Merge tag 'rtc-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "A new driver represents the bulk of the changes and then we get the
  usual small fixes.

  New driver:

   - Renesas RZN1 rtc

  Drivers:

   - sun6i: Add nvmem support"

* tag 'rtc-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  rtc: mxc: Silence a clang warning
  rtc: rzn1: Fix a variable type
  rtc: rzn1: Fix error code in probe
  rtc: rzn1: Avoid mixing variables
  rtc: ftrtc010: Fix error handling in ftrtc010_rtc_probe
  rtc: mt6397: check return value after calling platform_get_resource()
  rtc: rzn1: fix platform_no_drv_owner.cocci warning
  rtc: gamecube: Add missing iounmap in gamecube_rtc_read_offset_from_sram
  rtc: meson: Fix email address in MODULE_AUTHOR
  rtc: simplify the return expression of rx8025_set_offset()
  rtc: pcf85063: Add a compatible entry for pca85073a
  dt-binding: pcf85063: Add an entry for pca85073a
  MAINTAINERS: Add myself as maintainer of the RZN1 RTC driver
  rtc: rzn1: Add oscillator offset support
  rtc: rzn1: Add alarm support
  rtc: rzn1: Add new RTC driver
  dt-bindings: rtc: rzn1: Describe the RZN1 RTC
  rtc: sun6i: Add NVMEM provider

11 files changed, 500 insertions, 18 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 41c65b4d2baf..a00f901b5c1d 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1548,6 +1548,13 @@ config RTC_DRV_RS5C313
 	help
 	  If you say yes here you get support for the Ricoh RS5C313 RTC chips.
 
+config RTC_DRV_RZN1
+	tristate "Renesas RZ/N1 RTC"
+	depends on ARCH_RZN1 || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	help
+	  If you say yes here you get support for the Renesas RZ/N1 RTC.
+
 config RTC_DRV_GENERIC
 	tristate "Generic RTC support"
 	# Please consider writing a new RTC driver instead of using the generic
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 2d827d8261d5..fb04467b652d 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -151,6 +151,7 @@ obj-$(CONFIG_RTC_DRV_RX6110)	+= rtc-rx6110.o
 obj-$(CONFIG_RTC_DRV_RX8010)	+= rtc-rx8010.o
 obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
 obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
+obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
 obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
 obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
 obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o
diff --git a/drivers/rtc/rtc-ftrtc010.c b/drivers/rtc/rtc-ftrtc010.c
index 53bb08fe1cd4..25c6e7d9570f 100644
--- a/drivers/rtc/rtc-ftrtc010.c
+++ b/drivers/rtc/rtc-ftrtc010.c
@@ -137,26 +137,34 @@ static int ftrtc010_rtc_probe(struct platform_device *pdev)
 		ret = clk_prepare_enable(rtc->extclk);
 		if (ret) {
 			dev_err(dev, "failed to enable EXTCLK\n");
-			return ret;
+			goto err_disable_pclk;
 		}
 	}
 
 	rtc->rtc_irq = platform_get_irq(pdev, 0);
-	if (rtc->rtc_irq < 0)
-		return rtc->rtc_irq;
+	if (rtc->rtc_irq < 0) {
+		ret = rtc->rtc_irq;
+		goto err_disable_extclk;
+	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -ENODEV;
+	if (!res) {
+		ret = -ENODEV;
+		goto err_disable_extclk;
+	}
 
 	rtc->rtc_base = devm_ioremap(dev, res->start,
 				     resource_size(res));
-	if (!rtc->rtc_base)
-		return -ENOMEM;
+	if (!rtc->rtc_base) {
+		ret = -ENOMEM;
+		goto err_disable_extclk;
+	}
 
 	rtc->rtc_dev = devm_rtc_allocate_device(dev);
-	if (IS_ERR(rtc->rtc_dev))
-		return PTR_ERR(rtc->rtc_dev);
+	if (IS_ERR(rtc->rtc_dev)) {
+		ret = PTR_ERR(rtc->rtc_dev);
+		goto err_disable_extclk;
+	}
 
 	rtc->rtc_dev->ops = &ftrtc010_rtc_ops;
 
@@ -172,9 +180,15 @@ static int ftrtc010_rtc_probe(struct platform_device *pdev)
 	ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt,
 			       IRQF_SHARED, pdev->name, dev);
 	if (unlikely(ret))
-		return ret;
+		goto err_disable_extclk;
 
 	return devm_rtc_register_device(rtc->rtc_dev);
+
+err_disable_extclk:
+	clk_disable_unprepare(rtc->extclk);
+err_disable_pclk:
+	clk_disable_unprepare(rtc->pclk);
+	return ret;
 }
 
 static int ftrtc010_rtc_remove(struct platform_device *pdev)
diff --git a/drivers/rtc/rtc-gamecube.c b/drivers/rtc/rtc-gamecube.c
index 18ca3b38b2d0..c2717bb52b2b 100644
--- a/drivers/rtc/rtc-gamecube.c
+++ b/drivers/rtc/rtc-gamecube.c
@@ -267,6 +267,7 @@ static int gamecube_rtc_read_offset_from_sram(struct priv *d)
 	ret = regmap_read(d->regmap, RTC_SRAM_BIAS, &d->rtc_bias);
 	if (ret) {
 		pr_err("failed to get the RTC bias\n");
+		iounmap(hw_srnprot);
 		return -1;
 	}
 
diff --git a/drivers/rtc/rtc-meson.c b/drivers/rtc/rtc-meson.c
index 44bdc8b4a90d..db1d626edca5 100644
--- a/drivers/rtc/rtc-meson.c
+++ b/drivers/rtc/rtc-meson.c
@@ -399,7 +399,7 @@ static struct platform_driver meson_rtc_driver = {
 module_platform_driver(meson_rtc_driver);
 
 MODULE_DESCRIPTION("Amlogic Meson RTC Driver");
-MODULE_AUTHOR("Ben Dooks <ben.doosk@codethink.co.uk>");
+MODULE_AUTHOR("Ben Dooks <ben.dooks@codethink.co.uk>");
 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:meson-rtc");
diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
index 80dc479a6ff0..1d297af80f87 100644
--- a/drivers/rtc/rtc-mt6397.c
+++ b/drivers/rtc/rtc-mt6397.c
@@ -269,6 +269,8 @@ static int mtk_rtc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
 	rtc->addr_base = res->start;
 
 	rtc->data = of_device_get_match_data(&pdev->dev);
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
index 0f08f22df869..53d4e253e81f 100644
--- a/drivers/rtc/rtc-mxc.c
+++ b/drivers/rtc/rtc-mxc.c
@@ -311,7 +311,7 @@ static int mxc_rtc_probe(struct platform_device *pdev)
 	if (!pdata)
 		return -ENOMEM;
 
-	pdata->devtype = (enum imx_rtc_type)of_device_get_match_data(&pdev->dev);
+	pdata->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev);
 
 	pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(pdata->ioaddr))
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index 9760824ec199..095891999da1 100644
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -650,6 +650,7 @@ static int pcf85063_probe(struct i2c_client *client)
 }
 
 static const struct i2c_device_id pcf85063_ids[] = {
+	{ "pca85073a", PCF85063A },
 	{ "pcf85063", PCF85063 },
 	{ "pcf85063tp", PCF85063TP },
 	{ "pcf85063a", PCF85063A },
@@ -660,6 +661,7 @@ MODULE_DEVICE_TABLE(i2c, pcf85063_ids);
 
 #ifdef CONFIG_OF
 static const struct of_device_id pcf85063_of_match[] = {
+	{ .compatible = "nxp,pca85073a", .data = &pcf85063_cfg[PCF85063A] },
 	{ .compatible = "nxp,pcf85063", .data = &pcf85063_cfg[PCF85063] },
 	{ .compatible = "nxp,pcf85063tp", .data = &pcf85063_cfg[PCF85063TP] },
 	{ .compatible = "nxp,pcf85063a", .data = &pcf85063_cfg[PCF85063A] },
diff --git a/drivers/rtc/rtc-rx8025.c b/drivers/rtc/rtc-rx8025.c
index 5bfdd34a72ff..b32117ccd74b 100644
--- a/drivers/rtc/rtc-rx8025.c
+++ b/drivers/rtc/rtc-rx8025.c
@@ -436,7 +436,6 @@ static int rx8025_set_offset(struct device *dev, long offset)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	u8 digoff;
-	int err;
 
 	offset /= RX8025_ADJ_RESOLUTION;
 	if (offset > RX8025_ADJ_DATA_MAX)
@@ -449,11 +448,7 @@ static int rx8025_set_offset(struct device *dev, long offset)
 		offset += 128;
 	digoff = offset;
 
-	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
-	if (err)
-		return err;
-
-	return 0;
+	return rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
 }
 
 static const struct rtc_class_ops rx8025_rtc_ops = {
diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c
new file mode 100644
index 000000000000..ac788799c8e3
--- /dev/null
+++ b/drivers/rtc/rtc-rzn1.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Renesas RZ/N1 Real Time Clock interface for Linux
+ *
+ * Copyright:
+ * - 2014 Renesas Electronics Europe Limited
+ * - 2022 Schneider Electric
+ *
+ * Authors:
+ * - Michel Pollet <michel.pollet@bp.renesas.com>, <buserror@gmail.com>
+ * - Miquel Raynal <miquel.raynal@bootlin.com>
+ */
+
+#include <linux/bcd.h>
+#include <linux/init.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/rtc.h>
+
+#define RZN1_RTC_CTL0 0x00
+#define   RZN1_RTC_CTL0_SLSB_SUBU 0
+#define   RZN1_RTC_CTL0_SLSB_SCMP BIT(4)
+#define   RZN1_RTC_CTL0_AMPM BIT(5)
+#define   RZN1_RTC_CTL0_CE BIT(7)
+
+#define RZN1_RTC_CTL1 0x04
+#define   RZN1_RTC_CTL1_ALME BIT(4)
+
+#define RZN1_RTC_CTL2 0x08
+#define   RZN1_RTC_CTL2_WAIT BIT(0)
+#define   RZN1_RTC_CTL2_WST BIT(1)
+#define   RZN1_RTC_CTL2_WUST BIT(5)
+#define   RZN1_RTC_CTL2_STOPPED (RZN1_RTC_CTL2_WAIT | RZN1_RTC_CTL2_WST)
+
+#define RZN1_RTC_SEC 0x14
+#define RZN1_RTC_MIN 0x18
+#define RZN1_RTC_HOUR 0x1c
+#define RZN1_RTC_WEEK 0x20
+#define RZN1_RTC_DAY 0x24
+#define RZN1_RTC_MONTH 0x28
+#define RZN1_RTC_YEAR 0x2c
+
+#define RZN1_RTC_SUBU 0x38
+#define   RZN1_RTC_SUBU_DEV BIT(7)
+#define   RZN1_RTC_SUBU_DECR BIT(6)
+
+#define RZN1_RTC_ALM 0x40
+#define RZN1_RTC_ALH 0x44
+#define RZN1_RTC_ALW 0x48
+
+#define RZN1_RTC_SECC 0x4c
+#define RZN1_RTC_MINC 0x50
+#define RZN1_RTC_HOURC 0x54
+#define RZN1_RTC_WEEKC 0x58
+#define RZN1_RTC_DAYC 0x5c
+#define RZN1_RTC_MONTHC 0x60
+#define RZN1_RTC_YEARC 0x64
+
+struct rzn1_rtc {
+	struct rtc_device *rtcdev;
+	void __iomem *base;
+};
+
+static void rzn1_rtc_get_time_snapshot(struct rzn1_rtc *rtc, struct rtc_time *tm)
+{
+	tm->tm_sec = readl(rtc->base + RZN1_RTC_SECC);
+	tm->tm_min = readl(rtc->base + RZN1_RTC_MINC);
+	tm->tm_hour = readl(rtc->base + RZN1_RTC_HOURC);
+	tm->tm_wday = readl(rtc->base + RZN1_RTC_WEEKC);
+	tm->tm_mday = readl(rtc->base + RZN1_RTC_DAYC);
+	tm->tm_mon = readl(rtc->base + RZN1_RTC_MONTHC);
+	tm->tm_year = readl(rtc->base + RZN1_RTC_YEARC);
+}
+
+static unsigned int rzn1_rtc_tm_to_wday(struct rtc_time *tm)
+{
+	time64_t time;
+	unsigned int days;
+	u32 secs;
+
+	time = rtc_tm_to_time64(tm);
+	days = div_s64_rem(time, 86400, &secs);
+
+	/* day of the week, 1970-01-01 was a Thursday */
+	return (days + 4) % 7;
+}
+
+static int rzn1_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	u32 val, secs;
+
+	/*
+	 * The RTC was not started or is stopped and thus does not carry the
+	 * proper time/date.
+	 */
+	val = readl(rtc->base + RZN1_RTC_CTL2);
+	if (val & RZN1_RTC_CTL2_STOPPED)
+		return -EINVAL;
+
+	rzn1_rtc_get_time_snapshot(rtc, tm);
+	secs = readl(rtc->base + RZN1_RTC_SECC);
+	if (tm->tm_sec != secs)
+		rzn1_rtc_get_time_snapshot(rtc, tm);
+
+	tm->tm_sec = bcd2bin(tm->tm_sec);
+	tm->tm_min = bcd2bin(tm->tm_min);
+	tm->tm_hour = bcd2bin(tm->tm_hour);
+	tm->tm_wday = bcd2bin(tm->tm_wday);
+	tm->tm_mday = bcd2bin(tm->tm_mday);
+	tm->tm_mon = bcd2bin(tm->tm_mon);
+	tm->tm_year = bcd2bin(tm->tm_year);
+
+	return 0;
+}
+
+static int rzn1_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	u32 val;
+	int ret;
+
+	tm->tm_sec = bin2bcd(tm->tm_sec);
+	tm->tm_min = bin2bcd(tm->tm_min);
+	tm->tm_hour = bin2bcd(tm->tm_hour);
+	tm->tm_wday = bin2bcd(rzn1_rtc_tm_to_wday(tm));
+	tm->tm_mday = bin2bcd(tm->tm_mday);
+	tm->tm_mon = bin2bcd(tm->tm_mon);
+	tm->tm_year = bin2bcd(tm->tm_year);
+
+	val = readl(rtc->base + RZN1_RTC_CTL2);
+	if (!(val & RZN1_RTC_CTL2_STOPPED)) {
+		/* Hold the counter if it was counting up */
+		writel(RZN1_RTC_CTL2_WAIT, rtc->base + RZN1_RTC_CTL2);
+
+		/* Wait for the counter to stop: two 32k clock cycles */
+		usleep_range(61, 100);
+		ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, val,
+					 val & RZN1_RTC_CTL2_WST, 0, 100);
+		if (ret)
+			return ret;
+	}
+
+	writel(tm->tm_sec, rtc->base + RZN1_RTC_SEC);
+	writel(tm->tm_min, rtc->base + RZN1_RTC_MIN);
+	writel(tm->tm_hour, rtc->base + RZN1_RTC_HOUR);
+	writel(tm->tm_wday, rtc->base + RZN1_RTC_WEEK);
+	writel(tm->tm_mday, rtc->base + RZN1_RTC_DAY);
+	writel(tm->tm_mon, rtc->base + RZN1_RTC_MONTH);
+	writel(tm->tm_year, rtc->base + RZN1_RTC_YEAR);
+	writel(0, rtc->base + RZN1_RTC_CTL2);
+
+	return 0;
+}
+
+static irqreturn_t rzn1_rtc_alarm_irq(int irq, void *dev_id)
+{
+	struct rzn1_rtc *rtc = dev_id;
+
+	rtc_update_irq(rtc->rtcdev, 1, RTC_AF | RTC_IRQF);
+
+	return IRQ_HANDLED;
+}
+
+static int rzn1_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	u32 ctl1 = readl(rtc->base + RZN1_RTC_CTL1);
+
+	if (enable)
+		ctl1 |= RZN1_RTC_CTL1_ALME;
+	else
+		ctl1 &= ~RZN1_RTC_CTL1_ALME;
+
+	writel(ctl1, rtc->base + RZN1_RTC_CTL1);
+
+	return 0;
+}
+
+static int rzn1_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	struct rtc_time *tm = &alrm->time;
+	unsigned int min, hour, wday, delta_days;
+	time64_t alarm;
+	u32 ctl1;
+	int ret;
+
+	ret = rzn1_rtc_read_time(dev, tm);
+	if (ret)
+		return ret;
+
+	min = readl(rtc->base + RZN1_RTC_ALM);
+	hour = readl(rtc->base + RZN1_RTC_ALH);
+	wday = readl(rtc->base + RZN1_RTC_ALW);
+
+	tm->tm_sec = 0;
+	tm->tm_min = bcd2bin(min);
+	tm->tm_hour = bcd2bin(hour);
+	delta_days = ((fls(wday) - 1) - tm->tm_wday + 7) % 7;
+	tm->tm_wday = fls(wday) - 1;
+
+	if (delta_days) {
+		alarm = rtc_tm_to_time64(tm) + (delta_days * 86400);
+		rtc_time64_to_tm(alarm, tm);
+	}
+
+	ctl1 = readl(rtc->base + RZN1_RTC_CTL1);
+	alrm->enabled = !!(ctl1 & RZN1_RTC_CTL1_ALME);
+
+	return 0;
+}
+
+static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	struct rtc_time *tm = &alrm->time, tm_now;
+	unsigned long alarm, farest;
+	unsigned int days_ahead, wday;
+	int ret;
+
+	ret = rzn1_rtc_read_time(dev, &tm_now);
+	if (ret)
+		return ret;
+
+	/* We cannot set alarms more than one week ahead */
+	farest = rtc_tm_to_time64(&tm_now) + (7 * 86400);
+	alarm = rtc_tm_to_time64(tm);
+	if (time_after(alarm, farest))
+		return -ERANGE;
+
+	/* Convert alarm day into week day */
+	days_ahead = tm->tm_mday - tm_now.tm_mday;
+	wday = (tm_now.tm_wday + days_ahead) % 7;
+
+	writel(bin2bcd(tm->tm_min), rtc->base + RZN1_RTC_ALM);
+	writel(bin2bcd(tm->tm_hour), rtc->base + RZN1_RTC_ALH);
+	writel(BIT(wday), rtc->base + RZN1_RTC_ALW);
+
+	rzn1_rtc_alarm_irq_enable(dev, alrm->enabled);
+
+	return 0;
+}
+
+static int rzn1_rtc_read_offset(struct device *dev, long *offset)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	unsigned int ppb_per_step;
+	bool subtract;
+	u32 val;
+
+	val = readl(rtc->base + RZN1_RTC_SUBU);
+	ppb_per_step = val & RZN1_RTC_SUBU_DEV ? 1017 : 3051;
+	subtract = val & RZN1_RTC_SUBU_DECR;
+	val &= 0x3F;
+
+	if (!val)
+		*offset = 0;
+	else if (subtract)
+		*offset = -(((~val) & 0x3F) + 1) * ppb_per_step;
+	else
+		*offset = (val - 1) * ppb_per_step;
+
+	return 0;
+}
+
+static int rzn1_rtc_set_offset(struct device *dev, long offset)
+{
+	struct rzn1_rtc *rtc = dev_get_drvdata(dev);
+	int stepsh, stepsl, steps;
+	u32 subu = 0, ctl2;
+	int ret;
+
+	/*
+	 * Check which resolution mode (every 20 or 60s) can be used.
+	 * Between 2 and 124 clock pulses can be added or substracted.
+	 *
+	 * In 20s mode, the minimum resolution is 2 / (32768 * 20) which is
+	 * close to 3051 ppb. In 60s mode, the resolution is closer to 1017.
+	 */
+	stepsh = DIV_ROUND_CLOSEST(offset, 1017);
+	stepsl = DIV_ROUND_CLOSEST(offset, 3051);
+
+	if (stepsh >= -0x3E && stepsh <= 0x3E) {
+		/* 1017 ppb per step */
+		steps = stepsh;
+		subu |= RZN1_RTC_SUBU_DEV;
+	} else if (stepsl >= -0x3E && stepsl <= 0x3E) {
+		/* 3051 ppb per step */
+		steps = stepsl;
+	} else {
+		return -ERANGE;
+	}
+
+	if (!steps)
+		return 0;
+
+	if (steps > 0) {
+		subu |= steps + 1;
+	} else {
+		subu |= RZN1_RTC_SUBU_DECR;
+		subu |= (~(-steps - 1)) & 0x3F;
+	}
+
+	ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, ctl2,
+				 !(ctl2 & RZN1_RTC_CTL2_WUST), 100, 2000000);
+	if (ret)
+		return ret;
+
+	writel(subu, rtc->base + RZN1_RTC_SUBU);
+
+	return 0;
+}
+
+static const struct rtc_class_ops rzn1_rtc_ops = {
+	.read_time = rzn1_rtc_read_time,
+	.set_time = rzn1_rtc_set_time,
+	.read_alarm = rzn1_rtc_read_alarm,
+	.set_alarm = rzn1_rtc_set_alarm,
+	.alarm_irq_enable = rzn1_rtc_alarm_irq_enable,
+	.read_offset = rzn1_rtc_read_offset,
+	.set_offset = rzn1_rtc_set_offset,
+};
+
+static int rzn1_rtc_probe(struct platform_device *pdev)
+{
+	struct rzn1_rtc *rtc;
+	int alarm_irq;
+	int ret;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, rtc);
+
+	rtc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(rtc->base))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->base), "Missing reg\n");
+
+	alarm_irq = platform_get_irq(pdev, 0);
+	if (alarm_irq < 0)
+		return alarm_irq;
+
+	rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc->rtcdev))
+		return PTR_ERR(rtc->rtcdev);
+
+	rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099;
+	rtc->rtcdev->ops = &rzn1_rtc_ops;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtcdev->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtcdev->features);
+
+	devm_pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Ensure the clock counter is enabled.
+	 * Set 24-hour mode and possible oscillator offset compensation in SUBU mode.
+	 */
+	writel(RZN1_RTC_CTL0_CE | RZN1_RTC_CTL0_AMPM | RZN1_RTC_CTL0_SLSB_SUBU,
+	       rtc->base + RZN1_RTC_CTL0);
+
+	/* Disable all interrupts */
+	writel(0, rtc->base + RZN1_RTC_CTL1);
+
+	ret = devm_request_irq(&pdev->dev, alarm_irq, rzn1_rtc_alarm_irq, 0,
+			       dev_name(&pdev->dev), rtc);
+	if (ret) {
+		dev_err(&pdev->dev, "RTC timer interrupt not available\n");
+		goto dis_runtime_pm;
+	}
+
+	ret = devm_rtc_register_device(rtc->rtcdev);
+	if (ret)
+		goto dis_runtime_pm;
+
+	return 0;
+
+dis_runtime_pm:
+	pm_runtime_put(&pdev->dev);
+
+	return ret;
+}
+
+static int rzn1_rtc_remove(struct platform_device *pdev)
+{
+	pm_runtime_put(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id rzn1_rtc_of_match[] = {
+	{ .compatible	= "renesas,rzn1-rtc" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rzn1_rtc_of_match);
+
+static struct platform_driver rzn1_rtc_driver = {
+	.probe = rzn1_rtc_probe,
+	.remove = rzn1_rtc_remove,
+	.driver = {
+		.name	= "rzn1-rtc",
+		.of_match_table = rzn1_rtc_of_match,
+	},
+};
+module_platform_driver(rzn1_rtc_driver);
+
+MODULE_AUTHOR("Michel Pollet <Michel.Pollet@bp.renesas.com");
+MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
+MODULE_DESCRIPTION("RZ/N1 RTC driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index 5252ce4cbda4..57540727ce1c 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -71,6 +71,10 @@
 #define SUN6I_LOSC_OUT_GATING			0x0060
 #define SUN6I_LOSC_OUT_GATING_EN_OFFSET		0
 
+/* General-purpose data */
+#define SUN6I_GP_DATA				0x0100
+#define SUN6I_GP_DATA_SIZE			0x20
+
 /*
  * Get date values
  */
@@ -679,6 +683,39 @@ static const struct rtc_class_ops sun6i_rtc_ops = {
 	.alarm_irq_enable	= sun6i_rtc_alarm_irq_enable
 };
 
+static int sun6i_rtc_nvmem_read(void *priv, unsigned int offset, void *_val, size_t bytes)
+{
+	struct sun6i_rtc_dev *chip = priv;
+	u32 *val = _val;
+	int i;
+
+	for (i = 0; i < bytes / 4; ++i)
+		val[i] = readl(chip->base + SUN6I_GP_DATA + offset + 4 * i);
+
+	return 0;
+}
+
+static int sun6i_rtc_nvmem_write(void *priv, unsigned int offset, void *_val, size_t bytes)
+{
+	struct sun6i_rtc_dev *chip = priv;
+	u32 *val = _val;
+	int i;
+
+	for (i = 0; i < bytes / 4; ++i)
+		writel(val[i], chip->base + SUN6I_GP_DATA + offset + 4 * i);
+
+	return 0;
+}
+
+static struct nvmem_config sun6i_rtc_nvmem_cfg = {
+	.type		= NVMEM_TYPE_BATTERY_BACKED,
+	.reg_read	= sun6i_rtc_nvmem_read,
+	.reg_write	= sun6i_rtc_nvmem_write,
+	.size		= SUN6I_GP_DATA_SIZE,
+	.word_size	= 4,
+	.stride		= 4,
+};
+
 #ifdef CONFIG_PM_SLEEP
 /* Enable IRQ wake on suspend, to wake up from RTC. */
 static int sun6i_rtc_suspend(struct device *dev)
@@ -812,6 +849,11 @@ static int sun6i_rtc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	sun6i_rtc_nvmem_cfg.priv = chip;
+	ret = devm_rtc_nvmem_register(chip->rtc, &sun6i_rtc_nvmem_cfg);
+	if (ret)
+		return ret;
+
 	dev_info(&pdev->dev, "RTC enabled\n");
 
 	return 0;