Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 745 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
new file mode 100644
index 000000000..d1ef9e0da
--- /dev/null
+++ b/drivers/rtc/rtc-ds3232.c
@@ -0,0 +1,745 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
+ *
+ * Copyright (C) 2009-2011 Freescale Semiconductor.
+ * Author: Jack Lan <jack.lan@freescale.com>
+ * Copyright (C) 2008 MIMOMax Wireless Ltd.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/spi/spi.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <linux/hwmon.h>
+
+#define DS3232_REG_SECONDS      0x00
+#define DS3232_REG_MINUTES      0x01
+#define DS3232_REG_HOURS        0x02
+#define DS3232_REG_AMPM         0x02
+#define DS3232_REG_DAY          0x03
+#define DS3232_REG_DATE         0x04
+#define DS3232_REG_MONTH        0x05
+#define DS3232_REG_CENTURY      0x05
+#define DS3232_REG_YEAR         0x06
+#define DS3232_REG_ALARM1       0x07       /* Alarm 1 BASE */
+#define DS3232_REG_ALARM2       0x0B       /* Alarm 2 BASE */
+#define DS3232_REG_CR           0x0E       /* Control register */
+#       define DS3232_REG_CR_nEOSC   0x80
+#       define DS3232_REG_CR_INTCN   0x04
+#       define DS3232_REG_CR_A2IE    0x02
+#       define DS3232_REG_CR_A1IE    0x01
+
+#define DS3232_REG_SR           0x0F       /* control/status register */
+#       define DS3232_REG_SR_OSF     0x80
+#       define DS3232_REG_SR_BSY     0x04
+#       define DS3232_REG_SR_A2F     0x02
+#       define DS3232_REG_SR_A1F     0x01
+
+#define DS3232_REG_TEMPERATURE	0x11
+#define DS3232_REG_SRAM_START   0x14
+#define DS3232_REG_SRAM_END     0xFF
+
+#define DS3232_REG_SRAM_SIZE    236
+
+struct ds3232 {
+	struct device *dev;
+	struct regmap *regmap;
+	int irq;
+	struct rtc_device *rtc;
+
+	bool suspended;
+};
+
+static int ds3232_check_rtc_status(struct device *dev)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	int ret = 0;
+	int control, stat;
+
+	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
+	if (ret)
+		return ret;
+
+	if (stat & DS3232_REG_SR_OSF)
+		dev_warn(dev,
+				"oscillator discontinuity flagged, "
+				"time unreliable\n");
+
+	stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
+
+	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
+	if (ret)
+		return ret;
+
+	/* If the alarm is pending, clear it before requesting
+	 * the interrupt, so an interrupt event isn't reported
+	 * before everything is initialized.
+	 */
+
+	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
+	if (ret)
+		return ret;
+
+	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
+	control |= DS3232_REG_CR_INTCN;
+
+	return regmap_write(ds3232->regmap, DS3232_REG_CR, control);
+}
+
+static int ds3232_read_time(struct device *dev, struct rtc_time *time)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	int ret;
+	u8 buf[7];
+	unsigned int year, month, day, hour, minute, second;
+	unsigned int week, twelve_hr, am_pm;
+	unsigned int century, add_century = 0;
+
+	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
+	if (ret)
+		return ret;
+
+	second = buf[0];
+	minute = buf[1];
+	hour = buf[2];
+	week = buf[3];
+	day = buf[4];
+	month = buf[5];
+	year = buf[6];
+
+	/* Extract additional information for AM/PM and century */
+
+	twelve_hr = hour & 0x40;
+	am_pm = hour & 0x20;
+	century = month & 0x80;
+
+	/* Write to rtc_time structure */
+
+	time->tm_sec = bcd2bin(second);
+	time->tm_min = bcd2bin(minute);
+	if (twelve_hr) {
+		/* Convert to 24 hr */
+		if (am_pm)
+			time->tm_hour = bcd2bin(hour & 0x1F) + 12;
+		else
+			time->tm_hour = bcd2bin(hour & 0x1F);
+	} else {
+		time->tm_hour = bcd2bin(hour);
+	}
+
+	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
+	time->tm_wday = bcd2bin(week) - 1;
+	time->tm_mday = bcd2bin(day);
+	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
+	time->tm_mon = bcd2bin(month & 0x7F) - 1;
+	if (century)
+		add_century = 100;
+
+	time->tm_year = bcd2bin(year) + add_century;
+
+	return 0;
+}
+
+static int ds3232_set_time(struct device *dev, struct rtc_time *time)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	u8 buf[7];
+
+	/* Extract time from rtc_time and load into ds3232*/
+
+	buf[0] = bin2bcd(time->tm_sec);
+	buf[1] = bin2bcd(time->tm_min);
+	buf[2] = bin2bcd(time->tm_hour);
+	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
+	buf[3] = bin2bcd(time->tm_wday + 1);
+	buf[4] = bin2bcd(time->tm_mday); /* Date */
+	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
+	buf[5] = bin2bcd(time->tm_mon + 1);
+	if (time->tm_year >= 100) {
+		buf[5] |= 0x80;
+		buf[6] = bin2bcd(time->tm_year - 100);
+	} else {
+		buf[6] = bin2bcd(time->tm_year);
+	}
+
+	return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
+}
+
+/*
+ * DS3232 has two alarm, we only use alarm1
+ * According to linux specification, only support one-shot alarm
+ * no periodic alarm mode
+ */
+static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	int control, stat;
+	int ret;
+	u8 buf[4];
+
+	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
+	if (ret)
+		goto out;
+	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
+	if (ret)
+		goto out;
+	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
+	if (ret)
+		goto out;
+
+	alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
+	alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
+	alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
+	alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
+
+	alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
+	alarm->pending = !!(stat & DS3232_REG_SR_A1F);
+
+	ret = 0;
+out:
+	return ret;
+}
+
+/*
+ * linux rtc-module does not support wday alarm
+ * and only 24h time mode supported indeed
+ */
+static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	int control, stat;
+	int ret;
+	u8 buf[4];
+
+	if (ds3232->irq <= 0)
+		return -EINVAL;
+
+	buf[0] = bin2bcd(alarm->time.tm_sec);
+	buf[1] = bin2bcd(alarm->time.tm_min);
+	buf[2] = bin2bcd(alarm->time.tm_hour);
+	buf[3] = bin2bcd(alarm->time.tm_mday);
+
+	/* clear alarm interrupt enable bit */
+	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
+	if (ret)
+		goto out;
+	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
+	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
+	if (ret)
+		goto out;
+
+	/* clear any pending alarm flag */
+	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
+	if (ret)
+		goto out;
+	stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
+	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
+	if (ret)
+		goto out;
+
+	ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
+	if (ret)
+		goto out;
+
+	if (alarm->enabled) {
+		control |= DS3232_REG_CR_A1IE;
+		ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
+	}
+out:
+	return ret;
+}
+
+static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	int control;
+	int ret;
+
+	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
+	if (ret)
+		return ret;
+
+	if (enabled)
+		/* enable alarm1 interrupt */
+		control |= DS3232_REG_CR_A1IE;
+	else
+		/* disable alarm1 interrupt */
+		control &= ~(DS3232_REG_CR_A1IE);
+	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
+
+	return ret;
+}
+
+/*
+ * Temperature sensor support for ds3232/ds3234 devices.
+ * A user-initiated temperature conversion is not started by this function,
+ * so the temperature is updated once every 64 seconds.
+ */
+static int ds3232_hwmon_read_temp(struct device *dev, long int *mC)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	u8 temp_buf[2];
+	s16 temp;
+	int ret;
+
+	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_TEMPERATURE, temp_buf,
+			       sizeof(temp_buf));
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Temperature is represented as a 10-bit code with a resolution of
+	 * 0.25 degree celsius and encoded in two's complement format.
+	 */
+	temp = (temp_buf[0] << 8) | temp_buf[1];
+	temp >>= 6;
+	*mC = temp * 250;
+
+	return 0;
+}
+
+static umode_t ds3232_hwmon_is_visible(const void *data,
+				       enum hwmon_sensor_types type,
+				       u32 attr, int channel)
+{
+	if (type != hwmon_temp)
+		return 0;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		return 0444;
+	default:
+		return 0;
+	}
+}
+
+static int ds3232_hwmon_read(struct device *dev,
+			     enum hwmon_sensor_types type,
+			     u32 attr, int channel, long *temp)
+{
+	int err;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		err = ds3232_hwmon_read_temp(dev, temp);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	return err;
+}
+
+static const struct hwmon_channel_info * const ds3232_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+	NULL
+};
+
+static const struct hwmon_ops ds3232_hwmon_hwmon_ops = {
+	.is_visible = ds3232_hwmon_is_visible,
+	.read = ds3232_hwmon_read,
+};
+
+static const struct hwmon_chip_info ds3232_hwmon_chip_info = {
+	.ops = &ds3232_hwmon_hwmon_ops,
+	.info = ds3232_hwmon_info,
+};
+
+static void ds3232_hwmon_register(struct device *dev, const char *name)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	struct device *hwmon_dev;
+
+	if (!IS_ENABLED(CONFIG_RTC_DRV_DS3232_HWMON))
+		return;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, name, ds3232,
+							&ds3232_hwmon_chip_info,
+							NULL);
+	if (IS_ERR(hwmon_dev)) {
+		dev_err(dev, "unable to register hwmon device %ld\n",
+			PTR_ERR(hwmon_dev));
+	}
+}
+
+static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+
+	if (ds3232->irq <= 0)
+		return -EINVAL;
+
+	return ds3232_update_alarm(dev, enabled);
+}
+
+static irqreturn_t ds3232_irq(int irq, void *dev_id)
+{
+	struct device *dev = dev_id;
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+	int ret;
+	int stat, control;
+
+	rtc_lock(ds3232->rtc);
+
+	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
+	if (ret)
+		goto unlock;
+
+	if (stat & DS3232_REG_SR_A1F) {
+		ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
+		if (ret) {
+			dev_warn(ds3232->dev,
+				 "Read Control Register error %d\n", ret);
+		} else {
+			/* disable alarm1 interrupt */
+			control &= ~(DS3232_REG_CR_A1IE);
+			ret = regmap_write(ds3232->regmap, DS3232_REG_CR,
+					   control);
+			if (ret) {
+				dev_warn(ds3232->dev,
+					 "Write Control Register error %d\n",
+					 ret);
+				goto unlock;
+			}
+
+			/* clear the alarm pend flag */
+			stat &= ~DS3232_REG_SR_A1F;
+			ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
+			if (ret) {
+				dev_warn(ds3232->dev,
+					 "Write Status Register error %d\n",
+					 ret);
+				goto unlock;
+			}
+
+			rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);
+		}
+	}
+
+unlock:
+	rtc_unlock(ds3232->rtc);
+
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops ds3232_rtc_ops = {
+	.read_time = ds3232_read_time,
+	.set_time = ds3232_set_time,
+	.read_alarm = ds3232_read_alarm,
+	.set_alarm = ds3232_set_alarm,
+	.alarm_irq_enable = ds3232_alarm_irq_enable,
+};
+
+static int ds3232_nvmem_read(void *priv, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	struct regmap *ds3232_regmap = (struct regmap *)priv;
+
+	return regmap_bulk_read(ds3232_regmap, DS3232_REG_SRAM_START + offset,
+				val, bytes);
+}
+
+static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val,
+			      size_t bytes)
+{
+	struct regmap *ds3232_regmap = (struct regmap *)priv;
+
+	return regmap_bulk_write(ds3232_regmap, DS3232_REG_SRAM_START + offset,
+				 val, bytes);
+}
+
+static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
+			const char *name)
+{
+	struct ds3232 *ds3232;
+	int ret;
+	struct nvmem_config nvmem_cfg = {
+		.name = "ds3232_sram",
+		.stride = 1,
+		.size = DS3232_REG_SRAM_SIZE,
+		.word_size = 1,
+		.reg_read = ds3232_nvmem_read,
+		.reg_write = ds3232_nvmem_write,
+		.priv = regmap,
+		.type = NVMEM_TYPE_BATTERY_BACKED
+	};
+
+	ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
+	if (!ds3232)
+		return -ENOMEM;
+
+	ds3232->regmap = regmap;
+	ds3232->irq = irq;
+	ds3232->dev = dev;
+	dev_set_drvdata(dev, ds3232);
+
+	ret = ds3232_check_rtc_status(dev);
+	if (ret)
+		return ret;
+
+	if (ds3232->irq > 0)
+		device_init_wakeup(dev, true);
+
+	ds3232_hwmon_register(dev, name);
+
+	ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
+						THIS_MODULE);
+	if (IS_ERR(ds3232->rtc))
+		return PTR_ERR(ds3232->rtc);
+
+	ret = devm_rtc_nvmem_register(ds3232->rtc, &nvmem_cfg);
+	if(ret)
+		return ret;
+
+	if (ds3232->irq > 0) {
+		ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
+						ds3232_irq,
+						IRQF_SHARED | IRQF_ONESHOT,
+						name, dev);
+		if (ret) {
+			device_set_wakeup_capable(dev, 0);
+			ds3232->irq = 0;
+			dev_err(dev, "unable to request IRQ\n");
+		}
+	}
+
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_I2C)
+
+#ifdef CONFIG_PM_SLEEP
+static int ds3232_suspend(struct device *dev)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev)) {
+		if (enable_irq_wake(ds3232->irq))
+			dev_warn_once(dev, "Cannot set wakeup source\n");
+	}
+
+	return 0;
+}
+
+static int ds3232_resume(struct device *dev)
+{
+	struct ds3232 *ds3232 = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(ds3232->irq);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops ds3232_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
+};
+
+static int ds3232_i2c_probe(struct i2c_client *client)
+{
+	struct regmap *regmap;
+	static const struct regmap_config config = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = DS3232_REG_SRAM_END,
+	};
+
+	regmap = devm_regmap_init_i2c(client, &config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
+			__func__, PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return ds3232_probe(&client->dev, regmap, client->irq, client->name);
+}
+
+static const struct i2c_device_id ds3232_id[] = {
+	{ .name = "ds3232" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ds3232_id);
+
+static const  __maybe_unused 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,
+	.id_table = ds3232_id,
+};
+
+static int ds3232_register_driver(void)
+{
+	return i2c_add_driver(&ds3232_driver);
+}
+
+static void ds3232_unregister_driver(void)
+{
+	i2c_del_driver(&ds3232_driver);
+}
+
+#else
+
+static int ds3232_register_driver(void)
+{
+	return 0;
+}
+
+static void ds3232_unregister_driver(void)
+{
+}
+
+#endif
+
+#if IS_ENABLED(CONFIG_SPI_MASTER)
+
+static int ds3234_probe(struct spi_device *spi)
+{
+	int res;
+	unsigned int tmp;
+	static const struct regmap_config config = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = DS3232_REG_SRAM_END,
+		.write_flag_mask = 0x80,
+	};
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_spi(spi, &config);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
+			__func__, PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	spi->mode = SPI_MODE_3;
+	spi->bits_per_word = 8;
+	spi_setup(spi);
+
+	res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
+	if (res)
+		return res;
+
+	/* Control settings
+	 *
+	 * CONTROL_REG
+	 * BIT 7	6	5	4	3	2	1	0
+	 *     EOSC	BBSQW	CONV	RS2	RS1	INTCN	A2IE	A1IE
+	 *
+	 *     0	0	0	1	1	1	0	0
+	 *
+	 * CONTROL_STAT_REG
+	 * BIT 7	6	5	4	3	2	1	0
+	 *     OSF	BB32kHz	CRATE1	CRATE0	EN32kHz	BSY	A2F	A1F
+	 *
+	 *     1	0	0	0	1	0	0	0
+	 */
+	res = regmap_read(regmap, DS3232_REG_CR, &tmp);
+	if (res)
+		return res;
+	res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
+	if (res)
+		return res;
+
+	res = regmap_read(regmap, DS3232_REG_SR, &tmp);
+	if (res)
+		return res;
+	res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
+	if (res)
+		return res;
+
+	/* Print our settings */
+	res = regmap_read(regmap, DS3232_REG_CR, &tmp);
+	if (res)
+		return res;
+	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
+
+	res = regmap_read(regmap, DS3232_REG_SR, &tmp);
+	if (res)
+		return res;
+	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
+
+	return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
+}
+
+static struct spi_driver ds3234_driver = {
+	.driver = {
+		.name	 = "ds3234",
+	},
+	.probe	 = ds3234_probe,
+};
+
+static int ds3234_register_driver(void)
+{
+	return spi_register_driver(&ds3234_driver);
+}
+
+static void ds3234_unregister_driver(void)
+{
+	spi_unregister_driver(&ds3234_driver);
+}
+
+#else
+
+static int ds3234_register_driver(void)
+{
+	return 0;
+}
+
+static void ds3234_unregister_driver(void)
+{
+}
+
+#endif
+
+static int __init ds323x_init(void)
+{
+	int ret;
+
+	ret = ds3232_register_driver();
+	if (ret) {
+		pr_err("Failed to register ds3232 driver: %d\n", ret);
+		return ret;
+	}
+
+	ret = ds3234_register_driver();
+	if (ret) {
+		pr_err("Failed to register ds3234 driver: %d\n", ret);
+		ds3232_unregister_driver();
+	}
+
+	return ret;
+}
+module_init(ds323x_init)
+
+static void __exit ds323x_exit(void)
+{
+	ds3234_unregister_driver();
+	ds3232_unregister_driver();
+}
+module_exit(ds323x_exit)
+
+MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
+MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
+MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:ds3234");