Merge tag 'rtc-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "RTC subsystem update:
   - Add OF device ID table for i2c drivers

  New RTC driver:
   - Motorola CPCAP PMIC RTC

  RTC driver updates:
   - cmos: fix IRQ selection
   - ds1307: Add ST m41t0 support
   - ds1374: fix watchdog configuration
   - sh: Add rza series support"

* tag 'rtc-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (33 commits)
  rtc: gemini: add return value validation
  rtc: snvs: fix an incorrect check of return value
  rtc: ds1374: wdt: Fix stop/start ioctl always returning -EINVAL
  rtc: ds1374: wdt: Fix issue with timeout scaling from secs to wdt ticks
  rtc: sh: mark PM functions as unused
  rtc: hid-sensor-time: remove some dead code
  rtc: m41t80: Add proper compatible for rv4162
  rtc: ds1307: Add m41t0 to OF device ID table
  rtc: ds1307: support m41t0 variant
  rtc: cpcap: fix improper use of IRQ_NONE for request_threaded_irq
  rtc: cmos: Do not assume irq 8 for rtc when there are no legacy irqs
  x86: i8259: export legacy_pic symbol
  dt-bindings: rtc: document the rtc-sh bindings
  rtc: sh: add support for rza series
  rtc: cpcap: kfreeing devm allocated memory
  rtc: wm8350: Remove unused to_wm8350_from_rtc_dev
  rtc: cpcap: new rtc driver
  dt-bindings: Add vendor prefix for Motorola
  rtc: omap: mark PM methods as __maybe_unused
  rtc: omap: remove incorrect __exit markups
  ...

28 files changed, 721 insertions, 46 deletions

diff --git a/Documentation/devicetree/bindings/rtc/cpcap-rtc.txt b/Documentation/devicetree/bindings/rtc/cpcap-rtc.txt
new file mode 100644
index 000000000000..45750ff3112d
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/cpcap-rtc.txt
@@ -0,0 +1,18 @@
+Motorola CPCAP PMIC RTC
+-----------------------
+
+This module is part of the CPCAP. For more details about the whole
+chip see Documentation/devicetree/bindings/mfd/motorola-cpcap.txt.
+
+Requires node properties:
+- compatible: should contain "motorola,cpcap-rtc"
+- interrupts: An interrupt specifier for alarm and 1 Hz irq
+
+Example:
+
+&cpcap {
+	cpcap_rtc: rtc {
+		compatible = "motorola,cpcap-rtc";
+		interrupts = <39 IRQ_TYPE_NONE>, <26 IRQ_TYPE_NONE>;
+	};
+};
diff --git a/Documentation/devicetree/bindings/rtc/rtc-sh.txt b/Documentation/devicetree/bindings/rtc/rtc-sh.txt
new file mode 100644
index 000000000000..7676c7d28874
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/rtc-sh.txt
@@ -0,0 +1,28 @@
+* Real Time Clock for Renesas SH and ARM SoCs
+
+Required properties:
+- compatible: Should be "renesas,r7s72100-rtc" and "renesas,sh-rtc" as a
+  fallback.
+- reg: physical base address and length of memory mapped region.
+- interrupts: 3 interrupts for alarm, period, and carry.
+- interrupt-names: The interrupts should be labeled as "alarm", "period", and
+  "carry".
+- clocks: The functional clock source for the RTC controller must be listed
+  first (if exists). Additionally, potential clock counting sources are to be
+  listed.
+- clock-names: The functional clock must be labeled as "fck". Other clocks
+  may be named in accordance to the SoC hardware manuals.
+
+
+Example:
+rtc: rtc@fcff1000 {
+	compatible = "renesas,r7s72100-rtc", "renesas,sh-rtc";
+	reg = <0xfcff1000 0x2e>;
+	interrupts = <GIC_SPI 276 IRQ_TYPE_EDGE_RISING
+		      GIC_SPI 277 IRQ_TYPE_EDGE_RISING
+		      GIC_SPI 278 IRQ_TYPE_EDGE_RISING>;
+	interrupt-names = "alarm", "period", "carry";
+	clocks = <&mstp6_clks R7S72100_CLK_RTC>, <&rtc_x1_clk>,
+		 <&rtc_x3_clk>, <&extal_clk>;
+	clock-names = "fck", "rtc_x1", "rtc_x3", "extal";
+};
diff --git a/Documentation/devicetree/bindings/trivial-devices.txt b/Documentation/devicetree/bindings/trivial-devices.txt
index ad10fbe61562..3e0a34c88e07 100644
--- a/Documentation/devicetree/bindings/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/trivial-devices.txt
@@ -160,6 +160,7 @@ sii,s35390a		2-wire CMOS real-time clock
 silabs,si7020		Relative Humidity and Temperature Sensors
 skyworks,sky81452	Skyworks SKY81452: Six-Channel White LED Driver with Touch Panel Bias Supply
 st,24c256		i2c serial eeprom  (24cxx)
+st,m41t0		Serial real-time clock (RTC)
 st,m41t00		Serial real-time clock (RTC)
 st,m41t62		Serial real-time clock (RTC) with alarm
 st,m41t80		M41T80 - SERIAL ACCESS RTC WITH ALARMS
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 12e27844bb7b..c03d20140366 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -197,6 +197,7 @@ minix	MINIX Technology Ltd.
 miramems	MiraMEMS Sensing Technology Co., Ltd.
 mitsubishi	Mitsubishi Electric Corporation
 mosaixtech	Mosaix Technologies, Inc.
+motorola	Motorola, Inc.
 moxa	Moxa
 mpl	MPL AG
 mqmaker	mqmaker Inc.
diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c
index be22f5a2192e..4e3b8a587c88 100644
--- a/arch/x86/kernel/i8259.c
+++ b/arch/x86/kernel/i8259.c
@@ -418,6 +418,7 @@ struct legacy_pic default_legacy_pic = {
 };
 
 struct legacy_pic *legacy_pic = &default_legacy_pic;
+EXPORT_SYMBOL(legacy_pic);
 
 static int __init i8259A_init_ops(void)
 {
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index ee1b0e9dde79..8d3b95728326 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1303,10 +1303,10 @@ config RTC_DRV_SA1100
 
 config RTC_DRV_SH
 	tristate "SuperH On-Chip RTC"
-	depends on SUPERH && HAVE_CLK
+	depends on SUPERH || ARCH_RENESAS
 	help
 	  Say Y here to enable support for the on-chip RTC found in
-	  most SuperH processors.
+	  most SuperH processors. This RTC is also found in RZ/A SoCs.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called rtc-sh.
@@ -1731,6 +1731,13 @@ config RTC_DRV_STM32
 	   This driver can also be built as a module, if so, the module
 	   will be called "rtc-stm32".
 
+config RTC_DRV_CPCAP
+	depends on MFD_CPCAP
+	tristate "Motorola CPCAP RTC"
+	help
+	   Say y here for CPCAP rtc found on some Motorola phones
+	   and tablets such as Droid 4.
+
 comment "HID Sensor RTC drivers"
 
 config RTC_DRV_HID_SENSOR_TIME
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index f07297b1460a..13857d2fce09 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_RTC_DRV_BQ32K)	+= rtc-bq32k.o
 obj-$(CONFIG_RTC_DRV_BQ4802)	+= rtc-bq4802.o
 obj-$(CONFIG_RTC_DRV_CMOS)	+= rtc-cmos.o
 obj-$(CONFIG_RTC_DRV_COH901331)	+= rtc-coh901331.o
+obj-$(CONFIG_RTC_DRV_CPCAP)	+= rtc-cpcap.o
 obj-$(CONFIG_RTC_DRV_DA9052)	+= rtc-da9052.o
 obj-$(CONFIG_RTC_DRV_DA9055)	+= rtc-da9055.o
 obj-$(CONFIG_RTC_DRV_DA9063)	+= rtc-da9063.o
diff --git a/drivers/rtc/rtc-bq32k.c b/drivers/rtc/rtc-bq32k.c
index 2b223935001f..98ac8d5c7901 100644
--- a/drivers/rtc/rtc-bq32k.c
+++ b/drivers/rtc/rtc-bq32k.c
@@ -310,9 +310,16 @@ static const struct i2c_device_id bq32k_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, bq32k_id);
 
+static const struct of_device_id bq32k_of_match[] = {
+	{ .compatible = "ti,bq32000" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, bq32k_of_match);
+
 static struct i2c_driver bq32k_driver = {
 	.driver = {
 		.name	= "bq32k",
+		.of_match_table = of_match_ptr(bq32k_of_match),
 	},
 	.probe		= bq32k_probe,
 	.remove		= bq32k_remove,
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index f4a96dbdabf2..b3de973a6260 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -41,6 +41,9 @@
 #include <linux/pm.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
+#ifdef CONFIG_X86
+#include <asm/i8259.h>
+#endif
 
 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
 #include <linux/mc146818rtc.h>
@@ -1193,17 +1196,23 @@ static int cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 {
 	cmos_wake_setup(&pnp->dev);
 
-	if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0))
+	if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0)) {
+		unsigned int irq = 0;
+#ifdef CONFIG_X86
 		/* Some machines contain a PNP entry for the RTC, but
 		 * don't define the IRQ. It should always be safe to
-		 * hardcode it in these cases
+		 * hardcode it on systems with a legacy PIC.
 		 */
+		if (nr_legacy_irqs())
+			irq = 8;
+#endif
 		return cmos_do_probe(&pnp->dev,
-				pnp_get_resource(pnp, IORESOURCE_IO, 0), 8);
-	else
+				pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
+	} else {
 		return cmos_do_probe(&pnp->dev,
 				pnp_get_resource(pnp, IORESOURCE_IO, 0),
 				pnp_irq(pnp, 0));
+	}
 }
 
 static void cmos_pnp_remove(struct pnp_dev *pnp)
diff --git a/drivers/rtc/rtc-cpcap.c b/drivers/rtc/rtc-cpcap.c
new file mode 100644
index 000000000000..3a0333e1f21a
--- /dev/null
+++ b/drivers/rtc/rtc-cpcap.c
@@ -0,0 +1,330 @@
+/*
+ * Motorola CPCAP PMIC RTC driver
+ *
+ * Based on cpcap-regulator.c from Motorola Linux kernel tree
+ * Copyright (C) 2009 Motorola, Inc.
+ *
+ * Rewritten for mainline kernel
+ *  - use DT
+ *  - use regmap
+ *  - use standard interrupt framework
+ *  - use managed device resources
+ *  - remove custom "secure clock daemon" helpers
+ *
+ * Copyright (C) 2017 Sebastian Reichel <sre@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/err.h>
+#include <linux/regmap.h>
+#include <linux/mfd/motorola-cpcap.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+
+#define SECS_PER_DAY 86400
+#define DAY_MASK  0x7FFF
+#define TOD1_MASK 0x00FF
+#define TOD2_MASK 0x01FF
+
+struct cpcap_time {
+	int day;
+	int tod1;
+	int tod2;
+};
+
+struct cpcap_rtc {
+	struct regmap *regmap;
+	struct rtc_device *rtc_dev;
+	u16 vendor;
+	int alarm_irq;
+	bool alarm_enabled;
+	int update_irq;
+	bool update_enabled;
+};
+
+static void cpcap2rtc_time(struct rtc_time *rtc, struct cpcap_time *cpcap)
+{
+	unsigned long int tod;
+	unsigned long int time;
+
+	tod = (cpcap->tod1 & TOD1_MASK) | ((cpcap->tod2 & TOD2_MASK) << 8);
+	time = tod + ((cpcap->day & DAY_MASK) * SECS_PER_DAY);
+
+	rtc_time_to_tm(time, rtc);
+}
+
+static void rtc2cpcap_time(struct cpcap_time *cpcap, struct rtc_time *rtc)
+{
+	unsigned long time;
+
+	rtc_tm_to_time(rtc, &time);
+
+	cpcap->day = time / SECS_PER_DAY;
+	time %= SECS_PER_DAY;
+	cpcap->tod2 = (time >> 8) & TOD2_MASK;
+	cpcap->tod1 = time & TOD1_MASK;
+}
+
+static int cpcap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct cpcap_rtc *rtc = dev_get_drvdata(dev);
+
+	if (rtc->alarm_enabled == enabled)
+		return 0;
+
+	if (enabled)
+		enable_irq(rtc->alarm_irq);
+	else
+		disable_irq(rtc->alarm_irq);
+
+	rtc->alarm_enabled = !!enabled;
+
+	return 0;
+}
+
+static int cpcap_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct cpcap_rtc *rtc;
+	struct cpcap_time cpcap_tm;
+	int temp_tod2;
+	int ret;
+
+	rtc = dev_get_drvdata(dev);
+
+	ret = regmap_read(rtc->regmap, CPCAP_REG_TOD2, &temp_tod2);
+	ret |= regmap_read(rtc->regmap, CPCAP_REG_DAY, &cpcap_tm.day);
+	ret |= regmap_read(rtc->regmap, CPCAP_REG_TOD1, &cpcap_tm.tod1);
+	ret |= regmap_read(rtc->regmap, CPCAP_REG_TOD2, &cpcap_tm.tod2);
+
+	if (temp_tod2 > cpcap_tm.tod2)
+		ret |= regmap_read(rtc->regmap, CPCAP_REG_DAY, &cpcap_tm.day);
+
+	if (ret) {
+		dev_err(dev, "Failed to read time\n");
+		return -EIO;
+	}
+
+	cpcap2rtc_time(tm, &cpcap_tm);
+
+	return rtc_valid_tm(tm);
+}
+
+static int cpcap_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct cpcap_rtc *rtc;
+	struct cpcap_time cpcap_tm;
+	int ret = 0;
+
+	rtc = dev_get_drvdata(dev);
+
+	rtc2cpcap_time(&cpcap_tm, tm);
+
+	if (rtc->alarm_enabled)
+		disable_irq(rtc->alarm_irq);
+	if (rtc->update_enabled)
+		disable_irq(rtc->update_irq);
+
+	if (rtc->vendor == CPCAP_VENDOR_ST) {
+		/* The TOD1 and TOD2 registers MUST be written in this order
+		 * for the change to properly set.
+		 */
+		ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1,
+					  TOD1_MASK, cpcap_tm.tod1);
+		ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD2,
+					  TOD2_MASK, cpcap_tm.tod2);
+		ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_DAY,
+					  DAY_MASK, cpcap_tm.day);
+	} else {
+		/* Clearing the upper lower 8 bits of the TOD guarantees that
+		 * the upper half of TOD (TOD2) will not increment for 0xFF RTC
+		 * ticks (255 seconds).  During this time we can safely write
+		 * to DAY, TOD2, then TOD1 (in that order) and expect RTC to be
+		 * synchronized to the exact time requested upon the final write
+		 * to TOD1.
+		 */
+		ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1,
+					  TOD1_MASK, 0);
+		ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_DAY,
+					  DAY_MASK, cpcap_tm.day);
+		ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD2,
+					  TOD2_MASK, cpcap_tm.tod2);
+		ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1,
+					  TOD1_MASK, cpcap_tm.tod1);
+	}
+
+	if (rtc->update_enabled)
+		enable_irq(rtc->update_irq);
+	if (rtc->alarm_enabled)
+		enable_irq(rtc->alarm_irq);
+
+	return ret;
+}
+
+static int cpcap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct cpcap_rtc *rtc;
+	struct cpcap_time cpcap_tm;
+	int ret;
+
+	rtc = dev_get_drvdata(dev);
+
+	alrm->enabled = rtc->alarm_enabled;
+
+	ret = regmap_read(rtc->regmap, CPCAP_REG_DAYA, &cpcap_tm.day);
+	ret |= regmap_read(rtc->regmap, CPCAP_REG_TODA2, &cpcap_tm.tod2);
+	ret |= regmap_read(rtc->regmap, CPCAP_REG_TODA1, &cpcap_tm.tod1);
+
+	if (ret) {
+		dev_err(dev, "Failed to read time\n");
+		return -EIO;
+	}
+
+	cpcap2rtc_time(&alrm->time, &cpcap_tm);
+	return rtc_valid_tm(&alrm->time);
+}
+
+static int cpcap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct cpcap_rtc *rtc;
+	struct cpcap_time cpcap_tm;
+	int ret;
+
+	rtc = dev_get_drvdata(dev);
+
+	rtc2cpcap_time(&cpcap_tm, &alrm->time);
+
+	if (rtc->alarm_enabled)
+		disable_irq(rtc->alarm_irq);
+
+	ret = regmap_update_bits(rtc->regmap, CPCAP_REG_DAYA, DAY_MASK,
+				 cpcap_tm.day);
+	ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TODA2, TOD2_MASK,
+				  cpcap_tm.tod2);
+	ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TODA1, TOD1_MASK,
+				  cpcap_tm.tod1);
+
+	if (!ret) {
+		enable_irq(rtc->alarm_irq);
+		rtc->alarm_enabled = true;
+	}
+
+	return ret;
+}
+
+static const struct rtc_class_ops cpcap_rtc_ops = {
+	.read_time		= cpcap_rtc_read_time,
+	.set_time		= cpcap_rtc_set_time,
+	.read_alarm		= cpcap_rtc_read_alarm,
+	.set_alarm		= cpcap_rtc_set_alarm,
+	.alarm_irq_enable	= cpcap_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t cpcap_rtc_alarm_irq(int irq, void *data)
+{
+	struct cpcap_rtc *rtc = data;
+
+	rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t cpcap_rtc_update_irq(int irq, void *data)
+{
+	struct cpcap_rtc *rtc = data;
+
+	rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
+	return IRQ_HANDLED;
+}
+
+static int cpcap_rtc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cpcap_rtc *rtc;
+	int err;
+
+	rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	rtc->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!rtc->regmap)
+		return -ENODEV;
+
+	platform_set_drvdata(pdev, rtc);
+	rtc->rtc_dev = devm_rtc_device_register(dev, "cpcap_rtc",
+						&cpcap_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(rtc->rtc_dev))
+		return PTR_ERR(rtc->rtc_dev);
+
+	err = cpcap_get_vendor(dev, rtc->regmap, &rtc->vendor);
+	if (err)
+		return err;
+
+	rtc->alarm_irq = platform_get_irq(pdev, 0);
+	err = devm_request_threaded_irq(dev, rtc->alarm_irq, NULL,
+					cpcap_rtc_alarm_irq, IRQF_TRIGGER_NONE,
+					"rtc_alarm", rtc);
+	if (err) {
+		dev_err(dev, "Could not request alarm irq: %d\n", err);
+		return err;
+	}
+	disable_irq(rtc->alarm_irq);
+
+	/* Stock Android uses the 1 Hz interrupt for "secure clock daemon",
+	 * which is not supported by the mainline kernel. The mainline kernel
+	 * does not use the irq at the moment, but we explicitly request and
+	 * disable it, so that its masked and does not wake up the processor
+	 * every second.
+	 */
+	rtc->update_irq = platform_get_irq(pdev, 1);
+	err = devm_request_threaded_irq(dev, rtc->update_irq, NULL,
+					cpcap_rtc_update_irq, IRQF_TRIGGER_NONE,
+					"rtc_1hz", rtc);
+	if (err) {
+		dev_err(dev, "Could not request update irq: %d\n", err);
+		return err;
+	}
+	disable_irq(rtc->update_irq);
+
+	err = device_init_wakeup(dev, 1);
+	if (err) {
+		dev_err(dev, "wakeup initialization failed (%d)\n", err);
+		/* ignore error and continue without wakeup support */
+	}
+
+	return 0;
+}
+
+static const struct of_device_id cpcap_rtc_of_match[] = {
+	{ .compatible = "motorola,cpcap-rtc", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, cpcap_rtc_of_match);
+
+static struct platform_driver cpcap_rtc_driver = {
+	.probe		= cpcap_rtc_probe,
+	.driver		= {
+		.name	= "cpcap-rtc",
+		.of_match_table = cpcap_rtc_of_match,
+	},
+};
+
+module_platform_driver(cpcap_rtc_driver);
+
+MODULE_ALIAS("platform:cpcap-rtc");
+MODULE_DESCRIPTION("CPCAP RTC driver");
+MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 4ad97be48043..77339b3d50a1 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -16,6 +16,7 @@
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/of_device.h>
 #include <linux/rtc/ds1307.h>
 #include <linux/rtc.h>
 #include <linux/slab.h>
@@ -38,6 +39,7 @@ enum ds_type {
 	ds_1340,
 	ds_1388,
 	ds_3231,
+	m41t0,
 	m41t00,
 	mcp794xx,
 	rx_8025,
@@ -52,6 +54,7 @@ enum ds_type {
 #	define DS1340_BIT_nEOSC		0x80
 #	define MCP794XX_BIT_ST		0x80
 #define DS1307_REG_MIN		0x01	/* 00-59 */
+#	define M41T0_BIT_OF		0x80
 #define DS1307_REG_HOUR		0x02	/* 00-23, or 1-12{am,pm} */
 #	define DS1307_BIT_12HR		0x40	/* in REG_HOUR */
 #	define DS1307_BIT_PM		0x20	/* in REG_HOUR */
@@ -182,6 +185,7 @@ static const struct i2c_device_id ds1307_id[] = {
 	{ "ds1388", ds_1388 },
 	{ "ds1340", ds_1340 },
 	{ "ds3231", ds_3231 },
+	{ "m41t0", m41t0 },
 	{ "m41t00", m41t00 },
 	{ "mcp7940x", mcp794xx },
 	{ "mcp7941x", mcp794xx },
@@ -192,6 +196,69 @@ static const struct i2c_device_id ds1307_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, ds1307_id);
 
+#ifdef CONFIG_OF
+static const struct of_device_id ds1307_of_match[] = {
+	{
+		.compatible = "dallas,ds1307",
+		.data = (void *)ds_1307
+	},
+	{
+		.compatible = "dallas,ds1337",
+		.data = (void *)ds_1337
+	},
+	{
+		.compatible = "dallas,ds1338",
+		.data = (void *)ds_1338
+	},
+	{
+		.compatible = "dallas,ds1339",
+		.data = (void *)ds_1339
+	},
+	{
+		.compatible = "dallas,ds1388",
+		.data = (void *)ds_1388
+	},
+	{
+		.compatible = "dallas,ds1340",
+		.data = (void *)ds_1340
+	},
+	{
+		.compatible = "maxim,ds3231",
+		.data = (void *)ds_3231
+	},
+	{
+		.compatible = "st,m41t0",
+		.data = (void *)m41t00
+	},
+	{
+		.compatible = "st,m41t00",
+		.data = (void *)m41t00
+	},
+	{
+		.compatible = "microchip,mcp7940x",
+		.data = (void *)mcp794xx
+	},
+	{
+		.compatible = "microchip,mcp7941x",
+		.data = (void *)mcp794xx
+	},
+	{
+		.compatible = "pericom,pt7c4338",
+		.data = (void *)ds_1307
+	},
+	{
+		.compatible = "epson,rx8025",
+		.data = (void *)rx_8025
+	},
+	{
+		.compatible = "isil,isl12057",
+		.data = (void *)ds_1337
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ds1307_of_match);
+#endif
+
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id ds1307_acpi_ids[] = {
 	{ .id = "DS1307", .driver_data = ds_1307 },
@@ -201,6 +268,7 @@ static const struct acpi_device_id ds1307_acpi_ids[] = {
 	{ .id = "DS1388", .driver_data = ds_1388 },
 	{ .id = "DS1340", .driver_data = ds_1340 },
 	{ .id = "DS3231", .driver_data = ds_3231 },
+	{ .id = "M41T0", .driver_data = m41t0 },
 	{ .id = "M41T00", .driver_data = m41t00 },
 	{ .id = "MCP7940X", .driver_data = mcp794xx },
 	{ .id = "MCP7941X", .driver_data = mcp794xx },
@@ -396,6 +464,13 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 
 	dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
 
+	/* if oscillator fail bit is set, no data can be trusted */
+	if (ds1307->type == m41t0 &&
+	    ds1307->regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
+		dev_warn_once(dev, "oscillator failed, set time!\n");
+		return -EINVAL;
+	}
+
 	t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
 	t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
 	tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
@@ -1318,7 +1393,12 @@ static int ds1307_probe(struct i2c_client *client,
 	i2c_set_clientdata(client, ds1307);
 
 	ds1307->client	= client;
-	if (id) {
+
+	if (client->dev.of_node) {
+		ds1307->type = (enum ds_type)
+			of_device_get_match_data(&client->dev);
+		chip = &chips[ds1307->type];
+	} else if (id) {
 		chip = &chips[id->driver_data];
 		ds1307->type = id->driver_data;
 	} else {
@@ -1513,6 +1593,7 @@ read_rtc:
 	tmp = ds1307->regs[DS1307_REG_SECS];
 	switch (ds1307->type) {
 	case ds_1307:
+	case m41t0:
 	case m41t00:
 		/* clock halted?  turn it on, so clock can tick. */
 		if (tmp & DS1307_BIT_CH) {
@@ -1577,6 +1658,7 @@ read_rtc:
 	tmp = ds1307->regs[DS1307_REG_HOUR];
 	switch (ds1307->type) {
 	case ds_1340:
+	case m41t0:
 	case m41t00:
 		/*
 		 * NOTE: ignores century bits; fix before deploying
@@ -1711,6 +1793,7 @@ static int ds1307_remove(struct i2c_client *client)
 static struct i2c_driver ds1307_driver = {
 	.driver = {
 		.name	= "rtc-ds1307",
+		.of_match_table = of_match_ptr(ds1307_of_match),
 		.acpi_match_table = ACPI_PTR(ds1307_acpi_ids),
 	},
 	.probe		= ds1307_probe,
diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c
index 52429f0a57cc..38a2e9e684df 100644
--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -525,6 +525,10 @@ static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
 		if (get_user(new_margin, (int __user *)arg))
 			return -EFAULT;
 
+		/* the hardware's tick rate is 4096 Hz, so
+		 * the counter value needs to be scaled accordingly
+		 */
+		new_margin <<= 12;
 		if (new_margin < 1 || new_margin > 16777216)
 			return -EINVAL;
 
@@ -533,7 +537,8 @@ static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
 		ds1374_wdt_ping();
 		/* fallthrough */
 	case WDIOC_GETTIMEOUT:
-		return put_user(wdt_margin, (int __user *)arg);
+		/* when returning ... inverse is true */
+		return put_user((wdt_margin >> 12), (int __user *)arg);
 	case WDIOC_SETOPTIONS:
 		if (copy_from_user(&options, (int __user *)arg, sizeof(int)))
 			return -EFAULT;
@@ -541,14 +546,15 @@ static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
 		if (options & WDIOS_DISABLECARD) {
 			pr_info("disable watchdog\n");
 			ds1374_wdt_disable();
+			return 0;
 		}
 
 		if (options & WDIOS_ENABLECARD) {
 			pr_info("enable watchdog\n");
 			ds1374_wdt_settimeout(wdt_margin);
 			ds1374_wdt_ping();
+			return 0;
 		}
-
 		return -EINVAL;
 	}
 	return -ENOTTY;
@@ -704,6 +710,7 @@ static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume);
 static struct i2c_driver ds1374_driver = {
 	.driver = {
 		.name = "rtc-ds1374",
+		.of_match_table = of_match_ptr(ds1374_of_match),
 		.pm = &ds1374_pm,
 	},
 	.probe = ds1374_probe,
diff --git a/drivers/rtc/rtc-ds1672.c b/drivers/rtc/rtc-ds1672.c
index 5c18ac7394c4..7bf46bfe11a4 100644
--- a/drivers/rtc/rtc-ds1672.c
+++ b/drivers/rtc/rtc-ds1672.c
@@ -196,10 +196,17 @@ static struct i2c_device_id ds1672_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, ds1672_id);
 
+static const struct of_device_id ds1672_of_match[] = {
+	{ .compatible = "dallas,ds1672" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ds1672_of_match);
+
 static struct i2c_driver ds1672_driver = {
 	.driver = {
 		   .name = "rtc-ds1672",
-		   },
+		   .of_match_table = of_match_ptr(ds1672_of_match),
+	},
 	.probe = &ds1672_probe,
 	.id_table = ds1672_id,
 };
diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
index 9bb39a06b994..deff431a37c4 100644
--- a/drivers/rtc/rtc-ds3232.c
+++ b/drivers/rtc/rtc-ds3232.c
@@ -442,9 +442,16 @@ static const struct i2c_device_id ds3232_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, ds3232_id);
 
+static const struct of_device_id ds3232_of_match[] = {
+	{ .compatible = "dallas,ds3232" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ds3232_of_match);
+
 static struct i2c_driver ds3232_driver = {
 	.driver = {
 		.name = "rtc-ds3232",
+		.of_match_table = of_match_ptr(ds3232_of_match),
 		.pm	= &ds3232_pm_ops,
 	},
 	.probe = ds3232_i2c_probe,
diff --git a/drivers/rtc/rtc-gemini.c b/drivers/rtc/rtc-gemini.c
index ccf0dbadb62d..5279390bb42d 100644
--- a/drivers/rtc/rtc-gemini.c
+++ b/drivers/rtc/rtc-gemini.c
@@ -139,6 +139,8 @@ static int gemini_rtc_probe(struct platform_device *pdev)
 
 	rtc->rtc_base = devm_ioremap(dev, res->start,
 				     resource_size(res));
+	if (!rtc->rtc_base)
+		return -ENOMEM;
 
 	ret = devm_request_irq(dev, rtc->rtc_irq, gemini_rtc_interrupt,
 			       IRQF_SHARED, pdev->name, dev);
diff --git a/drivers/rtc/rtc-hid-sensor-time.c b/drivers/rtc/rtc-hid-sensor-time.c
index c398f74234c6..2751dba850c6 100644
--- a/drivers/rtc/rtc-hid-sensor-time.c
+++ b/drivers/rtc/rtc-hid-sensor-time.c
@@ -291,9 +291,9 @@ static int hid_time_probe(struct platform_device *pdev)
 					"hid-sensor-time", &hid_time_rtc_ops,
 					THIS_MODULE);
 
-	if (IS_ERR_OR_NULL(time_state->rtc)) {
+	if (IS_ERR(time_state->rtc)) {
 		hid_device_io_stop(hsdev->hdev);
-		ret = time_state->rtc ? PTR_ERR(time_state->rtc) : -ENODEV;
+		ret = PTR_ERR(time_state->rtc);
 		time_state->rtc = NULL;
 		dev_err(&pdev->dev, "rtc device register failed!\n");
 		goto err_rtc;
diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c
index 2893785f0eba..8dd299c6a1f3 100644
--- a/drivers/rtc/rtc-isl1208.c
+++ b/drivers/rtc/rtc-isl1208.c
@@ -687,10 +687,18 @@ static const struct i2c_device_id isl1208_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, isl1208_id);
 
+static const struct of_device_id isl1208_of_match[] = {
+	{ .compatible = "isil,isl1208" },
+	{ .compatible = "isil,isl1218" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, isl1208_of_match);
+
 static struct i2c_driver isl1208_driver = {
 	.driver = {
-		   .name = "rtc-isl1208",
-		   },
+		.name = "rtc-isl1208",
+		.of_match_table = of_match_ptr(isl1208_of_match),
+	},
 	.probe = isl1208_