[PATCH v9 02/11] dt-bindings: rtc: sun6i: Add H616 compatible string

[PATCH v9 02/11] dt-bindings: rtc: sun6i: Add H616 compatible string

[Andre Przywara]

Add the obvious compatible name to the existing RTC binding.
The actual RTC part of the device uses a different day/month/year
storage scheme, so it's not compatible with the previous devices.
Also the clock part is quite different, as there is no external 32K LOSC
oscillator input.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/rtc/allwinner,sun6i-a31-rtc.yaml      | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml b/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
index beeb90e55727..d8a6500e5840 100644
--- a/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
+++ b/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
@@ -26,6 +26,7 @@ properties:
           - const: allwinner,sun50i-a64-rtc
           - const: allwinner,sun8i-h3-rtc
       - const: allwinner,sun50i-h6-rtc
+      - const: allwinner,sun50i-h616-rtc
 
   reg:
     maxItems: 1
@@ -104,6 +105,19 @@ allOf:
           minItems: 3
           maxItems: 3
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: allwinner,sun50i-h616-rtc
+
+    then:
+      properties:
+        clock-output-names:
+          minItems: 3
+          maxItems: 3
+        clocks: false
+
   - if:
       properties:
         compatible:
-- 
2.17.6

[PATCH v9 03/11] rtc: sun6i: Fix time overflow handling

[Andre Przywara]

Using "unsigned long" for UNIX timestamps is never a good idea, and
comparing the value of such a variable against U32_MAX does not do
anything useful on 32-bit systems.

Use the proper time64_t type when dealing with timestamps, and avoid
cutting down the time range unnecessarily. This also fixes the flawed
check for the alarm time being too far into the future.

The check for this condition is actually somewhat theoretical, as the
RTC counts till 2033 only anyways, and 2^32 seconds from now is not
before the year 2157 - at which point I hope nobody will be using this
hardware anymore.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 drivers/rtc/rtc-sun6i.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index adec1b14a8de..c551ebf0ac00 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -138,7 +138,7 @@ struct sun6i_rtc_dev {
 	const struct sun6i_rtc_clk_data *data;
 	void __iomem *base;
 	int irq;
-	unsigned long alarm;
+	time64_t alarm;
 
 	struct clk_hw hw;
 	struct clk_hw *int_osc;
@@ -510,10 +510,8 @@ 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;
-	unsigned long time_now = 0;
-	unsigned long time_set = 0;
-	unsigned long time_gap = 0;
-	int ret = 0;
+	time64_t time_now, time_set;
+	int ret;
 
 	ret = sun6i_rtc_gettime(dev, &tm_now);
 	if (ret < 0) {
@@ -528,9 +526,7 @@ static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 		return -EINVAL;
 	}
 
-	time_gap = time_set - time_now;
-
-	if (time_gap > U32_MAX) {
+	if ((time_set - time_now) > U32_MAX) {
 		dev_err(dev, "Date too far in the future\n");
 		return -EINVAL;
 	}
@@ -539,7 +535,7 @@ static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 	writel(0, chip->base + SUN6I_ALRM_COUNTER);
 	usleep_range(100, 300);
 
-	writel(time_gap, chip->base + SUN6I_ALRM_COUNTER);
+	writel(time_set - time_now, chip->base + SUN6I_ALRM_COUNTER);
 	chip->alarm = time_set;
 
 	sun6i_rtc_setaie(wkalrm->enabled, chip);
-- 
2.17.6

[PATCH v9 04/11] rtc: sun6i: Add support for linear day storage

[Andre Przywara]

Newer versions of the Allwinner RTC, as for instance found in the H616
SoC, no longer store a broken-down day/month/year representation in the
RTC_DAY_REG, but just a linear day number.
The user manual does not give any indication about the expected epoch
time of this day count, but the BSP kernel uses the UNIX epoch, which
allows easy support due to existing conversion functions in the kernel.

Allow tagging a compatible string with a flag, and use that to mark
those new RTCs. Then convert between a UNIX day number (converted into
seconds) and the broken-down day representation using mktime64() and
time64_to_tm() in the set_time/get_time functions.

That enables support for the RTC in those new chips.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 drivers/rtc/rtc-sun6i.c | 69 +++++++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 23 deletions(-)

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index c551ebf0ac00..a980d4e7408d 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -110,6 +110,8 @@
 #define SUN6I_YEAR_MIN				1970
 #define SUN6I_YEAR_OFF				(SUN6I_YEAR_MIN - 1900)
 
+#define SECS_PER_DAY				(24 * 3600ULL)
+
 /*
  * There are other differences between models, including:
  *
@@ -133,12 +135,15 @@ struct sun6i_rtc_clk_data {
 	unsigned int has_auto_swt : 1;
 };
 
+#define RTC_LINEAR_DAY	BIT(0)
+
 struct sun6i_rtc_dev {
 	struct rtc_device *rtc;
 	const struct sun6i_rtc_clk_data *data;
 	void __iomem *base;
 	int irq;
 	time64_t alarm;
+	unsigned long flags;
 
 	struct clk_hw hw;
 	struct clk_hw *int_osc;
@@ -467,22 +472,30 @@ static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 	} while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||
 		 (time != readl(chip->base + SUN6I_RTC_HMS)));
 
+	if (chip->flags & RTC_LINEAR_DAY) {
+		/*
+		 * Newer chips store a linear day number, the manual
+		 * does not mandate any epoch base. The BSP driver uses
+		 * the UNIX epoch, let's just copy that, as it's the
+		 * easiest anyway.
+		 */
+		rtc_time64_to_tm((date & 0xffff) * SECS_PER_DAY, rtc_tm);
+	} else {
+		rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
+		rtc_tm->tm_mon  = SUN6I_DATE_GET_MON_VALUE(date) - 1;
+		rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
+
+		/*
+		 * switch from (data_year->min)-relative offset to
+		 * a (1900)-relative one
+		 */
+		rtc_tm->tm_year += SUN6I_YEAR_OFF;
+	}
+
 	rtc_tm->tm_sec  = SUN6I_TIME_GET_SEC_VALUE(time);
 	rtc_tm->tm_min  = SUN6I_TIME_GET_MIN_VALUE(time);
 	rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);
 
-	rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
-	rtc_tm->tm_mon  = SUN6I_DATE_GET_MON_VALUE(date);
-	rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
-
-	rtc_tm->tm_mon  -= 1;
-
-	/*
-	 * switch from (data_year->min)-relative offset to
-	 * a (1900)-relative one
-	 */
-	rtc_tm->tm_year += SUN6I_YEAR_OFF;
-
 	return 0;
 }
 
@@ -567,20 +580,25 @@ static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
 	u32 date = 0;
 	u32 time = 0;
 
-	rtc_tm->tm_year -= SUN6I_YEAR_OFF;
-	rtc_tm->tm_mon += 1;
-
-	date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
-		SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |
-		SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
-
-	if (is_leap_year(rtc_tm->tm_year + SUN6I_YEAR_MIN))
-		date |= SUN6I_LEAP_SET_VALUE(1);
-
 	time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec)  |
 		SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min)  |
 		SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
 
+	if (chip->flags & RTC_LINEAR_DAY) {
+		/* The division will cut off the H:M:S part of rtc_tm. */
+		date = div_u64(rtc_tm_to_time64(rtc_tm), SECS_PER_DAY);
+	} else {
+		rtc_tm->tm_year -= SUN6I_YEAR_OFF;
+		rtc_tm->tm_mon += 1;
+
+		date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
+			SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |
+			SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
+
+		if (is_leap_year(rtc_tm->tm_year + SUN6I_YEAR_MIN))
+			date |= SUN6I_LEAP_SET_VALUE(1);
+	}
+
 	/* Check whether registers are writable */
 	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
 			   SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
@@ -674,6 +692,8 @@ static int sun6i_rtc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, chip);
 
+	chip->flags = (unsigned long)of_device_get_match_data(&pdev->dev);
+
 	chip->irq = platform_get_irq(pdev, 0);
 	if (chip->irq < 0)
 		return chip->irq;
@@ -720,7 +740,10 @@ static int sun6i_rtc_probe(struct platform_device *pdev)
 		return PTR_ERR(chip->rtc);
 
 	chip->rtc->ops = &sun6i_rtc_ops;
-	chip->rtc->range_max = 2019686399LL; /* 2033-12-31 23:59:59 */
+	if (chip->flags & RTC_LINEAR_DAY)
+		chip->rtc->range_max = (65536 * SECS_PER_DAY) - 1;
+	else
+		chip->rtc->range_max = 2019686399LL; /* 2033-12-31 23:59:59 */
 
 	ret = devm_rtc_register_device(chip->rtc);
 	if (ret)
-- 
2.17.6

[PATCH v9 05/11] rtc: sun6i: Add support for broken-down alarm registers

[Andre Przywara]

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>
Reviewed by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 drivers/rtc/rtc-sun6i.c | 57 +++++++++++++++++++++++++++++------------
 1 file changed, 40 insertions(+), 17 deletions(-)

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index a980d4e7408d..752bea949050 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 +524,54 @@ 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) {
+		/*
+		 * 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);
+		/* The division will cut off the H:M:S part of alrm_tm. */
+		counter_val = div_u64(rtc_tm_to_time64(alrm_tm), 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

[PATCH v9 06/11] rtc: sun6i: Add support for RTCs without external LOSCs

[Andre Przywara]

Some newer Allwinner RTCs (for instance the one in the H616 SoC) lack
a pin for an external 32768 Hz oscillator. As a consequence, this LOSC
can't be selected as the RTC clock source, and we must rely on the
internal RC oscillator.
To allow additions of clocks to the RTC node, add a feature bit to ignore
any provided clocks for now (the current code would think this is the
external LOSC). Later DTs and code can then for instance add the PLL
based clock input, and older kernel won't get confused.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 drivers/rtc/rtc-sun6i.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index 752bea949050..fe1bee3a4ec6 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -134,6 +134,7 @@ struct sun6i_rtc_clk_data {
 	unsigned int export_iosc : 1;
 	unsigned int has_losc_en : 1;
 	unsigned int has_auto_swt : 1;
+	unsigned int no_ext_losc : 1;
 };
 
 #define RTC_LINEAR_DAY	BIT(0)
@@ -256,7 +257,7 @@ static void __init sun6i_rtc_clk_init(struct device_node *node,
 	}
 
 	/* Switch to the external, more precise, oscillator, if present */
-	if (of_get_property(node, "clocks", NULL)) {
+	if (!rtc->data->no_ext_losc && of_get_property(node, "clocks", NULL)) {
 		reg |= SUN6I_LOSC_CTRL_EXT_OSC;
 		if (rtc->data->has_losc_en)
 			reg |= SUN6I_LOSC_CTRL_EXT_LOSC_EN;
@@ -282,14 +283,19 @@ static void __init sun6i_rtc_clk_init(struct device_node *node,
 	}
 
 	parents[0] = clk_hw_get_name(rtc->int_osc);
-	/* If there is no external oscillator, this will be NULL and ... */
-	parents[1] = of_clk_get_parent_name(node, 0);
+	if (rtc->data->no_ext_losc) {
+		parents[1] = NULL;
+		init.num_parents = 1;
+	} else {
+		/* If there is no external oscillator, this will be NULL and */
+		parents[1] = of_clk_get_parent_name(node, 0);
+		/* ... number of clock parents will be 1. */
+		init.num_parents = of_clk_get_parent_count(node) + 1;
+	}
 
 	rtc->hw.init = &init;
 
 	init.parent_names = parents;
-	/* ... number of clock parents will be 1. */
-	init.num_parents = of_clk_get_parent_count(node) + 1;
 	of_property_read_string_index(node, "clock-output-names", 0,
 				      &init.name);
 
-- 
2.17.6

[PATCH v9 07/11] rtc: sun6i: Add Allwinner H616 support

[Andre Przywara]

The H616 RTC changes its day storage to the newly introduced linear day
scheme, so pair the new compatible string with this feature flag.
The clock part is missing an external 32768 Hz oscillator input pin,
for future expansion we must thus ignore any provided clock for now.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 drivers/rtc/rtc-sun6i.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index fe1bee3a4ec6..77db4f0a042c 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -392,6 +392,23 @@ static void __init sun50i_h6_rtc_clk_init(struct device_node *node)
 CLK_OF_DECLARE_DRIVER(sun50i_h6_rtc_clk, "allwinner,sun50i-h6-rtc",
 		      sun50i_h6_rtc_clk_init);
 
+static const struct sun6i_rtc_clk_data sun50i_h616_rtc_data = {
+	.rc_osc_rate = 16000000,
+	.fixed_prescaler = 32,
+	.has_prescaler = 1,
+	.has_out_clk = 1,
+	.export_iosc = 1,
+	.no_ext_losc = 1,
+};
+
+static void __init sun50i_h616_rtc_clk_init(struct device_node *node)
+{
+	sun6i_rtc_clk_init(node, &sun50i_h616_rtc_data);
+}
+
+CLK_OF_DECLARE_DRIVER(sun50i_h616_rtc_clk, "allwinner,sun50i-h616-rtc",
+		      sun50i_h616_rtc_clk_init);
+
 /*
  * The R40 user manual is self-conflicting on whether the prescaler is
  * fixed or configurable. The clock diagram shows it as fixed, but there
@@ -797,6 +814,8 @@ static const struct of_device_id sun6i_rtc_dt_ids[] = {
 	{ .compatible = "allwinner,sun8i-v3-rtc" },
 	{ .compatible = "allwinner,sun50i-h5-rtc" },
 	{ .compatible = "allwinner,sun50i-h6-rtc" },
+	{ .compatible = "allwinner,sun50i-h616-rtc",
+		.data = (void *)RTC_LINEAR_DAY },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
-- 
2.17.6

Re: [PATCH v9 02/11] dt-bindings: rtc: sun6i: Add H616 compatible string

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 1683 bytes --]

On Mon, Aug 02, 2021 at 01:39:43AM +0100, Andre Przywara wrote:
> Add the obvious compatible name to the existing RTC binding.
> The actual RTC part of the device uses a different day/month/year
> storage scheme, so it's not compatible with the previous devices.
> Also the clock part is quite different, as there is no external 32K LOSC
> oscillator input.
> 
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> ---
>  .../bindings/rtc/allwinner,sun6i-a31-rtc.yaml      | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml b/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
> index beeb90e55727..d8a6500e5840 100644
> --- a/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
> +++ b/Documentation/devicetree/bindings/rtc/allwinner,sun6i-a31-rtc.yaml
> @@ -26,6 +26,7 @@ properties:
>            - const: allwinner,sun50i-a64-rtc
>            - const: allwinner,sun8i-h3-rtc
>        - const: allwinner,sun50i-h6-rtc
> +      - const: allwinner,sun50i-h616-rtc
>  
>    reg:
>      maxItems: 1
> @@ -104,6 +105,19 @@ allOf:
>            minItems: 3
>            maxItems: 3
>  
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: allwinner,sun50i-h616-rtc
> +
> +    then:
> +      properties:
> +        clock-output-names:
> +          minItems: 3
> +          maxItems: 3

The comments I made here on the v7 are still relevant: you only need one
of these two, and the list of clocks should be documented.

Maxime

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