Merge tag 'rtc-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "It is now possible to add custom sysfs attributes while avoiding a
  possible race condition. Unused code has been removed resulting in a
  nice reduction of the code base. And more drivers have been switched
  to SPDX by their maintainers.

 Summary:

  Subsystem:
   - new helpers to add custom sysfs attributes
   - struct rtc_task removal along with rtc_irq_[un]register()
   - rtc_irq_set_state and rtc_irq_set_freq are not exported anymore

  Drivers:
   - armada38x: reset after rtc power loss
   - ds1307: now supports m41t11
   - isl1208: now supports isl1219 and tamper detection
   - pcf2127: internal SRAM support"

* tag 'rtc-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (34 commits)
  rtc: ds1307: simplify hwmon config
  rtc: s5m: Add SPDX license identifier
  rtc: maxim: Add SPDX license identifiers
  rtc: isl1219: add device tree documentation
  rtc: isl1208: set ev-evienb bit from device tree
  rtc: isl1208: Add "evdet" interrupt source for isl1219
  rtc: isl1208: add support for isl1219 with tamper detection
  rtc: sysfs: facilitate attribute add to rtc device
  rtc: remove struct rtc_task
  char: rtc: remove task handling
  rtc: pcf85063: preserve control register value between stop and start
  rtc: sh: remove unused variable rtc_dev
  rtc: unexport rtc_irq_set_*
  rtc: simplify rtc_irq_set_state/rtc_irq_set_freq
  rtc: remove irq_task and irq_task_lock
  rtc: remove rtc_irq_register/rtc_irq_unregister
  rtc: sh: remove dead code
  rtc: sa1100: don't set PIE frequency
  rtc: ds1307: support m41t11 variant
  rtc: ds1307: fix data pointer to m41t0
  ...

Documentation/devicetree/bindings/rtc/isil,isl1219.txt

+Intersil ISL1219 I2C RTC/Alarm chip with event in
+
+ISL1219 has additional pins EVIN and #EVDET for tamper detection.
+
+Required properties supported by the device:
+
+ - "compatible": must be "isil,isl1219"
+ - "reg": I2C bus address of the device
+
+Optional properties:
+
+ - "interrupt-names": list which may contains "irq" and "evdet"
+ - "interrupts": list of interrupts for "irq" and "evdet"
+ - "isil,ev-evienb": if present EV.EVIENB bit is set to the specified
+                     value for proper operation.
+
+
+Example isl1219 node with #IRQ pin connected to SoC gpio1 pin12
+ and #EVDET pin connected to SoC gpio2 pin 24:
+
+	isl1219: rtc@68 {
+		compatible = "isil,isl1219";
+		reg = <0x68>;
+		interrupt-names = "irq", "evdet";
+		interrupts-extended = <&gpio1 12 IRQ_TYPE_EDGE_FALLING>,
+			<&gpio2 24 IRQ_TYPE_EDGE_FALLING>;
+		isil,ev-evienb = <1>;
+	};
+

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

@@ -13,6 +13,7 @@ Required properties:
 	"maxim,ds3231",
 	"st,m41t0",
 	"st,m41t00",
+	"st,m41t11",
 	"microchip,mcp7940x",
 	"microchip,mcp7941x",
 	"pericom,pt7c4338",

drivers/char/rtc.c

@@ -193,14 +193,6 @@ static unsigned long rtc_freq;		/* Current periodic IRQ rate	*/
 static unsigned long rtc_irq_data;	/* our output to the world	*/
 static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
 
-#ifdef RTC_IRQ
-/*
- * rtc_task_lock nests inside rtc_lock.
- */
-static DEFINE_SPINLOCK(rtc_task_lock);
-static rtc_task_t *rtc_callback;
-#endif
-
 /*
  *	If this driver ever becomes modularised, it will be really nice
  *	to make the epoch retain its value across module reload...
@@ -264,11 +256,6 @@ static irqreturn_t rtc_interrupt(int irq, void *dev_id)
 
 	spin_unlock(&rtc_lock);
 
-	/* Now do the rest of the actions */
-	spin_lock(&rtc_task_lock);
-	if (rtc_callback)
-		rtc_callback->func(rtc_callback->private_data);
-	spin_unlock(&rtc_task_lock);
 	wake_up_interruptible(&rtc_wait);
 
 	kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);

drivers/rtc/Kconfig

@@ -244,15 +244,6 @@ config RTC_DRV_DS1307
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-ds1307.
 
-config RTC_DRV_DS1307_HWMON
-	bool "HWMON support for rtc-ds1307"
-	depends on RTC_DRV_DS1307 && HWMON
-	depends on !(RTC_DRV_DS1307=y && HWMON=m)
-	default y
-	help
-	  Say Y here if you want to expose temperature sensor data on
-	  rtc-ds1307 (only DS3231)
-
 config RTC_DRV_DS1307_CENTURY
 	bool "Century bit support for rtc-ds1307"
 	depends on RTC_DRV_DS1307
@@ -1027,18 +1018,6 @@ config RTC_DS1685_PROC_REGS
 
 	  Unless you are debugging this driver, choose N.
 
-config RTC_DS1685_SYSFS_REGS
-	bool "SysFS access to RTC register bits"
-	depends on RTC_DRV_DS1685_FAMILY && SYSFS
-	help
-	  Enable this to provide access to the RTC control register bits
-	  in /sys.  Some of the bits are read-write, others are read-only.
-
-	  Keep in mind that reading Control C's bits automatically clears
-	  all pending IRQ flags - this can cause lost interrupts.
-
-	  If you know that you need access to these bits, choose Y, Else N.
-
 config RTC_DRV_DS1742
 	tristate "Maxim/Dallas DS1742/1743"
 	depends on HAS_IOMEM

drivers/rtc/class.c

@@ -68,7 +68,7 @@ static int rtc_suspend(struct device *dev)
 		return 0;
 	}
 
-	getnstimeofday64(&old_system);
+	ktime_get_real_ts64(&old_system);
 	old_rtc.tv_sec = rtc_tm_to_time64(&tm);
 
 
@@ -110,7 +110,7 @@ static int rtc_resume(struct device *dev)
 		return 0;
 
 	/* snapshot the current rtc and system time at resume */
-	getnstimeofday64(&new_system);
+	ktime_get_real_ts64(&new_system);
 	err = rtc_read_time(rtc, &tm);
 	if (err < 0) {
 		pr_debug("%s:  fail to read rtc time\n", dev_name(&rtc->dev));
@@ -172,7 +172,6 @@ static struct rtc_device *rtc_allocate_device(void)
 
 	mutex_init(&rtc->ops_lock);
 	spin_lock_init(&rtc->irq_lock);
-	spin_lock_init(&rtc->irq_task_lock);
 	init_waitqueue_head(&rtc->irq_queue);
 
 	/* Init timerqueue */

drivers/rtc/interface.c

@@ -607,12 +607,6 @@ void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
 	rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
 	spin_unlock_irqrestore(&rtc->irq_lock, flags);
 
-	/* call the task func */
-	spin_lock_irqsave(&rtc->irq_task_lock, flags);
-	if (rtc->irq_task)
-		rtc->irq_task->func(rtc->irq_task->private_data);
-	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
-
 	wake_up_interruptible(&rtc->irq_queue);
 	kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
 }
@@ -721,39 +715,6 @@ void rtc_class_close(struct rtc_device *rtc)
 }
 EXPORT_SYMBOL_GPL(rtc_class_close);
 
-int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
-{
-	int retval = -EBUSY;
-
-	if (task == NULL || task->func == NULL)
-		return -EINVAL;
-
-	/* Cannot register while the char dev is in use */
-	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
-		return -EBUSY;
-
-	spin_lock_irq(&rtc->irq_task_lock);
-	if (rtc->irq_task == NULL) {
-		rtc->irq_task = task;
-		retval = 0;
-	}
-	spin_unlock_irq(&rtc->irq_task_lock);
-
-	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
-
-	return retval;
-}
-EXPORT_SYMBOL_GPL(rtc_irq_register);
-
-void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
-{
-	spin_lock_irq(&rtc->irq_task_lock);
-	if (rtc->irq_task == task)
-		rtc->irq_task = NULL;
-	spin_unlock_irq(&rtc->irq_task_lock);
-}
-EXPORT_SYMBOL_GPL(rtc_irq_unregister);
-
 static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
 {
 	/*
@@ -785,71 +746,45 @@ static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
  * Context: any
  *
  * Note that rtc_irq_set_freq() should previously have been used to
- * specify the desired frequency of periodic IRQ task->func() callbacks.
+ * specify the desired frequency of periodic IRQ.
  */
-int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
+int rtc_irq_set_state(struct rtc_device *rtc, int enabled)
 {
 	int err = 0;
-	unsigned long flags;
 
-retry:
-	spin_lock_irqsave(&rtc->irq_task_lock, flags);
-	if (rtc->irq_task != NULL && task == NULL)
-		err = -EBUSY;
-	else if (rtc->irq_task != task)
-		err = -EACCES;
-	else {
-		if (rtc_update_hrtimer(rtc, enabled) < 0) {
-			spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
-			cpu_relax();
-			goto retry;
-		}
-		rtc->pie_enabled = enabled;
-	}
-	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
+	while (rtc_update_hrtimer(rtc, enabled) < 0)
+		cpu_relax();
+
+	rtc->pie_enabled = enabled;
 
 	trace_rtc_irq_set_state(enabled, err);
 	return err;
 }
-EXPORT_SYMBOL_GPL(rtc_irq_set_state);
 
 /**
  * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
  * @rtc: the rtc device
  * @task: currently registered with rtc_irq_register()
- * @freq: positive frequency with which task->func() will be called
+ * @freq: positive frequency
  * Context: any
  *
  * Note that rtc_irq_set_state() is used to enable or disable the
  * periodic IRQs.
  */
-int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
+int rtc_irq_set_freq(struct rtc_device *rtc, int freq)
 {
 	int err = 0;
-	unsigned long flags;
 
 	if (freq <= 0 || freq > RTC_MAX_FREQ)
 		return -EINVAL;
-retry:
-	spin_lock_irqsave(&rtc->irq_task_lock, flags);
-	if (rtc->irq_task != NULL && task == NULL)
-		err = -EBUSY;
-	else if (rtc->irq_task != task)
-		err = -EACCES;
-	else {
-		rtc->irq_freq = freq;
-		if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
-			spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
-			cpu_relax();
-			goto retry;
-		}
-	}
-	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
+
+	rtc->irq_freq = freq;
+	while (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0)
+		cpu_relax();
 
 	trace_rtc_irq_set_freq(freq, err);
 	return err;
 }
-EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
 
 /**
  * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
@@ -979,8 +914,8 @@ void rtc_timer_do_work(struct work_struct *work)
 		timerqueue_del(&rtc->timerqueue, &timer->node);
 		trace_rtc_timer_dequeue(timer);
 		timer->enabled = 0;
-		if (timer->task.func)
-			timer->task.func(timer->task.private_data);
+		if (timer->func)
+			timer->func(timer->private_data);
 
 		trace_rtc_timer_fired(timer);
 		/* Re-add/fwd periodic timers */
@@ -1035,8 +970,8 @@ void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
 {
 	timerqueue_init(&timer->node);
 	timer->enabled = 0;
-	timer->task.func = f;
-	timer->task.private_data = data;
+	timer->func = f;
+	timer->private_data = data;
 }
 
 /* rtc_timer_start - Sets an rtc_timer to fire in the future

drivers/rtc/rtc-armada38x.c

@@ -30,6 +30,8 @@
 #define RTC_IRQ_FREQ_1HZ	    BIT(2)
 #define RTC_CCR		    0x18
 #define RTC_CCR_MODE		    BIT(15)
+#define RTC_CONF_TEST	    0x1C
+#define RTC_NOMINAL_TIMING	    BIT(13)
 
 #define RTC_TIME	    0xC
 #define RTC_ALARM1	    0x10
@@ -75,6 +77,7 @@ struct armada38x_rtc {
 	void __iomem	    *regs_soc;
 	spinlock_t	    lock;
 	int		    irq;
+	bool		    initialized;
 	struct value_to_freq *val_to_freq;
 	struct armada38x_rtc_data *data;
 };
@@ -226,6 +229,23 @@ static int armada38x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	return 0;
 }
 
+static void armada38x_rtc_reset(struct armada38x_rtc *rtc)
+{
+	u32 reg;
+
+	reg = rtc->data->read_rtc_reg(rtc, RTC_CONF_TEST);
+	/* If bits [7:0] are non-zero, assume RTC was uninitialized */
+	if (reg & 0xff) {
+		rtc_delayed_write(0, rtc, RTC_CONF_TEST);
+		msleep(500); /* Oscillator startup time */
+		rtc_delayed_write(0, rtc, RTC_TIME);
+		rtc_delayed_write(SOC_RTC_ALARM1 | SOC_RTC_ALARM2, rtc,
+				  RTC_STATUS);
+		rtc_delayed_write(RTC_NOMINAL_TIMING, rtc, RTC_CCR);
+	}
+	rtc->initialized = true;
+}
+
 static int armada38x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct armada38x_rtc *rtc = dev_get_drvdata(dev);
@@ -237,6 +257,9 @@ static int armada38x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	if (ret)
 		goto out;
 
+	if (!rtc->initialized)
+		armada38x_rtc_reset(rtc);
+
 	spin_lock_irqsave(&rtc->lock, flags);
 	rtc_delayed_write(time, rtc, RTC_TIME);
 	spin_unlock_irqrestore(&rtc->lock, flags);

drivers/rtc/rtc-bq4802.c

@@ -162,6 +162,10 @@ static int bq4802_probe(struct platform_device *pdev)
 	} else if (p->r->flags & IORESOURCE_MEM) {
 		p->regs = devm_ioremap(&pdev->dev, p->r->start,
 					resource_size(p->r));
+		if (!p->regs){
+			err = -ENOMEM;
+			goto out;
+		}
 		p->read = bq4802_read_mem;
 		p->write = bq4802_write_mem;
 	} else {

drivers/rtc/rtc-core.h

@@ -40,9 +40,23 @@ static inline void rtc_proc_del_device(struct rtc_device *rtc)
 
 #ifdef CONFIG_RTC_INTF_SYSFS
 const struct attribute_group **rtc_get_dev_attribute_groups(void);
+int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp);
+int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps);
 #else
 static inline const struct attribute_group **rtc_get_dev_attribute_groups(void)
 {
 	return NULL;
 }
+
+static inline
+int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
+{
+	return 0;
+}
+
+static inline
+int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
+{
+	return 0;
+}
 #endif

drivers/rtc/rtc-dev.c

@@ -341,11 +341,11 @@ static long rtc_dev_ioctl(struct file *file,
 		return rtc_set_time(rtc, &tm);
 
 	case RTC_PIE_ON:
-		err = rtc_irq_set_state(rtc, NULL, 1);
+		err = rtc_irq_set_state(rtc, 1);
 		break;
 
 	case RTC_PIE_OFF:
-		err = rtc_irq_set_state(rtc, NULL, 0);
+		err = rtc_irq_set_state(rtc, 0);
 		break;
 
 	case RTC_AIE_ON:
@@ -365,7 +365,7 @@ static long rtc_dev_ioctl(struct file *file,
 		return rtc_update_irq_enable(rtc, 0);
 
 	case RTC_IRQP_SET:
-		err = rtc_irq_set_freq(rtc, NULL, arg);
+		err = rtc_irq_set_freq(rtc, arg);
 		break;
 
 	case RTC_IRQP_READ:
@@ -427,7 +427,7 @@ static int rtc_dev_release(struct inode *inode, struct file *file)
 	/* Keep ioctl until all drivers are converted */
 	rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
 	rtc_update_irq_enable(rtc, 0);
-	rtc_irq_set_state(rtc, NULL, 0);
+	rtc_irq_set_state(rtc, 0);
 
 	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
 	return 0;

drivers/rtc/rtc-ds1307.c

@@ -44,6 +44,7 @@ enum ds_type {
 	ds_3231,
 	m41t0,
 	m41t00,
+	m41t11,
 	mcp794xx,
 	rx_8025,
 	rx_8130,
@@ -227,6 +228,11 @@ static const struct chip_desc chips[last_ds_type] = {
 		.irq_handler = rx8130_irq,
 		.rtc_ops = &rx8130_rtc_ops,
 	},
+	[m41t11] = {
+		/* this is battery backed SRAM */
+		.nvram_offset	= 8,
+		.nvram_size	= 56,
+	},
 	[mcp794xx] = {
 		.alarm		= 1,
 		/* this is battery backed SRAM */
@@ -249,6 +255,7 @@ static const struct i2c_device_id ds1307_id[] = {
 	{ "ds3231", ds_3231 },
 	{ "m41t0", m41t0 },
 	{ "m41t00", m41t00 },
+	{ "m41t11", m41t11 },
 	{ "mcp7940x", mcp794xx },
 	{ "mcp7941x", mcp794xx },
 	{ "pt7c4338", ds_1307 },
@@ -299,12 +306,16 @@ static const struct of_device_id ds1307_of_match[] = {
 	},
 	{
 		.compatible = "st,m41t0",
-		.data = (void *)m41t00
+		.data = (void *)m41t0
 	},
 	{
 		.compatible = "st,m41t00",
 		.data = (void *)m41t00
 	},
+	{
+		.compatible = "st,m41t11",
+		.data = (void *)m41t11
+	},
 	{
 		.compatible = "microchip,mcp7940x",
 		.data = (void *)mcp794xx
@@ -347,6 +358,7 @@ static const struct acpi_device_id ds1307_acpi_ids[] = {
 	{ .id = "DS3231", .driver_data = ds_3231 },
 	{ .id = "M41T0", .driver_data = m41t0 },
 	{ .id = "M41T00", .driver_data = m41t00 },
+	{ .id = "M41T11", .driver_data = m41t11 },
 	{ .id = "MCP7940X", .driver_data = mcp794xx },
 	{ .id = "MCP7941X", .driver_data = mcp794xx },
 	{ .id = "PT7C4338", .driver_data = ds_1307 },
@@ -1030,7 +1042,7 @@ static u8 ds1307_trickle_init(struct ds1307 *ds1307,
 
 /*----------------------------------------------------------------------*/
 
-#ifdef CONFIG_RTC_DRV_DS1307_HWMON
+#if IS_REACHABLE(CONFIG_HWMON)
 
 /*
  * Temperature sensor support for ds3231 devices.
@@ -1576,6 +1588,7 @@ static int ds1307_probe(struct i2c_client *client,
 	case ds_1307:
 	case m41t0:
 	case m41t00:
+	case m41t11:
 		/* clock halted?  turn it on, so clock can tick. */
 		if (tmp & DS1307_BIT_CH) {
 			regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
@@ -1641,6 +1654,7 @@ static int ds1307_probe(struct i2c_client *client,
 	case ds_1340:
 	case m41t0:
 	case m41t00:
+	case m41t11:
 		/*
 		 * NOTE: ignores century bits; fix before deploying
 		 * systems that will run through year 2100.

drivers/rtc/rtc-isl1208.c

@@ -14,6 +14,8 @@
 #include <linux/i2c.h>
 #include <linux/bcd.h>
 #include <linux/rtc.h>
+#include "rtc-core.h"
+#include <linux/of_irq.h>
 
 /* Register map */
 /* rtc section */
@@ -33,13 +35,16 @@
 #define ISL1208_REG_SR_ARST    (1<<7)	/* auto reset */
 #define ISL1208_REG_SR_XTOSCB  (1<<6)	/* crystal oscillator */
 #define ISL1208_REG_SR_WRTC    (1<<4)	/* write rtc */
+#define ISL1208_REG_SR_EVT     (1<<3)	/* event */
 #define ISL1208_REG_SR_ALM     (1<<2)	/* alarm */
 #define ISL1208_REG_SR_BAT     (1<<1)	/* battery */
 #define ISL1208_REG_SR_RTCF    (1<<0)	/* rtc fail */
 #define ISL1208_REG_INT 0x08
 #define ISL1208_REG_INT_ALME   (1<<6)   /* alarm enable */
 #define ISL1208_REG_INT_IM     (1<<7)   /* interrupt/alarm mode */
-#define ISL1208_REG_09  0x09	/* reserved */
+#define ISL1219_REG_EV  0x09
+#define ISL1219_REG_EV_EVEN    (1<<4)   /* event detection enable */
+#define ISL1219_REG_EV_EVIENB  (1<<7)   /* event in pull-up disable */
 #define ISL1208_REG_ATR 0x0a
 #define ISL1208_REG_DTR 0x0b
 
@@ -57,8 +62,24 @@
 #define ISL1208_REG_USR2 0x13
 #define ISL1208_USR_SECTION_LEN 2
 
+/* event section */
+#define ISL1219_REG_SCT 0x14
+#define ISL1219_REG_MNT 0x15
+#define ISL1219_REG_HRT 0x16
+#define ISL1219_REG_DTT 0x17
+#define ISL1219_REG_MOT 0x18
+#define ISL1219_REG_YRT 0x19
+#define ISL1219_EVT_SECTION_LEN 6
+
 static struct i2c_driver isl1208_driver;
 
+/* ISL1208 various variants */
+enum {
+	TYPE_ISL1208 = 0,
+	TYPE_ISL1218,
+	TYPE_ISL1219,
+};
+
 /* block read */
 static int
 isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
@@ -80,8 +101,8 @@ isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
 	};
 	int ret;
 
-	BUG_ON(reg > ISL1208_REG_USR2);
-	BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
+	WARN_ON(reg > ISL1219_REG_YRT);
+	WARN_ON(reg + len > ISL1219_REG_YRT + 1);
 
 	ret = i2c_transfer(client->adapter, msgs, 2);
 	if (ret > 0)
@@ -104,8 +125,8 @@ isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
 	};
 	int ret;
 
-	BUG_ON(reg > ISL1208_REG_USR2);
-	BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
+	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);
@@ -493,6 +514,73 @@ isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 	return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
 }
 
+static ssize_t timestamp0_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct i2c_client *client = dev_get_drvdata(dev);
+	int sr;
+
+	sr = isl1208_i2c_get_sr(client);
+	if (sr < 0) {
+		dev_err(dev, "%s: reading SR failed\n", __func__);
+		return sr;
+	}
+
+	sr &= ~ISL1208_REG_SR_EVT;
+
+	sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
+	if (sr < 0)
+		dev_err(dev, "%s: writing SR failed\n",
+			__func__);
+
+	return count;
+};
+
+static ssize_t timestamp0_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = dev_get_drvdata(dev);
+	u8 regs[ISL1219_EVT_SECTION_LEN] = { 0, };
+	struct rtc_time tm;
+	int sr;
+
+	sr = isl1208_i2c_get_sr(client);
+	if (sr < 0) {
+		dev_err(dev, "%s: reading SR failed\n", __func__);
+		return sr;
+	}
+
+	if (!(sr & ISL1208_REG_SR_EVT))
+		return 0;
+
+	sr = isl1208_i2c_read_regs(client, ISL1219_REG_SCT, regs,
+				   ISL1219_EVT_SECTION_LEN);
+	if (sr < 0) {
+		dev_err(dev, "%s: reading event section failed\n",
+			__func__);
+		return 0;
+	}
+
+	/* MSB of each alarm register is an enable bit */
+	tm.tm_sec = bcd2bin(regs[ISL1219_REG_SCT - ISL1219_REG_SCT] & 0x7f);
+	tm.tm_min = bcd2bin(regs[ISL1219_REG_MNT - ISL1219_REG_SCT] & 0x7f);
+	tm.tm_hour = bcd2bin(regs[ISL1219_REG_HRT - ISL1219_REG_SCT] & 0x3f);
+	tm.tm_mday = bcd2bin(regs[ISL1219_REG_DTT - ISL1219_REG_SCT] & 0x3f);
+	tm.tm_mon =
+		bcd2bin(regs[ISL1219_REG_MOT - ISL1219_REG_SCT] & 0x1f) - 1;
+	tm.tm_year = bcd2bin(regs[ISL1219_REG_YRT - ISL1219_REG_SCT]) + 100;
+
+	sr = rtc_valid_tm(&tm);
+	if (sr)
+		return sr;
+
+	return sprintf(buf, "%llu\n",
+				(unsigned long long)rtc_tm_to_time64(&tm));
+};
+
+static DEVICE_ATTR_RW(timestamp0);
+
 static irqreturn_t
 isl1208_rtc_interrupt(int irq, void *data)
 {
@@ -538,6 +626,13 @@ isl1208_rtc_interrupt(int irq, void *data)
 			return err;
 	}
 
+	if (sr & ISL1208_REG_SR_EVT) {
+		sysfs_notify(&rtc->dev.kobj, NULL,
+			     dev_attr_timestamp0.attr.name);
+		dev_warn(&client->dev, "event detected");
+		handled = 1;
+	}
+
 	return handled ? IRQ_HANDLED : IRQ_NONE;
 }
 
@@ -623,11 +718,39 @@ static const struct attribute_group isl1208_rtc_sysfs_files = {
 	.attrs	= isl1208_rtc_attrs,
 };
 
+static struct attribute *isl1219_rtc_attrs[] = {
+	&dev_attr_timestamp0.attr,
+	NULL
+};
+
+static const struct attribute_group isl1219_rtc_sysfs_files = {
+	.attrs	= isl1219_rtc_attrs,
+};
+
+static int isl1208_setup_irq(struct i2c_client *client, int irq)
+{
+	int rc = devm_request_threaded_irq(&client->dev, irq, NULL,
+					isl1208_rtc_interrupt,
+					IRQF_SHARED | IRQF_ONESHOT,
+					isl1208_driver.driver.name,
+					client);
+	if (!rc) {
+		device_init_wakeup(&client->dev, 1);
+		enable_irq_wake(irq);
+	} else {
+		dev_err(&client->dev,
+			"Unable to request irq %d, no alarm support\n",
+			irq);
+	}
+	return rc;
+}
+
 static int
 isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	int rc = 0;
 	struct rtc_device *rtc;
+	int evdet_irq = -1;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return -ENODEV;
@@ -642,6 +765,7 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	rtc->ops = &isl1208_rtc_ops;
 
 	i2c_set_clientdata(client, rtc);
+	dev_set_drvdata(&rtc->dev, client);
 
 	rc = isl1208_i2c_get_sr(client);
 	if (rc < 0) {
@@ -653,26 +777,46 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		dev_warn(&client->dev, "rtc power failure detected, "
 			 "please set clock.\n");
 
+	if (id->driver_data == TYPE_ISL1219) {
+		struct device_node *np = client->dev.of_node;
+		u32 evienb;
+
+		rc = i2c_smbus_read_byte_data(client, ISL1219_REG_EV);
+		if (rc < 0) {
+			dev_err(&client->dev, "failed to read EV reg\n");
+			return rc;
+		}
+		rc |= ISL1219_REG_EV_EVEN;
+		if (!of_property_read_u32(np, "isil,ev-evienb", &evienb)) {
+			if (evienb)
+				rc |= ISL1219_REG_EV_EVIENB;
+			else
+				rc &= ~ISL1219_REG_EV_EVIENB;
+		}
+		rc = i2c_smbus_write_byte_data(client, ISL1219_REG_EV, rc);
+		if (rc < 0) {
+			dev_err(&client->dev, "could not enable tamper detection\n");
+			return rc;
+		}
+		rc = rtc_add_group(rtc, &isl1219_rtc_sysfs_files);
+		if (rc)
+			return rc;
+		evdet_irq = of_irq_get_byname(np, "evdet");
+	}
+
 	rc = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
 	if (rc)
 		return rc;
 
-	if (client->irq > 0) {
-		rc = devm_request_threaded_irq(&client->dev, client->irq, NULL,
-					       isl1208_rtc_interrupt,
-					       IRQF_SHARED | IRQF_ONESHOT,
-					       isl1208_driver.driver.name,
-					       client);
-		if (!rc) {
-			device_init_wakeup(&client->dev, 1);
-			enable_irq_wake(client->irq);
-		} else {
-			dev_err(&client->dev,
-				"Unable to request irq %d, no alarm support\n",
-				client->irq);
-			client->irq = 0;
-		}
-	}
+	if (client->irq > 0)
+		rc = isl1208_setup_irq(client, client->irq);
+	if (rc)
+		return rc;
+
+	if (evdet_irq > 0 && evdet_irq != client->irq)
+		rc = isl1208_setup_irq(client, evdet_irq);
+	if (rc)
+		return rc;
 
 	return rtc_register_device(rtc);
 }
@@ -686,8 +830,9 @@ isl1208_remove(struct i2c_client *client)
 }
 
 static const struct i2c_device_id isl1208_id[] = {
-	{ "isl1208", 0 },
-	{ "isl1218", 0 },
+	{ "isl1208", TYPE_ISL1208 },
+	{ "isl1218", TYPE_ISL1218 },
+	{ "isl1219", TYPE_ISL1219 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, isl1208_id);
@@ -695,6 +840,7 @@ MODULE_DEVICE_TABLE(i2c, isl1208_id);
 static const struct of_device_id isl1208_of_match[] = {
 	{ .compatible = "isil,isl1208" },
 	{ .compatible = "isil,isl1218" },
+	{ .compatible = "isil,isl1219" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, isl1208_of_match);

drivers/rtc/rtc-m48t59.c

@@ -373,7 +373,6 @@ static int m48t59_rtc_probe(struct platform_device *pdev)
 	struct m48t59_private *m48t59 = NULL;
 	struct resource *res;
 	int ret = -ENOMEM;
-	char *name;
 	const struct rtc_class_ops *ops;
 	struct nvmem_config nvmem_cfg = {
 		.name = "m48t59-",
@@ -448,17 +447,14 @@ static int m48t59_rtc_probe(struct platform_device *pdev)
 	}
 	switch (pdata->type) {
 	case M48T59RTC_TYPE_M48T59:
-		name = "m48t59";
 		ops = &m48t59_rtc_ops;
 		pdata->offset = 0x1ff0;
 		break;
 	case M48T59RTC_TYPE_M48T02:
-		name = "m48t02";
 		ops = &m48t02_rtc_ops;
 		pdata->offset = 0x7f0;
 		break;
 	case M48T59RTC_TYPE_M48T08:
-		name = "m48t08";
 		ops = &m48t02_rtc_ops;
 		pdata->offset = 0x1ff0;
 		break;

drivers/rtc/rtc-max77686.c

-/*
- * RTC driver for Maxim MAX77686 and MAX77802
- *
- * Copyright (C) 2012 Samsung Electronics Co.Ltd
- *
- *  based on rtc-max8997.c
- *
- *  This program is free software; you can redistribute  it and/or modify it
- *  under  the terms of  the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the  License, or (at your
- *  option) any later version.
- *
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// RTC driver for Maxim MAX77686 and MAX77802
+//
+// Copyright (C) 2012 Samsung Electronics Co.Ltd
+//
+//  based on rtc-max8997.c
 
 #include <linux/i2c.h>
 #include <linux/slab.h>

drivers/rtc/rtc-max8997.c

-/*
- * RTC driver for Maxim MAX8997
- *
- * Copyright (C) 2013 Samsung Electronics Co.Ltd
- *
- *  based on rtc-max8998.c
- *
- *  This program is free software; you can redistribute  it and/or modify it
- *  under  the terms of  the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the  License, or (at your
- *  option) any later version.
- *
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// RTC driver for Maxim MAX8997
+//
+// Copyright (C) 2013 Samsung Electronics Co.Ltd
+//
+//  based on rtc-max8998.c
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 

drivers/rtc/rtc-max8998.c

-/*
- * RTC driver for Maxim MAX8998
- *
- * Copyright (C) 2010 Samsung Electronics Co.Ltd
- * Author: Minkyu Kang <mk7.kang@samsung.com>
- * Author: Joonyoung Shim <jy0922.shim@samsung.com>
- *
- *  This program is free software; you can redistribute  it and/or modify it
- *  under  the terms of  the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the  License, or (at your
- *  option) any later version.
- *
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// RTC driver for Maxim MAX8998
+//
+// Copyright (C) 2010 Samsung Electronics Co.Ltd
+// Author: Minkyu Kang <mk7.kang@samsung.com>
+// Author: Joonyoung Shim <jy0922.shim@samsung.com>
 
 #include <linux/module.h>
 #include <linux/i2c.h>

drivers/rtc/rtc-omap.c

@@ -449,6 +449,7 @@ static void omap_rtc_power_off(void)
 
 	if (tm2bcd(&tm) < 0) {
 		dev_err(&rtc->rtc->dev, "power off failed\n");
+		rtc->type->lock(rtc);
 		return;
 	}
 
@@ -582,9 +583,7 @@ static int rtc_pinconf_get(struct pinctrl_dev *pctldev,
 	u32 val;
 	u16 arg = 0;
 
-	rtc->type->unlock(rtc);
 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
-	rtc->type->lock(rtc);
 
 	switch (param) {
 	case PIN_CONFIG_INPUT_ENABLE:
@@ -614,9 +613,7 @@ static int rtc_pinconf_set(struct pinctrl_dev *pctldev,
 	u32 param_val;
 	int i;
 
-	rtc->type->unlock(rtc);
 	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
-	rtc->type->lock(rtc);
 
 	/* active low by default */
 	val |= OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
@@ -861,13 +858,6 @@ static int omap_rtc_probe(struct platform_device *pdev)
 			goto err;
 	}
 
-	if (rtc->is_pmic_controller) {
-		if (!pm_power_off) {
-			omap_rtc_power_off_rtc = rtc;
-			pm_power_off = omap_rtc_power_off;
-		}
-	}
-
 	/* Support ext_wakeup pinconf */
 	rtc_pinctrl_desc.name = dev_name(&pdev->dev);
 
@@ -880,12 +870,21 @@ static int omap_rtc_probe(struct platform_device *pdev)
 
 	ret = rtc_register_device(rtc->rtc);
 	if (ret)
-		goto err;
+		goto err_deregister_pinctrl;
 
 	rtc_nvmem_register(rtc->rtc, &omap_rtc_nvmem_config);
 
+	if (rtc->is_pmic_controller) {
+		if (!pm_power_off) {
+			omap_rtc_power_off_rtc = rtc;
+			pm_power_off = omap_rtc_power_off;
+		}
+	}
+
 	return 0;
 
+err_deregister_pinctrl:
+	pinctrl_unregister(rtc->pctldev);
 err:
 	clk_disable_unprepare(rtc->clk);
 	device_init_wakeup(&pdev->dev, false);

drivers/rtc/rtc-pcf2127.c

@@ -36,6 +36,11 @@
 #define PCF2127_REG_MO          (0x08)
 #define PCF2127_REG_YR          (0x09)
 
+/* the pcf2127 has 512 bytes nvmem, pcf2129 doesn't */
+#define PCF2127_REG_RAM_addr_MSB       0x1a
+#define PCF2127_REG_RAM_wrt_cmd        0x1c
+#define PCF2127_REG_RAM_rd_cmd         0x1d
+
 #define PCF2127_OSF             BIT(7)  /* Oscillator Fail flag */
 
 struct pcf2127 {
@@ -183,10 +188,47 @@ static const struct rtc_class_ops pcf2127_rtc_ops = {
 	.set_time	= pcf2127_rtc_set_time,
 };
 
+static int pcf2127_nvmem_read(void *priv, unsigned int offset,
+			      void *val, size_t bytes)
+{
+	struct pcf2127 *pcf2127 = priv;
+	int ret;
+	unsigned char offsetbuf[] = { offset >> 8, offset };
+
+	ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_addr_MSB,
+				offsetbuf, 2);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_RAM_rd_cmd,
+			       val, bytes);
+
+	return ret ?: bytes;
+}
+
+static int pcf2127_nvmem_write(void *priv, unsigned int offset,
+			       void *val, size_t bytes)
+{
+	struct pcf2127 *pcf2127 = priv;
+	int ret;
+	unsigned char offsetbuf[] = { offset >> 8, offset };
+
+	ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_addr_MSB,
+				offsetbuf, 2);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_wrt_cmd,
+				val, bytes);
+
+	return ret ?: bytes;
+}
+
 static int pcf2127_probe(struct device *dev, struct regmap *regmap,
-			const char *name)
+			const char *name, bool has_nvmem)
 {
 	struct pcf2127 *pcf2127;
+	int ret = 0;
 
 	dev_dbg(dev, "%s\n", __func__);
 
@@ -200,8 +242,21 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
 
 	pcf2127->rtc = devm_rtc_device_register(dev, name, &pcf2127_rtc_ops,
 						THIS_MODULE);
+	if (IS_ERR(pcf2127->rtc))
+		return PTR_ERR(pcf2127->rtc);
+
+	if (has_nvmem) {
+		struct nvmem_config nvmem_cfg = {
+			.priv = pcf2127,
+			.reg_read = pcf2127_nvmem_read,
+			.reg_write = pcf2127_nvmem_write,
+			.size = 512,
+		};
+
+		ret = rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg);
+	}
 
-	return PTR_ERR_OR_ZERO(pcf2127->rtc);
+	return ret;
 }
 
 #ifdef CONFIG_OF
@@ -309,11 +364,11 @@ static int pcf2127_i2c_probe(struct i2c_client *client,
 	}
 
 	return pcf2127_probe(&client->dev, regmap,
-				pcf2127_i2c_driver.driver.name);
+			     pcf2127_i2c_driver.driver.name, id->driver_data);
 }
 
 static const struct i2c_device_id pcf2127_i2c_id[] = {
-	{ "pcf2127", 0 },
+	{ "pcf2127", 1 },
 	{ "pcf2129", 0 },
 	{ }
 };
@@ -372,11 +427,12 @@ static int pcf2127_spi_probe(struct spi_device *spi)
 		return PTR_ERR(regmap);
 	}
 
-	return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name);
+	return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name,
+			     spi_get_device_id(spi)->driver_data);
 }
 
 static const struct spi_device_id pcf2127_spi_id[] = {
-	{ "pcf2127", 0 },
+	{ "pcf2127", 1 },
 	{ "pcf2129", 0 },
 	{ }
 };

drivers/rtc/rtc-pcf85063.c

@@ -43,37 +43,38 @@ static struct i2c_driver pcf85063_driver;
 
 static int pcf85063_stop_clock(struct i2c_client *client, u8 *ctrl1)
 {
-	s32 ret;
+	int rc;
+	u8 reg;
 
-	ret = i2c_smbus_read_byte_data(client, PCF85063_REG_CTRL1);
-	if (ret < 0) {
+	rc = i2c_smbus_read_byte_data(client, PCF85063_REG_CTRL1);
+	if (rc < 0) {
 		dev_err(&client->dev, "Failing to stop the clock\n");
 		return -EIO;
 	}
 
 	/* stop the clock */
-	ret |= PCF85063_REG_CTRL1_STOP;
+	reg = rc | PCF85063_REG_CTRL1_STOP;
 
-	ret = i2c_smbus_write_byte_data(client, PCF85063_REG_CTRL1, ret);
-	if (ret < 0) {
+	rc = i2c_smbus_write_byte_data(client, PCF85063_REG_CTRL1, reg);
+	if (rc < 0) {
 		dev_err(&client->dev, "Failing to stop the clock\n");
 		return -EIO;
 	}
 
-	*ctrl1 = ret;
+	*ctrl1 = reg;
 
 	return 0;
 }
 
 static int pcf85063_start_clock(struct i2c_client *client, u8 ctrl1)
 {
-	s32 ret;
+	int rc;
 
 	/* start the clock */
 	ctrl1 &= ~PCF85063_REG_CTRL1_STOP;
 
-	ret = i2c_smbus_write_byte_data(client, PCF85063_REG_CTRL1, ctrl1);
-	if (ret < 0) {
+	rc = i2c_smbus_write_byte_data(client, PCF85063_REG_CTRL1, ctrl1);
+	if (rc < 0) {
 		dev_err(&client->dev, "Failing to start the clock\n");
 		return -EIO;
 	}

drivers/rtc/rtc-s5m.c

-/*
- * Copyright (c) 2013-2014 Samsung Electronics Co., Ltd
- *	http://www.samsung.com
- *
- *  Copyright (C) 2013 Google, Inc
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright (c) 2013-2014 Samsung Electronics Co., Ltd
+//	http://www.samsung.com
+//
+//  Copyright (C) 2013 Google, Inc
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 

drivers/rtc/rtc-sa1100.c

@@ -224,7 +224,6 @@ int sa1100_rtc_init(struct platform_device *pdev, struct sa1100_rtc *info)
 	info->rtc = rtc;
 
 	rtc->max_user_freq = RTC_FREQ;
-	rtc_irq_set_freq(rtc, NULL, RTC_FREQ);
 
 	/* Fix for a nasty initialization problem the in SA11xx RTSR register.
 	 * See also the comments in sa1100_rtc_interrupt().

drivers/rtc/rtc-sh.c

@@ -143,8 +143,6 @@ static int __sh_rtc_alarm(struct sh_rtc *rtc)
 
 static int __sh_rtc_periodic(struct sh_rtc *rtc)
 {
-	struct rtc_device *rtc_dev = rtc->rtc_dev;
-	struct rtc_task *irq_task;
 	unsigned int tmp, pending;
 
 	tmp = readb(rtc->regbase + RCR2);
@@ -161,14 +159,7 @@ static int __sh_rtc_periodic(struct sh_rtc *rtc)
 	else {
 		if (rtc->periodic_freq & PF_HP)
 			rtc->periodic_freq |= PF_COUNT;
-		if (rtc->periodic_freq & PF_KOU) {
-			spin_lock(&rtc_dev->irq_task_lock);
-			irq_task = rtc_dev->irq_task;
-			if (irq_task)
-				irq_task->func(irq_task->private_data);
-			spin_unlock(&rtc_dev->irq_task_lock);
-		} else
-			rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
+		rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
 	}
 
 	return pending;
@@ -224,81 +215,6 @@ static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
 	return IRQ_RETVAL(ret);
 }
 
-static int sh_rtc_irq_set_state(struct device *dev, int enable)
-{
-	struct sh_rtc *rtc = dev_get_drvdata(dev);
-	unsigned int tmp;
-
-	spin_lock_irq(&rtc->lock);
-
-	tmp = readb(rtc->regbase + RCR2);
-
-	if (enable) {
-		rtc->periodic_freq |= PF_KOU;
-		tmp &= ~RCR2_PEF;	/* Clear PES bit */
-		tmp |= (rtc->periodic_freq & ~PF_HP);	/* Set PES2-0 */
-	} else {
-		rtc->periodic_freq &= ~PF_KOU;
-		tmp &= ~(RCR2_PESMASK | RCR2_PEF);
-	}
-
-	writeb(tmp, rtc->regbase + RCR2);
-
-	spin_unlock_irq(&rtc->lock);
-
-	return 0;
-}
-
-static int sh_rtc_irq_set_freq(struct device *dev, int freq)
-{
-	struct sh_rtc *rtc = dev_get_drvdata(dev);
-	int tmp, ret = 0;
-
-	spin_lock_irq(&rtc->lock);
-	tmp = rtc->periodic_freq & PF_MASK;
-
-	switch (freq) {
-	case 0:
-		rtc->periodic_freq = 0x00;
-		break;
-	case 1:
-		rtc->periodic_freq = 0x60;
-		break;
-	case 2:
-		rtc->periodic_freq = 0x50;
-		break;
-	case 4:
-		rtc->periodic_freq = 0x40;
-		break;
-	case 8:
-		rtc->periodic_freq = 0x30 | PF_HP;
-		break;
-	case 16:
-		rtc->periodic_freq = 0x30;
-		break;
-	case 32:
-		rtc->periodic_freq = 0x20 | PF_HP;
-		break;
-	case 64:
-		rtc->periodic_freq = 0x20;
-		break;
-	case 128:
-		rtc->periodic_freq = 0x10 | PF_HP;
-		break;
-	case 256:
-		rtc->periodic_freq = 0x10;
-		break;
-	default:
-		ret = -ENOTSUPP;
-	}
-
-	if (ret == 0)
-		rtc->periodic_freq |= tmp;
-
-	spin_unlock_irq(&rtc->lock);
-	return ret;
-}
-
 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
 {
 	struct sh_rtc *rtc = dev_get_drvdata(dev);
@@ -675,8 +591,6 @@ static int __init sh_rtc_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, rtc);
 
 	/* everything disabled by default */
-	sh_rtc_irq_set_freq(&pdev->dev, 0);
-	sh_rtc_irq_set_state(&pdev->dev, 0);
 	sh_rtc_setaie(&pdev->dev, 0);
 	sh_rtc_setcie(&pdev->dev, 0);
 
@@ -708,8 +622,6 @@ static int __exit sh_rtc_remove(struct platform_device *pdev)
 {
 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
 
-	sh_rtc_irq_set_state(&pdev->dev, 0);
-
 	sh_rtc_setaie(&pdev->dev, 0);
 	sh_rtc_setcie(&pdev->dev, 0);
 

drivers/rtc/rtc-snvs.c

@@ -40,49 +40,83 @@ struct snvs_rtc_data {
 	struct clk *clk;
 };
 
+/* Read 64 bit timer register, which could be in inconsistent state */
+static u64 rtc_read_lpsrt(struct snvs_rtc_data *data)
+{
+	u32 msb, lsb;
+
+	regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &msb);
+	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &lsb);
+	return (u64)msb << 32 | lsb;
+}
+
+/* Read the secure real time counter, taking care to deal with the cases of the
+ * counter updating while being read.
+ */
 static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
 {
 	u64 read1, read2;
-	u32 val;
+	unsigned int timeout = 100;
 
+	/* As expected, the registers might update between the read of the LSB
+	 * reg and the MSB reg.  It's also possible that one register might be
+	 * in partially modified state as well.
+	 */
+	read1 = rtc_read_lpsrt(data);
 	do {
-		regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &val);
-		read1 = val;
-		read1 <<= 32;
-		regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &val);
-		read1 |= val;
-
-		regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &val);
-		read2 = val;
-		read2 <<= 32;
-		regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &val);
-		read2 |= val;
-	} while (read1 != read2);
+		read2 = read1;
+		read1 = rtc_read_lpsrt(data);
+	} while (read1 != read2 && --timeout);
+	if (!timeout)
+		dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
 
 	/* Convert 47-bit counter to 32-bit raw second count */
 	return (u32) (read1 >> CNTR_TO_SECS_SH);
 }
 
-static void rtc_write_sync_lp(struct snvs_rtc_data *data)
+/* Just read the lsb from the counter, dealing with inconsistent state */
+static int rtc_read_lp_counter_lsb(struct snvs_rtc_data *data, u32 *lsb)
+{
+	u32 count1, count2;
+	unsigned int timeout = 100;
+
+	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
+	do {
+		count2 = count1;
+		regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
+	} while (count1 != count2 && --timeout);
+	if (!timeout) {
+		dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
+		return -ETIMEDOUT;
+	}
+
+	*lsb = count1;
+	return 0;
+}
+
+static int rtc_write_sync_lp(struct snvs_rtc_data *data)
 {
-	u32 count1, count2, count3;
-	int i;
-
-	/* Wait for 3 CKIL cycles */
-	for (i = 0; i < 3; i++) {
-		do {
-			regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
-			regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count2);
-		} while (count1 != count2);
-
-		/* Now wait until counter value changes */
-		do {
-			do {
-				regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count2);
-				regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count3);
-			} while (count2 != count3);
-		} while (count3 == count1);
+	u32 count1, count2;
+	u32 elapsed;
+	unsigned int timeout = 1000;
+	int ret;
+
+	ret = rtc_read_lp_counter_lsb(data, &count1);
+	if (ret)
+		return ret;
+
+	/* Wait for 3 CKIL cycles, about 61.0-91.5 µs */
+	do {
+		ret = rtc_read_lp_counter_lsb(data, &count2);
+		if (ret)
+			return ret;
+		elapsed = count2 - count1; /* wrap around _is_ handled! */
+	} while (elapsed < 3 && --timeout);
+	if (!timeout) {
+		dev_err(&data->rtc->dev, "Timeout waiting for LPSRT Counter to change\n");
+		return -ETIMEDOUT;
 	}
+	return 0;
 }
 
 static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
@@ -166,9 +200,7 @@ static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
 			   (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN),
 			   enable ? (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN) : 0);
 
-	rtc_write_sync_lp(data);
-
-	return 0;
+	return rtc_write_sync_lp(data);
 }
 
 static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
@@ -176,11 +208,14 @@ static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	struct snvs_rtc_data *data = dev_get_drvdata(dev);
 	struct rtc_time *alrm_tm = &alrm->time;
 	unsigned long time;
+	int ret;
 
 	rtc_tm_to_time(alrm_tm, &time);
 
 	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
-	rtc_write_sync_lp(data);
+	ret = rtc_write_sync_lp(data);
+	if (ret)
+		return ret;
 	regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);
 
 	/* Clear alarm interrupt status bit */

drivers/rtc/rtc-stmp3xxx.c

@@ -288,10 +288,22 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, rtc_data);
 
-	err = stmp_reset_block(rtc_data->io);
-	if (err) {
-		dev_err(&pdev->dev, "stmp_reset_block failed: %d\n", err);
-		return err;
+	/*
+	 * Resetting the rtc stops the watchdog timer that is potentially
+	 * running. So (assuming it is running on purpose) don't reset if the
+	 * watchdog is enabled.
+	 */
+	if (readl(rtc_data->io + STMP3XXX_RTC_CTRL) &
+	    STMP3XXX_RTC_CTRL_WATCHDOGEN) {
+		dev_info(&pdev->dev,
+			 "Watchdog is running, skip resetting rtc\n");
+	} else {
+		err = stmp_reset_block(rtc_data->io);
+		if (err) {
+			dev_err(&pdev->dev, "stmp_reset_block failed: %d\n",
+				err);
+			return err;
+		}
 	}
 
 	/*

drivers/rtc/rtc-sysfs.c

@@ -317,3 +317,46 @@ const struct attribute_group **rtc_get_dev_attribute_groups(void)
 {
 	return rtc_attr_groups;
 }
+
+int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
+{
+	size_t old_cnt = 0, add_cnt = 0, new_cnt;
+	const struct attribute_group **groups, **old;
+
+	if (rtc->registered)
+		return -EINVAL;
+	if (!grps)
+		return -EINVAL;
+
+	groups = rtc->dev.groups;
+	if (groups)
+		for (; *groups; groups++)
+			old_cnt++;
+
+	for (groups = grps; *groups; groups++)
+		add_cnt++;
+
+	new_cnt = old_cnt + add_cnt + 1;
+	groups = devm_kcalloc(&rtc->dev, new_cnt, sizeof(*groups), GFP_KERNEL);
+	if (IS_ERR_OR_NULL(groups))
+		return PTR_ERR(groups);
+	memcpy(groups, rtc->dev.groups, old_cnt * sizeof(*groups));
+	memcpy(groups + old_cnt, grps, add_cnt * sizeof(*groups));
+	groups[old_cnt + add_cnt] = NULL;
+
+	old = rtc->dev.groups;
+	rtc->dev.groups = groups;
+	if (old && old != rtc_attr_groups)
+		devm_kfree(&rtc->dev, old);
+
+	return 0;
+}
+EXPORT_SYMBOL(rtc_add_groups);
+
+int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
+{
+	const struct attribute_group *groups[] = { grp, NULL };
+
+	return rtc_add_groups(rtc, groups);
+}
+EXPORT_SYMBOL(rtc_add_group);

drivers/rtc/rtc-test.c

@@ -22,7 +22,7 @@ struct rtc_test_data {
 	bool alarm_en;
 };
 
-struct platform_device *pdev[MAX_RTC_TEST];
+static struct platform_device *pdev[MAX_RTC_TEST];
 
 static int test_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {

include/linux/rtc.h

@@ -87,16 +87,11 @@ struct rtc_class_ops {
 	int (*set_offset)(struct device *, long offset);
 };
 
-typedef struct rtc_task {
-	void (*func)(void *private_data);
-	void *private_data;
-} rtc_task_t;
-
-
 struct rtc_timer {
-	struct rtc_task	task;
 	struct timerqueue_node node;
 	ktime_t period;
+	void (*func)(void *private_data);
+	void *private_data;
 	int enabled;
 };
 
@@ -121,8 +116,6 @@ struct rtc_device {
 	wait_queue_head_t irq_queue;
 	struct fasync_struct *async_queue;
 
-	struct rtc_task *irq_task;
-	spinlock_t irq_task_lock;
 	int irq_freq;
 	int max_user_freq;
 
@@ -204,14 +197,8 @@ extern void rtc_update_irq(struct rtc_device *rtc,
 extern struct rtc_device *rtc_class_open(const char *name);
 extern void rtc_class_close(struct rtc_device *rtc);
 
-extern int rtc_irq_register(struct rtc_device *rtc,
-				struct rtc_task *task);
-extern void rtc_irq_unregister(struct rtc_device *rtc,
-				struct rtc_task *task);
-extern int rtc_irq_set_state(struct rtc_device *rtc,
-				struct rtc_task *task, int enabled);
-extern int rtc_irq_set_freq(struct rtc_device *rtc,
-				struct rtc_task *task, int freq);
+extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
+extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,