Merge tag 'rtc-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "Subsystem:
   - new %ptR printk format
   - rename core files
   - allow registration of multiple nvmem devices

  New driver:
   - i.MX system controller RTC

  Driver updates:
   - abx80x: handle voltage ioctls, correct binding doc
   - m41t80: correct month in alarm reads
   - pcf85363: add pcf85263 support
   - pcf8523: properly handle battery low flag
   - s3c: limit alarm to one year in the future as ALMYEAR is broken
   - sun6i: rework clock output binding"

* tag 'rtc-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (54 commits)
  rtc: rename core files
  rtc: nvmem: fix possible use after free
  rtc: add i.MX system controller RTC support
  dt-bindings: fsl: scu: add rtc binding
  rtc: pcf2123: Add Microcrystal rv2123
  rtc: class: reimplement devm_rtc_device_register
  rtc: enforce rtc_timer_init private_data type
  rtc: abx80x: Implement RTC_VL_READ,CLR ioctls
  rtc: pcf85363: Add support for NXP pcf85263 rtc
  dt-bindings: rtc: pcf85363: Document pcf85263 real-time clock
  rtc: pcf8523: don't return invalid date when battery is low
  dt-bindings: rtc: use a generic node name for ds1307
  PM: Switch to use %ptR
  m68k/mac: Switch to use %ptR
  Input: hp_sdc_rtc - Switch to use %ptR
  rtc: tegra: Switch to use %ptR
  rtc: s5m: Switch to use %ptR
  rtc: s3c: Switch to use %ptR
  rtc: rx8025: Switch to use %ptR
  rtc: rx6110: Switch to use %ptR
  ...

Documentation/core-api/printk-formats.rst

@@ -412,6 +412,24 @@ Examples::
 
 Passed by reference.
 
+Time and date (struct rtc_time)
+-------------------------------
+
+::
+
+	%ptR		YYYY-mm-ddTHH:MM:SS
+	%ptRd		YYYY-mm-dd
+	%ptRt		HH:MM:SS
+	%ptR[dt][r]
+
+For printing date and time as represented by struct rtc_time structure in
+human readable format.
+
+By default year will be incremented by 1900 and month by 1. Use %ptRr (raw)
+to suppress this behaviour.
+
+Passed by reference.
+
 struct clk
 ----------
 

Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt

@@ -109,6 +109,12 @@ Required properties for Pinctrl sub nodes:
 [2] Documentation/devicetree/bindings/power/power_domain.txt
 [3] Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt
 
+RTC bindings based on SCU Message Protocol
+------------------------------------------------------------
+
+Required properties:
+- compatible: should be "fsl,imx8qxp-sc-rtc";
+
 Example (imx8qxp):
 -------------
 lsio_mu1: mailbox@5d1c0000 {
@@ -151,6 +157,10 @@ firmware {
 			compatible = "fsl,imx8qxp-scu-pd";
 			#power-domain-cells = <1>;
 		};
+
+		rtc: rtc {
+			compatible = "fsl,imx8qxp-sc-rtc";
+		};
 	};
 };
 

Documentation/devicetree/bindings/rtc/abracon,abx80x.txt

@@ -27,4 +27,4 @@ and valid to enable charging:
 
  - "abracon,tc-diode": should be "standard" (0.6V) or "schottky" (0.3V)
  - "abracon,tc-resistor": should be <0>, <3>, <6> or <11>. 0 disables the output
-                          resistor, the other values are in ohm.
+                          resistor, the other values are in kOhm.

Documentation/devicetree/bindings/rtc/nxp,rtc-2123.txt

@@ -2,6 +2,7 @@ NXP PCF2123 SPI Real Time Clock
 
 Required properties:
 - compatible: should be: "nxp,rtc-pcf2123"
+                      or "microcrystal,rv2123"
 - reg: should be the SPI slave chipselect address
 
 Optional properties:

Documentation/devicetree/bindings/rtc/pcf85363.txt

-NXP PCF85363 Real Time Clock
+NXP PCF85263/PCF85363 Real Time Clock
 ============================
 
 Required properties:
-- compatible: Should contain "nxp,pcf85363".
+- compatible: Should contain "nxp,pcf85263" or "nxp,pcf85363".
 - reg: I2C address for chip.
 
 Optional properties:

Documentation/devicetree/bindings/rtc/rtc-ds1307.txt

@@ -35,7 +35,7 @@ Optional properties:
 	Should be given if internal trickle charger diode should be disabled
 
 Example:
-	rtc1: ds1339@68 {
+	ds1339: rtc@68 {
 		compatible = "dallas,ds1339";
 		reg = <0x68>;
 		interrupt-parent = <&gpio4>;

Documentation/devicetree/bindings/rtc/sun6i-rtc.txt

@@ -3,25 +3,44 @@
 RTC controller for the Allwinner A31
 
 Required properties:
-- compatible	: Should be "allwinner,sun6i-a31-rtc"
+- compatible	: Should be one of the following combinations:
+		    - "allwinner,sun6i-a31-rtc"
+		    - "allwinner,sun8i-a23-rtc"
+		    - "allwinner,sun8i-h3-rtc"
+		    - "allwinner,sun8i-r40-rtc", "allwinner,sun8i-h3-rtc"
+		    - "allwinner,sun8i-v3-rtc"
+		    - "allwinner,sun50i-a64-rtc", "allwinner,sun8i-h3-rtc"
+		    - "allwinner,sun50i-h5-rtc"
+
+		  Where there are two or more compatible strings, this
+		  denotes the hardware covered by the most specific one
+		  is backward-compatible with the latter ones, and the
+		  implementation for the latter ones can be used, albeit
+		  with reduced functionality.
+
 - reg		: physical base address of the controller and length of
 		  memory mapped region.
 - interrupts	: IRQ lines for the RTC alarm 0 and alarm 1, in that order.
 
 Required properties for new device trees
 - clocks	: phandle to the 32kHz external oscillator
-- clock-output-names : names of the LOSC and its external output clocks created
-- #clock-cells  : must be equals to 1. The RTC provides two clocks: the
-		  LOSC and its external output, with index 0 and 1
-		  respectively.
+- clock-output-names : names of up to three clock outputs. See below.
+- #clock-cells  : must be equal to 1.
+
+The RTC provides the following clocks at the given indices:
+- 0: LOSC
+- 1: LOSC external output, known as X32KFOUT in the datasheet.
+     This clock is not available on the A31 and is deprecated for old
+     device trees still using the "allwinner,sun6i-a31-rtc" compatible.
+- 2: InternalOSC, or internal RC oscillator (A64/H3/H5 only)
 
 Example:
 
 rtc: rtc@1f00000 {
 	compatible = "allwinner,sun6i-a31-rtc";
-	reg = <0x01f00000 0x54>;
+	reg = <0x01f00000 0x400>;
 	interrupts = <0 40 4>, <0 41 4>;
-	clock-output-names = "osc32k", "osc32k-out";
+	clock-output-names = "osc32k";
 	clocks = <&ext_osc32k>;
 	#clock-cells = <1>;
 };

arch/m68k/mac/misc.c

@@ -605,13 +605,9 @@ int mac_hwclk(int op, struct rtc_time *t)
 		unmktime(now, 0,
 			 &t->tm_year, &t->tm_mon, &t->tm_mday,
 			 &t->tm_hour, &t->tm_min, &t->tm_sec);
-		pr_debug("%s: read %04d-%02d-%-2d %02d:%02d:%02d\n",
-		         __func__, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
-		         t->tm_hour, t->tm_min, t->tm_sec);
+		pr_debug("%s: read %ptR\n", __func__, t);
 	} else { /* write */
-		pr_debug("%s: tried to write %04d-%02d-%-2d %02d:%02d:%02d\n",
-		         __func__, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
-		         t->tm_hour, t->tm_min, t->tm_sec);
+		pr_debug("%s: tried to write %ptR\n", __func__, t);
 
 		switch (macintosh_config->adb_type) {
 		case MAC_ADB_IOP:

drivers/base/power/trace.c

@@ -118,9 +118,7 @@ static unsigned int read_magic_time(void)
 	unsigned int val;
 
 	mc146818_get_time(&time);
-	pr_info("RTC time: %2d:%02d:%02d, date: %02d/%02d/%02d\n",
-		time.tm_hour, time.tm_min, time.tm_sec,
-		time.tm_mon + 1, time.tm_mday, time.tm_year % 100);
+	pr_info("RTC time: %ptRt, date: %ptRd\n", &time, &time);
 	val = time.tm_year;				/* 100 years */
 	if (val > 100)
 		val -= 100;

drivers/char/rtc.c

@@ -1125,11 +1125,10 @@ static int rtc_proc_show(struct seq_file *seq, void *v)
 	 * time or for Universal Standard Time (GMT). Probably local though.
 	 */
 	seq_printf(seq,
-		   "rtc_time\t: %02d:%02d:%02d\n"
-		   "rtc_date\t: %04d-%02d-%02d\n"
+		   "rtc_time\t: %ptRt\n"
+		   "rtc_date\t: %ptRd\n"
 		   "rtc_epoch\t: %04lu\n",
-		   tm.tm_hour, tm.tm_min, tm.tm_sec,
-		   tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
+		   &tm, &tm, epoch);
 
 	get_rtc_alm_time(&tm);
 

drivers/input/misc/hp_sdc_rtc.c

@@ -441,12 +441,10 @@ static int hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
 		seq_puts(m, "BBRTC\t\t: READ FAILED!\n");
 	} else {
 		seq_printf(m,
-			     "rtc_time\t: %02d:%02d:%02d\n"
-			     "rtc_date\t: %04d-%02d-%02d\n"
+			     "rtc_time\t: %ptRt\n"
+			     "rtc_date\t: %ptRd\n"
 			     "rtc_epoch\t: %04lu\n",
-			     tm.tm_hour, tm.tm_min, tm.tm_sec,
-			     tm.tm_year + 1900, tm.tm_mon + 1, 
-			     tm.tm_mday, epoch);
+			     &tm, &tm, epoch);
 	}
 
 	if (hp_sdc_rtc_read_rt(&tv)) {

drivers/rtc/Kconfig

@@ -1677,6 +1677,13 @@ config RTC_DRV_SNVS
 	   This driver can also be built as a module, if so, the module
 	   will be called "rtc-snvs".
 
+config RTC_DRV_IMX_SC
+	depends on IMX_SCU
+	tristate "NXP i.MX System Controller RTC support"
+	help
+	   If you say yes here you get support for the NXP i.MX System
+	   Controller RTC module.
+
 config RTC_DRV_SIRFSOC
 	tristate "SiRFSOC RTC"
 	depends on ARCH_SIRF

drivers/rtc/Makefile

@@ -5,7 +5,7 @@
 
 ccflags-$(CONFIG_RTC_DEBUG)	:= -DDEBUG
 
-obj-$(CONFIG_RTC_LIB)		+= rtc-lib.o
+obj-$(CONFIG_RTC_LIB)		+= lib.o
 obj-$(CONFIG_RTC_HCTOSYS)	+= hctosys.o
 obj-$(CONFIG_RTC_SYSTOHC)	+= systohc.o
 obj-$(CONFIG_RTC_CLASS)		+= rtc-core.o
@@ -17,9 +17,9 @@ rtc-core-y			+= rtc-efi-platform.o
 endif
 
 rtc-core-$(CONFIG_RTC_NVMEM)		+= nvmem.o
-rtc-core-$(CONFIG_RTC_INTF_DEV)		+= rtc-dev.o
-rtc-core-$(CONFIG_RTC_INTF_PROC)	+= rtc-proc.o
-rtc-core-$(CONFIG_RTC_INTF_SYSFS)	+= rtc-sysfs.o
+rtc-core-$(CONFIG_RTC_INTF_DEV)		+= dev.o
+rtc-core-$(CONFIG_RTC_INTF_PROC)	+= proc.o
+rtc-core-$(CONFIG_RTC_INTF_SYSFS)	+= sysfs.o
 
 # Keep the list ordered.
 
@@ -75,6 +75,7 @@ obj-$(CONFIG_RTC_DRV_GOLDFISH)	+= rtc-goldfish.o
 obj-$(CONFIG_RTC_DRV_HID_SENSOR_TIME) += rtc-hid-sensor-time.o
 obj-$(CONFIG_RTC_DRV_HYM8563)	+= rtc-hym8563.o
 obj-$(CONFIG_RTC_DRV_IMXDI)	+= rtc-imxdi.o
+obj-$(CONFIG_RTC_DRV_IMX_SC)	+= rtc-imx-sc.o
 obj-$(CONFIG_RTC_DRV_ISL12022)	+= rtc-isl12022.o
 obj-$(CONFIG_RTC_DRV_ISL12026)	+= rtc-isl12026.o
 obj-$(CONFIG_RTC_DRV_ISL1208)	+= rtc-isl1208.o

drivers/rtc/class.c

@@ -178,9 +178,9 @@ static struct rtc_device *rtc_allocate_device(void)
 	timerqueue_init_head(&rtc->timerqueue);
 	INIT_WORK(&rtc->irqwork, rtc_timer_do_work);
 	/* Init aie timer */
-	rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc);
+	rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, rtc);
 	/* Init uie timer */
-	rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc);
+	rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, rtc);
 	/* Init pie timer */
 	hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	rtc->pie_timer.function = rtc_pie_update_irq;
@@ -277,82 +277,6 @@ static void rtc_device_get_offset(struct rtc_device *rtc)
 		rtc->offset_secs = 0;
 }
 
-/**
- * rtc_device_register - register w/ RTC class
- * @dev: the device to register
- *
- * rtc_device_unregister() must be called when the class device is no
- * longer needed.
- *
- * Returns the pointer to the new struct class device.
- */
-static struct rtc_device *rtc_device_register(const char *name,
-					      struct device *dev,
-					      const struct rtc_class_ops *ops,
-					      struct module *owner)
-{
-	struct rtc_device *rtc;
-	struct rtc_wkalrm alrm;
-	int id, err;
-
-	id = rtc_device_get_id(dev);
-	if (id < 0) {
-		err = id;
-		goto exit;
-	}
-
-	rtc = rtc_allocate_device();
-	if (!rtc) {
-		err = -ENOMEM;
-		goto exit_ida;
-	}
-
-	rtc->id = id;
-	rtc->ops = ops;
-	rtc->owner = owner;
-	rtc->dev.parent = dev;
-
-	dev_set_name(&rtc->dev, "rtc%d", id);
-
-	rtc_device_get_offset(rtc);
-
-	/* Check to see if there is an ALARM already set in hw */
-	err = __rtc_read_alarm(rtc, &alrm);
-
-	if (!err && !rtc_valid_tm(&alrm.time))
-		rtc_initialize_alarm(rtc, &alrm);
-
-	rtc_dev_prepare(rtc);
-
-	err = cdev_device_add(&rtc->char_dev, &rtc->dev);
-	if (err) {
-		dev_warn(&rtc->dev, "%s: failed to add char device %d:%d\n",
-			 name, MAJOR(rtc->dev.devt), rtc->id);
-
-		/* This will free both memory and the ID */
-		put_device(&rtc->dev);
-		goto exit;
-	} else {
-		dev_dbg(&rtc->dev, "%s: dev (%d:%d)\n", name,
-			MAJOR(rtc->dev.devt), rtc->id);
-	}
-
-	rtc_proc_add_device(rtc);
-
-	dev_info(dev, "rtc core: registered %s as %s\n",
-			name, dev_name(&rtc->dev));
-
-	return rtc;
-
-exit_ida:
-	ida_simple_remove(&rtc_ida, id);
-
-exit:
-	dev_err(dev, "rtc core: unable to register %s, err = %d\n",
-			name, err);
-	return ERR_PTR(err);
-}
-
 /**
  * rtc_device_unregister - removes the previously registered RTC class device
  *
@@ -372,77 +296,6 @@ static void rtc_device_unregister(struct rtc_device *rtc)
 	put_device(&rtc->dev);
 }
 
-static void devm_rtc_device_release(struct device *dev, void *res)
-{
-	struct rtc_device *rtc = *(struct rtc_device **)res;
-
-	rtc_nvmem_unregister(rtc);
-	rtc_device_unregister(rtc);
-}
-
-static int devm_rtc_device_match(struct device *dev, void *res, void *data)
-{
-	struct rtc **r = res;
-
-	return *r == data;
-}
-
-/**
- * devm_rtc_device_register - resource managed rtc_device_register()
- * @dev: the device to register
- * @name: the name of the device
- * @ops: the rtc operations structure
- * @owner: the module owner
- *
- * @return a struct rtc on success, or an ERR_PTR on error
- *
- * Managed rtc_device_register(). The rtc_device returned from this function
- * are automatically freed on driver detach. See rtc_device_register()
- * for more information.
- */
-
-struct rtc_device *devm_rtc_device_register(struct device *dev,
-					const char *name,
-					const struct rtc_class_ops *ops,
-					struct module *owner)
-{
-	struct rtc_device **ptr, *rtc;
-
-	ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
-		return ERR_PTR(-ENOMEM);
-
-	rtc = rtc_device_register(name, dev, ops, owner);
-	if (!IS_ERR(rtc)) {
-		*ptr = rtc;
-		devres_add(dev, ptr);
-	} else {
-		devres_free(ptr);
-	}
-
-	return rtc;
-}
-EXPORT_SYMBOL_GPL(devm_rtc_device_register);
-
-/**
- * devm_rtc_device_unregister - resource managed devm_rtc_device_unregister()
- * @dev: the device to unregister
- * @rtc: the RTC class device to unregister
- *
- * Deallocated a rtc allocated with devm_rtc_device_register(). Normally this
- * function will not need to be called and the resource management code will
- * ensure that the resource is freed.
- */
-void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc)
-{
-	int rc;
-
-	rc = devres_release(dev, devm_rtc_device_release,
-				devm_rtc_device_match, rtc);
-	WARN_ON(rc);
-}
-EXPORT_SYMBOL_GPL(devm_rtc_device_unregister);
-
 static void devm_rtc_release_device(struct device *dev, void *res)
 {
 	struct rtc_device *rtc = *(struct rtc_device **)res;
@@ -529,6 +382,42 @@ int __rtc_register_device(struct module *owner, struct rtc_device *rtc)
 }
 EXPORT_SYMBOL_GPL(__rtc_register_device);
 
+/**
+ * devm_rtc_device_register - resource managed rtc_device_register()
+ * @dev: the device to register
+ * @name: the name of the device (unused)
+ * @ops: the rtc operations structure
+ * @owner: the module owner
+ *
+ * @return a struct rtc on success, or an ERR_PTR on error
+ *
+ * Managed rtc_device_register(). The rtc_device returned from this function
+ * are automatically freed on driver detach.
+ * This function is deprecated, use devm_rtc_allocate_device and
+ * rtc_register_device instead
+ */
+struct rtc_device *devm_rtc_device_register(struct device *dev,
+					const char *name,
+					const struct rtc_class_ops *ops,
+					struct module *owner)
+{
+	struct rtc_device *rtc;
+	int err;
+
+	rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc))
+		return rtc;
+
+	rtc->ops = ops;
+
+	err = __rtc_register_device(owner, rtc);
+	if (err)
+		return ERR_PTR(err);
+
+	return rtc;
+}
+EXPORT_SYMBOL_GPL(devm_rtc_device_register);
+
 static int __init rtc_init(void)
 {
 	rtc_class = class_create(THIS_MODULE, "rtc");

drivers/rtc/hctosys.c

@@ -58,12 +58,8 @@ static int __init rtc_hctosys(void)
 
 	err = do_settimeofday64(&tv64);
 
-	dev_info(rtc->dev.parent,
-		"setting system clock to "
-		"%d-%02d-%02d %02d:%02d:%02d UTC (%lld)\n",
-		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
-		tm.tm_hour, tm.tm_min, tm.tm_sec,
-		(long long) tv64.tv_sec);
+	dev_info(rtc->dev.parent, "setting system clock to %ptR UTC (%lld)\n",
+		 &tm, (long long)tv64.tv_sec);
 
 err_read:
 	rtc_class_close(rtc);

drivers/rtc/interface.c

@@ -368,12 +368,8 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 	err = rtc_valid_tm(&alarm->time);
 
 done:
-	if (err) {
-		dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
-			alarm->time.tm_year + 1900, alarm->time.tm_mon + 1,
-			alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min,
-			alarm->time.tm_sec);
-	}
+	if (err)
+		dev_warn(&rtc->dev, "invalid alarm value: %ptR\n", &alarm->time);
 
 	return err;
 }
@@ -613,26 +609,24 @@ void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
 
 /**
  * rtc_aie_update_irq - AIE mode rtctimer hook
- * @private: pointer to the rtc_device
+ * @rtc: pointer to the rtc_device
  *
  * This functions is called when the aie_timer expires.
  */
-void rtc_aie_update_irq(void *private)
+void rtc_aie_update_irq(struct rtc_device *rtc)
 {
-	struct rtc_device *rtc = (struct rtc_device *)private;
 	rtc_handle_legacy_irq(rtc, 1, RTC_AF);
 }
 
 
 /**
  * rtc_uie_update_irq - UIE mode rtctimer hook
- * @private: pointer to the rtc_device
+ * @rtc: pointer to the rtc_device
  *
  * This functions is called when the uie_timer expires.
  */
-void rtc_uie_update_irq(void *private)
+void rtc_uie_update_irq(struct rtc_device *rtc)
 {
-	struct rtc_device *rtc = (struct rtc_device *)private;
 	rtc_handle_legacy_irq(rtc, 1,  RTC_UF);
 }
 
@@ -912,7 +906,7 @@ void rtc_timer_do_work(struct work_struct *work)
 		trace_rtc_timer_dequeue(timer);
 		timer->enabled = 0;
 		if (timer->func)
-			timer->func(timer->private_data);
+			timer->func(timer->rtc);
 
 		trace_rtc_timer_fired(timer);
 		/* Re-add/fwd periodic timers */
@@ -959,16 +953,17 @@ void rtc_timer_do_work(struct work_struct *work)
 /* rtc_timer_init - Initializes an rtc_timer
  * @timer: timer to be intiialized
  * @f: function pointer to be called when timer fires
- * @data: private data passed to function pointer
+ * @rtc: pointer to the rtc_device
  *
  * Kernel interface to initializing an rtc_timer.
  */
-void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
+void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
+		    struct rtc_device *rtc)
 {
 	timerqueue_init(&timer->node);
 	timer->enabled = 0;
 	timer->func = f;
-	timer->private_data = data;
+	timer->rtc = rtc;
 }
 
 /* rtc_timer_start - Sets an rtc_timer to fire in the future

drivers/rtc/nvmem.c

@@ -12,6 +12,7 @@
 #include <linux/types.h>
 #include <linux/nvmem-consumer.h>
 #include <linux/rtc.h>
+#include <linux/slab.h>
 #include <linux/sysfs.h>
 
 /*
@@ -25,11 +26,9 @@ rtc_nvram_read(struct file *filp, struct kobject *kobj,
 	       struct bin_attribute *attr,
 	       char *buf, loff_t off, size_t count)
 {
-	struct rtc_device *rtc = attr->private;
-
 	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
 
-	return nvmem_device_read(rtc->nvmem, off, count, buf);
+	return nvmem_device_read(attr->private, off, count, buf);
 }
 
 static ssize_t
@@ -37,26 +36,23 @@ rtc_nvram_write(struct file *filp, struct kobject *kobj,
 		struct bin_attribute *attr,
 		char *buf, loff_t off, size_t count)
 {
-	struct rtc_device *rtc = attr->private;
-
 	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
 
-	return nvmem_device_write(rtc->nvmem, off, count, buf);
+	return nvmem_device_write(attr->private, off, count, buf);
 }
 
-static int rtc_nvram_register(struct rtc_device *rtc, size_t size)
+static int rtc_nvram_register(struct rtc_device *rtc,
+			      struct nvmem_device *nvmem, size_t size)
 {
 	int err;
 
-	rtc->nvram = devm_kzalloc(rtc->dev.parent,
-				sizeof(struct bin_attribute),
-				GFP_KERNEL);
+	rtc->nvram = kzalloc(sizeof(struct bin_attribute), GFP_KERNEL);
 	if (!rtc->nvram)
 		return -ENOMEM;
 
 	rtc->nvram->attr.name = "nvram";
 	rtc->nvram->attr.mode = 0644;
-	rtc->nvram->private = rtc;
+	rtc->nvram->private = nvmem;
 
 	sysfs_bin_attr_init(rtc->nvram);
 
@@ -67,7 +63,7 @@ static int rtc_nvram_register(struct rtc_device *rtc, size_t size)
 	err = sysfs_create_bin_file(&rtc->dev.parent->kobj,
 				    rtc->nvram);
 	if (err) {
-		devm_kfree(rtc->dev.parent, rtc->nvram);
+		kfree(rtc->nvram);
 		rtc->nvram = NULL;
 	}
 
@@ -77,6 +73,8 @@ static int rtc_nvram_register(struct rtc_device *rtc, size_t size)
 static void rtc_nvram_unregister(struct rtc_device *rtc)
 {
 	sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram);
+	kfree(rtc->nvram);
+	rtc->nvram = NULL;
 }
 
 /*
@@ -85,21 +83,20 @@ static void rtc_nvram_unregister(struct rtc_device *rtc)
 int rtc_nvmem_register(struct rtc_device *rtc,
 		       struct nvmem_config *nvmem_config)
 {
-	if (!IS_ERR_OR_NULL(rtc->nvmem))
-		return -EBUSY;
+	struct nvmem_device *nvmem;
 
 	if (!nvmem_config)
 		return -ENODEV;
 
 	nvmem_config->dev = rtc->dev.parent;
 	nvmem_config->owner = rtc->owner;
-	rtc->nvmem = nvmem_register(nvmem_config);
-	if (IS_ERR(rtc->nvmem))
-		return PTR_ERR(rtc->nvmem);
+	nvmem = devm_nvmem_register(rtc->dev.parent, nvmem_config);
+	if (IS_ERR(nvmem))
+		return PTR_ERR(nvmem);
 
 	/* Register the old ABI */
 	if (rtc->nvram_old_abi)
-		rtc_nvram_register(rtc, nvmem_config->size);
+		rtc_nvram_register(rtc, nvmem, nvmem_config->size);
 
 	return 0;
 }
@@ -107,12 +104,7 @@ EXPORT_SYMBOL_GPL(rtc_nvmem_register);
 
 void rtc_nvmem_unregister(struct rtc_device *rtc)
 {
-	if (IS_ERR_OR_NULL(rtc->nvmem))
-		return;
-
 	/* unregister the old ABI */
 	if (rtc->nvram)
 		rtc_nvram_unregister(rtc);
-
-	nvmem_unregister(rtc->nvmem);
 }

drivers/rtc/rtc-proc.c → drivers/rtc/proc.c

@@ -50,41 +50,15 @@ static int rtc_proc_show(struct seq_file *seq, void *offset)
 	err = rtc_read_time(rtc, &tm);
 	if (err == 0) {
 		seq_printf(seq,
-			"rtc_time\t: %02d:%02d:%02d\n"
-			"rtc_date\t: %04d-%02d-%02d\n",
-			tm.tm_hour, tm.tm_min, tm.tm_sec,
-			tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
+			   "rtc_time\t: %ptRt\n"
+			   "rtc_date\t: %ptRd\n",
+			   &tm, &tm);
 	}
 
 	err = rtc_read_alarm(rtc, &alrm);
 	if (err == 0) {
-		seq_printf(seq, "alrm_time\t: ");
-		if ((unsigned int)alrm.time.tm_hour <= 24)
-			seq_printf(seq, "%02d:", alrm.time.tm_hour);
-		else
-			seq_printf(seq, "**:");
-		if ((unsigned int)alrm.time.tm_min <= 59)
-			seq_printf(seq, "%02d:", alrm.time.tm_min);
-		else
-			seq_printf(seq, "**:");
-		if ((unsigned int)alrm.time.tm_sec <= 59)
-			seq_printf(seq, "%02d\n", alrm.time.tm_sec);
-		else
-			seq_printf(seq, "**\n");
-
-		seq_printf(seq, "alrm_date\t: ");
-		if ((unsigned int)alrm.time.tm_year <= 200)
-			seq_printf(seq, "%04d-", alrm.time.tm_year + 1900);
-		else
-			seq_printf(seq, "****-");
-		if ((unsigned int)alrm.time.tm_mon <= 11)
-			seq_printf(seq, "%02d-", alrm.time.tm_mon + 1);
-		else
-			seq_printf(seq, "**-");
-		if (alrm.time.tm_mday && (unsigned int)alrm.time.tm_mday <= 31)
-			seq_printf(seq, "%02d\n", alrm.time.tm_mday);
-		else
-			seq_printf(seq, "**\n");
+		seq_printf(seq, "alrm_time\t: %ptRt\n", &alrm.time);
+		seq_printf(seq, "alrm_date\t: %ptRd\n", &alrm.time);
 		seq_printf(seq, "alarm_IRQ\t: %s\n",
 				alrm.enabled ? "yes" : "no");
 		seq_printf(seq, "alrm_pending\t: %s\n",

drivers/rtc/rtc-abx80x.c

@@ -38,6 +38,7 @@
 
 #define ABX8XX_REG_STATUS	0x0f
 #define ABX8XX_STATUS_AF	BIT(2)
+#define ABX8XX_STATUS_BLF	BIT(4)
 #define ABX8XX_STATUS_WDT	BIT(6)
 
 #define ABX8XX_REG_CTRL1	0x10
@@ -507,12 +508,49 @@ static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
 	return err;
 }
 
+static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int status, tmp;
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
+		if (status < 0)
+			return status;
+
+		tmp = !!(status & ABX8XX_STATUS_BLF);
+
+		if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
+			return -EFAULT;
+
+		return 0;
+
+	case RTC_VL_CLR:
+		status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
+		if (status < 0)
+			return status;
+
+		status &= ~ABX8XX_STATUS_BLF;
+
+		tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
+		if (tmp < 0)
+			return tmp;
+
+		return 0;
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
 static const struct rtc_class_ops abx80x_rtc_ops = {
 	.read_time	= abx80x_rtc_read_time,
 	.set_time	= abx80x_rtc_set_time,
 	.read_alarm	= abx80x_read_alarm,
 	.set_alarm	= abx80x_set_alarm,
 	.alarm_irq_enable = abx80x_alarm_irq_enable,
+	.ioctl		= abx80x_ioctl,
 };
 
 static int abx80x_dt_trickle_cfg(struct device_node *np)

drivers/rtc/rtc-at91rm9200.c

@@ -147,9 +147,7 @@ static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
 	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 	tm->tm_year = tm->tm_year - 1900;
 
-	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
-		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "%s(): %ptR\n", __func__, tm);
 
 	return 0;
 }
@@ -161,9 +159,7 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
 {
 	unsigned long cr;
 
-	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
-		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "%s(): %ptR\n", __func__, tm);
 
 	wait_for_completion(&at91_rtc_upd_rdy);
 
@@ -209,8 +205,7 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
 			? 1 : 0;
 
-	dev_dbg(dev, "%s(): %02d-%02d %02d:%02d:%02d %sabled\n", __func__,
-		tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec,
+	dev_dbg(dev, "%s(): %ptR %sabled\n", __func__, tm,
 		alrm->enabled ? "en" : "dis");
 
 	return 0;
@@ -247,9 +242,7 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 		at91_rtc_write_ier(AT91_RTC_ALARM);
 	}
 
-	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
-		tm.tm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
-		tm.tm_min, tm.tm_sec);
+	dev_dbg(dev, "%s(): %ptR\n", __func__, &tm);
 
 	return 0;
 }

drivers/rtc/rtc-at91sam9.c

@@ -124,9 +124,7 @@ static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
 
 	rtc_time_to_tm(offset + secs, tm);
 
-	dev_dbg(dev, "%s: %4d-%02d-%02d %02d:%02d:%02d\n", "readtime",
-		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "%s: %ptR\n", __func__, tm);
 
 	return 0;
 }
@@ -141,9 +139,7 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
 	u32 offset, alarm, mr;
 	unsigned long secs;
 
-	dev_dbg(dev, "%s: %4d-%02d-%02d %02d:%02d:%02d\n", "settime",
-		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "%s: %ptR\n", __func__, tm);
 
 	err = rtc_tm_to_time(tm, &secs);
 	if (err != 0)
@@ -199,9 +195,7 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	if (alarm != ALARM_DISABLED && offset != 0) {
 		rtc_time_to_tm(offset + alarm, tm);
 
-		dev_dbg(dev, "%s: %4d-%02d-%02d %02d:%02d:%02d\n", "readalarm",
-			1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
-			tm->tm_hour, tm->tm_min, tm->tm_sec);
+		dev_dbg(dev, "%s: %ptR\n", __func__, tm);
 
 		if (rtt_readl(rtc, MR) & AT91_RTT_ALMIEN)
 			alrm->enabled = 1;
@@ -242,9 +236,7 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	if (alrm->enabled)
 		rtt_writel(rtc, MR, mr | AT91_RTT_ALMIEN);
 
-	dev_dbg(dev, "%s: %4d-%02d-%02d %02d:%02d:%02d\n", "setalarm",
-		tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour,
-		tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "%s: %ptR\n", __func__, tm);
 
 	return 0;
 }

drivers/rtc/rtc-imx-sc.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 NXP.
+ */
+
+#include <linux/firmware/imx/sci.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#define IMX_SC_TIMER_FUNC_GET_RTC_SEC1970	9
+#define IMX_SC_TIMER_FUNC_SET_RTC_TIME		6
+
+static struct imx_sc_ipc *rtc_ipc_handle;
+static struct rtc_device *imx_sc_rtc;
+
+struct imx_sc_msg_timer_get_rtc_time {
+	struct imx_sc_rpc_msg hdr;
+	u32 time;
+} __packed;
+
+static int imx_sc_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct imx_sc_msg_timer_get_rtc_time msg;
+	struct imx_sc_rpc_msg *hdr = &msg.hdr;
+	int ret;
+
+	hdr->ver = IMX_SC_RPC_VERSION;
+	hdr->svc = IMX_SC_RPC_SVC_TIMER;
+	hdr->func = IMX_SC_TIMER_FUNC_GET_RTC_SEC1970;
+	hdr->size = 1;
+
+	ret = imx_scu_call_rpc(rtc_ipc_handle, &msg, true);
+	if (ret) {
+		dev_err(dev, "read rtc time failed, ret %d\n", ret);
+		return ret;
+	}
+
+	rtc_time_to_tm(msg.time, tm);
+
+	return 0;
+}
+
+static const struct rtc_class_ops imx_sc_rtc_ops = {
+	.read_time = imx_sc_rtc_read_time,
+};
+
+static int imx_sc_rtc_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	ret = imx_scu_get_handle(&rtc_ipc_handle);
+	if (ret)
+		return ret;
+
+	imx_sc_rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(imx_sc_rtc))
+		return PTR_ERR(imx_sc_rtc);
+
+	imx_sc_rtc->ops = &imx_sc_rtc_ops;
+	imx_sc_rtc->range_min = 0;
+	imx_sc_rtc->range_max = U32_MAX;
+
+	ret = rtc_register_device(imx_sc_rtc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id imx_sc_dt_ids[] = {
+	{ .compatible = "fsl,imx8qxp-sc-rtc", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, imx_sc_dt_ids);
+
+static struct platform_driver imx_sc_rtc_driver = {
+	.driver = {
+		.name	= "imx-sc-rtc",
+		.of_match_table = imx_sc_dt_ids,
+	},
+	.probe		= imx_sc_rtc_probe,
+};
+module_platform_driver(imx_sc_rtc_driver);
+
+MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
+MODULE_DESCRIPTION("NXP i.MX System Controller RTC Driver");
+MODULE_LICENSE("GPL");

drivers/rtc/rtc-isl1208.c

@@ -84,29 +84,13 @@ static int
 isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
 		      unsigned len)
 {
-	u8 reg_addr[1] = { reg };
-	struct i2c_msg msgs[2] = {
-		{
-			.addr = client->addr,
-			.len = sizeof(reg_addr),
-			.buf = reg_addr
-		},
-		{
-			.addr = client->addr,
-			.flags = I2C_M_RD,
-			.len = len,
-			.buf = buf
-		}
-	};
 	int ret;
 
 	WARN_ON(reg > ISL1219_REG_YRT);
 	WARN_ON(reg + len > ISL1219_REG_YRT + 1);
 
-	ret = i2c_transfer(client->adapter, msgs, 2);
-	if (ret > 0)
-		ret = 0;
-	return ret;
+	ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
+	return (ret < 0) ? ret : 0;
 }
 
 /* block write */
@@ -114,26 +98,13 @@ static int
 isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
 		     unsigned len)
 {
-	u8 i2c_buf[ISL1208_REG_USR2 + 2];
-	struct i2c_msg msgs[1] = {
-		{
-			.addr = client->addr,
-			.len = len + 1,
-			.buf = i2c_buf
-		}
-	};
 	int ret;
 
 	WARN_ON(reg > ISL1219_REG_YRT);
 	WARN_ON(reg + len > ISL1219_REG_YRT + 1);
 
-	i2c_buf[0] = reg;
-	memcpy(&i2c_buf[1], &buf[0], len);
-
-	ret = i2c_transfer(client->adapter, msgs, 1);
-	if (ret > 0)
-		ret = 0;
-	return ret;
+	ret = i2c_smbus_write_i2c_block_data(client, reg, len, buf);
+	return (ret < 0) ? ret : 0;
 }
 
 /* simple check to see whether we have a isl1208 */

drivers/rtc/rtc-m41t80.c

@@ -217,7 +217,7 @@ static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
 					    sizeof(buf), buf);
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to read date\n");
-		return -EIO;
+		return err;
 	}
 
 	tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f);
@@ -274,10 +274,11 @@ static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	if (flags < 0)
 		return flags;
 
-	if (i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
-				      flags & ~M41T80_FLAGS_OF)) {
+	err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
+					flags & ~M41T80_FLAGS_OF);
+	if (err < 0) {
 		dev_err(&client->dev, "Unable to write flags register\n");
-		return -EIO;
+		return err;
 	}
 
 	return err;
@@ -287,10 +288,12 @@ static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct m41t80_data *clientdata = i2c_get_clientdata(client);
-	u8 reg;
+	int reg;
 
 	if (clientdata->features & M41T80_FEATURE_BL) {
 		reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
+		if (reg < 0)
+			return reg;
 		seq_printf(seq, "battery\t\t: %s\n",
 			   (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
 	}
@@ -393,7 +396,7 @@ static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	alrm->time.tm_min  = bcd2bin(alarmvals[3] & 0x7f);
 	alrm->time.tm_hour = bcd2bin(alarmvals[2] & 0x3f);
 	alrm->time.tm_mday = bcd2bin(alarmvals[1] & 0x3f);
-	alrm->time.tm_mon  = bcd2bin(alarmvals[0] & 0x3f);
+	alrm->time.tm_mon  = bcd2bin(alarmvals[0] & 0x3f) - 1;
 
 	alrm->enabled = !!(alarmvals[0] & M41T80_ALMON_AFE);
 	alrm->pending = (flags & M41T80_FLAGS_AF) && alrm->enabled;
@@ -939,11 +942,7 @@ static int m41t80_probe(struct i2c_client *client,
 		if (m41t80_data->features & M41T80_FEATURE_HT) {
 			m41t80_rtc_read_time(&client->dev, &tm);
 			dev_info(&client->dev, "HT bit was set!\n");
-			dev_info(&client->dev,
-				 "Power Down at %04i-%02i-%02i %02i:%02i:%02i\n",
-				 tm.tm_year + 1900,
-				 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
-				 tm.tm_min, tm.tm_sec);
+			dev_info(&client->dev, "Power Down at %ptR\n", &tm);
 		}
 		rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR,
 					       rc & ~M41T80_ALHOUR_HT);

drivers/rtc/rtc-m48t59.c

@@ -99,9 +99,7 @@ static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 	spin_unlock_irqrestore(&m48t59->lock, flags);
 
-	dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n",
-		tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "RTC read time %ptR\n", tm);
 	return 0;
 }
 
@@ -188,9 +186,7 @@ static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 	spin_unlock_irqrestore(&m48t59->lock, flags);
 
-	dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
-		tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "RTC read alarm time %ptR\n", tm);
 	return rtc_valid_tm(tm);
 }
 

drivers/rtc/rtc-max77686.c

@@ -360,7 +360,7 @@ static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
 
 out:
 	mutex_unlock(&info->lock);
-	return 0;
+	return ret;
 }
 
 static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)

drivers/rtc/rtc-max8997.c

@@ -215,7 +215,7 @@ static int max8997_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 
 out:
 	mutex_unlock(&info->lock);
-	return 0;
+	return ret;
 }
 
 static int max8997_rtc_stop_alarm(struct max8997_rtc_info *info)

drivers/rtc/rtc-mcp795.c

@@ -233,9 +233,7 @@ static int mcp795_set_time(struct device *dev, struct rtc_time *tim)
 	if (ret)
 		return ret;
 
-	dev_dbg(dev, "Set mcp795: %04d-%02d-%02d(%d) %02d:%02d:%02d\n",
-			tim->tm_year + 1900, tim->tm_mon, tim->tm_mday,
-			tim->tm_wday, tim->tm_hour, tim->tm_min, tim->tm_sec);
+	dev_dbg(dev, "Set mcp795: %ptR\n", tim);
 
 	return 0;
 }
@@ -258,9 +256,7 @@ static int mcp795_read_time(struct device *dev, struct rtc_time *tim)
 	tim->tm_mon	= bcd2bin(data[5] & 0x1F) - 1;
 	tim->tm_year	= bcd2bin(data[6]) + 100; /* Assume we are in 20xx */
 
-	dev_dbg(dev, "Read from mcp795: %04d-%02d-%02d(%d) %02d:%02d:%02d\n",
-			tim->tm_year + 1900, tim->tm_mon, tim->tm_mday,
-			tim->tm_wday, tim->tm_hour, tim->tm_min, tim->tm_sec);
+	dev_dbg(dev, "Read from mcp795: %ptR\n", tim);
 
 	return 0;
 }
@@ -319,9 +315,8 @@ static int mcp795_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 			return ret;
 		dev_dbg(dev, "Alarm IRQ armed\n");
 	}
-	dev_dbg(dev, "Set alarm: %02d-%02d(%d) %02d:%02d:%02d\n",
-			alm->time.tm_mon, alm->time.tm_mday, alm->time.tm_wday,
-			alm->time.tm_hour, alm->time.tm_min, alm->time.tm_sec);
+	dev_dbg(dev, "Set alarm: %ptRdr(%d) %ptRt\n",
+		&alm->time, alm->time.tm_wday, &alm->time);
 	return 0;
 }
 
@@ -345,9 +340,8 @@ static int mcp795_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 	alm->time.tm_isdst	= -1;
 	alm->time.tm_yday	= -1;
 
-	dev_dbg(dev, "Read alarm: %02d-%02d(%d) %02d:%02d:%02d\n",
-			alm->time.tm_mon, alm->time.tm_mday, alm->time.tm_wday,
-			alm->time.tm_hour, alm->time.tm_min, alm->time.tm_sec);
+	dev_dbg(dev, "Read alarm: %ptRdr(%d) %ptRt\n",
+		&alm->time, alm->time.tm_wday, &alm->time);
 	return 0;
 }
 

drivers/rtc/rtc-omap.c

@@ -566,9 +566,7 @@ static const struct pinctrl_ops rtc_pinctrl_ops = {
 	.dt_free_map = pinconf_generic_dt_free_map,
 };
 
-enum rtc_pin_config_param {
-	PIN_CONFIG_ACTIVE_HIGH = PIN_CONFIG_END + 1,
-};
+#define PIN_CONFIG_ACTIVE_HIGH		(PIN_CONFIG_END + 1)
 
 static const struct pinconf_generic_params rtc_params[] = {
 	{"ti,active-high", PIN_CONFIG_ACTIVE_HIGH, 0},

drivers/rtc/rtc-pcf2123.c

@@ -453,6 +453,7 @@ static int pcf2123_remove(struct spi_device *spi)
 #ifdef CONFIG_OF
 static const struct of_device_id pcf2123_dt_ids[] = {
 	{ .compatible = "nxp,rtc-pcf2123", },
+	{ .compatible = "microcrystal,rv2123", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, pcf2123_dt_ids);

drivers/rtc/rtc-pcf50633.c

@@ -131,9 +131,7 @@ static int pcf50633_rtc_read_time(struct device *dev, struct rtc_time *tm)
 
 	pcf2rtc_time(tm, &pcf_tm);
 
-	dev_dbg(dev, "RTC_TIME: %u.%u.%u %u:%u:%u\n",
-		tm->tm_mday, tm->tm_mon, tm->tm_year,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "RTC_TIME: %ptRr\n", tm);
 
 	return 0;
 }
@@ -146,9 +144,7 @@ static int pcf50633_rtc_set_time(struct device *dev, struct rtc_time *tm)
 
 	rtc = dev_get_drvdata(dev);
 
-	dev_dbg(dev, "RTC_TIME: %u.%u.%u %u:%u:%u\n",
-		tm->tm_mday, tm->tm_mon, tm->tm_year,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "RTC_TIME: %ptRr\n", tm);
 
 	rtc2pcf_time(&pcf_tm, tm);
 

drivers/rtc/rtc-pcf8523.c

@@ -85,6 +85,18 @@ static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value)
 	return 0;
 }
 
+static int pcf8523_voltage_low(struct i2c_client *client)
+{
+	u8 value;
+	int err;
+
+	err = pcf8523_read(client, REG_CONTROL3, &value);
+	if (err < 0)
+		return err;
+
+	return !!(value & REG_CONTROL3_BLF);
+}
+
 static int pcf8523_select_capacitance(struct i2c_client *client, bool high)
 {
 	u8 value;
@@ -167,6 +179,14 @@ static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	struct i2c_msg msgs[2];
 	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;
@@ -251,17 +271,13 @@ static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
 			     unsigned long arg)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	u8 value;
-	int ret = 0, err;
+	int ret;
 
 	switch (cmd) {
 	case RTC_VL_READ:
-		err = pcf8523_read(client, REG_CONTROL3, &value);
-		if (err < 0)
-			return err;
-
-		if (value & REG_CONTROL3_BLF)
-			ret = 1;
+		ret = pcf8523_voltage_low(client);
+		if (ret < 0)
+			return ret;
 
 		if (copy_to_user((void __user *)arg, &ret, sizeof(int)))
 			return -EFAULT;

drivers/rtc/rtc-pcf85363.c

@@ -120,6 +120,11 @@ struct pcf85363 {
 	struct regmap		*regmap;
 };
 
+struct pcf85x63_config {
+	struct regmap_config regmap;
+	unsigned int num_nvram;
+};
+
 static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
@@ -311,25 +316,75 @@ static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
 				 val, bytes);
 }
 
-static const struct regmap_config regmap_config = {
+static int pcf85x63_nvram_read(void *priv, unsigned int offset, void *val,
+			       size_t bytes)
+{
+	struct pcf85363 *pcf85363 = priv;
+	unsigned int tmp_val;
+	int ret;
+
+	ret = regmap_read(pcf85363->regmap, CTRL_RAMBYTE, &tmp_val);
+	(*(unsigned char *) val) = (unsigned char) tmp_val;
+
+	return ret;
+}
+
+static int pcf85x63_nvram_write(void *priv, unsigned int offset, void *val,
+				size_t bytes)
+{
+	struct pcf85363 *pcf85363 = priv;
+	unsigned char tmp_val;
+
+	tmp_val = *((unsigned char *)val);
+	return regmap_write(pcf85363->regmap, CTRL_RAMBYTE,
+				(unsigned int)tmp_val);
+}
+
+static const struct pcf85x63_config pcf_85263_config = {
+	.regmap = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = 0x2f,
+	},
+	.num_nvram = 1
+};
+
+static const struct pcf85x63_config pcf_85363_config = {
+	.regmap = {
 		.reg_bits = 8,
 		.val_bits = 8,
 		.max_register = 0x7f,
+	},
+	.num_nvram = 2
 };
 
 static int pcf85363_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
 	struct pcf85363 *pcf85363;
-	struct nvmem_config nvmem_cfg = {
+	const struct pcf85x63_config *config = &pcf_85363_config;
+	const void *data = of_device_get_match_data(&client->dev);
+	static struct nvmem_config nvmem_cfg[] = {
+		{
+			.name = "pcf85x63-",
+			.word_size = 1,
+			.stride = 1,
+			.size = 1,
+			.reg_read = pcf85x63_nvram_read,
+			.reg_write = pcf85x63_nvram_write,
+		}, {
 			.name = "pcf85363-",
 			.word_size = 1,
 			.stride = 1,
 			.size = NVRAM_SIZE,
 			.reg_read = pcf85363_nvram_read,
 			.reg_write = pcf85363_nvram_write,
+		},
 	};
-	int ret;
+	int ret, i;
+
+	if (data)
+		config = data;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return -ENODEV;
@@ -339,7 +394,7 @@ static int pcf85363_probe(struct i2c_client *client,
 	if (!pcf85363)
 		return -ENOMEM;
 
-	pcf85363->regmap = devm_regmap_init_i2c(client, &regmap_config);
+	pcf85363->regmap = devm_regmap_init_i2c(client, &config->regmap);
 	if (IS_ERR(pcf85363->regmap)) {
 		dev_err(&client->dev, "regmap allocation failed\n");
 		return PTR_ERR(pcf85363->regmap);
@@ -370,15 +425,18 @@ static int pcf85363_probe(struct i2c_client *client,
 
 	ret = rtc_register_device(pcf85363->rtc);
 
-	nvmem_cfg.priv = pcf85363;
-	rtc_nvmem_register(pcf85363->rtc, &nvmem_cfg);
+	for (i = 0; i < config->num_nvram; i++) {
+		nvmem_cfg[i].priv = pcf85363;
+		rtc_nvmem_register(pcf85363->rtc, &nvmem_cfg[i]);
+	}
 
 	return ret;
 }
 
 static const struct of_device_id dev_ids[] = {
-	{ .compatible = "nxp,pcf85363" },
-	{}
+	{ .compatible = "nxp,pcf85263", .data = &pcf_85263_config },
+	{ .compatible = "nxp,pcf85363", .data = &pcf_85363_config },
+	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dev_ids);
 
@@ -393,5 +451,5 @@ static struct i2c_driver pcf85363_driver = {
 module_i2c_driver(pcf85363_driver);
 
 MODULE_AUTHOR("Eric Nelson");
-MODULE_DESCRIPTION("pcf85363 I2C RTC driver");
+MODULE_DESCRIPTION("pcf85263/pcf85363 I2C RTC driver");
 MODULE_LICENSE("GPL");

drivers/rtc/rtc-pic32.c

@@ -170,9 +170,7 @@ static int pic32_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 
 	rtc_tm->tm_year += 100;
 
-	dev_dbg(dev, "read time %04d.%02d.%02d %02d:%02d:%02d\n",
-		1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
-		rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
+	dev_dbg(dev, "read time %ptR\n", rtc_tm);
 
 	clk_disable(pdata->clk);
 	return 0;
@@ -184,9 +182,7 @@ static int pic32_rtc_settime(struct device *dev, struct rtc_time *tm)
 	void __iomem *base = pdata->reg_base;
 	int year = tm->tm_year - 100;
 
-	dev_dbg(dev, "set time %04d.%02d.%02d %02d:%02d:%02d\n",
-		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "set time %ptR\n", tm);
 
 	if (year < 0 || year >= 100) {
 		dev_err(dev, "rtc only supports 100 years\n");
@@ -224,10 +220,7 @@ static int pic32_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 
 	alrm->enabled = (alm_en & PIC32_RTCALRM_ALRMEN) ? 1 : 0;
 
-	dev_dbg(dev, "getalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
-		alm_en,
-		1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
-		alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
+	dev_dbg(dev, "getalarm: %d, %ptR\n", alm_en, alm_tm);
 
 	alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
 	alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
@@ -247,10 +240,7 @@ static int pic32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	void __iomem *base = pdata->reg_base;
 
 	clk_enable(pdata->clk);
-	dev_dbg(dev, "setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
-		alrm->enabled,
-		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "setalarm: %d, %ptR\n", alrm->enabled, tm);
 
 	writel(0x00, base + PIC32_ALRMTIME);
 	writel(0x00, base + PIC32_ALRMDATE);

drivers/rtc/rtc-pm8xxx.c

@@ -217,9 +217,7 @@ static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
 
 	rtc_time_to_tm(secs, tm);
 
-	dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
-		secs, tm->tm_hour, tm->tm_min, tm->tm_sec,
-		tm->tm_mday, tm->tm_mon, tm->tm_year);
+	dev_dbg(dev, "secs = %lu, h:m:s == %ptRt, y-m-d = %ptRdr\n", secs, tm, tm);
 
 	return 0;
 }
@@ -264,10 +262,8 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 		goto rtc_rw_fail;
 	}
 
-	dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
-		alarm->time.tm_hour, alarm->time.tm_min,
-		alarm->time.tm_sec, alarm->time.tm_mday,
-		alarm->time.tm_mon, alarm->time.tm_year);
+	dev_dbg(dev, "Alarm Set for h:m:s=%ptRt, y-m-d=%ptRdr\n",
+		&alarm->time, &alarm->time);
 rtc_rw_fail:
 	spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
 	return rc;
@@ -298,10 +294,8 @@ static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 		return rc;
 	}
 
-	dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
-		alarm->time.tm_hour, alarm->time.tm_min,
-		alarm->time.tm_sec, alarm->time.tm_mday,
-		alarm->time.tm_mon, alarm->time.tm_year);
+	dev_dbg(dev, "Alarm set for - h:m:s=%ptRt, y-m-d=%ptRdr\n",
+		&alarm->time, &alarm->time);
 
 	return 0;
 }

drivers/rtc/rtc-puv3.c

@@ -90,9 +90,7 @@ static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 {
 	rtc_time_to_tm(readl(RTC_RCNR), rtc_tm);
 
-	dev_dbg(dev, "read time %02x.%02x.%02x %02x/%02x/%02x\n",
-		 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
-		 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
+	dev_dbg(dev, "read time %ptRr\n", rtc_tm);
 
 	return 0;
 }
@@ -101,9 +99,7 @@ static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
 {
 	unsigned long rtc_count = 0;
 
-	dev_dbg(dev, "set time %02d.%02d.%02d %02d/%02d/%02d\n",
-		 tm->tm_year, tm->tm_mon, tm->tm_mday,
-		 tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "set time %ptRr\n", tm);
 
 	rtc_tm_to_time(tm, &rtc_count);
 	writel(rtc_count, RTC_RCNR);
@@ -119,10 +115,7 @@ static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 
 	alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
 
-	dev_dbg(dev, "read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
-		 alrm->enabled,
-		 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
-		 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
+	dev_dbg(dev, "read alarm: %d, %ptRr\n", alrm->enabled, alm_tm);
 
 	return 0;
 }
@@ -132,10 +125,7 @@ static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	struct rtc_time *tm = &alrm->time;
 	unsigned long rtcalarm_count = 0;
 
-	dev_dbg(dev, "puv3_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
-		 alrm->enabled,
-		 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
-		 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
+	dev_dbg(dev, "set alarm: %d, %ptRr\n", alrm->enabled, tm);
 
 	rtc_tm_to_time(tm, &rtcalarm_count);
 	writel(rtcalarm_count, RTC_RTAR);

drivers/rtc/rtc-rk808.c

@@ -138,9 +138,7 @@ static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)
 	tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;
 	tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
 	rockchip_to_gregorian(tm);
-	dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
-		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
-		tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "RTC date/time %ptRd(%d) %ptRt\n", tm, tm->tm_wday, tm);
 
 	return ret;
 }
@@ -153,9 +151,7 @@ static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	u8 rtc_data[NUM_TIME_REGS];
 	int ret;
 
-	dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
-		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
-		tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "set RTC date/time %ptRd(%d) %ptRt\n", tm, tm->tm_wday, tm);
 	gregorian_to_rockchip(tm);
 	rtc_data[0] = bin2bcd(tm->tm_sec);
 	rtc_data[1] = bin2bcd(tm->tm_min);
@@ -216,10 +212,8 @@ static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 		return ret;
 	}
 
-	dev_dbg(dev, "alrm read RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
-		1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
-		alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
-		alrm->time.tm_min, alrm->time.tm_sec);
+	dev_dbg(dev, "alrm read RTC date/time %ptRd(%d) %ptRt\n",
+		&alrm->time, alrm->time.tm_wday, &alrm->time);
 
 	alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;
 
@@ -261,10 +255,8 @@ static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 		dev_err(dev, "Failed to stop alarm: %d\n", ret);
 		return ret;
 	}
-	dev_dbg(dev, "alrm set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
-		1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
-		alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
-		alrm->time.tm_min, alrm->time.tm_sec);
+	dev_dbg(dev, "alrm set RTC date/time %ptRd(%d) %ptRt\n",
+		&alrm->time, alrm->time.tm_wday, &alrm->time);
 
 	gregorian_to_rockchip(&alrm->time);
 	alrm_data[0] = bin2bcd(alrm->time.tm_sec);

drivers/rtc/rtc-rx6110.c

@@ -114,9 +114,7 @@ struct rx6110_data {
  */
 static int rx6110_rtc_tm_to_data(struct rtc_time *tm, u8 *data)
 {
-	pr_debug("%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
-		 tm->tm_sec, tm->tm_min, tm->tm_hour,
-		 tm->tm_mday, tm->tm_mon, tm->tm_year);
+	pr_debug("%s: date %ptRr\n", __func__, tm);
 
 	/*
 	 * The year in the RTC is a value between 0 and 99.
@@ -154,9 +152,7 @@ static int rx6110_data_to_rtc_tm(u8 *data, struct rtc_time *tm)
 	tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1;
 	tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100;
 
-	pr_debug("%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
-		 tm->tm_sec, tm->tm_min, tm->tm_hour,
-		 tm->tm_mday, tm->tm_mon, tm->tm_year);
+	pr_debug("%s: date %ptRr\n", __func__, tm);
 
 	/*
 	 * The year in the RTC is a value between 0 and 99.
@@ -248,9 +244,7 @@ static int rx6110_get_time(struct device *dev, struct rtc_time *tm)
 	if (ret)
 		return ret;
 
-	dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
-		tm->tm_sec, tm->tm_min, tm->tm_hour,
-		tm->tm_mday, tm->tm_mon, tm->tm_year);
+	dev_dbg(dev, "%s: date %ptRr\n", __func__, tm);
 
 	return 0;
 }

drivers/rtc/rtc-rx8025.c

@@ -193,10 +193,7 @@ static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
 	if (err)
 		return err;
 
-	dev_dbg(dev, "%s: read 0x%02x 0x%02x "
-		"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
-		date[0], date[1], date[2], date[3], date[4],
-		date[5], date[6]);
+	dev_dbg(dev, "%s: read %7ph\n", __func__, date);
 
 	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
 	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
@@ -210,9 +207,7 @@ static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
 	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
 	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
 
-	dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
-		dt->tm_sec, dt->tm_min, dt->tm_hour,
-		dt->tm_mday, dt->tm_mon, dt->tm_year);
+	dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
 
 	return 0;
 }
@@ -243,10 +238,7 @@ static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
 	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
 	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
 
-	dev_dbg(dev,
-		"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
-		__func__,
-		date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
+	dev_dbg(dev, "%s: write %7ph\n", __func__, date);
 
 	ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
 	if (ret < 0)
@@ -319,10 +311,7 @@ static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 		t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
 			+ (ald[1] & 0x20 ? 12 : 0);
 
-	dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
-		__func__,
-		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
-		t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
+	dev_dbg(dev, "%s: date: %ptRr\n", __func__, t);
 	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
 	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
 

drivers/rtc/rtc-s3c.c

@@ -225,13 +225,9 @@ static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 	s3c_rtc_disable_clk(info);
 
 	rtc_tm->tm_year += 100;
-
-	dev_dbg(dev, "read time %04d.%02d.%02d %02d:%02d:%02d\n",
-		1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
-		rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
-
 	rtc_tm->tm_mon -= 1;
 
+	dev_dbg(dev, "read time %ptR\n", rtc_tm);
 	return 0;
 }
 
@@ -241,9 +237,7 @@ static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
 	int year = tm->tm_year - 100;
 	int ret;
 
-	dev_dbg(dev, "set time %04d.%02d.%02d %02d:%02d:%02d\n",
-		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "set time %ptR\n", tm);
 
 	/* we get around y2k by simply not supporting it */
 
@@ -292,10 +286,7 @@ static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 
 	alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
 
-	dev_dbg(dev, "read alarm %d, %04d.%02d.%02d %02d:%02d:%02d\n",
-		alm_en,
-		1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
-		alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
+	dev_dbg(dev, "read alarm %d, %ptR\n", alm_en, alm_tm);
 
 	/* decode the alarm enable field */
 	if (alm_en & S3C2410_RTCALM_SECEN)
@@ -327,12 +318,8 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	struct rtc_time *tm = &alrm->time;
 	unsigned int alrm_en;
 	int ret;
-	int year = tm->tm_year - 100;
 
-	dev_dbg(dev, "s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
-		alrm->enabled,
-		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec);
+	dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm);
 
 	ret = s3c_rtc_enable_clk(info);
 	if (ret)
@@ -356,11 +343,6 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 		writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);
 	}
 
-	if (year < 100 && year >= 0) {
-		alrm_en |= S3C2410_RTCALM_YEAREN;
-		writeb(bin2bcd(year), info->base + S3C2410_ALMYEAR);
-	}
-
 	if (tm->tm_mon < 12 && tm->tm_mon >= 0) {
 		alrm_en |= S3C2410_RTCALM_MONEN;
 		writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);

drivers/rtc/rtc-s5m.c

@@ -406,9 +406,7 @@ static int s5m_rtc_read_time(struct device *dev, struct rtc_time *tm)
 		return -EINVAL;
 	}
 
-	dev_dbg(dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
-		1900 + tm->tm_year, 1 + tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_wday);
+	dev_dbg(dev, "%s: %ptR(%d)\n", __func__, tm, tm->tm_wday);
 
 	return 0;
 }
@@ -436,9 +434,7 @@ static int s5m_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	if (ret < 0)
 		return ret;
 
-	dev_dbg(dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
-		1900 + tm->tm_year, 1 + tm->tm_mon, tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_wday);
+	dev_dbg(dev, "%s: %ptR(%d)\n", __func__, tm, tm->tm_wday);
 
 	ret = regmap_raw_write(info->regmap, info->regs->time, data,
 			info->regs->regs_count);
@@ -490,11 +486,7 @@ static int s5m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 		return -EINVAL;
 	}
 
-	dev_dbg(dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
-		1900 + alrm->time.tm_year, 1 + alrm->time.tm_mon,
-		alrm->time.tm_mday, alrm->time.tm_hour,
-		alrm->time.tm_min, alrm->time.tm_sec,
-		alrm->time.tm_wday);
+	dev_dbg(dev, "%s: %ptR(%d)\n", __func__, &alrm->time, alrm->time.tm_wday);
 
 	ret = s5m_check_peding_alarm_interrupt(info, alrm);
 
@@ -513,9 +505,7 @@ static int s5m_rtc_stop_alarm(struct s5m_rtc_info *info)
 		return ret;
 
 	s5m8767_data_to_tm(data, &tm, info->rtc_24hr_mode);
-	dev_dbg(info->dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
-		1900 + tm.tm_year, 1 + tm.tm_mon, tm.tm_mday,
-		tm.tm_hour, tm.tm_min, tm.tm_sec, tm.tm_wday);
+	dev_dbg(info->dev, "%s: %ptR(%d)\n", __func__, &tm, tm.tm_wday);
 
 	switch (info->device_type) {
 	case S5M8763X:
@@ -558,9 +548,7 @@ static int s5m_rtc_start_alarm(struct s5m_rtc_info *info)
 		return ret;
 
 	s5m8767_data_to_tm(data, &tm, info->rtc_24hr_mode);
-	dev_dbg(info->dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
-		1900 + tm.tm_year, 1 + tm.tm_mon, tm.tm_mday,
-		tm.tm_hour, tm.tm_min, tm.tm_sec, tm.tm_wday);
+	dev_dbg(info->dev, "%s: %ptR(%d)\n", __func__, &tm, tm.tm_wday);
 
 	switch (info->device_type) {
 	case S5M8763X:
@@ -620,10 +608,7 @@ static int s5m_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 		return -EINVAL;
 	}
 
-	dev_dbg(dev, "%s: %d/%d/%d %d:%d:%d(%d)\n", __func__,
-		1900 + alrm->time.tm_year, 1 + alrm->time.tm_mon,
-		alrm->time.tm_mday, alrm->time.tm_hour, alrm->time.tm_min,
-		alrm->time.tm_sec, alrm->time.tm_wday);
+	dev_dbg(dev, "%s: %ptR(%d)\n", __func__, &alrm->time, alrm->time.tm_wday);
 
 	ret = s5m_rtc_stop_alarm(info);
 	if (ret < 0)

drivers/rtc/rtc-sh.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * SuperH On-Chip RTC Support
  *
@@ -9,10 +10,6 @@
  *
  *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
  *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
  */
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
@@ -681,5 +678,5 @@ MODULE_DESCRIPTION("SuperH on-chip RTC driver");
 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
 	      "Jamie Lenehan <lenehan@twibble.org>, "
 	      "Angelo Castello <angelo.castello@st.com>");
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:" DRV_NAME);

drivers/rtc/rtc-sun6i.c

@@ -118,9 +118,31 @@
 #define SUN6I_YEAR_MAX				2033
 #define SUN6I_YEAR_OFF				(SUN6I_YEAR_MIN - 1900)
 
+/*
+ * There are other differences between models, including:
+ *
+ *   - number of GPIO pins that can be configured to hold a certain level
+ *   - crypto-key related registers (H5, H6)
+ *   - boot process related (super standby, secondary processor entry address)
+ *     registers (R40, H6)
+ *   - SYS power domain controls (R40)
+ *   - DCXO controls (H6)
+ *   - RC oscillator calibration (H6)
+ *
+ * These functions are not covered by this driver.
+ */
+struct sun6i_rtc_clk_data {
+	unsigned long rc_osc_rate;
+	unsigned int fixed_prescaler : 16;
+	unsigned int has_prescaler : 1;
+	unsigned int has_out_clk : 1;
+	unsigned int export_iosc : 1;
+};
+
 struct sun6i_rtc_dev {
 	struct rtc_device *rtc;
 	struct device *dev;
+	const struct sun6i_rtc_clk_data *data;
 	void __iomem *base;
 	int irq;
 	unsigned long alarm;
@@ -139,14 +161,19 @@ static unsigned long sun6i_rtc_osc_recalc_rate(struct clk_hw *hw,
 					       unsigned long parent_rate)
 {
 	struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
-	u32 val;
+	u32 val = 0;
 
 	val = readl(rtc->base + SUN6I_LOSC_CTRL);
 	if (val & SUN6I_LOSC_CTRL_EXT_OSC)
 		return parent_rate;
 
+	if (rtc->data->fixed_prescaler)
+		parent_rate /= rtc->data->fixed_prescaler;
+
+	if (rtc->data->has_prescaler) {
 		val = readl(rtc->base + SUN6I_LOSC_CLK_PRESCAL);
 		val &= GENMASK(4, 0);
+	}
 
 	return parent_rate / (val + 1);
 }
@@ -185,13 +212,16 @@ static const struct clk_ops sun6i_rtc_osc_ops = {
 	.set_parent	= sun6i_rtc_osc_set_parent,
 };
 
-static void __init sun6i_rtc_clk_init(struct device_node *node)
+static void __init sun6i_rtc_clk_init(struct device_node *node,
+				      const struct sun6i_rtc_clk_data *data)
 {
 	struct clk_hw_onecell_data *clk_data;
 	struct sun6i_rtc_dev *rtc;
 	struct clk_init_data init = {
 		.ops		= &sun6i_rtc_osc_ops,
+		.name		= "losc",
 	};
+	const char *iosc_name = "rtc-int-osc";
 	const char *clkout_name = "osc32k-out";
 	const char *parents[2];
 
@@ -199,7 +229,8 @@ static void __init sun6i_rtc_clk_init(struct device_node *node)
 	if (!rtc)
 		return;
 
-	clk_data = kzalloc(struct_size(clk_data, hws, 2), GFP_KERNEL);
+	rtc->data = data;
+	clk_data = kzalloc(struct_size(clk_data, hws, 3), GFP_KERNEL);
 	if (!clk_data) {
 		kfree(rtc);
 		return;
@@ -224,10 +255,15 @@ static void __init sun6i_rtc_clk_init(struct device_node *node)
 	if (!of_get_property(node, "clocks", NULL))
 		goto err;
 
+	/* Only read IOSC name from device tree if it is exported */
+	if (rtc->data->export_iosc)
+		of_property_read_string_index(node, "clock-output-names", 2,
+					      &iosc_name);
+
 	rtc->int_osc = clk_hw_register_fixed_rate_with_accuracy(NULL,
-								"rtc-int-osc",
+								iosc_name,
 								NULL, 0,
-								667000,
+								rtc->data->rc_osc_rate,
 								300000000);
 	if (IS_ERR(rtc->int_osc)) {
 		pr_crit("Couldn't register the internal oscillator\n");
@@ -264,14 +300,71 @@ static void __init sun6i_rtc_clk_init(struct device_node *node)
 	clk_data->num = 2;
 	clk_data->hws[0] = &rtc->hw;
 	clk_data->hws[1] = __clk_get_hw(rtc->ext_losc);
+	if (rtc->data->export_iosc) {
+		clk_data->hws[2] = rtc->int_osc;
+		clk_data->num = 3;
+	}
 	of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
 	return;
 
 err:
 	kfree(clk_data);
 }
-CLK_OF_DECLARE_DRIVER(sun6i_rtc_clk, "allwinner,sun6i-a31-rtc",
-		      sun6i_rtc_clk_init);
+
+static const struct sun6i_rtc_clk_data sun6i_a31_rtc_data = {
+	.rc_osc_rate = 667000, /* datasheet says 600 ~ 700 KHz */
+	.has_prescaler = 1,
+};
+
+static void __init sun6i_a31_rtc_clk_init(struct device_node *node)
+{
+	sun6i_rtc_clk_init(node, &sun6i_a31_rtc_data);
+}
+CLK_OF_DECLARE_DRIVER(sun6i_a31_rtc_clk, "allwinner,sun6i-a31-rtc",
+		      sun6i_a31_rtc_clk_init);
+
+static const struct sun6i_rtc_clk_data sun8i_a23_rtc_data = {
+	.rc_osc_rate = 667000, /* datasheet says 600 ~ 700 KHz */
+	.has_prescaler = 1,
+	.has_out_clk = 1,
+};
+
+static void __init sun8i_a23_rtc_clk_init(struct device_node *node)
+{
+	sun6i_rtc_clk_init(node, &sun8i_a23_rtc_data);
+}
+CLK_OF_DECLARE_DRIVER(sun8i_a23_rtc_clk, "allwinner,sun8i-a23-rtc",
+		      sun8i_a23_rtc_clk_init);
+
+static const struct sun6i_rtc_clk_data sun8i_h3_rtc_data = {
+	.rc_osc_rate = 16000000,
+	.fixed_prescaler = 32,
+	.has_prescaler = 1,
+	.has_out_clk = 1,
+	.export_iosc = 1,
+};
+
+static void __init sun8i_h3_rtc_clk_init(struct device_node *node)
+{
+	sun6i_rtc_clk_init(node, &sun8i_h3_rtc_data);
+}
+CLK_OF_DECLARE_DRIVER(sun8i_h3_rtc_clk, "allwinner,sun8i-h3-rtc",
+		      sun8i_h3_rtc_clk_init);
+/* As far as we are concerned, clocks for H5 are the same as H3 */
+CLK_OF_DECLARE_DRIVER(sun50i_h5_rtc_clk, "allwinner,sun50i-h5-rtc",
+		      sun8i_h3_rtc_clk_init);
+
+static const struct sun6i_rtc_clk_data sun8i_v3_rtc_data = {
+	.rc_osc_rate = 32000,
+	.has_out_clk = 1,
+};
+
+static void __init sun8i_v3_rtc_clk_init(struct device_node *node)
+{
+	sun6i_rtc_clk_init(node, &sun8i_v3_rtc_data);
+}
+CLK_OF_DECLARE_DRIVER(sun8i_v3_rtc_clk, "allwinner,sun8i-v3-rtc",
+		      sun8i_v3_rtc_clk_init);
 
 static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
 {
@@ -578,8 +671,18 @@ static int sun6i_rtc_probe(struct platform_device *pdev)
 	return 0;
 }
 
+/*
+ * As far as RTC functionality goes, all models are the same. The
+ * datasheets claim that different models have different number of
+ * registers available for non-volatile storage, but experiments show
+ * that all SoCs have 16 registers available for this purpose.
+ */
 static const struct of_device_id sun6i_rtc_dt_ids[] = {
 	{ .compatible = "allwinner,sun6i-a31-rtc" },
+	{ .compatible = "allwinner,sun8i-a23-rtc" },
+	{ .compatible = "allwinner,sun8i-h3-rtc" },
+	{ .compatible = "allwinner,sun8i-v3-rtc" },
+	{ .compatible = "allwinner,sun50i-h5-rtc" },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);

drivers/rtc/rtc-tegra.c

@@ -125,15 +125,7 @@ static int tegra_rtc_read_time(struct device *dev, struct rtc_time *tm)
 
 	rtc_time_to_tm(sec, tm);
 
-	dev_vdbg(dev, "time read as %lu. %d/%d/%d %d:%02u:%02u\n",
-		sec,
-		tm->tm_mon + 1,
-		tm->tm_mday,
-		tm->tm_year + 1900,
-		tm->tm_hour,
-		tm->tm_min,
-		tm->tm_sec
-	);
+	dev_vdbg(dev, "time read as %lu. %ptR\n", sec, tm);
 
 	return 0;
 }
@@ -147,15 +139,7 @@ static int tegra_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	/* convert tm to seconds. */
 	rtc_tm_to_time(tm, &sec);
 
-	dev_vdbg(dev, "time set to %lu. %d/%d/%d %d:%02u:%02u\n",
-		sec,
-		tm->tm_mon+1,
-		tm->tm_mday,
-		tm->tm_year+1900,
-		tm->tm_hour,
-		tm->tm_min,
-		tm->tm_sec
-	);
+	dev_vdbg(dev, "time set to %lu. %ptR\n", sec, tm);
 
 	/* seconds only written if wait succeeded. */
 	ret = tegra_rtc_wait_while_busy(dev);
@@ -232,15 +216,7 @@ static int tegra_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 	/* if successfully written and alarm is enabled ... */
 	if (sec) {
 		tegra_rtc_alarm_irq_enable(dev, 1);
-
-		dev_vdbg(dev, "alarm set as %lu. %d/%d/%d %d:%02u:%02u\n",
-			sec,
-			alarm->time.tm_mon+1,
-			alarm->time.tm_mday,
-			alarm->time.tm_year+1900,
-			alarm->time.tm_hour,
-			alarm->time.tm_min,
-			alarm->time.tm_sec);
+		dev_vdbg(dev, "alarm set as %lu. %ptR\n", sec, &alarm->time);
 	} else {
 		/* disable alarm if 0 or write error. */
 		dev_vdbg(dev, "alarm disabled\n");

drivers/rtc/rtc-sysfs.c → drivers/rtc/sysfs.c

@@ -39,12 +39,10 @@ date_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct rtc_time tm;
 
 	retval = rtc_read_time(to_rtc_device(dev), &tm);
-	if (retval == 0) {
-		retval = sprintf(buf, "%04d-%02d-%02d\n",
-			tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
-	}
-
+	if (retval)
 		return retval;
+
+	return sprintf(buf, "%ptRd\n", &tm);
 }
 static DEVICE_ATTR_RO(date);
 
@@ -55,12 +53,10 @@ time_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct rtc_time tm;
 
 	retval = rtc_read_time(to_rtc_device(dev), &tm);
-	if (retval == 0) {
-		retval = sprintf(buf, "%02d:%02d:%02d\n",
-			tm.tm_hour, tm.tm_min, tm.tm_sec);
-	}
-
+	if (retval)
 		return retval;
+
+	return sprintf(buf, "%ptRt\n", &tm);
 }
 static DEVICE_ATTR_RO(time);
 

include/linux/rtc.h

@@ -87,15 +87,16 @@ struct rtc_class_ops {
 	int (*set_offset)(struct device *, long offset);
 };
 
+struct rtc_device;
+
 struct rtc_timer {
 	struct timerqueue_node node;
 	ktime_t period;
-	void (*func)(void *private_data);
-	void *private_data;
+	void (*func)(struct rtc_device *rtc);
+	struct rtc_device *rtc;
 	int enabled;
 };
 
-
 /* flags */
 #define RTC_DEV_BUSY 0
 
@@ -138,7 +139,6 @@ struct rtc_device {
 
 	bool registered;
 
-	struct nvmem_device *nvmem;
 	/* Old ABI support */
 	bool nvram_old_abi;
 	struct bin_attribute *nvram;
@@ -173,8 +173,6 @@ extern struct rtc_device *devm_rtc_device_register(struct device *dev,
 					struct module *owner);
 struct rtc_device *devm_rtc_allocate_device(struct device *dev);
 int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
-extern void devm_rtc_device_unregister(struct device *dev,
-					struct rtc_device *rtc);
 
 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
@@ -200,11 +198,12 @@ extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
 						unsigned int enabled);
 
 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
-void rtc_aie_update_irq(void *private);
-void rtc_uie_update_irq(void *private);
+void rtc_aie_update_irq(struct rtc_device *rtc);
+void rtc_uie_update_irq(struct rtc_device *rtc);
 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
 
-void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
+void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
+		    struct rtc_device *rtc);
 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
 		    ktime_t expires, ktime_t period);
 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);

lib/test_printf.c

@@ -9,6 +9,7 @@
 #include <linux/module.h>
 #include <linux/printk.h>
 #include <linux/random.h>
+#include <linux/rtc.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 
@@ -249,12 +250,11 @@ plain_format(void)
 #endif	/* BITS_PER_LONG == 64 */
 
 static int __init
-plain_hash(void)
+plain_hash_to_buffer(const void *p, char *buf, size_t len)
 {
-	char buf[PLAIN_BUF_SIZE];
 	int nchars;
 
-	nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
+	nchars = snprintf(buf, len, "%p", p);
 
 	if (nchars != PTR_WIDTH)
 		return -1;
@@ -265,6 +265,20 @@ plain_hash(void)
 		return 0;
 	}
 
+	return 0;
+}
+
+
+static int __init
+plain_hash(void)
+{
+	char buf[PLAIN_BUF_SIZE];
+	int ret;
+
+	ret = plain_hash_to_buffer(PTR, buf, PLAIN_BUF_SIZE);
+	if (ret)
+		return ret;
+
 	if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0)
 		return -1;
 
@@ -294,6 +308,23 @@ plain(void)
 	}
 }
 
+static void __init
+test_hashed(const char *fmt, const void *p)
+{
+	char buf[PLAIN_BUF_SIZE];
+	int ret;
+
+	/*
+	 * No need to increase failed test counter since this is assumed
+	 * to be called after plain().
+	 */
+	ret = plain_hash_to_buffer(p, buf, PLAIN_BUF_SIZE);
+	if (ret)
+		return;
+
+	test(buf, fmt, p);
+}
+
 static void __init
 symbol_ptr(void)
 {
@@ -418,6 +449,29 @@ struct_va_format(void)
 {
 }
 
+static void __init
+struct_rtc_time(void)
+{
+	/* 1543210543 */
+	const struct rtc_time tm = {
+		.tm_sec = 43,
+		.tm_min = 35,
+		.tm_hour = 5,
+		.tm_mday = 26,
+		.tm_mon = 10,
+		.tm_year = 118,
+	};
+
+	test_hashed("%pt", &tm);
+
+	test("2018-11-26T05:35:43", "%ptR", &tm);
+	test("0118-10-26T05:35:43", "%ptRr", &tm);
+	test("05:35:43|2018-11-26", "%ptRt|%ptRd", &tm, &tm);
+	test("05:35:43|0118-10-26", "%ptRtr|%ptRdr", &tm, &tm);
+	test("05:35:43|2018-11-26", "%ptRttr|%ptRdtr", &tm, &tm);
+	test("05:35:43 tr|2018-11-26 tr", "%ptRt tr|%ptRd tr", &tm, &tm);
+}
+
 static void __init
 struct_clk(void)
 {
@@ -529,6 +583,7 @@ test_pointer(void)
 	uuid();
 	dentry();
 	struct_va_format();
+	struct_rtc_time();
 	struct_clk();
 	bitmap();
 	netdev_features();

lib/vsprintf.c

@@ -30,6 +30,7 @@
 #include <linux/ioport.h>
 #include <linux/dcache.h>
 #include <linux/cred.h>
+#include <linux/rtc.h>
 #include <linux/uuid.h>
 #include <linux/of.h>
 #include <net/addrconf.h>
@@ -822,6 +823,20 @@ static const struct printf_spec default_dec_spec = {
 	.precision = -1,
 };
 
+static const struct printf_spec default_dec02_spec = {
+	.base = 10,
+	.field_width = 2,
+	.precision = -1,
+	.flags = ZEROPAD,
+};
+
+static const struct printf_spec default_dec04_spec = {
+	.base = 10,
+	.field_width = 4,
+	.precision = -1,
+	.flags = ZEROPAD,
+};
+
 static noinline_for_stack
 char *resource_string(char *buf, char *end, struct resource *res,
 		      struct printf_spec spec, const char *fmt)
@@ -1549,6 +1564,87 @@ char *address_val(char *buf, char *end, const void *addr, const char *fmt)
 	return special_hex_number(buf, end, num, size);
 }
 
+static noinline_for_stack
+char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
+{
+	int year = tm->tm_year + (r ? 0 : 1900);
+	int mon = tm->tm_mon + (r ? 0 : 1);
+
+	buf = number(buf, end, year, default_dec04_spec);
+	if (buf < end)
+		*buf = '-';
+	buf++;
+
+	buf = number(buf, end, mon, default_dec02_spec);
+	if (buf < end)
+		*buf = '-';
+	buf++;
+
+	return number(buf, end, tm->tm_mday, default_dec02_spec);
+}
+
+static noinline_for_stack
+char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
+{
+	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
+	if (buf < end)
+		*buf = ':';
+	buf++;
+
+	buf = number(buf, end, tm->tm_min, default_dec02_spec);
+	if (buf < end)
+		*buf = ':';
+	buf++;
+
+	return number(buf, end, tm->tm_sec, default_dec02_spec);
+}
+
+static noinline_for_stack
+char *rtc_str(char *buf, char *end, const struct rtc_time *tm, const char *fmt)
+{
+	bool have_t = true, have_d = true;
+	bool raw = false;
+	int count = 2;
+
+	switch (fmt[count]) {
+	case 'd':
+		have_t = false;
+		count++;
+		break;
+	case 't':
+		have_d = false;
+		count++;
+		break;
+	}
+
+	raw = fmt[count] == 'r';
+
+	if (have_d)
+		buf = date_str(buf, end, tm, raw);
+	if (have_d && have_t) {
+		/* Respect ISO 8601 */
+		if (buf < end)
+			*buf = 'T';
+		buf++;
+	}
+	if (have_t)
+		buf = time_str(buf, end, tm, raw);
+
+	return buf;
+}
+
+static noinline_for_stack
+char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
+		    const char *fmt)
+{
+	switch (fmt[1]) {
+	case 'R':
+		return rtc_str(buf, end, (const struct rtc_time *)ptr, fmt);
+	default:
+		return ptr_to_id(buf, end, ptr, spec);
+	}
+}
+
 static noinline_for_stack
 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
 	    const char *fmt)
@@ -1828,6 +1924,8 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
  * - 'd[234]' For a dentry name (optionally 2-4 last components)
  * - 'D[234]' Same as 'd' but for a struct file
  * - 'g' For block_device name (gendisk + partition number)
+ * - 't[R][dt][r]' For time and date as represented:
+ *      R    struct rtc_time
  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
  *       (legacy clock framework) of the clock
  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
@@ -1952,6 +2050,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 		return address_val(buf, end, ptr, fmt);
 	case 'd':
 		return dentry_name(buf, end, ptr, spec, fmt);
+	case 't':
+		return time_and_date(buf, end, ptr, spec, fmt);
 	case 'C':
 		return clock(buf, end, ptr, spec, fmt);
 	case 'D':