round down 
anyway. In such way you hide RTC internal representation detail which doesn't 
need to be exposed here.

Once fixed:
Reviewed by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

> +		counter_val = div_u64(seconds, SECS_PER_DAY);
> +	} else {
> +		/* The alarm register holds the number of seconds left. 
*/
> +		time64_t time_now;
> +
> +		ret = sun6i_rtc_gettime(dev, &tm_now);
> +		if (ret < 0) {
> +			dev_err(dev, "Error in getting time\n");
> +			return -EINVAL;
> +		}
> +
> +		time_now = rtc_tm_to_time64(&tm_now);
> +		if (time_set <= time_now) {
> +			dev_err(dev, "Date to set in the past\n");
> +			return -EINVAL;
> +		}
> +		if ((time_set - time_now) > U32_MAX) {
> +			dev_err(dev, "Date too far in the future\n");
> +			return -EINVAL;
> +		}
> +
> +		counter_val = time_set - time_now;
>  	}
>  
>  	sun6i_rtc_setaie(0, chip);
>  	writel(0, chip->base + SUN6I_ALRM_COUNTER);
> +	if (chip->flags & RTC_LINEAR_DAY)
> +		writel(0, chip->base + SUN6I_ALRM_COUNTER_HMS);
>  	usleep_range(100, 300);
>  
> -	writel(time_set - time_now, chip->base + SUN6I_ALRM_COUNTER);
> +	writel(counter_val, chip->base + SUN6I_ALRM_COUNTER);
> +	if (chip->flags & RTC_LINEAR_DAY)
> +		writel(counter_val_hms, chip->base + 
SUN6I_ALRM_COUNTER_HMS);
>  	chip->alarm = time_set;
>  
>  	sun6i_rtc_setaie(wkalrm->enabled, chip);
> -- 
> 2.17.6
> 
>
Andre Przywara Aug. 2, 2021, 12:39 a.m. UTC | #2
On Sun, 25 Jul 2021 08:11:49 +0200
Jernej Škrabec <jernej.skrabec@gmail.com> wrote:

Hi Jernej,

> Dne petek, 23. julij 2021 ob 17:38:32 CEST je Andre Przywara napisal(a):
> > Newer versions of the Allwinner RTC, for instance as found in the H616
> > SoC, not only store the current day as a linear number, but also change
> > the way the alarm is handled: There are now two registers, that
> > explicitly store the wakeup time, in the same format as the current
> > time.
> > 
> > Add support for that variant by writing the requested wakeup time
> > directly into the registers, instead of programming the seconds left, as
> > the old SoCs required.
> > 
> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> > ---
> >  drivers/rtc/rtc-sun6i.c | 60 +++++++++++++++++++++++++++++------------
> >  1 file changed, 43 insertions(+), 17 deletions(-)
> > 
> > diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
> > index a02be8bca6f3..f0ee20bfdccb 100644
> > --- a/drivers/rtc/rtc-sun6i.c
> > +++ b/drivers/rtc/rtc-sun6i.c
> > @@ -48,7 +48,8 @@
> >  
> >  /* Alarm 0 (counter) */
> >  #define SUN6I_ALRM_COUNTER			0x0020
> > -#define SUN6I_ALRM_CUR_VAL			0x0024
> > +/* This holds the remaining alarm seconds on older SoCs (current value) */
> > +#define SUN6I_ALRM_COUNTER_HMS			0x0024
> >  #define SUN6I_ALRM_EN				0x0028
> >  #define SUN6I_ALRM_EN_CNT_EN			BIT(0)
> >  #define SUN6I_ALRM_IRQ_EN			0x002c
> > @@ -523,32 +524,57 @@ static int sun6i_rtc_setalarm(struct device *dev,   
> struct rtc_wkalrm *wkalrm)
> >  	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
> >  	struct rtc_time *alrm_tm = &wkalrm->time;
> >  	struct rtc_time tm_now;
> > -	time64_t time_now, time_set;
> > +	time64_t time_set;
> > +	u32 counter_val, counter_val_hms;
> >  	int ret;
> >  
> > -	ret = sun6i_rtc_gettime(dev, &tm_now);
> > -	if (ret < 0) {
> > -		dev_err(dev, "Error in getting time\n");
> > -		return -EINVAL;
> > -	}
> > -
> >  	time_set = rtc_tm_to_time64(alrm_tm);
> > -	time_now = rtc_tm_to_time64(&tm_now);
> > -	if (time_set <= time_now) {
> > -		dev_err(dev, "Date to set in the past\n");
> > -		return -EINVAL;
> > -	}
> >  
> > -	if ((time_set - time_now) > U32_MAX) {
> > -		dev_err(dev, "Date too far in the future\n");
> > -		return -EINVAL;
> > +	if (chip->flags & RTC_LINEAR_DAY) {
> > +		time64_t seconds;
> > +
> > +		/*
> > +		 * The alarm registers hold the actual alarm time,   
> encoded
> > +		 * in the same way (linear day + HMS) as the current   
> time.
> > +		 */
> > +		counter_val_hms = SUN6I_TIME_SET_SEC_VALUE(alrm_tm-
> >tm_sec)  |
> > +				    
> SUN6I_TIME_SET_MIN_VALUE(alrm_tm->tm_min)  |
> > +				    
> SUN6I_TIME_SET_HOUR_VALUE(alrm_tm->tm_hour);
> > +		seconds = mktime64(alrm_tm->tm_year + 1900, alrm_tm-
> >tm_mon,
> > +				   alrm_tm->tm_mday, 0, 0, 0);  
> 
> While above line should work, it's confusing why you're adding 1900 to years. 
> In my opinion it would be better to use same trick you used in patch 4 - 
> rtc_tm_to_time64() with hours, minutes and seconds set to 0.

IIRC setalarm does not want the time struct to be changed, but this is
OK in settime. But anyway ...

> Or maybe you 
> don't even need to do that, since division by SECS_PER_DAY will round down 
> anyway. In such way you hide RTC internal representation detail which doesn't 
> need to be exposed here.

That is indeed a very clever idea! I changed both settime and setalarm
accordingly now, adding a comment about this.

> 
> Once fixed:
> Reviewed by: Jernej Skrabec <jernej.skrabec@gmail.com>

Many thanks for the reviews!

Cheers,
Andre

> > +		counter_val = div_u64(seconds, SECS_PER_DAY);
> > +	} else {
> > +		/* The alarm register holds the number of seconds left.   
> */
> > +		time64_t time_now;
> > +
> > +		ret = sun6i_rtc_gettime(dev, &tm_now);
> > +		if (ret < 0) {
> > +			dev_err(dev, "Error in getting time\n");
> > +			return -EINVAL;
> > +		}
> > +
> > +		time_now = rtc_tm_to_time64(&tm_now);
> > +		if (time_set <= time_now) {
> > +			dev_err(dev, "Date to set in the past\n");
> > +			return -EINVAL;
> > +		}
> > +		if ((time_set - time_now) > U32_MAX) {
> > +			dev_err(dev, "Date too far in the future\n");
> > +			return -EINVAL;
> > +		}
> > +
> > +		counter_val = time_set - time_now;
> >  	}
> >  
> >  	sun6i_rtc_setaie(0, chip);
> >  	writel(0, chip->base + SUN6I_ALRM_COUNTER);
> > +	if (chip->flags & RTC_LINEAR_DAY)
> > +		writel(0, chip->base + SUN6I_ALRM_COUNTER_HMS);
> >  	usleep_range(100, 300);
> >  
> > -	writel(time_set - time_now, chip->base + SUN6I_ALRM_COUNTER);
> > +	writel(counter_val, chip->base + SUN6I_ALRM_COUNTER);
> > +	if (chip->flags & RTC_LINEAR_DAY)
> > +		writel(counter_val_hms, chip->base +   
> SUN6I_ALRM_COUNTER_HMS);
> >  	chip->alarm = time_set;
> >  
> >  	sun6i_rtc_setaie(wkalrm->enabled, chip);
> > -- 
> > 2.17.6
> > 
> >   
> 
> 
>
diff mbox series

Patch

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index a02be8bca6f3..f0ee20bfdccb 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -48,7 +48,8 @@ 
 
 /* Alarm 0 (counter) */
 #define SUN6I_ALRM_COUNTER			0x0020
-#define SUN6I_ALRM_CUR_VAL			0x0024
+/* This holds the remaining alarm seconds on older SoCs (current value) */
+#define SUN6I_ALRM_COUNTER_HMS			0x0024
 #define SUN6I_ALRM_EN				0x0028
 #define SUN6I_ALRM_EN_CNT_EN			BIT(0)
 #define SUN6I_ALRM_IRQ_EN			0x002c
@@ -523,32 +524,57 @@  static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 	struct rtc_time *alrm_tm = &wkalrm->time;
 	struct rtc_time tm_now;
-	time64_t time_now, time_set;
+	time64_t time_set;
+	u32 counter_val, counter_val_hms;
 	int ret;
 
-	ret = sun6i_rtc_gettime(dev, &tm_now);
-	if (ret < 0) {
-		dev_err(dev, "Error in getting time\n");
-		return -EINVAL;
-	}
-
 	time_set = rtc_tm_to_time64(alrm_tm);
-	time_now = rtc_tm_to_time64(&tm_now);
-	if (time_set <= time_now) {
-		dev_err(dev, "Date to set in the past\n");
-		return -EINVAL;
-	}
 
-	if ((time_set - time_now) > U32_MAX) {
-		dev_err(dev, "Date too far in the future\n");
-		return -EINVAL;
+	if (chip->flags & RTC_LINEAR_DAY) {
+		time64_t seconds;
+
+		/*
+		 * The alarm registers hold the actual alarm time, encoded
+		 * in the same way (linear day + HMS) as the current time.
+		 */
+		counter_val_hms = SUN6I_TIME_SET_SEC_VALUE(alrm_tm->tm_sec)  |
+				  SUN6I_TIME_SET_MIN_VALUE(alrm_tm->tm_min)  |
+				  SUN6I_TIME_SET_HOUR_VALUE(alrm_tm->tm_hour);
+		seconds = mktime64(alrm_tm->tm_year + 1900, alrm_tm->tm_mon,
+				   alrm_tm->tm_mday, 0, 0, 0);
+		counter_val = div_u64(seconds, SECS_PER_DAY);
+	} else {
+		/* The alarm register holds the number of seconds left. */
+		time64_t time_now;
+
+		ret = sun6i_rtc_gettime(dev, &tm_now);
+		if (ret < 0) {
+			dev_err(dev, "Error in getting time\n");
+			return -EINVAL;
+		}
+
+		time_now = rtc_tm_to_time64(&tm_now);
+		if (time_set <= time_now) {
+			dev_err(dev, "Date to set in the past\n");
+			return -EINVAL;
+		}
+		if ((time_set - time_now) > U32_MAX) {
+			dev_err(dev, "Date too far in the future\n");
+			return -EINVAL;
+		}
+
+		counter_val = time_set - time_now;
 	}
 
 	sun6i_rtc_setaie(0, chip);
 	writel(0, chip->base + SUN6I_ALRM_COUNTER);
+	if (chip->flags & RTC_LINEAR_DAY)
+		writel(0, chip->base + SUN6I_ALRM_COUNTER_HMS);
 	usleep_range(100, 300);
 
-	writel(time_set - time_now, chip->base + SUN6I_ALRM_COUNTER);
+	writel(counter_val, chip->base + SUN6I_ALRM_COUNTER);
+	if (chip->flags & RTC_LINEAR_DAY)
+		writel(counter_val_hms, chip->base + SUN6I_ALRM_COUNTER_HMS);
 	chip->alarm = time_set;
 
 	sun6i_rtc_setaie(wkalrm->enabled, chip);