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[PATCH v2 1/4] rtc: ds1307: fix century bit support

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  [PATCH v2 1/4] rtc: ds1307: fix century bit support Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-13 02:10 +0200
    [PATCH v2 2/4] rtc: ds1307: add Intersil ISL12057 support Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-13 02:10 +0200
    [PATCH v2 4/4] Documentation: dt: Intersil isl12057 is not a trivial device Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-13 02:10 +0200
    [PATCH v2 3/4] rtc: isl12057: remove driver Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-13 02:10 +0200

#1461535 — [PATCH v2 1/4] rtc: ds1307: fix century bit support

Add an option to properly support the century bit of ds1337 and compatibles
and ds1340.
Because the driver had a bug until now, it is not possible to switch users
to the fixed code directly as RTCs in the field will wrongly have the
century bit set.

Acked-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Changes in v2:
 - use proper bit operations (& instead of &&)


 drivers/rtc/Kconfig      | 14 ++++++++++++++
 drivers/rtc/rtc-ds1307.c | 48 +++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 57 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e215f50794b6..022e833c2143 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -224,6 +224,20 @@ config RTC_DRV_DS1307_HWMON
 	  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
+	default n
+	help
+	  The DS1307 driver suffered from a bug where it was enabling the
+	  century bit inconditionnally but never used it when reading the time.
+	  It made the driver unable to support dates beyond 2099.
+	  Setting this option will add proper support for the century bit but if
+	  the time was previously set using a kernel predating this option,
+	  reading the date will return a date in the next century.
+	  To solve that, you could boot a kernel without this option set, set
+	  the RTC date and then boot a kernel with this option set.
+
 config RTC_DRV_DS1374
 	tristate "Dallas/Maxim DS1374"
 	help
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 8e1c5cb6ece6..712e221d2415 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -382,10 +382,25 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 	t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
 	tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
 	t->tm_mon = bcd2bin(tmp) - 1;
-
-	/* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
 	t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
 
+#ifdef CONFIG_RTC_DRV_DS1307_CENTURY
+	switch (ds1307->type) {
+	case ds_1337:
+	case ds_1339:
+	case ds_3231:
+		if (ds1307->regs[DS1307_REG_MONTH] & DS1337_BIT_CENTURY)
+			t->tm_year += 100;
+		break;
+	case ds_1340:
+		if (ds1307->regs[DS1307_REG_HOUR] & DS1340_BIT_CENTURY)
+			t->tm_year += 100;
+		break;
+	default:
+		break;
+	}
+#endif
+
 	dev_dbg(dev, "%s secs=%d, mins=%d, "
 		"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
 		"read", t->tm_sec, t->tm_min,
@@ -409,6 +424,27 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 		t->tm_hour, t->tm_mday,
 		t->tm_mon, t->tm_year, t->tm_wday);
 
+#ifdef CONFIG_RTC_DRV_DS1307_CENTURY
+	if (t->tm_year < 100)
+		return -EINVAL;
+
+	switch (ds1307->type) {
+	case ds_1337:
+	case ds_1339:
+	case ds_3231:
+	case ds_1340:
+		if (t->tm_year > 299)
+			return -EINVAL;
+	default:
+		if (t->tm_year > 199)
+			return -EINVAL;
+		break;
+	}
+#else
+	if (t->tm_year < 100 || t->tm_year > 199)
+		return -EINVAL;
+#endif
+
 	buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
 	buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
 	buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
@@ -424,11 +460,13 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 	case ds_1337:
 	case ds_1339:
 	case ds_3231:
-		buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
+		if (t->tm_year > 199)
+			buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
 		break;
 	case ds_1340:
-		buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
-				| DS1340_BIT_CENTURY;
+		buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN;
+		if (t->tm_year > 199)
+			buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY;
 		break;
 	case mcp794xx:
 		/*
-- 
2.8.1

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#1461536 — [PATCH v2 2/4] rtc: ds1307: add Intersil ISL12057 support

Intersil ISL12057 is a drop-in replacement for DS1337. It can be supported
by the ds1307 driver.

Acked-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Changes in v2:
 - fix i2c_device_id name

 drivers/rtc/Kconfig      | 8 ++++----
 drivers/rtc/rtc-ds1307.c | 6 ++++++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 022e833c2143..5d3079c672f9 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -198,14 +198,14 @@ config RTC_DRV_AS3722
 	  will be called rtc-as3722.
 
 config RTC_DRV_DS1307
-	tristate "Dallas/Maxim DS1307/37/38/39/40, ST M41T00, EPSON RX-8025"
+	tristate "Dallas/Maxim DS1307/37/38/39/40, ST M41T00, EPSON RX-8025, ISL12057"
 	help
 	  If you say yes here you get support for various compatible RTC
 	  chips (often with battery backup) connected with I2C. This driver
 	  should handle DS1307, DS1337, DS1338, DS1339, DS1340, ST M41T00,
-	  EPSON RX-8025 and probably other chips. In some cases the RTC
-	  must already have been initialized (by manufacturing or a
-	  bootloader).
+	  EPSON RX-8025, Intersil ISL12057 and probably other chips. In some
+	  cases the RTC must already have been initialized (by manufacturing or
+	  a bootloader).
 
 	  The first seven registers on these chips hold an RTC, and other
 	  registers may add features such as NVRAM, a trickle charger for
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 712e221d2415..4e31036ee259 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -186,6 +186,7 @@ static const struct i2c_device_id ds1307_id[] = {
 	{ "mcp7941x", mcp794xx },
 	{ "pt7c4338", ds_1307 },
 	{ "rx8025", rx_8025 },
+	{ "isl12057", ds_1337 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ds1307_id);
@@ -1333,6 +1334,11 @@ static int ds1307_probe(struct i2c_client *client,
 	if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
 		ds1307_can_wakeup_device = true;
 	}
+	/* Intersil ISL12057 DT backward compatibility */
+	if (of_property_read_bool(client->dev.of_node,
+				  "isil,irq2-can-wakeup-machine")) {
+		ds1307_can_wakeup_device = true;
+	}
 #endif
 
 	switch (ds1307->type) {
-- 
2.8.1

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#1461537 — [PATCH v2 4/4] Documentation: dt: Intersil isl12057 is not a trivial device

The ISL12057 has a documentation file, remove it from trivial-devices.txt

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 Documentation/devicetree/bindings/i2c/trivial-devices.txt | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index 5c70ce9c1954..43af4765d5fe 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -50,7 +50,6 @@ fsl,sgtl5000		SGTL5000: Ultra Low-Power Audio Codec
 gmt,g751		G751: Digital Temperature Sensor and Thermal Watchdog with Two-Wire Interface
 infineon,slb9635tt	Infineon SLB9635 (Soft-) I2C TPM (old protocol, max 100khz)
 infineon,slb9645tt	Infineon SLB9645 I2C TPM (new protocol, max 400khz)
-isil,isl12057		Intersil ISL12057 I2C RTC Chip
 isil,isl29028		Intersil ISL29028 Ambient Light and Proximity Sensor
 maxim,ds1050		5 Bit Programmable, Pulse-Width Modulator
 maxim,max1237		Low-Power, 4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
-- 
2.8.1

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#1461538 — [PATCH v2 3/4] rtc: isl12057: remove driver

The Intersil isl12057 is now supported by the ds1307 driver.

Acked-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/rtc/Kconfig        |  10 -
 drivers/rtc/Makefile       |   1 -
 drivers/rtc/rtc-isl12057.c | 643 ---------------------------------------------
 3 files changed, 654 deletions(-)
 delete mode 100644 drivers/rtc/rtc-isl12057.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 5d3079c672f9..4621cd0ba59e 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -378,16 +378,6 @@ config RTC_DRV_ISL12022
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-isl12022.
 
-config RTC_DRV_ISL12057
-	select REGMAP_I2C
-	tristate "Intersil ISL12057"
-	help
-	  If you say yes here you get support for the Intersil ISL12057
-	  I2C RTC chip.
-
-	  This driver can also be built as a module. If so, the module
-	  will be called rtc-isl12057.
-
 config RTC_DRV_X1205
 	tristate "Xicor/Intersil X1205"
 	help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 7cf7ad559c79..0e0c15bab5d2 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -71,7 +71,6 @@ obj-$(CONFIG_RTC_DRV_HID_SENSOR_TIME) += rtc-hid-sensor-time.o
 obj-$(CONFIG_RTC_DRV_HYM8563)	+= rtc-hym8563.o
 obj-$(CONFIG_RTC_DRV_IMXDI)	+= rtc-imxdi.o
 obj-$(CONFIG_RTC_DRV_ISL12022)	+= rtc-isl12022.o
-obj-$(CONFIG_RTC_DRV_ISL12057)	+= rtc-isl12057.o
 obj-$(CONFIG_RTC_DRV_ISL1208)	+= rtc-isl1208.o
 obj-$(CONFIG_RTC_DRV_JZ4740)	+= rtc-jz4740.o
 obj-$(CONFIG_RTC_DRV_LP8788)	+= rtc-lp8788.o
diff --git a/drivers/rtc/rtc-isl12057.c b/drivers/rtc/rtc-isl12057.c
deleted file mode 100644
index 0e7f0f52bfe4..000000000000
--- a/drivers/rtc/rtc-isl12057.c
+++ /dev/null
@@ -1,643 +0,0 @@
-/*
- * rtc-isl12057 - Driver for Intersil ISL12057 I2C Real Time Clock
- *
- * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
- *
- * This work is largely based on Intersil ISL1208 driver developed by
- * Hebert Valerio Riedel <hvr@gnu.org>.
- *
- * Detailed datasheet on which this development is based is available here:
- *
- *  http://natisbad.org/NAS2/refs/ISL12057.pdf
- *
- * 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.
- */
-
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/rtc.h>
-#include <linux/i2c.h>
-#include <linux/bcd.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
-#include <linux/regmap.h>
-
-#define DRV_NAME "rtc-isl12057"
-
-/* RTC section */
-#define ISL12057_REG_RTC_SC	0x00	/* Seconds */
-#define ISL12057_REG_RTC_MN	0x01	/* Minutes */
-#define ISL12057_REG_RTC_HR	0x02	/* Hours */
-#define ISL12057_REG_RTC_HR_PM	BIT(5)	/* AM/PM bit in 12h format */
-#define ISL12057_REG_RTC_HR_MIL BIT(6)	/* 24h/12h format */
-#define ISL12057_REG_RTC_DW	0x03	/* Day of the Week */
-#define ISL12057_REG_RTC_DT	0x04	/* Date */
-#define ISL12057_REG_RTC_MO	0x05	/* Month */
-#define ISL12057_REG_RTC_MO_CEN	BIT(7)	/* Century bit */
-#define ISL12057_REG_RTC_YR	0x06	/* Year */
-#define ISL12057_RTC_SEC_LEN	7
-
-/* Alarm 1 section */
-#define ISL12057_REG_A1_SC	0x07	/* Alarm 1 Seconds */
-#define ISL12057_REG_A1_MN	0x08	/* Alarm 1 Minutes */
-#define ISL12057_REG_A1_HR	0x09	/* Alarm 1 Hours */
-#define ISL12057_REG_A1_HR_PM	BIT(5)	/* AM/PM bit in 12h format */
-#define ISL12057_REG_A1_HR_MIL	BIT(6)	/* 24h/12h format */
-#define ISL12057_REG_A1_DWDT	0x0A	/* Alarm 1 Date / Day of the week */
-#define ISL12057_REG_A1_DWDT_B	BIT(6)	/* DW / DT selection bit */
-#define ISL12057_A1_SEC_LEN	4
-
-/* Alarm 2 section */
-#define ISL12057_REG_A2_MN	0x0B	/* Alarm 2 Minutes */
-#define ISL12057_REG_A2_HR	0x0C	/* Alarm 2 Hours */
-#define ISL12057_REG_A2_DWDT	0x0D	/* Alarm 2 Date / Day of the week */
-#define ISL12057_A2_SEC_LEN	3
-
-/* Control/Status registers */
-#define ISL12057_REG_INT	0x0E
-#define ISL12057_REG_INT_A1IE	BIT(0)	/* Alarm 1 interrupt enable bit */
-#define ISL12057_REG_INT_A2IE	BIT(1)	/* Alarm 2 interrupt enable bit */
-#define ISL12057_REG_INT_INTCN	BIT(2)	/* Interrupt control enable bit */
-#define ISL12057_REG_INT_RS1	BIT(3)	/* Freq out control bit 1 */
-#define ISL12057_REG_INT_RS2	BIT(4)	/* Freq out control bit 2 */
-#define ISL12057_REG_INT_EOSC	BIT(7)	/* Oscillator enable bit */
-
-#define ISL12057_REG_SR		0x0F
-#define ISL12057_REG_SR_A1F	BIT(0)	/* Alarm 1 interrupt bit */
-#define ISL12057_REG_SR_A2F	BIT(1)	/* Alarm 2 interrupt bit */
-#define ISL12057_REG_SR_OSF	BIT(7)	/* Oscillator failure bit */
-
-/* Register memory map length */
-#define ISL12057_MEM_MAP_LEN	0x10
-
-struct isl12057_rtc_data {
-	struct rtc_device *rtc;
-	struct regmap *regmap;
-	struct mutex lock;
-	int irq;
-};
-
-static void isl12057_rtc_regs_to_tm(struct rtc_time *tm, u8 *regs)
-{
-	tm->tm_sec = bcd2bin(regs[ISL12057_REG_RTC_SC]);
-	tm->tm_min = bcd2bin(regs[ISL12057_REG_RTC_MN]);
-
-	if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_MIL) { /* AM/PM */
-		tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x1f);
-		if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_PM)
-			tm->tm_hour += 12;
-	} else {					    /* 24 hour mode */
-		tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x3f);
-	}
-
-	tm->tm_mday = bcd2bin(regs[ISL12057_REG_RTC_DT]);
-	tm->tm_wday = bcd2bin(regs[ISL12057_REG_RTC_DW]) - 1; /* starts at 1 */
-	tm->tm_mon  = bcd2bin(regs[ISL12057_REG_RTC_MO] & 0x1f) - 1; /* ditto */
-	tm->tm_year = bcd2bin(regs[ISL12057_REG_RTC_YR]) + 100;
-
-	/* Check if years register has overflown from 99 to 00 */
-	if (regs[ISL12057_REG_RTC_MO] & ISL12057_REG_RTC_MO_CEN)
-		tm->tm_year += 100;
-}
-
-static int isl12057_rtc_tm_to_regs(u8 *regs, struct rtc_time *tm)
-{
-	u8 century_bit;
-
-	/*
-	 * The clock has an 8 bit wide bcd-coded register for the year.
-	 * It also has a century bit encoded in MO flag which provides
-	 * information about overflow of year register from 99 to 00.
-	 * tm_year is an offset from 1900 and we are interested in the
-	 * 2000-2199 range, so any value less than 100 or larger than
-	 * 299 is invalid.
-	 */
-	if (tm->tm_year < 100 || tm->tm_year > 299)
-		return -EINVAL;
-
-	century_bit = (tm->tm_year > 199) ? ISL12057_REG_RTC_MO_CEN : 0;
-
-	regs[ISL12057_REG_RTC_SC] = bin2bcd(tm->tm_sec);
-	regs[ISL12057_REG_RTC_MN] = bin2bcd(tm->tm_min);
-	regs[ISL12057_REG_RTC_HR] = bin2bcd(tm->tm_hour); /* 24-hour format */
-	regs[ISL12057_REG_RTC_DT] = bin2bcd(tm->tm_mday);
-	regs[ISL12057_REG_RTC_MO] = bin2bcd(tm->tm_mon + 1) | century_bit;
-	regs[ISL12057_REG_RTC_YR] = bin2bcd(tm->tm_year % 100);
-	regs[ISL12057_REG_RTC_DW] = bin2bcd(tm->tm_wday + 1);
-
-	return 0;
-}
-
-/*
- * Try and match register bits w/ fixed null values to see whether we
- * are dealing with an ISL12057. Note: this function is called early
- * during init and hence does need mutex protection.
- */
-static int isl12057_i2c_validate_chip(struct regmap *regmap)
-{
-	u8 regs[ISL12057_MEM_MAP_LEN];
-	static const u8 mask[ISL12057_MEM_MAP_LEN] = { 0x80, 0x80, 0x80, 0xf8,
-						       0xc0, 0x60, 0x00, 0x00,
-						       0x00, 0x00, 0x00, 0x00,
-						       0x00, 0x00, 0x60, 0x7c };
-	int ret, i;
-
-	ret = regmap_bulk_read(regmap, 0, regs, ISL12057_MEM_MAP_LEN);
-	if (ret)
-		return ret;
-
-	for (i = 0; i < ISL12057_MEM_MAP_LEN; ++i) {
-		if (regs[i] & mask[i])	/* check if bits are cleared */
-			return -ENODEV;
-	}
-
-	return 0;
-}
-
-static int _isl12057_rtc_clear_alarm(struct device *dev)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-	int ret;
-
-	ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
-				 ISL12057_REG_SR_A1F, 0);
-	if (ret)
-		dev_err(dev, "%s: clearing alarm failed (%d)\n", __func__, ret);
-
-	return ret;
-}
-
-static int _isl12057_rtc_update_alarm(struct device *dev, int enable)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-	int ret;
-
-	ret = regmap_update_bits(data->regmap, ISL12057_REG_INT,
-				 ISL12057_REG_INT_A1IE,
-				 enable ? ISL12057_REG_INT_A1IE : 0);
-	if (ret)
-		dev_err(dev, "%s: changing alarm interrupt flag failed (%d)\n",
-			__func__, ret);
-
-	return ret;
-}
-
-/*
- * Note: as we only read from device and do not perform any update, there is
- * no need for an equivalent function which would try and get driver's main
- * lock. Here, it is safe for everyone if we just use regmap internal lock
- * on the device when reading.
- */
-static int _isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-	u8 regs[ISL12057_RTC_SEC_LEN];
-	unsigned int sr;
-	int ret;
-
-	ret = regmap_read(data->regmap, ISL12057_REG_SR, &sr);
-	if (ret) {
-		dev_err(dev, "%s: unable to read oscillator status flag (%d)\n",
-			__func__, ret);
-		goto out;
-	} else {
-		if (sr & ISL12057_REG_SR_OSF) {
-			ret = -ENODATA;
-			goto out;
-		}
-	}
-
-	ret = regmap_bulk_read(data->regmap, ISL12057_REG_RTC_SC, regs,
-			       ISL12057_RTC_SEC_LEN);
-	if (ret)
-		dev_err(dev, "%s: unable to read RTC time section (%d)\n",
-			__func__, ret);
-
-out:
-	if (ret)
-		return ret;
-
-	isl12057_rtc_regs_to_tm(tm, regs);
-
-	return rtc_valid_tm(tm);
-}
-
-static int isl12057_rtc_update_alarm(struct device *dev, int enable)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-	int ret;
-
-	mutex_lock(&data->lock);
-	ret = _isl12057_rtc_update_alarm(dev, enable);
-	mutex_unlock(&data->lock);
-
-	return ret;
-}
-
-static int isl12057_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-	struct rtc_time *alarm_tm = &alarm->time;
-	u8 regs[ISL12057_A1_SEC_LEN];
-	unsigned int ir;
-	int ret;
-
-	mutex_lock(&data->lock);
-	ret = regmap_bulk_read(data->regmap, ISL12057_REG_A1_SC, regs,
-			       ISL12057_A1_SEC_LEN);
-	if (ret) {
-		dev_err(dev, "%s: reading alarm section failed (%d)\n",
-			__func__, ret);
-		goto err_unlock;
-	}
-
-	alarm_tm->tm_sec  = bcd2bin(regs[0] & 0x7f);
-	alarm_tm->tm_min  = bcd2bin(regs[1] & 0x7f);
-	alarm_tm->tm_hour = bcd2bin(regs[2] & 0x3f);
-	alarm_tm->tm_mday = bcd2bin(regs[3] & 0x3f);
-
-	ret = regmap_read(data->regmap, ISL12057_REG_INT, &ir);
-	if (ret) {
-		dev_err(dev, "%s: reading alarm interrupt flag failed (%d)\n",
-			__func__, ret);
-		goto err_unlock;
-	}
-
-	alarm->enabled = !!(ir & ISL12057_REG_INT_A1IE);
-
-err_unlock:
-	mutex_unlock(&data->lock);
-
-	return ret;
-}
-
-static int isl12057_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-	struct rtc_time *alarm_tm = &alarm->time;
-	unsigned long rtc_secs, alarm_secs;
-	u8 regs[ISL12057_A1_SEC_LEN];
-	struct rtc_time rtc_tm;
-	int ret, enable = 1;
-
-	mutex_lock(&data->lock);
-	ret = _isl12057_rtc_read_time(dev, &rtc_tm);
-	if (ret)
-		goto err_unlock;
-
-	ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
-	if (ret)
-		goto err_unlock;
-
-	ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
-	if (ret)
-		goto err_unlock;
-
-	/* If alarm time is before current time, disable the alarm */
-	if (!alarm->enabled || alarm_secs <= rtc_secs) {
-		enable = 0;
-	} else {
-		/*
-		 * Chip only support alarms up to one month in the future. Let's
-		 * return an error if we get something after that limit.
-		 * Comparison is done by incrementing rtc_tm month field by one
-		 * and checking alarm value is still below.
-		 */
-		if (rtc_tm.tm_mon == 11) { /* handle year wrapping */
-			rtc_tm.tm_mon = 0;
-			rtc_tm.tm_year += 1;
-		} else {
-			rtc_tm.tm_mon += 1;
-		}
-
-		ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
-		if (ret)
-			goto err_unlock;
-
-		if (alarm_secs > rtc_secs) {
-			dev_err(dev, "%s: max for alarm is one month (%d)\n",
-				__func__, ret);
-			ret = -EINVAL;
-			goto err_unlock;
-		}
-	}
-
-	/* Disable the alarm before modifying it */
-	ret = _isl12057_rtc_update_alarm(dev, 0);
-	if (ret < 0) {
-		dev_err(dev, "%s: unable to disable the alarm (%d)\n",
-			__func__, ret);
-		goto err_unlock;
-	}
-
-	/* Program alarm registers */
-	regs[0] = bin2bcd(alarm_tm->tm_sec) & 0x7f;
-	regs[1] = bin2bcd(alarm_tm->tm_min) & 0x7f;
-	regs[2] = bin2bcd(alarm_tm->tm_hour) & 0x3f;
-	regs[3] = bin2bcd(alarm_tm->tm_mday) & 0x3f;
-
-	ret = regmap_bulk_write(data->regmap, ISL12057_REG_A1_SC, regs,
-				ISL12057_A1_SEC_LEN);
-	if (ret < 0) {
-		dev_err(dev, "%s: writing alarm section failed (%d)\n",
-			__func__, ret);
-		goto err_unlock;
-	}
-
-	/* Enable or disable alarm */
-	ret = _isl12057_rtc_update_alarm(dev, enable);
-
-err_unlock:
-	mutex_unlock(&data->lock);
-
-	return ret;
-}
-
-static int isl12057_rtc_set_time(struct device *dev, struct rtc_time *tm)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-	u8 regs[ISL12057_RTC_SEC_LEN];
-	int ret;
-
-	ret = isl12057_rtc_tm_to_regs(regs, tm);
-	if (ret)
-		return ret;
-
-	mutex_lock(&data->lock);
-	ret = regmap_bulk_write(data->regmap, ISL12057_REG_RTC_SC, regs,
-				ISL12057_RTC_SEC_LEN);
-	if (ret) {
-		dev_err(dev, "%s: unable to write RTC time section (%d)\n",
-			__func__, ret);
-		goto out;
-	}
-
-	/*
-	 * Now that RTC time has been updated, let's clear oscillator
-	 * failure flag, if needed.
-	 */
-	ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
-				 ISL12057_REG_SR_OSF, 0);
-	if (ret < 0)
-		dev_err(dev, "%s: unable to clear osc. failure bit (%d)\n",
-			__func__, ret);
-
-out:
-	mutex_unlock(&data->lock);
-
-	return ret;
-}
-
-/*
- * Check current RTC status and enable/disable what needs to be. Return 0 if
- * everything went ok and a negative value upon error. Note: this function
- * is called early during init and hence does need mutex protection.
- */
-static int isl12057_check_rtc_status(struct device *dev, struct regmap *regmap)
-{
-	int ret;
-
-	/* Enable oscillator if not already running */
-	ret = regmap_update_bits(regmap, ISL12057_REG_INT,
-				 ISL12057_REG_INT_EOSC, 0);
-	if (ret < 0) {
-		dev_err(dev, "%s: unable to enable oscillator (%d)\n",
-			__func__, ret);
-		return ret;
-	}
-
-	/* Clear alarm bit if needed */
-	ret = regmap_update_bits(regmap, ISL12057_REG_SR,
-				 ISL12057_REG_SR_A1F, 0);
-	if (ret < 0) {
-		dev_err(dev, "%s: unable to clear alarm bit (%d)\n",
-			__func__, ret);
-		return ret;
-	}
-
-	return 0;
-}
-
-#ifdef CONFIG_OF
-/*
- * One would expect the device to be marked as a wakeup source only
- * when an IRQ pin of the RTC is routed to an interrupt line of the
- * CPU. In practice, such an IRQ pin can be connected to a PMIC and
- * this allows the device to be powered up when RTC alarm rings. This
- * is for instance the case on ReadyNAS 102, 104 and 2120. On those
- * devices with no IRQ driectly connected to the SoC, the RTC chip
- * can be forced as a wakeup source by stating that explicitly in
- * the device's .dts file using the "wakeup-source" boolean property.
- * This will guarantee 'wakealarm' sysfs entry is available on the device.
- *
- * The function below returns 1, i.e. the capability of the chip to
- * wakeup the device, based on IRQ availability or if the boolean
- * property has been set in the .dts file. Otherwise, it returns 0.
- */
-
-static bool isl12057_can_wakeup_machine(struct device *dev)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-
-	return data->irq || of_property_read_bool(dev->of_node, "wakeup-source")
-		|| of_property_read_bool(dev->of_node, /* legacy */
-					 "isil,irq2-can-wakeup-machine");
-}
-#else
-static bool isl12057_can_wakeup_machine(struct device *dev)
-{
-	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-
-	return !!data->irq;
-}
-#endif
-
-static int isl12057_rtc_alarm_irq_enable(struct device *dev,
-					 unsigned int enable)
-{
-	struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
-	int ret = -ENOTTY;
-
-	if (rtc_data->irq)
-		ret = isl12057_rtc_update_alarm(dev, enable);
-
-	return ret;
-}
-
-static irqreturn_t isl12057_rtc_interrupt(int irq, void *data)
-{
-	struct i2c_client *client = data;
-	struct isl12057_rtc_data *rtc_data = dev_get_drvdata(&client->dev);
-	struct rtc_device *rtc = rtc_data->rtc;
-	int ret, handled = IRQ_NONE;
-	unsigned int sr;
-
-	ret = regmap_read(rtc_data->regmap, ISL12057_REG_SR, &sr);
-	if (!ret && (sr & ISL12057_REG_SR_A1F)) {
-		dev_dbg(&client->dev, "RTC alarm!\n");
-
-		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
-
-		/* Acknowledge and disable the alarm */
-		_isl12057_rtc_clear_alarm(&client->dev);
-		_isl12057_rtc_update_alarm(&client->dev, 0);
-
-		handled = IRQ_HANDLED;
-	}
-
-	return handled;
-}
-
-static const struct rtc_class_ops rtc_ops = {
-	.read_time = _isl12057_rtc_read_time,
-	.set_time = isl12057_rtc_set_time,
-	.read_alarm = isl12057_rtc_read_alarm,
-	.set_alarm = isl12057_rtc_set_alarm,
-	.alarm_irq_enable = isl12057_rtc_alarm_irq_enable,
-};
-
-static const struct regmap_config isl12057_rtc_regmap_config = {
-	.reg_bits = 8,
-	.val_bits = 8,
-};
-
-static int isl12057_probe(struct i2c_client *client,
-			  const struct i2c_device_id *id)
-{
-	struct device *dev = &client->dev;
-	struct isl12057_rtc_data *data;
-	struct regmap *regmap;
-	int ret;
-
-	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
-				     I2C_FUNC_SMBUS_BYTE_DATA |
-				     I2C_FUNC_SMBUS_I2C_BLOCK))
-		return -ENODEV;
-
-	regmap = devm_regmap_init_i2c(client, &isl12057_rtc_regmap_config);
-	if (IS_ERR(regmap)) {
-		ret = PTR_ERR(regmap);
-		dev_err(dev, "%s: regmap allocation failed (%d)\n",
-			__func__, ret);
-		return ret;
-	}
-
-	ret = isl12057_i2c_validate_chip(regmap);
-	if (ret)
-		return ret;
-
-	ret = isl12057_check_rtc_status(dev, regmap);
-	if (ret)
-		return ret;
-
-	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	mutex_init(&data->lock);
-	data->regmap = regmap;
-	dev_set_drvdata(dev, data);
-
-	if (client->irq > 0) {
-		ret = devm_request_threaded_irq(dev, client->irq, NULL,
-						isl12057_rtc_interrupt,
-						IRQF_SHARED|IRQF_ONESHOT,
-						DRV_NAME, client);
-		if (!ret)
-			data->irq = client->irq;
-		else
-			dev_err(dev, "%s: irq %d unavailable (%d)\n", __func__,
-				client->irq, ret);
-	}
-
-	if (isl12057_can_wakeup_machine(dev))
-		device_init_wakeup(dev, true);
-
-	data->rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops,
-					     THIS_MODULE);
-	ret = PTR_ERR_OR_ZERO(data->rtc);
-	if (ret) {
-		dev_err(dev, "%s: unable to register RTC device (%d)\n",
-			__func__, ret);
-		goto err;
-	}
-
-	/* We cannot support UIE mode if we do not have an IRQ line */
-	if (!data->irq)
-		data->rtc->uie_unsupported = 1;
-
-err:
-	return ret;
-}
-
-static int isl12057_remove(struct i2c_client *client)
-{
-	if (isl12057_can_wakeup_machine(&client->dev))
-		device_init_wakeup(&client->dev, false);
-
-	return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int isl12057_rtc_suspend(struct device *dev)
-{
-	struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
-
-	if (rtc_data->irq && device_may_wakeup(dev))
-		return enable_irq_wake(rtc_data->irq);
-
-	return 0;
-}
-
-static int isl12057_rtc_resume(struct device *dev)
-{
-	struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
-
-	if (rtc_data->irq && device_may_wakeup(dev))
-		return disable_irq_wake(rtc_data->irq);
-
-	return 0;
-}
-#endif
-
-static SIMPLE_DEV_PM_OPS(isl12057_rtc_pm_ops, isl12057_rtc_suspend,
-			 isl12057_rtc_resume);
-
-#ifdef CONFIG_OF
-static const struct of_device_id isl12057_dt_match[] = {
-	{ .compatible = "isl,isl12057" }, /* for backward compat., don't use */
-	{ .compatible = "isil,isl12057" },
-	{ },
-};
-MODULE_DEVICE_TABLE(of, isl12057_dt_match);
-#endif
-
-static const struct i2c_device_id isl12057_id[] = {
-	{ "isl12057", 0 },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, isl12057_id);
-
-static struct i2c_driver isl12057_driver = {
-	.driver = {
-		.name = DRV_NAME,
-		.pm = &isl12057_rtc_pm_ops,
-		.of_match_table = of_match_ptr(isl12057_dt_match),
-	},
-	.probe	  = isl12057_probe,
-	.remove	  = isl12057_remove,
-	.id_table = isl12057_id,
-};
-module_i2c_driver(isl12057_driver);
-
-MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
-MODULE_DESCRIPTION("Intersil ISL12057 RTC driver");
-MODULE_LICENSE("GPL");
-- 
2.8.1

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