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From: Icenowy Zheng <icenowy@sipeed.com>
To: Rob Herring <robh+dt@kernel.org>,
	Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Andre Przywara <andre.przywara@arm.com>,
	Samuel Holland <samuel@sholland.org>
Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH 02/17] rtc: sun6i: Add support for linear day storage
Date: Mon,  2 Aug 2021 14:21:57 +0800	[thread overview]
Message-ID: <20210802062212.73220-3-icenowy@sipeed.com> (raw)
In-Reply-To: <20210802062212.73220-1-icenowy@sipeed.com>

From: Andre Przywara <andre.przywara@arm.com>

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)
-- 
2.30.2


  parent reply	other threads:[~2021-08-02  6:22 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-02  6:21 [PATCH 00/17] Basical Allwinner R329 support Icenowy Zheng
2021-08-02  6:21 ` [PATCH 01/17] rtc: sun6i: Fix time overflow handling Icenowy Zheng
2021-08-02  6:21 ` Icenowy Zheng [this message]
2021-08-02  6:21 ` [PATCH 03/17] rtc: sun6i: Add support for broken-down alarm registers Icenowy Zheng
2021-08-02  6:21 ` [PATCH 04/17] dt-bindings: rtc: sun6i: add compatible string for R329 RTC Icenowy Zheng
2021-08-06 21:39   ` Rob Herring
2021-08-02  6:22 ` [PATCH 05/17] rtc: sun6i: add support " Icenowy Zheng
2021-08-02  6:22 ` [PATCH 06/17] dt-bindings: pinctrl: document Allwinner R329 PIO and R-PIO Icenowy Zheng
2021-08-06 21:40   ` Rob Herring
2021-08-18  8:48   ` Maxime Ripard
2021-08-19  2:40   ` Samuel Holland
2021-08-02  6:22 ` [PATCH 07/17] pinctrl: sunxi: add support for R329 CPUX pin controller Icenowy Zheng
2021-08-11  9:23   ` Linus Walleij
2021-08-18  8:48   ` Maxime Ripard
2021-08-19  3:09   ` Samuel Holland
2021-08-02  6:22 ` [PATCH 08/17] pinctrl: sunxi: add support for R329 R-PIO " Icenowy Zheng
2021-08-18  8:52   ` Maxime Ripard
2021-08-19  3:22   ` Samuel Holland
2021-08-02  6:22 ` [PATCH 09/17] dt-bindings: clock: sunxi-ng: add compatibles for R329 CCUs Icenowy Zheng
2021-08-06 21:41   ` Rob Herring
2021-08-02  6:22 ` [PATCH 10/17] clk: sunxi=ng: add support for R329 R-CCU Icenowy Zheng
2021-08-06 21:42   ` Rob Herring
2021-08-18  8:50   ` Maxime Ripard
2021-08-20  0:55   ` Samuel Holland
2021-08-20  4:34     ` Jernej Škrabec
2021-08-25 14:50       ` Maxime Ripard
2021-08-25 15:03         ` Jernej Škrabec
2021-08-25 15:37           ` Maxime Ripard
2021-08-26  0:20       ` Samuel Holland
2021-08-02  6:22 ` [PATCH 11/17] clk: sunxi-ng: add support for Allwinner R329 CCU Icenowy Zheng
2021-08-06 21:42   ` Rob Herring
2021-08-20  2:41   ` Samuel Holland
2021-08-25 14:54     ` Maxime Ripard
2021-08-02  6:22 ` [PATCH 12/17] dt-bindings: mmc: sunxi-mmc: add R329 MMC compatible string Icenowy Zheng
2021-08-06 21:42   ` Rob Herring
2021-08-18  8:47   ` Maxime Ripard
2021-08-02  6:22 ` [PATCH 13/17] mmc: sunxi: add support for R329 MMC controllers Icenowy Zheng
2021-08-18  8:47   ` Maxime Ripard
2021-08-20  2:43   ` Samuel Holland
2021-08-02  6:22 ` [PATCH 14/17] dt-bindings: arm: sunxi: add compatible strings for Sipeed MaixSense Icenowy Zheng
2021-08-06 21:43   ` Rob Herring
2021-08-18  9:03   ` Maxime Ripard
2021-08-02  6:22 ` [PATCH 15/17] arm64: allwinner: dts: add DTSI file for R329 SoC Icenowy Zheng
2021-08-18  9:01   ` Maxime Ripard
     [not found]     ` <74F51516-2470-4A49-972B-E19D8EDD9A3D@sipeed.com>
2021-08-19  2:32       ` Samuel Holland
2021-08-20  3:06         ` Samuel Holland
2021-08-25 15:00           ` Maxime Ripard
2021-08-20  2:59   ` Samuel Holland
2021-08-02  6:22 ` [PATCH 16/17] arm64: allwinner: dts: r329: add DTSI file for Sipeed Maix IIA Icenowy Zheng
2021-08-02  6:22 ` [PATCH 17/17] arm64: allwinner: dts: r329: add support for Sipeed MaixSense Icenowy Zheng
2021-08-10 11:04 ` [PATCH 00/17] Basical Allwinner R329 support Ulf Hansson

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