diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index b1cb341..cdf1430 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -39,6 +39,7 @@ 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)
+isl,isl12057		Intersil ISL12057 I2C RTC Chip
 maxim,ds1050		5 Bit Programmable, Pulse-Width Modulator
 maxim,max1237		Low-Power, 4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
 maxim,max6625		9-Bit/12-Bit Temperature Sensors with I²C-Compatible Serial Interface
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index edbb8d8..ed0f63f 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -39,6 +39,7 @@ ibm	International Business Machines (IBM)
 idt	Integrated Device Technologies, Inc.
 img	Imagination Technologies Ltd.
 intercontrol	Inter Control Group
+isl	Intersil
 lg	LG Corporation
 linux	Linux-specific binding
 lsi	LSI Corp. (LSI Logic)
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 0077302..9608210 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -304,6 +304,17 @@ 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
+       depends on I2C
+       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 27b4bd8..d4089c0 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_RTC_DRV_HID_SENSOR_TIME) += rtc-hid-sensor-time.o
 obj-$(CONFIG_RTC_DRV_IMXDI)	+= rtc-imxdi.o
 obj-$(CONFIG_RTC_DRV_ISL1208)	+= rtc-isl1208.o
 obj-$(CONFIG_RTC_DRV_ISL12022)	+= rtc-isl12022.o
+obj-$(CONFIG_RTC_DRV_ISL12057)	+= rtc-isl12057.o
 obj-$(CONFIG_RTC_DRV_JZ4740)	+= rtc-jz4740.o
 obj-$(CONFIG_RTC_DRV_LP8788)	+= rtc-lp8788.o
 obj-$(CONFIG_RTC_DRV_LPC32XX)	+= rtc-lpc32xx.o
diff --git a/drivers/rtc/rtc-isl12057.c b/drivers/rtc/rtc-isl12057.c
new file mode 100644
index 0000000..068ce3a
--- /dev/null
+++ b/drivers/rtc/rtc-isl12057.c
@@ -0,0 +1,351 @@
+/*
+ * 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/rtc.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_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 regmap *regmap;
+	struct mutex lock;
+};
+
+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] & 0x0f);
+		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]) - 1; /* starts at 1 */
+	tm->tm_year = bcd2bin(regs[ISL12057_REG_RTC_YR]) + 100;
+}
+
+static int isl12057_rtc_tm_to_regs(u8 *regs, struct rtc_time *tm)
+{
+	/*
+	 * The clock has an 8 bit wide bcd-coded register for the year.
+	 * tm_year is an offset from 1900 and we are interested in the
+	 * 2000-2099 range, so any value less than 100 is invalid.
+	 */
+	if (tm->tm_year < 100)
+		return -EINVAL;
+
+	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);
+	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];
+	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_read_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;
+
+	mutex_lock(&data->lock);
+	ret = regmap_bulk_read(data->regmap, ISL12057_REG_RTC_SC, regs,
+			       ISL12057_RTC_SEC_LEN);
+	mutex_unlock(&data->lock);
+
+	if (ret) {
+		dev_err(dev, "%s: RTC read failed\n", __func__);
+		return ret;
+	}
+
+	isl12057_rtc_regs_to_tm(tm, regs);
+
+	return rtc_valid_tm(tm);
+}
+
+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);
+	mutex_unlock(&data->lock);
+
+	if (ret)
+		dev_err(dev, "%s: RTC write failed\n", __func__);
+
+	return ret;
+}
+
+static int isl12057_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
+	int reg, ret;
+
+	mutex_lock(&data->lock);
+
+	/* Status register */
+	ret = regmap_read(data->regmap, ISL12057_REG_SR, &reg);
+	if (ret) {
+		dev_err(dev, "%s: reading SR failed\n", __func__);
+		goto out;
+	}
+
+	seq_printf(seq, "status_reg\t:%s%s%s (0x%.2x)\n",
+		   (reg & ISL12057_REG_SR_OSF) ? " OSF" : "",
+		   (reg & ISL12057_REG_SR_A1F) ? " A1F" : "",
+		   (reg & ISL12057_REG_SR_A2F) ? " A2F" : "", reg);
+
+	/* Control register */
+	ret = regmap_read(data->regmap, ISL12057_REG_INT, &reg);
+	if (ret) {
+		dev_err(dev, "%s: reading INT failed\n", __func__);
+		goto out;
+	}
+
+	seq_printf(seq, "control_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
+		   (reg & ISL12057_REG_INT_A1IE) ?  " A1IE"  : "",
+		   (reg & ISL12057_REG_INT_A2IE) ?  " A2IE"  : "",
+		   (reg & ISL12057_REG_INT_INTCN) ? " INTCN" : "",
+		   (reg & ISL12057_REG_INT_RS1) ?   " RS1"   : "",
+		   (reg & ISL12057_REG_INT_RS2) ?   " RS2"   : "",
+		   (reg & ISL12057_REG_INT_EOSC) ?  " EOSC"  : "", reg);
+
+ 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, "Unable to enable oscillator\n");
+		return ret;
+	}
+
+	/* Clear oscillator failure bit if needed */
+	ret = regmap_update_bits(regmap, ISL12057_REG_SR,
+				 ISL12057_REG_SR_OSF, 0);
+	if (ret < 0) {
+		dev_err(dev, "Unable to clear oscillator failure bit\n");
+		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, "Unable to clear alarm bit\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct rtc_class_ops rtc_ops = {
+	.read_time = isl12057_rtc_read_time,
+	.set_time = isl12057_rtc_set_time,
+	.proc = isl12057_rtc_proc,
+};
+
+static 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 rtc_device *rtc;
+	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, "regmap allocation failed: %d\n", 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);
+
+	rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static struct of_device_id isl12057_dt_match[] = {
+	{ .compatible = "isl,isl12057" },
+	{ },
+};
+#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,
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(isl12057_dt_match),
+	},
+	.probe	  = isl12057_probe,
+	.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");
