Merge tag 'rtc-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
"This includes new ioctls to get and set parameters and in particular
the backup switch mode that is needed for some RTCs to actually enable
the backup voltage (and have a useful RTC).

The same interface can also be used to get the actual features
supported by the RTC so userspace has a better way than trying and
failing.

Summary:

Subsystem:
- Add new ioctl to get and set extra RTC parameters, this includes
backup switch mode
- Expose available features to userspace, in particular, when alarmas
have a resolution of one minute instead of a second.
- Let the core handle those alarms with a minute resolution

New driver:
- MSTAR MSC313 RTC

Drivers:
- Add SPI ID table where necessary
- Add BSM support for rv3028, rv3032 and pcf8523
- s3c: set RTC range
- rx8025: set range, implement .set_offset and .read_offset"

* tag 'rtc-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (50 commits)
rtc: rx8025: use .set_offset/.read_offset
rtc: rx8025: use rtc_add_group
rtc: rx8025: clear RTC_FEATURE_ALARM when alarm are not supported
rtc: rx8025: set range
rtc: rx8025: let the core handle the alarm resolution
rtc: rx8025: switch to devm_rtc_allocate_device
rtc: ab8500: let the core handle the alarm resolution
rtc: ab-eoz9: support UIE when available
rtc: ab-eoz9: use RTC_FEATURE_UPDATE_INTERRUPT
rtc: rv3032: let the core handle the alarm resolution
rtc: s35390a: let the core handle the alarm resolution
rtc: handle alarms with a minute resolution
rtc: pcf85063: silence cppcheck warning
rtc: rv8803: fix writing back ctrl in flag register
rtc: s3c: Add time range
rtc: s3c: Extract read/write IO into separate functions
rtc: s3c: Remove usage of devm_rtc_device_register()
rtc: tps80031: Remove driver
rtc: sun6i: Allow probing without an early clock provider
rtc: pcf8523: add BSM support
...

Documentation/devicetree/bindings/rtc/mstar,msc313-rtc.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/mstar,msc313-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mstar MSC313e RTC Device Tree Bindings
+
+allOf:
+  - $ref: "rtc.yaml#"
+
+maintainers:
+  - Daniel Palmer <[e-mail]>
+  - Romain Perier <[e-mail]>
+
+properties:
+  compatible:
+    enum:
+      - mstar,msc313-rtc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  start-year: true
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    rtc@2400 {
+        compatible = "mstar,msc313-rtc";
+        reg = <0x2400 0x40>;
+        clocks = <&xtal_div2>;
+        interrupts-extended = <&intc_irq GIC_SPI 44 IRQ_TYPE_LEVEL_HIGH>;
+    };
+...

Documentation/devicetree/bindings/rtc/nxp,pcf85063.txt

···
   expressed in femto Farad (fF). Valid values are 7000 and 12500.
   Default value (if no value is specified) is 7000fF.
 
+Optional child node:
+- clock: Provide this if the square wave pin is used as boot-enabled fixed clock.
+
 Example:
 
 pcf85063: rtc@51 {
 	compatible = "nxp,pcf85063";
 	reg = <0x51>;
 	quartz-load-femtofarads = <12500>;
+
+		clock {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <32768>;
+		};
 };

MAINTAINERS

···
 F:	arch/arm/mach-mstar/
 F:	drivers/clk/mstar/
 F:	drivers/gpio/gpio-msc313.c
+F:	drivers/rtc/rtc-msc313.c
 F:	drivers/watchdog/msc313e_wdt.c
 F:	include/dt-bindings/clock/mstar-*
 F:	include/dt-bindings/gpio/msc313-gpio.h

drivers/rtc/Kconfig

···
 
 config RTC_DRV_PCF8523
 	tristate "NXP PCF8523"
+	select REGMAP_I2C
 	help
 	  If you say yes here you get support for the NXP PCF8523 RTC
 	  chips.
···
 
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-tps65910.
-
-config RTC_DRV_TPS80031
-	tristate "TI TPS80031/TPS80032 RTC driver"
-	depends on MFD_TPS80031
-	help
-	  TI Power Management IC TPS80031 supports RTC functionality
-	  along with alarm. This driver supports the RTC driver for
-	  the TPS80031 RTC module.
 
 config RTC_DRV_RC5T583
 	tristate "RICOH 5T583 RTC driver"
···
 
 	  This can also be built as a module. If so, the module will
 	  be named "rtc_wilco_ec".
+
+config RTC_DRV_MSC313
+	tristate "MStar MSC313 RTC"
+        depends on ARCH_MSTARV7 || COMPILE_TEST
+	help
+	  If you say yes here you get support for the Mstar MSC313e On-Chip
+	  Real Time Clock.
+
+	  This driver can also be built as a module, if so, the module
+	  will be called "rtc-msc313".
 
 endif # RTC_CLASS

drivers/rtc/Makefile

···
 obj-$(CONFIG_RTC_DRV_MESON)	+= rtc-meson.o
 obj-$(CONFIG_RTC_DRV_MOXART)	+= rtc-moxart.o
 obj-$(CONFIG_RTC_DRV_MPC5121)	+= rtc-mpc5121.o
+obj-$(CONFIG_RTC_DRV_MSC313)	+= rtc-msc313.o
 obj-$(CONFIG_RTC_DRV_MSM6242)	+= rtc-msm6242.o
 obj-$(CONFIG_RTC_DRV_MT2712)	+= rtc-mt2712.o
 obj-$(CONFIG_RTC_DRV_MT6397)	+= rtc-mt6397.o
···
 obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o
 obj-$(CONFIG_RTC_DRV_TPS6586X)	+= rtc-tps6586x.o
 obj-$(CONFIG_RTC_DRV_TPS65910)	+= rtc-tps65910.o
-obj-$(CONFIG_RTC_DRV_TPS80031)	+= rtc-tps80031.o
 obj-$(CONFIG_RTC_DRV_TWL4030)	+= rtc-twl.o
 obj-$(CONFIG_RTC_DRV_V3020)	+= rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_VR41XX)	+= rtc-vr41xx.o

drivers/rtc/class.c

···
 	rtc->pie_enabled = 0;
 
 	set_bit(RTC_FEATURE_ALARM, rtc->features);
+	set_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
 
 	return rtc;
 }
···
 	 * letting any rtc_class_open() users access it again
 	 */
 	rtc_proc_del_device(rtc);
-	cdev_device_del(&rtc->char_dev, &rtc->dev);
+	if (!test_bit(RTC_NO_CDEV, &rtc->flags))
+		cdev_device_del(&rtc->char_dev, &rtc->dev);
 	rtc->ops = NULL;
 	mutex_unlock(&rtc->ops_lock);
 }
···
 
 	rtc->id = id;
 	rtc->dev.parent = dev;
-	dev_set_name(&rtc->dev, "rtc%d", id);
+	err = dev_set_name(&rtc->dev, "rtc%d", id);
+	if (err)
+		return ERR_PTR(err);
 
 	err = devm_add_action_or_reset(dev, devm_rtc_release_device, rtc);
 	if (err)
···
 	if (!rtc->ops->set_alarm)
 		clear_bit(RTC_FEATURE_ALARM, rtc->features);
 
+	if (rtc->uie_unsupported)
+		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
+
+	if (rtc->ops->set_offset)
+		set_bit(RTC_FEATURE_CORRECTION, rtc->features);
+
 	rtc->owner = owner;
 	rtc_device_get_offset(rtc);
 
···
 	rtc_dev_prepare(rtc);
 
 	err = cdev_device_add(&rtc->char_dev, &rtc->dev);
-	if (err)
+	if (err) {
+		set_bit(RTC_NO_CDEV, &rtc->flags);
 		dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n",
 			 MAJOR(rtc->dev.devt), rtc->id);
-	else
+	} else {
 		dev_dbg(rtc->dev.parent, "char device (%d:%d)\n",
 			MAJOR(rtc->dev.devt), rtc->id);
+	}
 
 	rtc_proc_add_device(rtc);
 

drivers/rtc/dev.c

···
 	const struct rtc_class_ops *ops = rtc->ops;
 	struct rtc_time tm;
 	struct rtc_wkalrm alarm;
+	struct rtc_param param;
 	void __user *uarg = (void __user *)arg;
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
···
 	switch (cmd) {
 	case RTC_EPOCH_SET:
 	case RTC_SET_TIME:
+	case RTC_PARAM_SET:
 		if (!capable(CAP_SYS_TIME))
 			err = -EACCES;
 		break;
···
 		if (copy_to_user(uarg, &alarm, sizeof(alarm)))
 			err = -EFAULT;
 		return err;
+
+	case RTC_PARAM_GET:
+		if (copy_from_user(&param, uarg, sizeof(param))) {
+			mutex_unlock(&rtc->ops_lock);
+			return -EFAULT;
+		}
+
+		switch(param.param) {
+			long offset;
+		case RTC_PARAM_FEATURES:
+			if (param.index != 0)
+				err = -EINVAL;
+			param.uvalue = rtc->features[0];
+			break;
+
+		case RTC_PARAM_CORRECTION:
+			mutex_unlock(&rtc->ops_lock);
+			if (param.index != 0)
+				return -EINVAL;
+			err = rtc_read_offset(rtc, &offset);
+			mutex_lock(&rtc->ops_lock);
+			if (err == 0)
+				param.svalue = offset;
+			break;
+
+		default:
+			if (rtc->ops->param_get)
+				err = rtc->ops->param_get(rtc->dev.parent, &param);
+			else
+				err = -EINVAL;
+		}
+
+		if (!err)
+			if (copy_to_user(uarg, &param, sizeof(param)))
+				err = -EFAULT;
+
+		break;
+
+	case RTC_PARAM_SET:
+		if (copy_from_user(&param, uarg, sizeof(param))) {
+			mutex_unlock(&rtc->ops_lock);
+			return -EFAULT;
+		}
+
+		switch(param.param) {
+		case RTC_PARAM_FEATURES:
+			err = -EINVAL;
+			break;
+
+		case RTC_PARAM_CORRECTION:
+			mutex_unlock(&rtc->ops_lock);
+			if (param.index != 0)
+				return -EINVAL;
+			return rtc_set_offset(rtc, param.svalue);
+
+		default:
+			if (rtc->ops->param_set)
+				err = rtc->ops->param_set(rtc->dev.parent, &param);
+			else
+				err = -EINVAL;
+		}
+
+		break;
 
 	default:
 		/* Finally try the driver's ioctl interface */

drivers/rtc/interface.c

···
 	if (err)
 		return err;
 	now = rtc_tm_to_time64(&tm);
+
 	if (scheduled <= now)
 		return -ETIME;
 	/*
···
 
 int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 {
+	ktime_t alarm_time;
 	int err;
 
 	if (!rtc->ops)
···
 	if (rtc->aie_timer.enabled)
 		rtc_timer_remove(rtc, &rtc->aie_timer);
 
-	rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
+	alarm_time = rtc_tm_to_ktime(alarm->time);
+	/*
+	 * Round down so we never miss a deadline, checking for past deadline is
+	 * done in __rtc_set_alarm
+	 */
+	if (test_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features))
+		alarm_time = ktime_sub_ns(alarm_time, (u64)alarm->time.tm_sec * NSEC_PER_SEC);
+
+	rtc->aie_timer.node.expires = alarm_time;
 	rtc->aie_timer.period = 0;
 	if (alarm->enabled)
 		err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
···
 	if (rtc->uie_rtctimer.enabled == enabled)
 		goto out;
 
-	if (rtc->uie_unsupported || !test_bit(RTC_FEATURE_ALARM, rtc->features)) {
+	if (!test_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features) ||
+	    !test_bit(RTC_FEATURE_ALARM, rtc->features)) {
 		mutex_unlock(&rtc->ops_lock);
 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
 		return rtc_dev_update_irq_enable_emul(rtc, enabled);

drivers/rtc/rtc-ab-eoz9.c

···
 	data->rtc->ops = &rtc_ops;
 	data->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	data->rtc->range_max = RTC_TIMESTAMP_END_2099;
-	data->rtc->uie_unsupported = 1;
 	clear_bit(RTC_FEATURE_ALARM, data->rtc->features);
 
 	if (client->irq > 0) {
···
 			dev_err(dev, "failed to request alarm irq\n");
 			return ret;
 		}
+	} else {
+		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, data->rtc->features);
 	}
 
 	if (client->irq > 0 || device_property_read_bool(dev, "wakeup-source")) {

drivers/rtc/rtc-ab8500.c

···
 {
 	int retval, i;
 	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
-	unsigned long mins, secs = 0, cursec = 0;
-	struct rtc_time curtm;
+	unsigned long mins;
 
-	/* Get the number of seconds since 1970 */
-	secs = rtc_tm_to_time64(&alarm->time);
-
-	/*
-	 * Check whether alarm is set less than 1min.
-	 * Since our RTC doesn't support alarm resolution less than 1min,
-	 * return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
-	 */
-	ab8500_rtc_read_time(dev, &curtm); /* Read current time */
-	cursec = rtc_tm_to_time64(&curtm);
-	if ((secs - cursec) < 59) {
-		dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
-		return -EINVAL;
-	}
-
-	mins = secs / 60;
+	mins = (unsigned long)rtc_tm_to_time64(&alarm->time) / 60;
 
 	buf[2] = mins & 0xFF;
 	buf[1] = (mins >> 8) & 0xFF;
···
 	dev_pm_set_wake_irq(&pdev->dev, irq);
 	platform_set_drvdata(pdev, rtc);
 
-	rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
 
 	rtc->range_max = (1ULL << 24) * 60 - 1; // 24-bit minutes + 59 secs
 	rtc->start_secs = RTC_TIMESTAMP_BEGIN_2000;

drivers/rtc/rtc-ds1302.c

···
 MODULE_DEVICE_TABLE(of, ds1302_dt_ids);
 #endif
 
+static const struct spi_device_id ds1302_spi_ids[] = {
+	{ .name = "ds1302", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, ds1302_spi_ids);
+
 static struct spi_driver ds1302_driver = {
 	.driver.name	= "rtc-ds1302",
 	.driver.of_match_table = of_match_ptr(ds1302_dt_ids),
 	.probe		= ds1302_probe,
 	.remove		= ds1302_remove,
+	.id_table	= ds1302_spi_ids,
 };
 
 module_spi_driver(ds1302_driver);

drivers/rtc/rtc-ds1390.c

···
 };
 MODULE_DEVICE_TABLE(of, ds1390_of_match);
 
+static const struct spi_device_id ds1390_spi_ids[] = {
+	{ .name = "ds1390" },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ds1390_spi_ids);
+
 static struct spi_driver ds1390_driver = {
 	.driver = {
 		.name	= "rtc-ds1390",
 		.of_match_table = of_match_ptr(ds1390_of_match),
 	},
 	.probe	= ds1390_probe,
+	.id_table = ds1390_spi_ids,
 };
 
 module_spi_driver(ds1390_driver);

drivers/rtc/rtc-m41t80.c

···
 		 * registered automatically when being referenced.
 		 */
 		of_node_put(fixed_clock);
-		return 0;
+		return NULL;
 	}
 
 	/* First disable the clock */

drivers/rtc/rtc-mcp795.c

···
 MODULE_DEVICE_TABLE(of, mcp795_of_match);
 #endif
 
+static const struct spi_device_id mcp795_spi_ids[] = {
+	{ .name = "mcp795" },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, mcp795_spi_ids);
+
 static struct spi_driver mcp795_driver = {
 		.driver = {
 				.name = "rtc-mcp795",
 				.of_match_table = of_match_ptr(mcp795_of_match),
 		},
 		.probe = mcp795_probe,
+		.id_table = mcp795_spi_ids,
 };
 
 module_spi_driver(mcp795_driver);

drivers/rtc/rtc-msc313.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Real time clocks driver for MStar/SigmaStar ARMv7 SoCs.
+ * Based on "Real Time Clock driver for msb252x." that was contained
+ * in various MStar kernels.
+ *
+ * (C) 2019 Daniel Palmer
+ * (C) 2021 Romain Perier
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+/* Registers */
+#define REG_RTC_CTRL		0x00
+#define REG_RTC_FREQ_CW_L	0x04
+#define REG_RTC_FREQ_CW_H	0x08
+#define REG_RTC_LOAD_VAL_L	0x0C
+#define REG_RTC_LOAD_VAL_H	0x10
+#define REG_RTC_MATCH_VAL_L	0x14
+#define REG_RTC_MATCH_VAL_H	0x18
+#define REG_RTC_STATUS_INT	0x1C
+#define REG_RTC_CNT_VAL_L	0x20
+#define REG_RTC_CNT_VAL_H	0x24
+
+/* Control bits for REG_RTC_CTRL */
+#define SOFT_RSTZ_BIT		BIT(0)
+#define CNT_EN_BIT		BIT(1)
+#define WRAP_EN_BIT		BIT(2)
+#define LOAD_EN_BIT		BIT(3)
+#define READ_EN_BIT		BIT(4)
+#define INT_MASK_BIT		BIT(5)
+#define INT_FORCE_BIT		BIT(6)
+#define INT_CLEAR_BIT		BIT(7)
+
+/* Control bits for REG_RTC_STATUS_INT */
+#define RAW_INT_BIT		BIT(0)
+#define ALM_INT_BIT		BIT(1)
+
+struct msc313_rtc {
+	struct rtc_device *rtc_dev;
+	void __iomem *rtc_base;
+};
+
+static int msc313_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct msc313_rtc *priv = dev_get_drvdata(dev);
+	unsigned long seconds;
+
+	seconds = readw(priv->rtc_base + REG_RTC_MATCH_VAL_L)
+			| ((unsigned long)readw(priv->rtc_base + REG_RTC_MATCH_VAL_H) << 16);
+
+	rtc_time64_to_tm(seconds, &alarm->time);
+
+	if (!(readw(priv->rtc_base + REG_RTC_CTRL) & INT_MASK_BIT))
+		alarm->enabled = 1;
+
+	return 0;
+}
+
+static int msc313_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct msc313_rtc *priv = dev_get_drvdata(dev);
+	u16 reg;
+
+	reg = readw(priv->rtc_base + REG_RTC_CTRL);
+	if (enabled)
+		reg &= ~INT_MASK_BIT;
+	else
+		reg |= INT_MASK_BIT;
+	writew(reg, priv->rtc_base + REG_RTC_CTRL);
+	return 0;
+}
+
+static int msc313_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct msc313_rtc *priv = dev_get_drvdata(dev);
+	unsigned long seconds;
+
+	seconds = rtc_tm_to_time64(&alarm->time);
+	writew((seconds & 0xFFFF), priv->rtc_base + REG_RTC_MATCH_VAL_L);
+	writew((seconds >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_MATCH_VAL_H);
+
+	msc313_rtc_alarm_irq_enable(dev, alarm->enabled);
+
+	return 0;
+}
+
+static bool msc313_rtc_get_enabled(struct msc313_rtc *priv)
+{
+	return readw(priv->rtc_base + REG_RTC_CTRL) & CNT_EN_BIT;
+}
+
+static void msc313_rtc_set_enabled(struct msc313_rtc *priv)
+{
+	u16 reg;
+
+	reg = readw(priv->rtc_base + REG_RTC_CTRL);
+	reg |= CNT_EN_BIT;
+	writew(reg, priv->rtc_base + REG_RTC_CTRL);
+}
+
+static int msc313_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct msc313_rtc *priv = dev_get_drvdata(dev);
+	u32 seconds;
+	u16 reg;
+
+	if (!msc313_rtc_get_enabled(priv))
+		return -EINVAL;
+
+	reg = readw(priv->rtc_base + REG_RTC_CTRL);
+	writew(reg | READ_EN_BIT, priv->rtc_base + REG_RTC_CTRL);
+
+	/* Wait for HW latch done */
+	while (readw(priv->rtc_base + REG_RTC_CTRL) & READ_EN_BIT)
+		udelay(1);
+
+	seconds = readw(priv->rtc_base + REG_RTC_CNT_VAL_L)
+			| ((unsigned long)readw(priv->rtc_base + REG_RTC_CNT_VAL_H) << 16);
+
+	rtc_time64_to_tm(seconds, tm);
+
+	return 0;
+}
+
+static int msc313_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct msc313_rtc *priv = dev_get_drvdata(dev);
+	unsigned long seconds;
+	u16 reg;
+
+	seconds = rtc_tm_to_time64(tm);
+	writew(seconds & 0xFFFF, priv->rtc_base + REG_RTC_LOAD_VAL_L);
+	writew((seconds >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_LOAD_VAL_H);
+
+	/* Enable load for loading value into internal RTC counter */
+	reg = readw(priv->rtc_base + REG_RTC_CTRL);
+	writew(reg | LOAD_EN_BIT, priv->rtc_base + REG_RTC_CTRL);
+
+	/* Wait for HW latch done */
+	while (readw(priv->rtc_base + REG_RTC_CTRL) & LOAD_EN_BIT)
+		udelay(1);
+	msc313_rtc_set_enabled(priv);
+	return 0;
+}
+
+static const struct rtc_class_ops msc313_rtc_ops = {
+	.read_time = msc313_rtc_read_time,
+	.set_time = msc313_rtc_set_time,
+	.read_alarm = msc313_rtc_read_alarm,
+	.set_alarm = msc313_rtc_set_alarm,
+	.alarm_irq_enable = msc313_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t msc313_rtc_interrupt(s32 irq, void *dev_id)
+{
+	struct msc313_rtc *priv = dev_get_drvdata(dev_id);
+	u16 reg;
+
+	reg = readw(priv->rtc_base + REG_RTC_STATUS_INT);
+	if (!(reg & ALM_INT_BIT))
+		return IRQ_NONE;
+
+	reg = readw(priv->rtc_base + REG_RTC_CTRL);
+	reg |= INT_CLEAR_BIT;
+	reg &= ~INT_FORCE_BIT;
+	writew(reg, priv->rtc_base + REG_RTC_CTRL);
+
+	rtc_update_irq(priv->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+	return IRQ_HANDLED;
+}
+
+static int msc313_rtc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct msc313_rtc *priv;
+	unsigned long rate;
+	struct clk *clk;
+	int ret;
+	int irq;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(struct msc313_rtc), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->rtc_base))
+		return PTR_ERR(priv->rtc_base);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -EINVAL;
+
+	priv->rtc_dev = devm_rtc_allocate_device(dev);
+	if (IS_ERR(priv->rtc_dev))
+		return PTR_ERR(priv->rtc_dev);
+
+	priv->rtc_dev->ops = &msc313_rtc_ops;
+	priv->rtc_dev->range_max = U32_MAX;
+
+	ret = devm_request_irq(dev, irq, msc313_rtc_interrupt, IRQF_SHARED,
+			       dev_name(&pdev->dev), &pdev->dev);
+	if (ret) {
+		dev_err(dev, "Could not request IRQ\n");
+		return ret;
+	}
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(dev, "No input reference clock\n");
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable the reference clock, %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(dev, (void (*) (void *))clk_disable_unprepare, clk);
+	if (ret)
+		return ret;
+
+	rate = clk_get_rate(clk);
+	writew(rate & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_L);
+	writew((rate >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_H);
+
+	platform_set_drvdata(pdev, priv);
+
+	return devm_rtc_register_device(priv->rtc_dev);
+}
+
+static const struct of_device_id msc313_rtc_of_match_table[] = {
+	{ .compatible = "mstar,msc313-rtc" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, msc313_rtc_of_match_table);
+
+static struct platform_driver msc313_rtc_driver = {
+	.probe = msc313_rtc_probe,
+	.driver = {
+		.name = "msc313-rtc",
+		.of_match_table = msc313_rtc_of_match_table,
+	},
+};
+
+module_platform_driver(msc313_rtc_driver);
+
+MODULE_AUTHOR("Daniel Palmer <[e-mail]>");
+MODULE_AUTHOR("Romain Perier <[e-mail]>");
+MODULE_DESCRIPTION("MStar RTC Driver");
+MODULE_LICENSE("GPL v2");

drivers/rtc/rtc-omap.c

···
 
 module_platform_driver(omap_rtc_driver);
 
-MODULE_ALIAS("platform:omap_rtc");
 MODULE_AUTHOR("George G. Davis (and others)");
 MODULE_LICENSE("GPL");

drivers/rtc/rtc-pcf2123.c

···
 MODULE_DEVICE_TABLE(of, pcf2123_dt_ids);
 #endif
 
+static const struct spi_device_id pcf2123_spi_ids[] = {
+	{ .name = "pcf2123", },
+	{ .name = "rv2123", },
+	{ .name = "rtc-pcf2123", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, pcf2123_spi_ids);
+
 static struct spi_driver pcf2123_driver = {
 	.driver	= {
 			.name	= "rtc-pcf2123",
 			.of_match_table = of_match_ptr(pcf2123_dt_ids),
 	},
 	.probe	= pcf2123_probe,
+	.id_table = pcf2123_spi_ids,
 };
 
 module_spi_driver(pcf2123_driver);

drivers/rtc/rtc-pcf85063.c

···
 #define PCF85063_REG_CTRL1		0x00 /* status */
 #define PCF85063_REG_CTRL1_CAP_SEL	BIT(0)
 #define PCF85063_REG_CTRL1_STOP		BIT(5)
+#define PCF85063_REG_CTRL1_EXT_TEST	BIT(7)
 
 #define PCF85063_REG_CTRL2		0x01
 #define PCF85063_CTRL2_AF		BIT(6)
···
 	 * reset state until all time/date registers are written
 	 */
 	rc = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
+				PCF85063_REG_CTRL1_EXT_TEST |
 				PCF85063_REG_CTRL1_STOP,
 				PCF85063_REG_CTRL1_STOP);
 	if (rc)
···
 		if (ret < 0)
 			return ret;
 
-		status = status & PCF85063_REG_SC_OS ? RTC_VL_DATA_INVALID : 0;
+		status = (status & PCF85063_REG_SC_OS) ? RTC_VL_DATA_INVALID : 0;
 
 		return put_user(status, (unsigned int __user *)arg);
 
···
 	struct clk *clk;
 	struct clk_init_data init;
 	struct device_node *node = pcf85063->rtc->dev.parent->of_node;
+	struct device_node *fixed_clock;
+
+	fixed_clock = of_get_child_by_name(node, "clock");
+	if (fixed_clock) {
+		/*
+		 * skip registering square wave clock when a fixed
+		 * clock has been registered. The fixed clock is
+		 * registered automatically when being referenced.
+		 */
+		of_node_put(fixed_clock);
+		return NULL;
+	}
 
 	init.name = "pcf85063-clkout";
 	init.ops = &pcf85063_clkout_ops;

drivers/rtc/rtc-pcf8523.c

···
  */
 
 #include <linux/bcd.h>
+#include <linux/bitfield.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
+#include <linux/regmap.h>
 #include <linux/rtc.h>
 #include <linux/of.h>
 #include <linux/pm_wakeirq.h>
···
 #define PCF8523_CONTROL2_AF BIT(3)
 
 #define PCF8523_REG_CONTROL3 0x02
-#define PCF8523_CONTROL3_PM_BLD BIT(7) /* battery low detection disabled */
-#define PCF8523_CONTROL3_PM_VDD BIT(6) /* switch-over disabled */
-#define PCF8523_CONTROL3_PM_DSM BIT(5) /* direct switching mode */
-#define PCF8523_CONTROL3_PM_MASK 0xe0
+#define PCF8523_CONTROL3_PM  GENMASK(7,5)
+#define PCF8523_PM_STANDBY   0x7
 #define PCF8523_CONTROL3_BLF BIT(2) /* battery low bit, read-only */
+#define PCF8523_CONTROL3_BSF BIT(3)
 
 #define PCF8523_REG_SECONDS  0x03
 #define PCF8523_SECONDS_OS BIT(7)
···
 
 struct pcf8523 {
 	struct rtc_device *rtc;
-	struct i2c_client *client;
+	struct regmap *regmap;
 };
 
-static int pcf8523_read(struct i2c_client *client, u8 reg, u8 *valuep)
+static int pcf8523_load_capacitance(struct pcf8523 *pcf8523, struct device_node *node)
 {
-	struct i2c_msg msgs[2];
-	u8 value = 0;
-	int err;
-
-	msgs[0].addr = client->addr;
-	msgs[0].flags = 0;
-	msgs[0].len = sizeof(reg);
-	msgs[0].buf = &reg;
-
-	msgs[1].addr = client->addr;
-	msgs[1].flags = I2C_M_RD;
-	msgs[1].len = sizeof(value);
-	msgs[1].buf = &value;
-
-	err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
-	if (err < 0)
-		return err;
-
-	*valuep = value;
-
-	return 0;
-}
-
-static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value)
-{
-	u8 buffer[2] = { reg, value };
-	struct i2c_msg msg;
-	int err;
-
-	msg.addr = client->addr;
-	msg.flags = 0;
-	msg.len = sizeof(buffer);
-	msg.buf = buffer;
-
-	err = i2c_transfer(client->adapter, &msg, 1);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
-static int pcf8523_voltage_low(struct i2c_client *client)
-{
-	u8 value;
-	int err;
-
-	err = pcf8523_read(client, PCF8523_REG_CONTROL3, &value);
-	if (err < 0)
-		return err;
-
-	return !!(value & PCF8523_CONTROL3_BLF);
-}
-
-static int pcf8523_load_capacitance(struct i2c_client *client)
-{
-	u32 load;
-	u8 value;
-	int err;
-
-	err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
-	if (err < 0)
-		return err;
+	u32 load, value = 0;
 
 	load = 12500;
-	of_property_read_u32(client->dev.of_node, "quartz-load-femtofarads",
-			     &load);
+	of_property_read_u32(node, "quartz-load-femtofarads", &load);
 
 	switch (load) {
 	default:
-		dev_warn(&client->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 12500",
+		dev_warn(&pcf8523->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 12500",
 			 load);
 		fallthrough;
 	case 12500:
 		value |= PCF8523_CONTROL1_CAP_SEL;
 		break;
 	case 7000:
-		value &= ~PCF8523_CONTROL1_CAP_SEL;
 		break;
 	}
 
-	err = pcf8523_write(client, PCF8523_REG_CONTROL1, value);
-
-	return err;
-}
-
-static int pcf8523_set_pm(struct i2c_client *client, u8 pm)
-{
-	u8 value;
-	int err;
-
-	err = pcf8523_read(client, PCF8523_REG_CONTROL3, &value);
-	if (err < 0)
-		return err;
-
-	value = (value & ~PCF8523_CONTROL3_PM_MASK) | pm;
-
-	err = pcf8523_write(client, PCF8523_REG_CONTROL3, value);
-	if (err < 0)
-		return err;
-
-	return 0;
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				  PCF8523_CONTROL1_CAP_SEL, value);
 }
 
 static irqreturn_t pcf8523_irq(int irq, void *dev_id)
 {
-	struct pcf8523 *pcf8523 = i2c_get_clientdata(dev_id);
-	u8 value;
+	struct pcf8523 *pcf8523 = dev_id;
+	u32 value;
 	int err;
 
-	err = pcf8523_read(pcf8523->client, PCF8523_REG_CONTROL2, &value);
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL2, &value);
 	if (err < 0)
 		return IRQ_HANDLED;
 
 	if (value & PCF8523_CONTROL2_AF) {
 		value &= ~PCF8523_CONTROL2_AF;
-		pcf8523_write(pcf8523->client, PCF8523_REG_CONTROL2, value);
+		regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL2, value);
 		rtc_update_irq(pcf8523->rtc, 1, RTC_IRQF | RTC_AF);
 
 		return IRQ_HANDLED;
···
 	return IRQ_NONE;
 }
 
-static int pcf8523_stop_rtc(struct i2c_client *client)
-{
-	u8 value;
-	int err;
-
-	err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
-	if (err < 0)
-		return err;
-
-	value |= PCF8523_CONTROL1_STOP;
-
-	err = pcf8523_write(client, PCF8523_REG_CONTROL1, value);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
-static int pcf8523_start_rtc(struct i2c_client *client)
-{
-	u8 value;
-	int err;
-
-	err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
-	if (err < 0)
-		return err;
-
-	value &= ~PCF8523_CONTROL1_STOP;
-
-	err = pcf8523_write(client, PCF8523_REG_CONTROL1, value);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
 static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	u8 start = PCF8523_REG_SECONDS, regs[7];
-	struct i2c_msg msgs[2];
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[7];
 	int err;
 
-	err = pcf8523_voltage_low(client);
-	if (err < 0) {
-		return err;
-	} else if (err > 0) {
-		dev_err(dev, "low voltage detected, time is unreliable\n");
-		return -EINVAL;
-	}
-
-	msgs[0].addr = client->addr;
-	msgs[0].flags = 0;
-	msgs[0].len = 1;
-	msgs[0].buf = &start;
-
-	msgs[1].addr = client->addr;
-	msgs[1].flags = I2C_M_RD;
-	msgs[1].len = sizeof(regs);
-	msgs[1].buf = regs;
-
-	err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_SECONDS, regs,
+			       sizeof(regs));
 	if (err < 0)
 		return err;
 
···
 
 static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct i2c_msg msg;
-	u8 regs[8];
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[7];
 	int err;
 
-	err = pcf8523_stop_rtc(client);
+	err = regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				 PCF8523_CONTROL1_STOP, PCF8523_CONTROL1_STOP);
 	if (err < 0)
 		return err;
 
-	regs[0] = PCF8523_REG_SECONDS;
 	/* This will purposely overwrite PCF8523_SECONDS_OS */
-	regs[1] = bin2bcd(tm->tm_sec);
-	regs[2] = bin2bcd(tm->tm_min);
-	regs[3] = bin2bcd(tm->tm_hour);
-	regs[4] = bin2bcd(tm->tm_mday);
-	regs[5] = tm->tm_wday;
-	regs[6] = bin2bcd(tm->tm_mon + 1);
-	regs[7] = bin2bcd(tm->tm_year - 100);
+	regs[0] = bin2bcd(tm->tm_sec);
+	regs[1] = bin2bcd(tm->tm_min);
+	regs[2] = bin2bcd(tm->tm_hour);
+	regs[3] = bin2bcd(tm->tm_mday);
+	regs[4] = tm->tm_wday;
+	regs[5] = bin2bcd(tm->tm_mon + 1);
+	regs[6] = bin2bcd(tm->tm_year - 100);
 
-	msg.addr = client->addr;
-	msg.flags = 0;
-	msg.len = sizeof(regs);
-	msg.buf = regs;
-
-	err = i2c_transfer(client->adapter, &msg, 1);
+	err = regmap_bulk_write(pcf8523->regmap, PCF8523_REG_SECONDS, regs,
+				sizeof(regs));
 	if (err < 0) {
 		/*
 		 * If the time cannot be set, restart the RTC anyway. Note
 		 * that errors are ignored if the RTC cannot be started so
 		 * that we have a chance to propagate the original error.
 		 */
-		pcf8523_start_rtc(client);
+		regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				   PCF8523_CONTROL1_STOP, 0);
 		return err;
 	}
 
-	return pcf8523_start_rtc(client);
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				 PCF8523_CONTROL1_STOP, 0);
 }
 
 static int pcf8523_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	u8 start = PCF8523_REG_MINUTE_ALARM, regs[4];
-	struct i2c_msg msgs[2];
-	u8 value;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[4];
+	u32 value;
 	int err;
 
-	msgs[0].addr = client->addr;
-	msgs[0].flags = 0;
-	msgs[0].len = 1;
-	msgs[0].buf = &start;
-
-	msgs[1].addr = client->addr;
-	msgs[1].flags = I2C_M_RD;
-	msgs[1].len = sizeof(regs);
-	msgs[1].buf = regs;
-
-	err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_MINUTE_ALARM, regs,
+			       sizeof(regs));
 	if (err < 0)
 		return err;
 
···
 	tm->time.tm_mday = bcd2bin(regs[2] & 0x3F);
 	tm->time.tm_wday = bcd2bin(regs[3] & 0x7);
 
-	err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL1, &value);
 	if (err < 0)
 		return err;
 	tm->enabled = !!(value & PCF8523_CONTROL1_AIE);
 
-	err = pcf8523_read(client, PCF8523_REG_CONTROL2, &value);
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL2, &value);
 	if (err < 0)
 		return err;
 	tm->pending = !!(value & PCF8523_CONTROL2_AF);
···
 
 static int pcf8523_irq_enable(struct device *dev, unsigned int enabled)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	u8 value;
-	int err;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
 
-	err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
-	if (err < 0)
-		return err;
-
-	value &= PCF8523_CONTROL1_AIE;
-
-	if (enabled)
-		value |= PCF8523_CONTROL1_AIE;
-
-	err = pcf8523_write(client, PCF8523_REG_CONTROL1, value);
-	if (err < 0)
-		return err;
-
-	return 0;
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				  PCF8523_CONTROL1_AIE, enabled ?
+				  PCF8523_CONTROL1_AIE : 0);
 }
 
 static int pcf8523_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct i2c_msg msg;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
 	u8 regs[5];
 	int err;
 
···
 	if (err)
 		return err;
 
-	err = pcf8523_write(client, PCF8523_REG_CONTROL2, 0);
+	err = regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL2, 0);
 	if (err < 0)
 		return err;
 
···
 		rtc_time64_to_tm(alarm_time, &tm->time);
 	}
 
-	regs[0] = PCF8523_REG_MINUTE_ALARM;
-	regs[1] = bin2bcd(tm->time.tm_min);
-	regs[2] = bin2bcd(tm->time.tm_hour);
-	regs[3] = bin2bcd(tm->time.tm_mday);
-	regs[4] = ALARM_DIS;
-	msg.addr = client->addr;
-	msg.flags = 0;
-	msg.len = sizeof(regs);
-	msg.buf = regs;
-	err = i2c_transfer(client->adapter, &msg, 1);
+	regs[0] = bin2bcd(tm->time.tm_min);
+	regs[1] = bin2bcd(tm->time.tm_hour);
+	regs[2] = bin2bcd(tm->time.tm_mday);
+	regs[3] = ALARM_DIS;
+
+	err = regmap_bulk_write(pcf8523->regmap, PCF8523_REG_MINUTE_ALARM, regs,
+				sizeof(regs));
 	if (err < 0)
 		return err;
 
···
 	return 0;
 }
 
-#ifdef CONFIG_RTC_INTF_DEV
+static int pcf8523_param_get(struct device *dev, struct rtc_param *param)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	int ret;
+
+	switch(param->param) {
+		u32 value;
+
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
+		if (ret < 0)
+			return ret;
+
+		value = FIELD_GET(PCF8523_CONTROL3_PM, value);
+
+		switch(value) {
+		case 0x0:
+		case 0x4:
+			param->uvalue = RTC_BSM_LEVEL;
+			break;
+		case 0x1:
+		case 0x5:
+			param->uvalue = RTC_BSM_DIRECT;
+			break;
+		case PCF8523_PM_STANDBY:
+			param->uvalue = RTC_BSM_STANDBY;
+			break;
+		default:
+			param->uvalue = RTC_BSM_DISABLED;
+		}
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pcf8523_param_set(struct device *dev, struct rtc_param *param)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+
+	switch(param->param) {
+		u8 mode;
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		switch (param->uvalue) {
+		case RTC_BSM_DISABLED:
+			mode = 0x2;
+			break;
+		case RTC_BSM_DIRECT:
+			mode = 0x1;
+			break;
+		case RTC_BSM_LEVEL:
+			mode = 0x0;
+			break;
+		case RTC_BSM_STANDBY:
+			mode = PCF8523_PM_STANDBY;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL3,
+					  PCF8523_CONTROL3_PM,
+					  FIELD_PREP(PCF8523_CONTROL3_PM, mode));
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
 			     unsigned long arg)
 {
-	struct i2c_client *client = to_i2c_client(dev);
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
 	unsigned int flags = 0;
-	u8 value;
+	u32 value;
 	int ret;
 
 	switch (cmd) {
 	case RTC_VL_READ:
-		ret = pcf8523_voltage_low(client);
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
 		if (ret < 0)
 			return ret;
-		if (ret)
+
+		if (value & PCF8523_CONTROL3_BLF)
 			flags |= RTC_VL_BACKUP_LOW;
 
-		ret = pcf8523_read(client, PCF8523_REG_SECONDS, &value);
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS, &value);
 		if (ret < 0)
 			return ret;
 
···
 		return -ENOIOCTLCMD;
 	}
 }
-#else
-#define pcf8523_rtc_ioctl NULL
-#endif
 
 static int pcf8523_rtc_read_offset(struct device *dev, long *offset)
 {
-	struct i2c_client *client = to_i2c_client(dev);
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
 	int err;
-	u8 value;
+	u32 value;
 	s8 val;
 
-	err = pcf8523_read(client, PCF8523_REG_OFFSET, &value);
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_OFFSET, &value);
 	if (err < 0)
 		return err;
 
···
 
 static int pcf8523_rtc_set_offset(struct device *dev, long offset)
 {
-	struct i2c_client *client = to_i2c_client(dev);
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
 	long reg_m0, reg_m1;
-	u8 value;
+	u32 value;
 
 	reg_m0 = clamp(DIV_ROUND_CLOSEST(offset, 4340), -64L, 63L);
 	reg_m1 = clamp(DIV_ROUND_CLOSEST(offset, 4069), -64L, 63L);
···
 	else
 		value = (reg_m1 & 0x7f) | PCF8523_OFFSET_MODE;
 
-	return pcf8523_write(client, PCF8523_REG_OFFSET, value);
+	return regmap_write(pcf8523->regmap, PCF8523_REG_OFFSET, value);
 }
 
 static const struct rtc_class_ops pcf8523_rtc_ops = {
···
 	.ioctl = pcf8523_rtc_ioctl,
 	.read_offset = pcf8523_rtc_read_offset,
 	.set_offset = pcf8523_rtc_set_offset,
+	.param_get = pcf8523_param_get,
+	.param_set = pcf8523_param_set,
+};
+
+static const struct regmap_config regmap_config = {
+        .reg_bits = 8,
+        .val_bits = 8,
+        .max_register = 0x13,
 };
 
 static int pcf8523_probe(struct i2c_client *client,
···
 	struct pcf8523 *pcf8523;
 	struct rtc_device *rtc;
 	bool wakeup_source = false;
+	u32 value;
 	int err;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
···
 	if (!pcf8523)
 		return -ENOMEM;
 
+	pcf8523->regmap = devm_regmap_init_i2c(client, &regmap_config);
+	if (IS_ERR(pcf8523->regmap))
+		return PTR_ERR(pcf8523->regmap);
+
 	i2c_set_clientdata(client, pcf8523);
-	pcf8523->client = client;
-
-	err = pcf8523_load_capacitance(client);
-	if (err < 0)
-		dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
-			 err);
-
-	err = pcf8523_set_pm(client, 0);
-	if (err < 0)
-		return err;
 
 	rtc = devm_rtc_allocate_device(&client->dev);
 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);
-
 	pcf8523->rtc = rtc;
+
+	err = pcf8523_load_capacitance(pcf8523, client->dev.of_node);
+	if (err < 0)
+		dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
+			 err);
+
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS, &value);
+	if (err < 0)
+		return err;
+
+	if (value & PCF8523_SECONDS_OS) {
+		err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
+		if (err < 0)
+			return err;
+
+		if (FIELD_GET(PCF8523_CONTROL3_PM, value) == PCF8523_PM_STANDBY) {
+			err = regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL3,
+					   value & ~PCF8523_CONTROL3_PM);
+			if (err < 0)
+				return err;
+		}
+	}
+
 	rtc->ops = &pcf8523_rtc_ops;
 	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	rtc->range_max = RTC_TIMESTAMP_END_2099;
 	rtc->uie_unsupported = 1;
 
 	if (client->irq > 0) {
-		err = pcf8523_write(client, PCF8523_TMR_CLKOUT_CTRL, 0x38);
+		err = regmap_write(pcf8523->regmap, PCF8523_TMR_CLKOUT_CTRL, 0x38);
 		if (err < 0)
 			return err;
 
 		err = devm_request_threaded_irq(&client->dev, client->irq,
 						NULL, pcf8523_irq,
 						IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
-						dev_name(&rtc->dev), client);
+						dev_name(&rtc->dev), pcf8523);
 		if (err)
 			return err;
 
 		dev_pm_set_wake_irq(&client->dev, client->irq);
 	}
 
-#ifdef CONFIG_OF
 	wakeup_source = of_property_read_bool(client->dev.of_node, "wakeup-source");
-#endif
 	if (client->irq > 0 || wakeup_source)
 		device_init_wakeup(&client->dev, true);
 
···
 };
 MODULE_DEVICE_TABLE(i2c, pcf8523_id);
 
-#ifdef CONFIG_OF
 static const struct of_device_id pcf8523_of_match[] = {
 	{ .compatible = "nxp,pcf8523" },
 	{ .compatible = "microcrystal,rv8523" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, pcf8523_of_match);
-#endif
 
 static struct i2c_driver pcf8523_driver = {
 	.driver = {
 		.name = "rtc-pcf8523",
-		.of_match_table = of_match_ptr(pcf8523_of_match),
+		.of_match_table = pcf8523_of_match,
 	},
 	.probe = pcf8523_probe,
 	.id_table = pcf8523_id,

drivers/rtc/rtc-rv3028.c

···
 
 #include <linux/clk-provider.h>
 #include <linux/bcd.h>
+#include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
···
 
 #define RV3028_BACKUP_TCE		BIT(5)
 #define RV3028_BACKUP_TCR_MASK		GENMASK(1,0)
+#define RV3028_BACKUP_BSM		GENMASK(3,2)
+
+#define RV3028_BACKUP_BSM_DSM		0x1
+#define RV3028_BACKUP_BSM_LSM		0x3
 
 #define OFFSET_STEP_PPT			953674
 
···
 
 }
 
+static int rv3028_param_get(struct device *dev, struct rtc_param *param)
+{
+	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
+	int ret;
+
+	switch(param->param) {
+		u32 value;
+
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
+		if (ret < 0)
+			return ret;
+
+		value = FIELD_GET(RV3028_BACKUP_BSM, value);
+
+		switch(value) {
+		case RV3028_BACKUP_BSM_DSM:
+			param->uvalue = RTC_BSM_DIRECT;
+			break;
+		case RV3028_BACKUP_BSM_LSM:
+			param->uvalue = RTC_BSM_LEVEL;
+			break;
+		default:
+			param->uvalue = RTC_BSM_DISABLED;
+		}
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int rv3028_param_set(struct device *dev, struct rtc_param *param)
+{
+	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
+
+	switch(param->param) {
+		u8 mode;
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		switch (param->uvalue) {
+		case RTC_BSM_DISABLED:
+			mode = 0;
+			break;
+		case RTC_BSM_DIRECT:
+			mode = RV3028_BACKUP_BSM_DSM;
+			break;
+		case RTC_BSM_LEVEL:
+			mode = RV3028_BACKUP_BSM_LSM;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		return rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_BSM,
+					 FIELD_PREP(RV3028_BACKUP_BSM, mode));
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
 	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
···
 	.read_offset = rv3028_read_offset,
 	.set_offset = rv3028_set_offset,
 	.ioctl = rv3028_ioctl,
+	.param_get = rv3028_param_get,
+	.param_set = rv3028_param_set,
 };
 
 static const struct regmap_config regmap_config = {
···
 	ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
 	if (ret)
 		return ret;
+
+	set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3028->rtc->features);
 
 	rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;

drivers/rtc/rtc-rv3032.c

···
 struct rv3032_data {
 	struct regmap *regmap;
 	struct rtc_device *rtc;
+	bool trickle_charger_set;
 #ifdef CONFIG_COMMON_CLK
 	struct clk_hw clkout_hw;
 #endif
···
 	u8 ctrl = 0;
 	int ret;
 
-	/* The alarm has no seconds, round up to nearest minute */
-	if (alrm->time.tm_sec) {
-		time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
-
-		alarm_time += 60 - alrm->time.tm_sec;
-		rtc_time64_to_tm(alarm_time, &alrm->time);
-	}
-
 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
 				 RV3032_CTRL2_AIE | RV3032_CTRL2_UIE, 0);
 	if (ret)
···
 
 	return rv3032_update_cfg(rv3032, RV3032_OFFSET, RV3032_OFFSET_MSK,
 				 FIELD_PREP(RV3032_OFFSET_MSK, offset));
+}
+
+static int rv3032_param_get(struct device *dev, struct rtc_param *param)
+{
+	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
+	int ret;
+
+	switch(param->param) {
+		u32 value;
+
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		ret = regmap_read(rv3032->regmap, RV3032_PMU, &value);
+		if (ret < 0)
+			return ret;
+
+		value = FIELD_GET(RV3032_PMU_BSM, value);
+
+		switch(value) {
+		case RV3032_PMU_BSM_DSM:
+			param->uvalue = RTC_BSM_DIRECT;
+			break;
+		case RV3032_PMU_BSM_LSM:
+			param->uvalue = RTC_BSM_LEVEL;
+			break;
+		default:
+			param->uvalue = RTC_BSM_DISABLED;
+		}
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int rv3032_param_set(struct device *dev, struct rtc_param *param)
+{
+	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
+
+	switch(param->param) {
+		u8 mode;
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		if (rv3032->trickle_charger_set)
+			return -EINVAL;
+
+		switch (param->uvalue) {
+		case RTC_BSM_DISABLED:
+			mode = 0;
+			break;
+		case RTC_BSM_DIRECT:
+			mode = RV3032_PMU_BSM_DSM;
+			break;
+		case RTC_BSM_LEVEL:
+			mode = RV3032_PMU_BSM_LSM;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		return rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_BSM,
+					 FIELD_PREP(RV3032_PMU_BSM, mode));
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
 static int rv3032_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
···
 		return 0;
 	}
 
+	rv3032->trickle_charger_set = true;
+
 	return rv3032_update_cfg(rv3032, RV3032_PMU,
 				 RV3032_PMU_TCR | RV3032_PMU_TCM | RV3032_PMU_BSM,
 				 val | FIELD_PREP(RV3032_PMU_TCR, i));
···
 
 	ret = rv3032_enter_eerd(rv3032, &eerd);
 	if (ret)
-		goto exit_eerd;
+		return ret;
 
 	ret = regmap_write(rv3032->regmap, RV3032_CLKOUT1, hfd & 0xff);
 	if (ret)
-		return ret;
+		goto exit_eerd;
 
 	ret = regmap_write(rv3032->regmap, RV3032_CLKOUT2, RV3032_CLKOUT2_OS |
 			    FIELD_PREP(RV3032_CLKOUT2_HFD_MSK, hfd >> 8));
···
 	.read_alarm = rv3032_get_alarm,
 	.set_alarm = rv3032_set_alarm,
 	.alarm_irq_enable = rv3032_alarm_irq_enable,
+	.param_get = rv3032_param_get,
+	.param_set = rv3032_param_set,
 };
 
 static const struct regmap_config regmap_config = {
···
 		return ret;
 
 	rv3032_trickle_charger_setup(&client->dev, rv3032);
+
+	set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3032->rtc->features);
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rv3032->rtc->features);
 
 	rv3032->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	rv3032->rtc->range_max = RTC_TIMESTAMP_END_2099;

drivers/rtc/rtc-rv8803.c

···
 		}
 	}
 
-	ctrl[1] &= ~RV8803_FLAG_AF;
-	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
+	ctrl[0] &= ~RV8803_FLAG_AF;
+	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[0]);
 	mutex_unlock(&rv8803->flags_lock);
 	if (err)
 		return err;

drivers/rtc/rtc-rx6110.c

···
 static int rx6110_i2c_probe(struct i2c_client *client,
 			    const struct i2c_device_id *id)
 {
-	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct i2c_adapter *adapter = client->adapter;
 	struct rx6110_data *rx6110;
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA

drivers/rtc/rtc-rx8025.c

···
 	u8 date[7];
 	int ret;
 
-	if ((dt->tm_year < 100) || (dt->tm_year > 199))
-		return -EINVAL;
-
 	/*
 	 * Here the read-only bits are written as "0".  I'm not sure if that
 	 * is sound.
···
 	u8 ald[2];
 	int ctrl2, err;
 
-	if (client->irq <= 0)
-		return -EINVAL;
-
 	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
 	if (err)
 		return err;
···
 	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 	u8 ald[2];
 	int err;
-
-	if (client->irq <= 0)
-		return -EINVAL;
-
-	/*
-	 * Hardware alarm precision is 1 minute!
-	 * round up to nearest minute
-	 */
-	if (t->time.tm_sec) {
-		time64_t alarm_time = rtc_tm_to_time64(&t->time);
-
-		alarm_time += 60 - t->time.tm_sec;
-		rtc_time64_to_tm(alarm_time, &t->time);
-	}
 
 	ald[0] = bin2bcd(t->time.tm_min);
 	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
···
 	return 0;
 }
 
-static const struct rtc_class_ops rx8025_rtc_ops = {
-	.read_time = rx8025_get_time,
-	.set_time = rx8025_set_time,
-	.read_alarm = rx8025_read_alarm,
-	.set_alarm = rx8025_set_alarm,
-	.alarm_irq_enable = rx8025_alarm_irq_enable,
-};
-
 /*
- * Clock precision adjustment support
- *
  * According to the RX8025 SA/NB application manual the frequency and
  * temperature characteristics can be approximated using the following
  * equation:
···
  *   a : Coefficient = (-35 +-5) * 10**-9
  *   ut: Ultimate temperature in degree = +25 +-5 degree
  *   t : Any temperature in degree
- *
- * Note that the clock adjustment in ppb must be entered (which is
- * the negative value of the deviation).
  */
-static int rx8025_get_clock_adjust(struct device *dev, int *adj)
+static int rx8025_read_offset(struct device *dev, long *offset)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	int digoff;
···
 	if (digoff < 0)
 		return digoff;
 
-	*adj = digoff >= 64 ? digoff - 128 : digoff;
-	if (*adj > 0)
-		(*adj)--;
-	*adj *= -RX8025_ADJ_RESOLUTION;
+	*offset = digoff >= 64 ? digoff - 128 : digoff;
+	if (*offset > 0)
+		(*offset)--;
+	*offset *= RX8025_ADJ_RESOLUTION;
 
 	return 0;
 }
 
-static int rx8025_set_clock_adjust(struct device *dev, int adj)
+static int rx8025_set_offset(struct device *dev, long offset)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	u8 digoff;
 	int err;
 
-	adj /= -RX8025_ADJ_RESOLUTION;
-	if (adj > RX8025_ADJ_DATA_MAX)
-		adj = RX8025_ADJ_DATA_MAX;
-	else if (adj < RX8025_ADJ_DATA_MIN)
-		adj = RX8025_ADJ_DATA_MIN;
-	else if (adj > 0)
-		adj++;
-	else if (adj < 0)
-		adj += 128;
-	digoff = adj;
+	offset /= RX8025_ADJ_RESOLUTION;
+	if (offset > RX8025_ADJ_DATA_MAX)
+		offset = RX8025_ADJ_DATA_MAX;
+	else if (offset < RX8025_ADJ_DATA_MIN)
+		offset = RX8025_ADJ_DATA_MIN;
+	else if (offset > 0)
+		offset++;
+	else if (offset < 0)
+		offset += 128;
+	digoff = offset;
 
 	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
 	if (err)
 		return err;
 
-	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
-
 	return 0;
 }
+
+static const struct rtc_class_ops rx8025_rtc_ops = {
+	.read_time = rx8025_get_time,
+	.set_time = rx8025_set_time,
+	.read_alarm = rx8025_read_alarm,
+	.set_alarm = rx8025_set_alarm,
+	.alarm_irq_enable = rx8025_alarm_irq_enable,
+	.read_offset = rx8025_read_offset,
+	.set_offset = rx8025_set_offset,
+};
 
 static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
 					      struct device_attribute *attr,
 					      char *buf)
 {
-	int err, adj;
+	long adj;
+	int err;
 
-	err = rx8025_get_clock_adjust(dev, &adj);
+	dev_warn_once(dev, "clock_adjust_ppb is deprecated, use offset\n");
+	err = rx8025_read_offset(dev, &adj);
 	if (err)
 		return err;
 
-	return sprintf(buf, "%d\n", adj);
+	return sprintf(buf, "%ld\n", -adj);
 }
 
 static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
 					       struct device_attribute *attr,
 					       const char *buf, size_t count)
 {
-	int adj, err;
+	long adj;
+	int err;
 
-	if (sscanf(buf, "%i", &adj) != 1)
+	dev_warn_once(dev, "clock_adjust_ppb is deprecated, use offset\n");
+	if (kstrtol(buf, 10, &adj) != 0)
 		return -EINVAL;
 
-	err = rx8025_set_clock_adjust(dev, adj);
+	err = rx8025_set_offset(dev, -adj);
 
 	return err ? err : count;
 }
···
 		   rx8025_sysfs_show_clock_adjust,
 		   rx8025_sysfs_store_clock_adjust);
 
-static int rx8025_sysfs_register(struct device *dev)
-{
-	return device_create_file(dev, &dev_attr_clock_adjust_ppb);
-}
+static struct attribute *rx8025_attrs[] = {
+	&dev_attr_clock_adjust_ppb.attr,
+	NULL
+};
 
-static void rx8025_sysfs_unregister(struct device *dev)
-{
-	device_remove_file(dev, &dev_attr_clock_adjust_ppb);
-}
+static const struct attribute_group rx8025_attr_group = {
+	.attrs	= rx8025_attrs,
+};
 
 static int rx8025_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
···
 	if (err)
 		return err;
 
-	rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
-					  &rx8025_rtc_ops, THIS_MODULE);
-	if (IS_ERR(rx8025->rtc)) {
-		dev_err(&client->dev, "unable to register the class device\n");
+	rx8025->rtc = devm_rtc_allocate_device(&client->dev);
+	if (IS_ERR(rx8025->rtc))
 		return PTR_ERR(rx8025->rtc);
-	}
+
+	rx8025->rtc->ops = &rx8025_rtc_ops;
+	rx8025->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
+	rx8025->rtc->range_max = RTC_TIMESTAMP_END_2099;
 
 	if (client->irq > 0) {
 		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
···
 						rx8025_handle_irq,
 						IRQF_ONESHOT,
 						"rx8025", client);
-		if (err) {
-			dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
-			client->irq = 0;
-		}
+		if (err)
+			clear_bit(RTC_FEATURE_ALARM, rx8025->rtc->features);
 	}
 
 	rx8025->rtc->max_user_freq = 1;
 
-	/* the rx8025 alarm only supports a minute accuracy */
-	rx8025->rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rx8025->rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rx8025->rtc->features);
 
-	err = rx8025_sysfs_register(&client->dev);
-	return err;
-}
+	err = rtc_add_group(rx8025->rtc, &rx8025_attr_group);
+	if (err)
+		return err;
 
-static int rx8025_remove(struct i2c_client *client)
-{
-	rx8025_sysfs_unregister(&client->dev);
-	return 0;
+	return devm_rtc_register_device(rx8025->rtc);
 }
 
 static struct i2c_driver rx8025_driver = {
···
 		.name = "rtc-rx8025",
 	},
 	.probe		= rx8025_probe,
-	.remove		= rx8025_remove,
 	.id_table	= rx8025_id,
 };
 

drivers/rtc/rtc-s35390a.c

···
 		alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
 		alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
 
-	if (alm->time.tm_sec != 0)
-		dev_warn(&client->dev, "Alarms are only supported on a per minute basis!\n");
-
 	/* disable interrupt (which deasserts the irq line) */
 	err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
 	if (err < 0)
···
 	s35390a->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	s35390a->rtc->range_max = RTC_TIMESTAMP_END_2099;
 
-	/* supports per-minute alarms only, therefore set uie_unsupported */
-	s35390a->rtc->uie_unsupported = 1;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, s35390a->rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, s35390a->rtc->features );
 
 	if (status1 & S35390A_FLAG_INT2)
 		rtc_update_irq(s35390a->rtc, 1, RTC_AF);

drivers/rtc/rtc-s3c.c

···
 	return ret;
 }
 
-/* Time read/write */
-static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
+/* Read time from RTC and convert it from BCD */
+static int s3c_rtc_read_time(struct s3c_rtc *info, struct rtc_time *tm)
 {
-	struct s3c_rtc *info = dev_get_drvdata(dev);
 	unsigned int have_retried = 0;
 	int ret;
 
···
 		return ret;
 
 retry_get_time:
-	rtc_tm->tm_min  = readb(info->base + S3C2410_RTCMIN);
-	rtc_tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
-	rtc_tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
-	rtc_tm->tm_mon  = readb(info->base + S3C2410_RTCMON);
-	rtc_tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
-	rtc_tm->tm_sec  = readb(info->base + S3C2410_RTCSEC);
+	tm->tm_min  = readb(info->base + S3C2410_RTCMIN);
+	tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
+	tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
+	tm->tm_mon  = readb(info->base + S3C2410_RTCMON);
+	tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
+	tm->tm_sec  = readb(info->base + S3C2410_RTCSEC);
 
-	/* the only way to work out whether the system was mid-update
+	/*
+	 * The only way to work out whether the system was mid-update
 	 * when we read it is to check the second counter, and if it
 	 * is zero, then we re-try the entire read
 	 */
-
-	if (rtc_tm->tm_sec == 0 && !have_retried) {
+	if (tm->tm_sec == 0 && !have_retried) {
 		have_retried = 1;
 		goto retry_get_time;
 	}
 
-	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
-	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
-	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
-	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
-	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
-	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
-
 	s3c_rtc_disable_clk(info);
 
-	rtc_tm->tm_year += 100;
-	rtc_tm->tm_mon -= 1;
+	tm->tm_sec  = bcd2bin(tm->tm_sec);
+	tm->tm_min  = bcd2bin(tm->tm_min);
+	tm->tm_hour = bcd2bin(tm->tm_hour);
+	tm->tm_mday = bcd2bin(tm->tm_mday);
+	tm->tm_mon  = bcd2bin(tm->tm_mon);
+	tm->tm_year = bcd2bin(tm->tm_year);
 
-	dev_dbg(dev, "read time %ptR\n", rtc_tm);
 	return 0;
 }
 
-static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
+/* Convert time to BCD and write it to RTC */
+static int s3c_rtc_write_time(struct s3c_rtc *info, const struct rtc_time *tm)
 {
-	struct s3c_rtc *info = dev_get_drvdata(dev);
-	int year = tm->tm_year - 100;
 	int ret;
-
-	dev_dbg(dev, "set time %ptR\n", tm);
-
-	/* we get around y2k by simply not supporting it */
-
-	if (year < 0 || year >= 100) {
-		dev_err(dev, "rtc only supports 100 years\n");
-		return -EINVAL;
-	}
 
 	ret = s3c_rtc_enable_clk(info);
 	if (ret)
···
 	writeb(bin2bcd(tm->tm_min),  info->base + S3C2410_RTCMIN);
 	writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);
 	writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);
-	writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_RTCMON);
-	writeb(bin2bcd(year), info->base + S3C2410_RTCYEAR);
+	writeb(bin2bcd(tm->tm_mon),  info->base + S3C2410_RTCMON);
+	writeb(bin2bcd(tm->tm_year), info->base + S3C2410_RTCYEAR);
 
 	s3c_rtc_disable_clk(info);
 
 	return 0;
+}
+
+static int s3c_rtc_gettime(struct device *dev, struct rtc_time *tm)
+{
+	struct s3c_rtc *info = dev_get_drvdata(dev);
+	int ret;
+
+	ret = s3c_rtc_read_time(info, tm);
+	if (ret)
+		return ret;
+
+	/* Convert internal representation to actual date/time */
+	tm->tm_year += 100;
+	tm->tm_mon -= 1;
+
+	dev_dbg(dev, "read time %ptR\n", tm);
+	return 0;
+}
+
+static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	struct s3c_rtc *info = dev_get_drvdata(dev);
+	struct rtc_time rtc_tm = *tm;
+
+	dev_dbg(dev, "set time %ptR\n", tm);
+
+	/*
+	 * Convert actual date/time to internal representation.
+	 * We get around Y2K by simply not supporting it.
+	 */
+	rtc_tm.tm_year -= 100;
+	rtc_tm.tm_mon += 1;
+
+	return s3c_rtc_write_time(info, &rtc_tm);
 }
 
 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
···
 
 	device_init_wakeup(&pdev->dev, 1);
 
-	/* register RTC and exit */
-	info->rtc = devm_rtc_device_register(&pdev->dev, "s3c", &s3c_rtcops,
-					     THIS_MODULE);
+	info->rtc = devm_rtc_allocate_device(&pdev->dev);
 	if (IS_ERR(info->rtc)) {
-		dev_err(&pdev->dev, "cannot attach rtc\n");
 		ret = PTR_ERR(info->rtc);
 		goto err_nortc;
 	}
+
+	info->rtc->ops = &s3c_rtcops;
+	info->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	info->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+	ret = devm_rtc_register_device(info->rtc);
+	if (ret)
+		goto err_nortc;
 
 	ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,
 			       0, "s3c2410-rtc alarm", info);

drivers/rtc/rtc-s5m.c

···
 MODULE_AUTHOR("Sangbeom Kim <[e-mail]>");
 MODULE_DESCRIPTION("Samsung S5M/S2MPS14 RTC driver");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:s5m-rtc");

drivers/rtc/rtc-sun6i.c

···
 	struct sun6i_rtc_dev *chip = sun6i_rtc;
 	int ret;
 
-	if (!chip)
-		return -ENODEV;
+	if (!chip) {
+		chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+		if (!chip)
+			return -ENOMEM;
+
+		spin_lock_init(&chip->lock);
+
+		chip->base = devm_platform_ioremap_resource(pdev, 0);
+		if (IS_ERR(chip->base))
+			return PTR_ERR(chip->base);
+	}
 
 	platform_set_drvdata(pdev, chip);
 

drivers/rtc/rtc-tps80031.c

···
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * rtc-tps80031.c -- TI TPS80031/TPS80032 RTC driver
- *
- * RTC driver for TI TPS80031/TPS80032 Fully Integrated
- * Power Management with Power Path and Battery Charger
- *
- * Copyright (c) 2012, NVIDIA Corporation.
- *
- * Author: Laxman Dewangan <[e-mail]>
- */
-
-#include <linux/bcd.h>
-#include <linux/device.h>
-#include <linux/err.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/mfd/tps80031.h>
-#include <linux/platform_device.h>
-#include <linux/pm.h>
-#include <linux/rtc.h>
-#include <linux/slab.h>
-
-#define ENABLE_ALARM_INT			0x08
-#define ALARM_INT_STATUS			0x40
-
-/**
- * Setting bit to 1 in STOP_RTC will run the RTC and
- * setting this bit to 0 will freeze RTC.
- */
-#define STOP_RTC				0x1
-
-/* Power on reset Values of RTC registers */
-#define TPS80031_RTC_POR_YEAR			0
-#define TPS80031_RTC_POR_MONTH			1
-#define TPS80031_RTC_POR_DAY			1
-
-/* Numbers of registers for time and alarms */
-#define TPS80031_RTC_TIME_NUM_REGS		7
-#define TPS80031_RTC_ALARM_NUM_REGS		6
-
-/**
- * PMU RTC have only 2 nibbles to store year information, so using an
- * offset of 100 to set the base year as 2000 for our driver.
- */
-#define RTC_YEAR_OFFSET 100
-
-struct tps80031_rtc {
-	struct rtc_device	*rtc;
-	int			irq;
-};
-
-static int tps80031_rtc_read_time(struct device *dev, struct rtc_time *tm)
-{
-	u8 buff[TPS80031_RTC_TIME_NUM_REGS];
-	int ret;
-
-	ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
-			TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff);
-	if (ret < 0) {
-		dev_err(dev, "reading RTC_SECONDS_REG failed, err = %d\n", ret);
-		return ret;
-	}
-
-	tm->tm_sec = bcd2bin(buff[0]);
-	tm->tm_min = bcd2bin(buff[1]);
-	tm->tm_hour = bcd2bin(buff[2]);
-	tm->tm_mday = bcd2bin(buff[3]);
-	tm->tm_mon = bcd2bin(buff[4]) - 1;
-	tm->tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
-	tm->tm_wday = bcd2bin(buff[6]);
-	return 0;
-}
-
-static int tps80031_rtc_set_time(struct device *dev, struct rtc_time *tm)
-{
-	u8 buff[7];
-	int ret;
-
-	buff[0] = bin2bcd(tm->tm_sec);
-	buff[1] = bin2bcd(tm->tm_min);
-	buff[2] = bin2bcd(tm->tm_hour);
-	buff[3] = bin2bcd(tm->tm_mday);
-	buff[4] = bin2bcd(tm->tm_mon + 1);
-	buff[5] = bin2bcd(tm->tm_year % RTC_YEAR_OFFSET);
-	buff[6] = bin2bcd(tm->tm_wday);
-
-	/* Stop RTC while updating the RTC time registers */
-	ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
-				TPS80031_RTC_CTRL_REG, STOP_RTC);
-	if (ret < 0) {
-		dev_err(dev->parent, "Stop RTC failed, err = %d\n", ret);
-		return ret;
-	}
-
-	ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
-			TPS80031_SECONDS_REG,
-			TPS80031_RTC_TIME_NUM_REGS, buff);
-	if (ret < 0) {
-		dev_err(dev, "writing RTC_SECONDS_REG failed, err %d\n", ret);
-		return ret;
-	}
-
-	ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
-				TPS80031_RTC_CTRL_REG, STOP_RTC);
-	if (ret < 0)
-		dev_err(dev->parent, "Start RTC failed, err = %d\n", ret);
-	return ret;
-}
-
-static int tps80031_rtc_alarm_irq_enable(struct device *dev,
-					 unsigned int enable)
-{
-	int ret;
-
-	if (enable)
-		ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
-				TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
-	else
-		ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
-				TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
-	if (ret < 0) {
-		dev_err(dev, "Update on RTC_INT failed, err = %d\n", ret);
-		return ret;
-	}
-	return 0;
-}
-
-static int tps80031_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
-{
-	u8 buff[TPS80031_RTC_ALARM_NUM_REGS];
-	int ret;
-
-	buff[0] = bin2bcd(alrm->time.tm_sec);
-	buff[1] = bin2bcd(alrm->time.tm_min);
-	buff[2] = bin2bcd(alrm->time.tm_hour);
-	buff[3] = bin2bcd(alrm->time.tm_mday);
-	buff[4] = bin2bcd(alrm->time.tm_mon + 1);
-	buff[5] = bin2bcd(alrm->time.tm_year % RTC_YEAR_OFFSET);
-	ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
-			TPS80031_ALARM_SECONDS_REG,
-			TPS80031_RTC_ALARM_NUM_REGS, buff);
-	if (ret < 0) {
-		dev_err(dev, "Writing RTC_ALARM failed, err %d\n", ret);
-		return ret;
-	}
-	return tps80031_rtc_alarm_irq_enable(dev, alrm->enabled);
-}
-
-static int tps80031_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
-{
-	u8 buff[6];
-	int ret;
-
-	ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
-			TPS80031_ALARM_SECONDS_REG,
-			TPS80031_RTC_ALARM_NUM_REGS, buff);
-	if (ret < 0) {
-		dev_err(dev->parent,
-			"reading RTC_ALARM failed, err = %d\n", ret);
-		return ret;
-	}
-
-	alrm->time.tm_sec = bcd2bin(buff[0]);
-	alrm->time.tm_min = bcd2bin(buff[1]);
-	alrm->time.tm_hour = bcd2bin(buff[2]);
-	alrm->time.tm_mday = bcd2bin(buff[3]);
-	alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
-	alrm->time.tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
-	return 0;
-}
-
-static int clear_alarm_int_status(struct device *dev, struct tps80031_rtc *rtc)
-{
-	int ret;
-	u8 buf;
-
-	/**
-	 * As per datasheet, A dummy read of this  RTC_STATUS_REG register
-	 * is necessary before each I2C read in order to update the status
-	 * register value.
-	 */
-	ret = tps80031_read(dev->parent, TPS80031_SLAVE_ID1,
-				TPS80031_RTC_STATUS_REG, &buf);
-	if (ret < 0) {
-		dev_err(dev, "reading RTC_STATUS failed. err = %d\n", ret);
-		return ret;
-	}
-
-	/* clear Alarm status bits.*/
-	ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
-			TPS80031_RTC_STATUS_REG, ALARM_INT_STATUS);
-	if (ret < 0) {
-		dev_err(dev, "clear Alarm INT failed, err = %d\n", ret);
-		return ret;
-	}
-	return 0;
-}
-
-static irqreturn_t tps80031_rtc_irq(int irq, void *data)
-{
-	struct device *dev = data;
-	struct tps80031_rtc *rtc = dev_get_drvdata(dev);
-	int ret;
-
-	ret = clear_alarm_int_status(dev, rtc);
-	if (ret < 0)
-		return ret;
-
-	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
-	return IRQ_HANDLED;
-}
-
-static const struct rtc_class_ops tps80031_rtc_ops = {
-	.read_time = tps80031_rtc_read_time,
-	.set_time = tps80031_rtc_set_time,
-	.set_alarm = tps80031_rtc_set_alarm,
-	.read_alarm = tps80031_rtc_read_alarm,
-	.alarm_irq_enable = tps80031_rtc_alarm_irq_enable,
-};
-
-static int tps80031_rtc_probe(struct platform_device *pdev)
-{
-	struct tps80031_rtc *rtc;
-	struct rtc_time tm;
-	int ret;
-
-	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
-	if (!rtc)
-		return -ENOMEM;
-
-	rtc->irq = platform_get_irq(pdev, 0);
-	platform_set_drvdata(pdev, rtc);
-
-	/* Start RTC */
-	ret = tps80031_set_bits(pdev->dev.parent, TPS80031_SLAVE_ID1,
-			TPS80031_RTC_CTRL_REG, STOP_RTC);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to start RTC. err = %d\n", ret);
-		return ret;
-	}
-
-	/* If RTC have POR values, set time 01:01:2000 */
-	tps80031_rtc_read_time(&pdev->dev, &tm);
-	if ((tm.tm_year == RTC_YEAR_OFFSET + TPS80031_RTC_POR_YEAR) &&
-		(tm.tm_mon == (TPS80031_RTC_POR_MONTH - 1)) &&
-		(tm.tm_mday == TPS80031_RTC_POR_DAY)) {
-		tm.tm_year = 2000;
-		tm.tm_mday = 1;
-		tm.tm_mon = 1;
-		ret = tps80031_rtc_set_time(&pdev->dev, &tm);
-		if (ret < 0) {
-			dev_err(&pdev->dev,
-				"RTC set time failed, err = %d\n", ret);
-			return ret;
-		}
-	}
-
-	/* Clear alarm intretupt status if it is there */
-	ret = clear_alarm_int_status(&pdev->dev, rtc);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Clear alarm int failed, err = %d\n", ret);
-		return ret;
-	}
-
-	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
-			       &tps80031_rtc_ops, THIS_MODULE);
-	if (IS_ERR(rtc->rtc)) {
-		ret = PTR_ERR(rtc->rtc);
-		dev_err(&pdev->dev, "RTC registration failed, err %d\n", ret);
-		return ret;
-	}
-
-	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
-			tps80031_rtc_irq,
-			IRQF_ONESHOT,
-			dev_name(&pdev->dev), rtc);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
-			 rtc->irq, ret);
-		return ret;
-	}
-	device_set_wakeup_capable(&pdev->dev, 1);
-	return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int tps80031_rtc_suspend(struct device *dev)
-{
-	struct tps80031_rtc *rtc = dev_get_drvdata(dev);
-
-	if (device_may_wakeup(dev))
-		enable_irq_wake(rtc->irq);
-	return 0;
-}
-
-static int tps80031_rtc_resume(struct device *dev)
-{
-	struct tps80031_rtc *rtc = dev_get_drvdata(dev);
-
-	if (device_may_wakeup(dev))
-		disable_irq_wake(rtc->irq);
-	return 0;
-};
-#endif
-
-static SIMPLE_DEV_PM_OPS(tps80031_pm_ops, tps80031_rtc_suspend,
-			tps80031_rtc_resume);
-
-static struct platform_driver tps80031_rtc_driver = {
-	.driver	= {
-		.name	= "tps80031-rtc",
-		.pm	= &tps80031_pm_ops,
-	},
-	.probe	= tps80031_rtc_probe,
-};
-
-module_platform_driver(tps80031_rtc_driver);
-
-MODULE_ALIAS("platform:tps80031-rtc");
-MODULE_DESCRIPTION("TI TPS80031/TPS80032 RTC driver");
-MODULE_AUTHOR("Laxman Dewangan <[e-mail]>");
-MODULE_LICENSE("GPL v2");

include/linux/rtc.h

···
 	int (*alarm_irq_enable)(struct device *, unsigned int enabled);
 	int (*read_offset)(struct device *, long *offset);
 	int (*set_offset)(struct device *, long offset);
+	int (*param_get)(struct device *, struct rtc_param *param);
+	int (*param_set)(struct device *, struct rtc_param *param);
 };
 
 struct rtc_device;
···
 
 /* flags */
 #define RTC_DEV_BUSY 0
+#define RTC_NO_CDEV  1
 
 struct rtc_device {
 	struct device dev;

include/uapi/linux/rtc.h

···
 
 #include <linux/const.h>
 #include <linux/ioctl.h>
+#include <linux/types.h>
 
 /*
  * The struct used to pass data via the following ioctl. Similar to the
···
 	long pll_clock;     /* base PLL frequency */
 };
 
+struct rtc_param {
+	__u64 param;
+	union {
+		__u64 uvalue;
+		__s64 svalue;
+		__u64 ptr;
+	};
+	__u32 index;
+	__u32 __pad;
+};
+
 /*
  * ioctl calls that are permitted to the /dev/rtc interface, if
  * any of the RTC drivers are enabled.
···
 #define RTC_PLL_GET	_IOR('p', 0x11, struct rtc_pll_info)  /* Get PLL correction */
 #define RTC_PLL_SET	_IOW('p', 0x12, struct rtc_pll_info)  /* Set PLL correction */
 
+#define RTC_PARAM_GET	_IOW('p', 0x13, struct rtc_param)  /* Get parameter */
+#define RTC_PARAM_SET	_IOW('p', 0x14, struct rtc_param)  /* Set parameter */
+
 #define RTC_VL_DATA_INVALID	_BITUL(0) /* Voltage too low, RTC data is invalid */
 #define RTC_VL_BACKUP_LOW	_BITUL(1) /* Backup voltage is low */
 #define RTC_VL_BACKUP_EMPTY	_BITUL(2) /* Backup empty or not present */
···
 #define RTC_FEATURE_ALARM		0
 #define RTC_FEATURE_ALARM_RES_MINUTE	1
 #define RTC_FEATURE_NEED_WEEK_DAY	2
-#define RTC_FEATURE_CNT			3
+#define RTC_FEATURE_ALARM_RES_2S	3
+#define RTC_FEATURE_UPDATE_INTERRUPT	4
+#define RTC_FEATURE_CORRECTION		5
+#define RTC_FEATURE_BACKUP_SWITCH_MODE	6
+#define RTC_FEATURE_CNT			7
+
+/* parameter list */
+#define RTC_PARAM_FEATURES		0
+#define RTC_PARAM_CORRECTION		1
+#define RTC_PARAM_BACKUP_SWITCH_MODE	2
+
+#define RTC_BSM_DISABLED	0
+#define RTC_BSM_DIRECT		1
+#define RTC_BSM_LEVEL		2
+#define RTC_BSM_STANDBY		3
 
 #define RTC_MAX_FREQ	8192