Merge tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "RTC for 4.8

  Cleanups:
   - huge cleanup of rtc-generic and char/genrtc this allowed to cleanup
     rtc-cmos, rtc-sh, rtc-m68k, rtc-powerpc and rtc-parisc
   - move mn10300 to rtc-cmos

  Subsystem:
   - fix wakealarms after hibernate
   - multiples fixes for rctest
   - simplify implementations of .read_alarm

  New drivers:
   - Maxim MAX6916

  Drivers:
   - ds1307: fix weekday
   - m41t80: add wakeup support
   - pcf85063: add support for PCF85063A variant
   - rv8803: extend i2c fix and other fixes
   - s35390a: fix alarm reading, this fixes instant reboot after
     shutdown for QNAP TS-41x
   - s3c: clock fixes"

* tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (65 commits)
  rtc: rv8803: Clear V1F when setting the time
  rtc: rv8803: Stop the clock while setting the time
  rtc: rv8803: Always apply the I²C workaround
  rtc: rv8803: Fix read day of week
  rtc: rv8803: Remove the check for valid time
  rtc: rv8803: Kconfig: Indicate rx8900 support
  rtc: asm9260: remove .owner field for driver
  rtc: at91sam9: Fix missing spin_lock_init()
  rtc: m41t80: add suspend handlers for alarm IRQ
  rtc: m41t80: make it a real error message
  rtc: pcf85063: Add support for the PCF85063A device
  rtc: pcf85063: fix year range
  rtc: hym8563: in .read_alarm set .tm_sec to 0 to signal minute accuracy
  rtc: explicitly set tm_sec = 0 for drivers with minute accurancy
  rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()
  rtc: s3c: Remove unnecessary call to disable already disabled clock
  rtc: abx80x: use devm_add_action_or_reset()
  rtc: m41t80: use devm_add_action_or_reset()
  rtc: fix a typo and reduce three empty lines to one
  rtc: s35390a: improve two comments in .set_alarm
  ...

drivers/rtc/rtc-m41t80.c

@@ -244,7 +244,7 @@ static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled)
 
 	retval = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, flags);
 	if (retval < 0) {
-		dev_info(dev, "Unable to enable alarm IRQ %d\n", retval);
+		dev_err(dev, "Unable to enable alarm IRQ %d\n", retval);
 		return retval;
 	}
 	return 0;
@@ -320,10 +320,8 @@ static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	alrm->time.tm_sec  = bcd2bin(alarmvals[4] & 0x7f);
 	alrm->time.tm_min  = bcd2bin(alarmvals[3] & 0x7f);
 	alrm->time.tm_hour = bcd2bin(alarmvals[2] & 0x3f);
-	alrm->time.tm_wday = -1;
 	alrm->time.tm_mday = bcd2bin(alarmvals[1] & 0x3f);
 	alrm->time.tm_mon  = bcd2bin(alarmvals[0] & 0x3f);
-	alrm->time.tm_year = -1;
 
 	alrm->enabled = !!(alarmvals[0] & M41T80_ALMON_AFE);
 	alrm->pending = (flags & M41T80_FLAGS_AF) && alrm->enabled;
@@ -337,6 +335,30 @@ static struct rtc_class_ops m41t80_rtc_ops = {
 	.proc = m41t80_rtc_proc,
 };
 
+#ifdef CONFIG_PM_SLEEP
+static int m41t80_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	if (client->irq >= 0 && device_may_wakeup(dev))
+		enable_irq_wake(client->irq);
+
+	return 0;
+}
+
+static int m41t80_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	if (client->irq >= 0 && device_may_wakeup(dev))
+		disable_irq_wake(client->irq);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(m41t80_pm, m41t80_suspend, m41t80_resume);
+
 static ssize_t flags_show(struct device *dev,
 			  struct device_attribute *attr, char *buf)
 {
@@ -831,10 +853,9 @@ static int m41t80_probe(struct i2c_client *client,
 		return rc;
 	}
 
-	rc = devm_add_action(&client->dev, m41t80_remove_sysfs_group,
-			     &client->dev);
+	rc = devm_add_action_or_reset(&client->dev, m41t80_remove_sysfs_group,
+				      &client->dev);
 	if (rc) {
-		m41t80_remove_sysfs_group(&client->dev);
 		dev_err(&client->dev,
 			"Failed to add sysfs cleanup action: %d\n", rc);
 		return rc;
@@ -873,6 +894,7 @@ static int m41t80_remove(struct i2c_client *client)
 static struct i2c_driver m41t80_driver = {
 	.driver = {
 		.name = "rtc-m41t80",
+		.pm = &m41t80_pm,
 	},
 	.probe = m41t80_probe,
 	.remove = m41t80_remove,

drivers/rtc/rtc-m48t86.c

@@ -16,7 +16,7 @@
 #include <linux/module.h>
 #include <linux/rtc.h>
 #include <linux/platform_device.h>
-#include <linux/m48t86.h>
+#include <linux/platform_data/rtc-m48t86.h>
 #include <linux/bcd.h>
 
 #define M48T86_REG_SEC		0x00

drivers/rtc/rtc-max6916.c

+/* rtc-max6916.c
+ *
+ * Driver for MAXIM  max6916 Low Current, SPI Compatible
+ * Real Time Clock
+ *
+ * Author : Venkat Prashanth B U <venkat.prashanth2498@gmail.com>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/spi/spi.h>
+#include <linux/bcd.h>
+
+/* Registers in max6916 rtc */
+
+#define MAX6916_SECONDS_REG	0x01
+#define MAX6916_MINUTES_REG	0x02
+#define MAX6916_HOURS_REG	0x03
+#define MAX6916_DATE_REG	0x04
+#define MAX6916_MONTH_REG	0x05
+#define MAX6916_DAY_REG	0x06
+#define MAX6916_YEAR_REG	0x07
+#define MAX6916_CONTROL_REG	0x08
+#define MAX6916_STATUS_REG	0x0C
+#define MAX6916_CLOCK_BURST	0x3F
+
+static int max6916_read_reg(struct device *dev, unsigned char address,
+			    unsigned char *data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	*data = address | 0x80;
+
+	return spi_write_then_read(spi, data, 1, data, 1);
+}
+
+static int max6916_write_reg(struct device *dev, unsigned char address,
+			     unsigned char data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	unsigned char buf[2];
+
+	buf[0] = address & 0x7F;
+	buf[1] = data;
+
+	return spi_write_then_read(spi, buf, 2, NULL, 0);
+}
+
+static int max6916_read_time(struct device *dev, struct rtc_time *dt)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	int err;
+	unsigned char buf[8];
+
+	buf[0] = MAX6916_CLOCK_BURST | 0x80;
+
+	err = spi_write_then_read(spi, buf, 1, buf, 8);
+
+	if (err)
+		return err;
+
+	dt->tm_sec = bcd2bin(buf[0]);
+	dt->tm_min = bcd2bin(buf[1]);
+	dt->tm_hour = bcd2bin(buf[2] & 0x3F);
+	dt->tm_mday = bcd2bin(buf[3]);
+	dt->tm_mon = bcd2bin(buf[4]) - 1;
+	dt->tm_wday = bcd2bin(buf[5]) - 1;
+	dt->tm_year = bcd2bin(buf[6]) + 100;
+
+	return rtc_valid_tm(dt);
+}
+
+static int max6916_set_time(struct device *dev, struct rtc_time *dt)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	unsigned char buf[9];
+
+	if (dt->tm_year < 100 || dt->tm_year > 199) {
+		dev_err(&spi->dev, "Year must be between 2000 and 2099. It's %d.\n",
+			dt->tm_year + 1900);
+	return -EINVAL;
+	}
+
+	buf[0] = MAX6916_CLOCK_BURST & 0x7F;
+	buf[1] = bin2bcd(dt->tm_sec);
+	buf[2] = bin2bcd(dt->tm_min);
+	buf[3] = (bin2bcd(dt->tm_hour) & 0X3F);
+	buf[4] = bin2bcd(dt->tm_mday);
+	buf[5] = bin2bcd(dt->tm_mon + 1);
+	buf[6] = bin2bcd(dt->tm_wday + 1);
+	buf[7] = bin2bcd(dt->tm_year % 100);
+	buf[8] = bin2bcd(0x00);
+
+	/* write the rtc settings */
+	return spi_write_then_read(spi, buf, 9, NULL, 0);
+}
+
+static const struct rtc_class_ops max6916_rtc_ops = {
+	.read_time = max6916_read_time,
+	.set_time = max6916_set_time,
+};
+
+static int max6916_probe(struct spi_device *spi)
+{
+	struct rtc_device *rtc;
+	unsigned char data;
+	int res;
+
+	/* spi setup with max6916 in mode 3 and bits per word as 8 */
+	spi->mode = SPI_MODE_3;
+	spi->bits_per_word = 8;
+	spi_setup(spi);
+
+	/* RTC Settings */
+	res = max6916_read_reg(&spi->dev, MAX6916_SECONDS_REG, &data);
+	if (res)
+		return res;
+
+	/* Disable the write protect of rtc */
+	max6916_read_reg(&spi->dev, MAX6916_CONTROL_REG, &data);
+	data = data & ~(1 << 7);
+	max6916_write_reg(&spi->dev, MAX6916_CONTROL_REG, data);
+
+	/*Enable oscillator,disable oscillator stop flag, glitch filter*/
+	max6916_read_reg(&spi->dev, MAX6916_STATUS_REG, &data);
+	data = data & 0x1B;
+	max6916_write_reg(&spi->dev, MAX6916_STATUS_REG, data);
+
+	/* display the settings */
+	max6916_read_reg(&spi->dev, MAX6916_CONTROL_REG, &data);
+	dev_info(&spi->dev, "MAX6916 RTC CTRL Reg = 0x%02x\n", data);
+
+	max6916_read_reg(&spi->dev, MAX6916_STATUS_REG, &data);
+	dev_info(&spi->dev, "MAX6916 RTC Status Reg = 0x%02x\n", data);
+
+	rtc = devm_rtc_device_register(&spi->dev, "max6916",
+				       &max6916_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	spi_set_drvdata(spi, rtc);
+
+	return 0;
+}
+
+static struct spi_driver max6916_driver = {
+	.driver = {
+		.name = "max6916",
+	},
+	.probe = max6916_probe,
+};
+module_spi_driver(max6916_driver);
+
+MODULE_DESCRIPTION("MAX6916 SPI RTC DRIVER");
+MODULE_AUTHOR("Venkat Prashanth B U <venkat.prashanth2498@gmail.com>");
+MODULE_LICENSE("GPL v2");

include/asm-generic/rtc.h → drivers/rtc/rtc-mc146818-lib.c

-/* 
- * include/asm-generic/rtc.h
- *
- * Author: Tom Rini <trini@mvista.com>
- *
- * Based on:
- * drivers/char/rtc.c
- *
- * Please read the COPYING file for all license details.
- */
-
-#ifndef __ASM_RTC_H__
-#define __ASM_RTC_H__
-
-#include <linux/mc146818rtc.h>
-#include <linux/rtc.h>
 #include <linux/bcd.h>
 #include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/mc146818rtc.h>
+
 #ifdef CONFIG_ACPI
 #include <linux/acpi.h>
 #endif
 
-#define RTC_PIE 0x40		/* periodic interrupt enable */
-#define RTC_AIE 0x20		/* alarm interrupt enable */
-#define RTC_UIE 0x10		/* update-finished interrupt enable */
-
-/* some dummy definitions */
-#define RTC_BATT_BAD 0x100	/* battery bad */
-#define RTC_SQWE 0x08		/* enable square-wave output */
-#define RTC_DM_BINARY 0x04	/* all time/date values are BCD if clear */
-#define RTC_24H 0x02		/* 24 hour mode - else hours bit 7 means pm */
-#define RTC_DST_EN 0x01	        /* auto switch DST - works f. USA only */
-
 /*
  * Returns true if a clock update is in progress
  */
-static inline unsigned char rtc_is_updating(void)
+static inline unsigned char mc146818_is_updating(void)
 {
 	unsigned char uip;
 	unsigned long flags;
@@ -45,7 +21,7 @@ static inline unsigned char rtc_is_updating(void)
 	return uip;
 }
 
-static inline unsigned int __get_rtc_time(struct rtc_time *time)
+unsigned int mc146818_get_time(struct rtc_time *time)
 {
 	unsigned char ctrl;
 	unsigned long flags;
@@ -60,11 +36,11 @@ static inline unsigned int __get_rtc_time(struct rtc_time *time)
 	 * can take just over 2ms. We wait 20ms. There is no need to
 	 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
 	 * If you need to know *exactly* when a second has started, enable
-	 * periodic update complete interrupts, (via ioctl) and then 
+	 * periodic update complete interrupts, (via ioctl) and then
 	 * immediately read /dev/rtc which will block until you get the IRQ.
 	 * Once the read clears, read the RTC time (again via ioctl). Easy.
 	 */
-	if (rtc_is_updating())
+	if (mc146818_is_updating())
 		mdelay(20);
 
 	/*
@@ -120,13 +96,10 @@ static inline unsigned int __get_rtc_time(struct rtc_time *time)
 
 	return RTC_24H;
 }
-
-#ifndef get_rtc_time
-#define get_rtc_time	__get_rtc_time
-#endif
+EXPORT_SYMBOL_GPL(mc146818_get_time);
 
 /* Set the current date and time in the real time clock. */
-static inline int __set_rtc_time(struct rtc_time *time)
+int mc146818_set_time(struct rtc_time *time)
 {
 	unsigned long flags;
 	unsigned char mon, day, hrs, min, sec;
@@ -222,26 +195,4 @@ static inline int __set_rtc_time(struct rtc_time *time)
 
 	return 0;
 }
-
-#ifndef set_rtc_time
-#define set_rtc_time	__set_rtc_time
-#endif
-
-static inline unsigned int get_rtc_ss(void)
-{
-	struct rtc_time h;
-
-	get_rtc_time(&h);
-	return h.tm_sec;
-}
-
-static inline int get_rtc_pll(struct rtc_pll_info *pll)
-{
-	return -EINVAL;
-}
-static inline int set_rtc_pll(struct rtc_pll_info *pll)
-{
-	return -EINVAL;
-}
-
-#endif /* __ASM_RTC_H__ */
+EXPORT_SYMBOL_GPL(mc146818_set_time);

drivers/rtc/rtc-mrst.c

@@ -32,11 +32,11 @@
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <linux/kernel.h>
+#include <linux/mc146818rtc.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/sfi.h>
 
-#include <asm-generic/rtc.h>
 #include <asm/intel_scu_ipc.h>
 #include <asm/intel-mid.h>
 #include <asm/intel_mid_vrtc.h>
@@ -149,14 +149,6 @@ static int mrst_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 	if (mrst->irq <= 0)
 		return -EIO;
 
-	/* Basic alarms only support hour, minute, and seconds fields.
-	 * Some also support day and month, for alarms up to a year in
-	 * the future.
-	 */
-	t->time.tm_mday = -1;
-	t->time.tm_mon = -1;
-	t->time.tm_year = -1;
-
 	/* vRTC only supports binary mode */
 	spin_lock_irq(&rtc_lock);
 	t->time.tm_sec = vrtc_cmos_read(RTC_SECONDS_ALARM);

drivers/rtc/rtc-pcf2123.c

@@ -96,7 +96,7 @@
 #define CD_TMR_TE		BIT(3)	/* Countdown timer enable */
 
 /* PCF2123_REG_OFFSET BITS */
-#define OFFSET_SIGN_BIT		BIT(6)	/* 2's complement sign bit */
+#define OFFSET_SIGN_BIT		6	/* 2's complement sign bit */
 #define OFFSET_COARSE		BIT(7)	/* Coarse mode offset */
 #define OFFSET_STEP		(2170)	/* Offset step in parts per billion */
 
@@ -217,7 +217,7 @@ static int pcf2123_read_offset(struct device *dev, long *offset)
 	if (reg & OFFSET_COARSE)
 		reg <<= 1; /* multiply by 2 and sign extend */
 	else
-		reg |= (reg & OFFSET_SIGN_BIT) << 1; /* sign extend only */
+		reg = sign_extend32(reg, OFFSET_SIGN_BIT);
 
 	*offset = ((long)reg) * OFFSET_STEP;
 

drivers/rtc/rtc-pcf85063.c

@@ -16,6 +16,16 @@
 #include <linux/rtc.h>
 #include <linux/module.h>
 
+/*
+ * Information for this driver was pulled from the following datasheets.
+ *
+ *  http://www.nxp.com/documents/data_sheet/PCF85063A.pdf
+ *  http://www.nxp.com/documents/data_sheet/PCF85063TP.pdf
+ *
+ *  PCF85063A -- Rev. 6 — 18 November 2015
+ *  PCF85063TP -- Rev. 4 — 6 May 2015
+*/
+
 #define PCF85063_REG_CTRL1		0x00 /* status */
 #define PCF85063_REG_CTRL1_STOP		BIT(5)
 #define PCF85063_REG_CTRL2		0x01
@@ -55,10 +65,22 @@ static int pcf85063_stop_clock(struct i2c_client *client, u8 *ctrl1)
 	return 0;
 }
 
-/*
- * In the routines that deal directly with the pcf85063 hardware, we use
- * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
- */
+static int pcf85063_start_clock(struct i2c_client *client, u8 ctrl1)
+{
+	s32 ret;
+
+	/* start the clock */
+	ctrl1 &= PCF85063_REG_CTRL1_STOP;
+
+	ret = i2c_smbus_write_byte_data(client, PCF85063_REG_CTRL1, ctrl1);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failing to start the clock\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
 static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	int rc;
@@ -90,8 +112,7 @@ static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 	tm->tm_wday = regs[4] & 0x07;
 	tm->tm_mon = bcd2bin(regs[5] & 0x1F) - 1; /* rtc mn 1-12 */
 	tm->tm_year = bcd2bin(regs[6]);
-	if (tm->tm_year < 70)
-		tm->tm_year += 100;	/* assume we are in 1970...2069 */
+	tm->tm_year += 100;
 
 	return rtc_valid_tm(tm);
 }
@@ -99,13 +120,17 @@ static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	int rc;
-	u8 regs[8];
+	u8 regs[7];
+	u8 ctrl1;
+
+	if ((tm->tm_year < 100) || (tm->tm_year > 199))
+		return -EINVAL;
 
 	/*
 	 * to accurately set the time, reset the divider chain and keep it in
 	 * reset state until all time/date registers are written
 	 */
-	rc = pcf85063_stop_clock(client, &regs[7]);
+	rc = pcf85063_stop_clock(client, &ctrl1);
 	if (rc != 0)
 		return rc;
 
@@ -125,14 +150,7 @@ static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 	regs[5] = bin2bcd(tm->tm_mon + 1);
 
 	/* year and century */
-	regs[6] = bin2bcd(tm->tm_year % 100);
-
-	/*
-	 * after all time/date registers are written, let the 'address auto
-	 * increment' feature wrap around and write register CTRL1 to re-enable
-	 * the clock divider chain again
-	 */
-	regs[7] &= ~PCF85063_REG_CTRL1_STOP;
+	regs[6] = bin2bcd(tm->tm_year - 100);
 
 	/* write all registers at once */
 	rc = i2c_smbus_write_i2c_block_data(client, PCF85063_REG_SC,
@@ -142,6 +160,15 @@ static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 		return rc;
 	}
 
+	/*
+	 * Write the control register as a separate action since the size of
+	 * the register space is different between the PCF85063TP and
+	 * PCF85063A devices.  The rollover point can not be used.
+	 */
+	rc = pcf85063_start_clock(client, ctrl1);
+	if (rc != 0)
+		return rc;
+
 	return 0;
 }
 

drivers/rtc/rtc-pcf8563.c

@@ -341,14 +341,11 @@ static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
 		"%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
 		__func__, buf[0], buf[1], buf[2], buf[3]);
 
+	tm->time.tm_sec = 0;
 	tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
 	tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
 	tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
 	tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
-	tm->time.tm_mon = -1;
-	tm->time.tm_year = -1;
-	tm->time.tm_yday = -1;
-	tm->time.tm_isdst = -1;
 
 	err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
 	if (err < 0)

drivers/rtc/rtc-rc5t583.c

@@ -128,6 +128,7 @@ static int rc5t583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 		return ret;
 	}
 
+	alm->time.tm_sec = 0;
 	alm->time.tm_min = bcd2bin(alarm_data[0]);
 	alm->time.tm_hour = bcd2bin(alarm_data[1]);
 	alm->time.tm_mday = bcd2bin(alarm_data[2]);

drivers/rtc/rtc-rs5c372.c

@@ -341,12 +341,6 @@ static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 	t->time.tm_sec = 0;
 	t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 	t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
-	t->time.tm_mday = -1;
-	t->time.tm_mon = -1;
-	t->time.tm_year = -1;
-	t->time.tm_wday = -1;
-	t->time.tm_yday = -1;
-	t->time.tm_isdst = -1;
 
 	/* ... and status */
 	t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);

drivers/rtc/rtc-rv8803.c

@@ -13,12 +13,15 @@
 
 #include <linux/bcd.h>
 #include <linux/bitops.h>
+#include <linux/log2.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/rtc.h>
 
+#define RV8803_I2C_TRY_COUNT		4
+
 #define RV8803_SEC			0x00
 #define RV8803_MIN			0x01
 #define RV8803_HOUR			0x02
@@ -56,19 +59,85 @@ struct rv8803_data {
 	u8 ctrl;
 };
 
+static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
+{
+	int try = RV8803_I2C_TRY_COUNT;
+	s32 ret;
+
+	/*
+	 * There is a 61µs window during which the RTC does not acknowledge I2C
+	 * transfers. In that case, ensure that there are multiple attempts.
+	 */
+	do
+		ret = i2c_smbus_read_byte_data(client, reg);
+	while ((ret == -ENXIO || ret == -EIO) && --try);
+	if (ret < 0)
+		dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
+
+	return ret;
+}
+
+static int rv8803_read_regs(const struct i2c_client *client,
+			    u8 reg, u8 count, u8 *values)
+{
+	int try = RV8803_I2C_TRY_COUNT;
+	s32 ret;
+
+	do
+		ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
+	while ((ret == -ENXIO || ret == -EIO) && --try);
+	if (ret != count) {
+		dev_err(&client->dev,
+			"Unable to read registers 0x%02x..0x%02x\n",
+			reg, reg + count - 1);
+		return ret < 0 ? ret : -EIO;
+	}
+
+	return 0;
+}
+
+static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
+{
+	int try = RV8803_I2C_TRY_COUNT;
+	s32 ret;
+
+	do
+		ret = i2c_smbus_write_byte_data(client, reg, value);
+	while ((ret == -ENXIO || ret == -EIO) && --try);
+	if (ret)
+		dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
+
+	return ret;
+}
+
+static int rv8803_write_regs(const struct i2c_client *client,
+			     u8 reg, u8 count, const u8 *values)
+{
+	int try = RV8803_I2C_TRY_COUNT;
+	s32 ret;
+
+	do
+		ret = i2c_smbus_write_i2c_block_data(client, reg, count,
+						     values);
+	while ((ret == -ENXIO || ret == -EIO) && --try);
+	if (ret)
+		dev_err(&client->dev,
+			"Unable to write registers 0x%02x..0x%02x\n",
+			reg, reg + count - 1);
+
+	return ret;
+}
+
 static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
 {
 	struct i2c_client *client = dev_id;
 	struct rv8803_data *rv8803 = i2c_get_clientdata(client);
 	unsigned long events = 0;
-	int flags, try = 0;
+	int flags;
 
 	mutex_lock(&rv8803->flags_lock);
 
-	do {
-		flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
-		try++;
-	} while ((flags == -ENXIO) && (try < 3));
+	flags = rv8803_read_reg(client, RV8803_FLAG);
 	if (flags <= 0) {
 		mutex_unlock(&rv8803->flags_lock);
 		return IRQ_NONE;
@@ -100,9 +169,8 @@ static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
 
 	if (events) {
 		rtc_update_irq(rv8803->rtc, 1, events);
-		i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
-		i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
-					  rv8803->ctrl);
+		rv8803_write_reg(client, RV8803_FLAG, flags);
+		rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl);
 	}
 
 	mutex_unlock(&rv8803->flags_lock);
@@ -118,7 +186,7 @@ static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
 	u8 *date = date1;
 	int ret, flags;
 
-	flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
+	flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
 	if (flags < 0)
 		return flags;
 
@@ -127,16 +195,14 @@ static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
 		return -EINVAL;
 	}
 
-	ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
-					    7, date);
-	if (ret != 7)
-		return ret < 0 ? ret : -EIO;
+	ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
+	if (ret)
+		return ret;
 
 	if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
-		ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
-						    7, date2);
-		if (ret != 7)
-			return ret < 0 ? ret : -EIO;
+		ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
+		if (ret)
+			return ret;
 
 		if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
 			date = date2;
@@ -145,23 +211,33 @@ static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
 	tm->tm_sec  = bcd2bin(date[RV8803_SEC] & 0x7f);
 	tm->tm_min  = bcd2bin(date[RV8803_MIN] & 0x7f);
 	tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
-	tm->tm_wday = ffs(date[RV8803_WEEK] & 0x7f);
+	tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f);
 	tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
 	tm->tm_mon  = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
 	tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
 
-	return rtc_valid_tm(tm);
+	return 0;
 }
 
 static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 	u8 date[7];
-	int flags, ret;
+	int ctrl, flags, ret;
 
 	if ((tm->tm_year < 100) || (tm->tm_year > 199))
 		return -EINVAL;
 
+	ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
+	if (ctrl < 0)
+		return ctrl;
+
+	/* Stop the clock */
+	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
+			       ctrl | RV8803_CTRL_RESET);
+	if (ret)
+		return ret;
+
 	date[RV8803_SEC]   = bin2bcd(tm->tm_sec);
 	date[RV8803_MIN]   = bin2bcd(tm->tm_min);
 	date[RV8803_HOUR]  = bin2bcd(tm->tm_hour);
@@ -170,21 +246,26 @@ static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
 	date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
 	date[RV8803_YEAR]  = bin2bcd(tm->tm_year - 100);
 
-	ret = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_SEC,
-					     7, date);
-	if (ret < 0)
+	ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
+	if (ret)
+		return ret;
+
+	/* Restart the clock */
+	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
+			       ctrl & ~RV8803_CTRL_RESET);
+	if (ret)
 		return ret;
 
 	mutex_lock(&rv8803->flags_lock);
 
-	flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
+	flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
 	if (flags < 0) {
 		mutex_unlock(&rv8803->flags_lock);
 		return flags;
 	}
 
-	ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG,
-					flags & ~RV8803_FLAG_V2F);
+	ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
+			       flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F));
 
 	mutex_unlock(&rv8803->flags_lock);
 
@@ -198,22 +279,18 @@ static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	u8 alarmvals[3];
 	int flags, ret;
 
-	ret = i2c_smbus_read_i2c_block_data(client, RV8803_ALARM_MIN,
-					    3, alarmvals);
-	if (ret != 3)
-		return ret < 0 ? ret : -EIO;
+	ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
+	if (ret)
+		return ret;
 
-	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
+	flags = rv8803_read_reg(client, RV8803_FLAG);
 	if (flags < 0)
 		return flags;
 
 	alrm->time.tm_sec  = 0;
 	alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
 	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
-	alrm->time.tm_wday = -1;
 	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
-	alrm->time.tm_mon  = -1;
-	alrm->time.tm_year = -1;
 
 	alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
 	alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
@@ -239,10 +316,10 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 
 	mutex_lock(&rv8803->flags_lock);
 
-	ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl);
-	if (ret != 2) {
+	ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
+	if (ret) {
 		mutex_unlock(&rv8803->flags_lock);
-		return ret < 0 ? ret : -EIO;
+		return ret;
 	}
 
 	alarmvals[0] = bin2bcd(alrm->time.tm_min);
@@ -251,8 +328,8 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 
 	if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) {
 		rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE);
-		err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
-						rv8803->ctrl);
+		err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
+				       rv8803->ctrl);
 		if (err) {
 			mutex_unlock(&rv8803->flags_lock);
 			return err;
@@ -260,13 +337,12 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	}
 
 	ctrl[1] &= ~RV8803_FLAG_AF;
-	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]);
+	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
 	mutex_unlock(&rv8803->flags_lock);
 	if (err)
 		return err;
 
-	err = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_ALARM_MIN,
-					     3, alarmvals);
+	err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
 	if (err)
 		return err;
 
@@ -276,8 +352,8 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 		if (rv8803->rtc->aie_timer.enabled)
 			rv8803->ctrl |= RV8803_CTRL_AIE;
 
-		err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
-						rv8803->ctrl);
+		err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
+				       rv8803->ctrl);
 		if (err)
 			return err;
 	}
@@ -306,21 +382,20 @@ static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
 	}
 
 	mutex_lock(&rv8803->flags_lock);
-	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
+	flags = rv8803_read_reg(client, RV8803_FLAG);
 	if (flags < 0) {
 		mutex_unlock(&rv8803->flags_lock);
 		return flags;
 	}
 	flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
-	err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
+	err = rv8803_write_reg(client, RV8803_FLAG, flags);
 	mutex_unlock(&rv8803->flags_lock);
 	if (err)
 		return err;
 
 	if (ctrl != rv8803->ctrl) {
 		rv8803->ctrl = ctrl;
-		err = i2c_smbus_write_byte_data(client, RV8803_CTRL,
-						rv8803->ctrl);
+		err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
 		if (err)
 			return err;
 	}
@@ -336,7 +411,7 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 
 	switch (cmd) {
 	case RTC_VL_READ:
-		flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
+		flags = rv8803_read_reg(client, RV8803_FLAG);
 		if (flags < 0)
 			return flags;
 
@@ -355,16 +430,16 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 
 	case RTC_VL_CLR:
 		mutex_lock(&rv8803->flags_lock);
-		flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
+		flags = rv8803_read_reg(client, RV8803_FLAG);
 		if (flags < 0) {
 			mutex_unlock(&rv8803->flags_lock);
 			return flags;
 		}
 
 		flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
-		ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
+		ret = rv8803_write_reg(client, RV8803_FLAG, flags);
 		mutex_unlock(&rv8803->flags_lock);
-		if (ret < 0)
+		if (ret)
 			return ret;
 
 		return 0;
@@ -382,8 +457,8 @@ static ssize_t rv8803_nvram_write(struct file *filp, struct kobject *kobj,
 	struct i2c_client *client = to_i2c_client(dev);
 	int ret;
 
-	ret = i2c_smbus_write_byte_data(client, RV8803_RAM, buf[0]);
-	if (ret < 0)
+	ret = rv8803_write_reg(client, RV8803_RAM, buf[0]);
+	if (ret)
 		return ret;
 
 	return 1;
@@ -397,7 +472,7 @@ static ssize_t rv8803_nvram_read(struct file *filp, struct kobject *kobj,
 	struct i2c_client *client = to_i2c_client(dev);
 	int ret;
 
-	ret = i2c_smbus_read_byte_data(client, RV8803_RAM);
+	ret = rv8803_read_reg(client, RV8803_RAM);
 	if (ret < 0)
 		return ret;
 
@@ -427,7 +502,7 @@ static int rv8803_probe(struct i2c_client *client,
 {
 	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 	struct rv8803_data *rv8803;
-	int err, flags, try = 0;
+	int err, flags;
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 				     I2C_FUNC_SMBUS_I2C_BLOCK)) {
@@ -444,16 +519,7 @@ static int rv8803_probe(struct i2c_client *client,
 	rv8803->client = client;
 	i2c_set_clientdata(client, rv8803);
 
-	/*
-	 * There is a 60µs window where the RTC may not reply on the i2c bus in
-	 * that case, the transfer is not ACKed. In that case, ensure there are
-	 * multiple attempts.
-	 */
-	do {
-		flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
-		try++;
-	} while ((flags == -ENXIO) && (try < 3));
-
+	flags = rv8803_read_reg(client, RV8803_FLAG);
 	if (flags < 0)
 		return flags;
 
@@ -488,12 +554,7 @@ static int rv8803_probe(struct i2c_client *client,
 		return PTR_ERR(rv8803->rtc);
 	}
 
-	try = 0;
-	do {
-		err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT,
-						RV8803_EXT_WADA);
-		try++;
-	} while ((err == -ENXIO) && (try < 3));
+	err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
 	if (err)
 		return err;
 

drivers/rtc/rtc-rx8010.c

@@ -272,15 +272,9 @@ static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 	t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
 	t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
 
-	if (alarmvals[2] & RX8010_ALARM_AE)
-		t->time.tm_mday = -1;
-	else
+	if (!(alarmvals[2] & RX8010_ALARM_AE))
 		t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
 
-	t->time.tm_wday = -1;
-	t->time.tm_mon = -1;
-	t->time.tm_year = -1;
-
 	t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
 	t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
 

drivers/rtc/rtc-rx8025.c

@@ -319,11 +319,6 @@ 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);
 
-	t->time.tm_wday = -1;
-	t->time.tm_mday = -1;
-	t->time.tm_mon = -1;
-	t->time.tm_year = -1;
-
 	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,

drivers/rtc/rtc-s35390a.c

@@ -15,6 +15,7 @@
 #include <linux/bitrev.h>
 #include <linux/bcd.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 
 #define S35390A_CMD_STATUS1	0
 #define S35390A_CMD_STATUS2	1
@@ -34,10 +35,14 @@
 #define S35390A_ALRM_BYTE_HOURS	1
 #define S35390A_ALRM_BYTE_MINS	2
 
+/* flags for STATUS1 */
 #define S35390A_FLAG_POC	0x01
 #define S35390A_FLAG_BLD	0x02
+#define S35390A_FLAG_INT2	0x04
 #define S35390A_FLAG_24H	0x40
 #define S35390A_FLAG_RESET	0x80
+
+/* flag for STATUS2 */
 #define S35390A_FLAG_TEST	0x01
 
 #define S35390A_INT2_MODE_MASK		0xF0
@@ -94,19 +99,63 @@ static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
 	return 0;
 }
 
-static int s35390a_reset(struct s35390a *s35390a)
+/*
+ * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset.
+ * To keep the information if an irq is pending, pass the value read from
+ * STATUS1 to the caller.
+ */
+static int s35390a_reset(struct s35390a *s35390a, char *status1)
 {
-	char buf[1];
-
-	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0)
-		return -EIO;
-
-	if (!(buf[0] & (S35390A_FLAG_POC | S35390A_FLAG_BLD)))
+	char buf;
+	int ret;
+	unsigned initcount = 0;
+
+	ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
+	if (ret < 0)
+		return ret;
+
+	if (*status1 & S35390A_FLAG_POC)
+		/*
+		 * Do not communicate for 0.5 seconds since the power-on
+		 * detection circuit is in operation.
+		 */
+		msleep(500);
+	else if (!(*status1 & S35390A_FLAG_BLD))
+		/*
+		 * If both POC and BLD are unset everything is fine.
+		 */
 		return 0;
 
-	buf[0] |= (S35390A_FLAG_RESET | S35390A_FLAG_24H);
-	buf[0] &= 0xf0;
-	return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
+	/*
+	 * At least one of POC and BLD are set, so reinitialise chip. Keeping
+	 * this information in the hardware to know later that the time isn't
+	 * valid is unfortunately not possible because POC and BLD are cleared
+	 * on read. So the reset is best done now.
+	 *
+	 * The 24H bit is kept over reset, so set it already here.
+	 */
+initialize:
+	*status1 = S35390A_FLAG_24H;
+	buf = S35390A_FLAG_RESET | S35390A_FLAG_24H;
+	ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
+
+	if (ret < 0)
+		return ret;
+
+	ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
+	if (ret < 0)
+		return ret;
+
+	if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) {
+		/* Try up to five times to reset the chip */
+		if (initcount < 5) {
+			++initcount;
+			goto initialize;
+		} else
+			return -EIO;
+	}
+
+	return 1;
 }
 
 static int s35390a_disable_test_mode(struct s35390a *s35390a)
@@ -217,12 +266,12 @@ static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
 		alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
 		alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
 
-	/* disable interrupt */
+	/* disable interrupt (which deasserts the irq line) */
 	err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
 	if (err < 0)
 		return err;
 
-	/* clear pending interrupt, if any */
+	/* clear pending interrupt (in STATUS1 only), if any */
 	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
 	if (err < 0)
 		return err;
@@ -242,6 +291,8 @@ static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
 
 	if (alm->time.tm_wday != -1)
 		buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
+	else
+		buf[S35390A_ALRM_BYTE_WDAY] = 0;
 
 	buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
 			alm->time.tm_hour) | 0x80;
@@ -269,23 +320,43 @@ static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
 	if (err < 0)
 		return err;
 
-	if (bitrev8(sts) != S35390A_INT2_MODE_ALARM)
-		return -EINVAL;
+	if ((bitrev8(sts) & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
+		/*
+		 * When the alarm isn't enabled, the register to configure
+		 * the alarm time isn't accessible.
+		 */
+		alm->enabled = 0;
+		return 0;
+	} else {
+		alm->enabled = 1;
+	}
 
 	err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
 	if (err < 0)
 		return err;
 
 	/* This chip returns the bits of each byte in reverse order */
-	for (i = 0; i < 3; ++i) {
+	for (i = 0; i < 3; ++i)
 		buf[i] = bitrev8(buf[i]);
-		buf[i] &= ~0x80;
-	}
 
-	alm->time.tm_wday = bcd2bin(buf[S35390A_ALRM_BYTE_WDAY]);
-	alm->time.tm_hour = s35390a_reg2hr(s35390a,
-						buf[S35390A_ALRM_BYTE_HOURS]);
-	alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS]);
+	/*
+	 * B0 of the three matching registers is an enable flag. Iff it is set
+	 * the configured value is used for matching.
+	 */
+	if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
+		alm->time.tm_wday =
+			bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);
+
+	if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
+		alm->time.tm_hour =
+			s35390a_reg2hr(s35390a,
+				       buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);
+
+	if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
+		alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);
+
+	/* alarm triggers always at s=0 */
+	alm->time.tm_sec = 0;
 
 	dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
 			__func__, alm->time.tm_min, alm->time.tm_hour,
@@ -327,11 +398,11 @@ static struct i2c_driver s35390a_driver;
 static int s35390a_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
-	int err;
+	int err, err_reset;
 	unsigned int i;
 	struct s35390a *s35390a;
 	struct rtc_time tm;
-	char buf[1];
+	char buf, status1;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		err = -ENODEV;
@@ -360,29 +431,35 @@ static int s35390a_probe(struct i2c_client *client,
 		}
 	}
 
-	err = s35390a_reset(s35390a);
-	if (err < 0) {
+	err_reset = s35390a_reset(s35390a, &status1);
+	if (err_reset < 0) {
+		err = err_reset;
 		dev_err(&client->dev, "error resetting chip\n");
 		goto exit_dummy;
 	}
 
-	err = s35390a_disable_test_mode(s35390a);
-	if (err < 0) {
-		dev_err(&client->dev, "error disabling test mode\n");
-		goto exit_dummy;
-	}
-
-	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
-	if (err < 0) {
-		dev_err(&client->dev, "error checking 12/24 hour mode\n");
-		goto exit_dummy;
-	}
-	if (buf[0] & S35390A_FLAG_24H)
+	if (status1 & S35390A_FLAG_24H)
 		s35390a->twentyfourhour = 1;
 	else
 		s35390a->twentyfourhour = 0;
 
-	if (s35390a_get_datetime(client, &tm) < 0)
+	if (status1 & S35390A_FLAG_INT2) {
+		/* disable alarm (and maybe test mode) */
+		buf = 0;
+		err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
+		if (err < 0) {
+			dev_err(&client->dev, "error disabling alarm");
+			goto exit_dummy;
+		}
+	} else {
+		err = s35390a_disable_test_mode(s35390a);
+		if (err < 0) {
+			dev_err(&client->dev, "error disabling test mode\n");
+			goto exit_dummy;
+		}
+	}
+
+	if (err_reset > 0 || s35390a_get_datetime(client, &tm) < 0)
 		dev_warn(&client->dev, "clock needs to be set\n");
 
 	device_set_wakeup_capable(&client->dev, 1);
@@ -395,6 +472,10 @@ static int s35390a_probe(struct i2c_client *client,
 		err = PTR_ERR(s35390a->rtc);
 		goto exit_dummy;
 	}
+
+	if (status1 & S35390A_FLAG_INT2)
+		rtc_update_irq(s35390a->rtc, 1, RTC_AF);
+
 	return 0;
 
 exit_dummy:

drivers/rtc/rtc-s3c.c

@@ -149,12 +149,14 @@ static int s3c_rtc_setfreq(struct s3c_rtc *info, int freq)
 	if (!is_power_of_2(freq))
 		return -EINVAL;
 
+	s3c_rtc_enable_clk(info);
 	spin_lock_irq(&info->pie_lock);
 
 	if (info->data->set_freq)
 		info->data->set_freq(info, freq);
 
 	spin_unlock_irq(&info->pie_lock);
+	s3c_rtc_disable_clk(info);
 
 	return 0;
 }
@@ -264,35 +266,23 @@ static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	/* decode the alarm enable field */
 	if (alm_en & S3C2410_RTCALM_SECEN)
 		alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
-	else
-		alm_tm->tm_sec = -1;
 
 	if (alm_en & S3C2410_RTCALM_MINEN)
 		alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
-	else
-		alm_tm->tm_min = -1;
 
 	if (alm_en & S3C2410_RTCALM_HOUREN)
 		alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
-	else
-		alm_tm->tm_hour = -1;
 
 	if (alm_en & S3C2410_RTCALM_DAYEN)
 		alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
-	else
-		alm_tm->tm_mday = -1;
 
 	if (alm_en & S3C2410_RTCALM_MONEN) {
 		alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
 		alm_tm->tm_mon -= 1;
-	} else {
-		alm_tm->tm_mon = -1;
 	}
 
 	if (alm_en & S3C2410_RTCALM_YEAREN)
 		alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
-	else
-		alm_tm->tm_year = -1;
 
 	return 0;
 }
@@ -577,8 +567,6 @@ static int s3c_rtc_probe(struct platform_device *pdev)
 
 	s3c_rtc_setfreq(info, 1);
 
-	s3c_rtc_disable_clk(info);
-
 	return 0;
 
  err_nortc:

drivers/rtc/rtc-sh.c

@@ -481,7 +481,6 @@ static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
 	if (tm->tm_mon > 0)
 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
-	tm->tm_year     = 0xffff;
 
 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
 
@@ -500,52 +499,13 @@ static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
 }
 
-static int sh_rtc_check_alarm(struct rtc_time *tm)
-{
-	/*
-	 * The original rtc says anything > 0xc0 is "don't care" or "match
-	 * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
-	 * The original rtc doesn't support years - some things use -1 and
-	 * some 0xffff. We use -1 to make out tests easier.
-	 */
-	if (tm->tm_year == 0xffff)
-		tm->tm_year = -1;
-	if (tm->tm_mon >= 0xff)
-		tm->tm_mon = -1;
-	if (tm->tm_mday >= 0xff)
-		tm->tm_mday = -1;
-	if (tm->tm_wday >= 0xff)
-		tm->tm_wday = -1;
-	if (tm->tm_hour >= 0xff)
-		tm->tm_hour = -1;
-	if (tm->tm_min >= 0xff)
-		tm->tm_min = -1;
-	if (tm->tm_sec >= 0xff)
-		tm->tm_sec = -1;
-
-	if (tm->tm_year > 9999 ||
-		tm->tm_mon >= 12 ||
-		tm->tm_mday == 0 || tm->tm_mday >= 32 ||
-		tm->tm_wday >= 7 ||
-		tm->tm_hour >= 24 ||
-		tm->tm_min >= 60 ||
-		tm->tm_sec >= 60)
-		return -EINVAL;
-
-	return 0;
-}
-
 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
 	unsigned int rcr1;
 	struct rtc_time *tm = &wkalrm->time;
-	int mon, err;
-
-	err = sh_rtc_check_alarm(tm);
-	if (unlikely(err < 0))
-		return err;
+	int mon;
 
 	spin_lock_irq(&rtc->lock);
 

drivers/rtc/rtc-tegra.c

@@ -179,12 +179,6 @@ static int tegra_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 	if (sec == 0) {
 		/* alarm is disabled. */
 		alarm->enabled = 0;
-		alarm->time.tm_mon = -1;
-		alarm->time.tm_mday = -1;
-		alarm->time.tm_year = -1;
-		alarm->time.tm_hour = -1;
-		alarm->time.tm_min = -1;
-		alarm->time.tm_sec = -1;
 	} else {
 		/* alarm is enabled. */
 		alarm->enabled = 1;

drivers/rtc/rtc-v3020.c

@@ -25,7 +25,7 @@
 #include <linux/rtc.h>
 #include <linux/types.h>
 #include <linux/bcd.h>
-#include <linux/rtc-v3020.h>
+#include <linux/platform_data/rtc-v3020.h>
 #include <linux/delay.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>

include/linux/ds17287rtc.h

-/*
- * ds17287rtc.h - register definitions for the ds1728[57] RTC / CMOS RAM
- *
- * 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.
- *
- * (C) 2003 Guido Guenther <agx@sigxcpu.org>
- */
-#ifndef __LINUX_DS17287RTC_H
-#define __LINUX_DS17287RTC_H
-
-#include <linux/rtc.h>			/* get the user-level API */
-#include <linux/mc146818rtc.h>
-
-/* Register A */
-#define DS_REGA_DV2	0x40		/* countdown chain */
-#define DS_REGA_DV1	0x20		/* oscillator enable */
-#define DS_REGA_DV0	0x10		/* bank select */
-
-/* bank 1 registers */
-#define DS_B1_MODEL	0x40		/* model number byte */
-#define DS_B1_SN1 	0x41		/* serial number byte 1 */
-#define DS_B1_SN2 	0x42		/* serial number byte 2 */
-#define DS_B1_SN3 	0x43		/* serial number byte 3 */
-#define DS_B1_SN4 	0x44		/* serial number byte 4 */
-#define DS_B1_SN5 	0x45		/* serial number byte 5 */
-#define DS_B1_SN6 	0x46		/* serial number byte 6 */
-#define DS_B1_CRC 	0x47		/* CRC byte */
-#define DS_B1_CENTURY 	0x48		/* Century byte */
-#define DS_B1_DALARM 	0x49		/* date alarm */
-#define DS_B1_XCTRL4A	0x4a		/* extendec control register 4a */
-#define DS_B1_XCTRL4B	0x4b		/* extendec control register 4b */
-#define DS_B1_RTCADDR2 	0x4e		/* rtc address 2 */
-#define DS_B1_RTCADDR3 	0x4f		/* rtc address 3 */
-#define DS_B1_RAMLSB	0x50		/* extended ram LSB */
-#define DS_B1_RAMMSB	0x51		/* extended ram MSB */
-#define DS_B1_RAMDPORT	0x53		/* extended ram data port */
-
-/* register details */
-/* extended control register 4a */
-#define DS_XCTRL4A_VRT2	0x80 		/* valid ram and time */
-#define DS_XCTRL4A_INCR	0x40		/* increment progress status */
-#define DS_XCTRL4A_BME	0x20		/* burst mode enable */
-#define DS_XCTRL4A_PAB	0x08		/* power active bar ctrl */
-#define DS_XCTRL4A_RF	0x04		/* ram clear flag */
-#define DS_XCTRL4A_WF	0x02		/* wake up alarm flag */
-#define DS_XCTRL4A_KF	0x01		/* kickstart flag */
-
-/* interrupt causes */
-#define DS_XCTRL4A_IFS	(DS_XCTRL4A_RF|DS_XCTRL4A_WF|DS_XCTRL4A_KF)
-
-/* extended control register 4b */
-#define DS_XCTRL4B_ABE	0x80 		/* auxiliary battery enable */
-#define DS_XCTRL4B_E32K	0x40		/* enable 32.768 kHz Output */
-#define DS_XCTRL4B_CS	0x20		/* crystal select */
-#define DS_XCTRL4B_RCE	0x10		/* ram clear enable */
-#define DS_XCTRL4B_PRS	0x08		/* PAB resec select */
-#define DS_XCTRL4B_RIE	0x04		/* ram clear interrupt enable */
-#define DS_XCTRL4B_WFE	0x02		/* wake up alarm interrupt enable */
-#define DS_XCTRL4B_KFE	0x01		/* kickstart interrupt enable */
-
-/* interrupt enable bits */
-#define DS_XCTRL4B_IFES	(DS_XCTRL4B_RIE|DS_XCTRL4B_WFE|DS_XCTRL4B_KFE)
-
-#endif /* __LINUX_DS17287RTC_H */

include/linux/mc146818rtc.h

@@ -14,6 +14,8 @@
 #include <asm/io.h>
 #include <linux/rtc.h>			/* get the user-level API */
 #include <asm/mc146818rtc.h>		/* register access macros */
+#include <linux/bcd.h>
+#include <linux/delay.h>
 
 #ifdef __KERNEL__
 #include <linux/spinlock.h>		/* spinlock_t */
@@ -120,4 +122,7 @@ struct cmos_rtc_board_info {
 #define RTC_IO_EXTENT_USED      RTC_IO_EXTENT
 #endif /* ARCH_RTC_LOCATION */
 
+unsigned int mc146818_get_time(struct rtc_time *time);
+int mc146818_set_time(struct rtc_time *time);
+
 #endif /* _MC146818RTC_H */