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, 924 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-rv3029c2.c b/drivers/rtc/rtc-rv3029c2.c
new file mode 100644
index 000000000..98953af2a
--- /dev/null
+++ b/drivers/rtc/rtc-rv3029c2.c
@@ -0,0 +1,924 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Micro Crystal RV-3029 / RV-3049 rtc class driver
+ *
+ * Author: Gregory Hermant <gregory.hermant@calao-systems.com>
+ *         Michael Buesch <m@bues.ch>
+ *
+ * based on previously existing rtc class drivers
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/spi/spi.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/kstrtox.h>
+#include <linux/regmap.h>
+
+/* Register map */
+/* control section */
+#define RV3029_ONOFF_CTRL		0x00
+#define RV3029_ONOFF_CTRL_WE		BIT(0)
+#define RV3029_ONOFF_CTRL_TE		BIT(1)
+#define RV3029_ONOFF_CTRL_TAR		BIT(2)
+#define RV3029_ONOFF_CTRL_EERE		BIT(3)
+#define RV3029_ONOFF_CTRL_SRON		BIT(4)
+#define RV3029_ONOFF_CTRL_TD0		BIT(5)
+#define RV3029_ONOFF_CTRL_TD1		BIT(6)
+#define RV3029_ONOFF_CTRL_CLKINT	BIT(7)
+#define RV3029_IRQ_CTRL			0x01
+#define RV3029_IRQ_CTRL_AIE		BIT(0)
+#define RV3029_IRQ_CTRL_TIE		BIT(1)
+#define RV3029_IRQ_CTRL_V1IE		BIT(2)
+#define RV3029_IRQ_CTRL_V2IE		BIT(3)
+#define RV3029_IRQ_CTRL_SRIE		BIT(4)
+#define RV3029_IRQ_FLAGS		0x02
+#define RV3029_IRQ_FLAGS_AF		BIT(0)
+#define RV3029_IRQ_FLAGS_TF		BIT(1)
+#define RV3029_IRQ_FLAGS_V1IF		BIT(2)
+#define RV3029_IRQ_FLAGS_V2IF		BIT(3)
+#define RV3029_IRQ_FLAGS_SRF		BIT(4)
+#define RV3029_STATUS			0x03
+#define RV3029_STATUS_VLOW1		BIT(2)
+#define RV3029_STATUS_VLOW2		BIT(3)
+#define RV3029_STATUS_SR		BIT(4)
+#define RV3029_STATUS_PON		BIT(5)
+#define RV3029_STATUS_EEBUSY		BIT(7)
+#define RV3029_RST_CTRL			0x04
+#define RV3029_RST_CTRL_SYSR		BIT(4)
+#define RV3029_CONTROL_SECTION_LEN	0x05
+
+/* watch section */
+#define RV3029_W_SEC			0x08
+#define RV3029_W_MINUTES		0x09
+#define RV3029_W_HOURS			0x0A
+#define RV3029_REG_HR_12_24		BIT(6) /* 24h/12h mode */
+#define RV3029_REG_HR_PM		BIT(5) /* PM/AM bit in 12h mode */
+#define RV3029_W_DATE			0x0B
+#define RV3029_W_DAYS			0x0C
+#define RV3029_W_MONTHS			0x0D
+#define RV3029_W_YEARS			0x0E
+#define RV3029_WATCH_SECTION_LEN	0x07
+
+/* alarm section */
+#define RV3029_A_SC			0x10
+#define RV3029_A_MN			0x11
+#define RV3029_A_HR			0x12
+#define RV3029_A_DT			0x13
+#define RV3029_A_DW			0x14
+#define RV3029_A_MO			0x15
+#define RV3029_A_YR			0x16
+#define RV3029_A_AE_X			BIT(7)
+#define RV3029_ALARM_SECTION_LEN	0x07
+
+/* timer section */
+#define RV3029_TIMER_LOW		0x18
+#define RV3029_TIMER_HIGH		0x19
+
+/* temperature section */
+#define RV3029_TEMP_PAGE		0x20
+
+/* eeprom data section */
+#define RV3029_E2P_EEDATA1		0x28
+#define RV3029_E2P_EEDATA2		0x29
+#define RV3029_E2PDATA_SECTION_LEN	0x02
+
+/* eeprom control section */
+#define RV3029_CONTROL_E2P_EECTRL	0x30
+#define RV3029_EECTRL_THP		BIT(0) /* temp scan interval */
+#define RV3029_EECTRL_THE		BIT(1) /* thermometer enable */
+#define RV3029_EECTRL_FD0		BIT(2) /* CLKOUT */
+#define RV3029_EECTRL_FD1		BIT(3) /* CLKOUT */
+#define RV3029_TRICKLE_1K		BIT(4) /* 1.5K resistance */
+#define RV3029_TRICKLE_5K		BIT(5) /* 5K   resistance */
+#define RV3029_TRICKLE_20K		BIT(6) /* 20K  resistance */
+#define RV3029_TRICKLE_80K		BIT(7) /* 80K  resistance */
+#define RV3029_TRICKLE_MASK		(RV3029_TRICKLE_1K |\
+					 RV3029_TRICKLE_5K |\
+					 RV3029_TRICKLE_20K |\
+					 RV3029_TRICKLE_80K)
+#define RV3029_TRICKLE_SHIFT		4
+#define RV3029_CONTROL_E2P_XOFFS	0x31 /* XTAL offset */
+#define RV3029_CONTROL_E2P_XOFFS_SIGN	BIT(7) /* Sign: 1->pos, 0->neg */
+#define RV3029_CONTROL_E2P_QCOEF	0x32 /* XTAL temp drift coef */
+#define RV3029_CONTROL_E2P_TURNOVER	0x33 /* XTAL turnover temp (in *C) */
+#define RV3029_CONTROL_E2P_TOV_MASK	0x3F /* XTAL turnover temp mask */
+
+/* user ram section */
+#define RV3029_RAM_PAGE			0x38
+#define RV3029_RAM_SECTION_LEN		8
+
+struct rv3029_data {
+	struct device		*dev;
+	struct rtc_device	*rtc;
+	struct regmap		*regmap;
+	int irq;
+};
+
+static int rv3029_eeprom_busywait(struct rv3029_data *rv3029)
+{
+	unsigned int sr;
+	int i, ret;
+
+	for (i = 100; i > 0; i--) {
+		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
+		if (ret < 0)
+			break;
+		if (!(sr & RV3029_STATUS_EEBUSY))
+			break;
+		usleep_range(1000, 10000);
+	}
+	if (i <= 0) {
+		dev_err(rv3029->dev, "EEPROM busy wait timeout.\n");
+		return -ETIMEDOUT;
+	}
+
+	return ret;
+}
+
+static int rv3029_eeprom_exit(struct rv3029_data *rv3029)
+{
+	/* Re-enable eeprom refresh */
+	return regmap_update_bits(rv3029->regmap, RV3029_ONOFF_CTRL,
+				  RV3029_ONOFF_CTRL_EERE,
+				  RV3029_ONOFF_CTRL_EERE);
+}
+
+static int rv3029_eeprom_enter(struct rv3029_data *rv3029)
+{
+	unsigned int sr;
+	int ret;
+
+	/* Check whether we are in the allowed voltage range. */
+	ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
+	if (ret < 0)
+		return ret;
+	if (sr & RV3029_STATUS_VLOW2)
+		return -ENODEV;
+	if (sr & RV3029_STATUS_VLOW1) {
+		/* We clear the bits and retry once just in case
+		 * we had a brown out in early startup.
+		 */
+		ret = regmap_update_bits(rv3029->regmap, RV3029_STATUS,
+					 RV3029_STATUS_VLOW1, 0);
+		if (ret < 0)
+			return ret;
+		usleep_range(1000, 10000);
+		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
+		if (ret < 0)
+			return ret;
+		if (sr & RV3029_STATUS_VLOW1) {
+			dev_err(rv3029->dev,
+				"Supply voltage is too low to safely access the EEPROM.\n");
+			return -ENODEV;
+		}
+	}
+
+	/* Disable eeprom refresh. */
+	ret = regmap_update_bits(rv3029->regmap, RV3029_ONOFF_CTRL,
+				 RV3029_ONOFF_CTRL_EERE, 0);
+	if (ret < 0)
+		return ret;
+
+	/* Wait for any previous eeprom accesses to finish. */
+	ret = rv3029_eeprom_busywait(rv3029);
+	if (ret < 0)
+		rv3029_eeprom_exit(rv3029);
+
+	return ret;
+}
+
+static int rv3029_eeprom_read(struct rv3029_data *rv3029, u8 reg,
+			      u8 buf[], size_t len)
+{
+	int ret, err;
+
+	err = rv3029_eeprom_enter(rv3029);
+	if (err < 0)
+		return err;
+
+	ret = regmap_bulk_read(rv3029->regmap, reg, buf, len);
+
+	err = rv3029_eeprom_exit(rv3029);
+	if (err < 0)
+		return err;
+
+	return ret;
+}
+
+static int rv3029_eeprom_write(struct rv3029_data *rv3029, u8 reg,
+			       u8 const buf[], size_t len)
+{
+	unsigned int tmp;
+	int ret, err;
+	size_t i;
+
+	err = rv3029_eeprom_enter(rv3029);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < len; i++, reg++) {
+		ret = regmap_read(rv3029->regmap, reg, &tmp);
+		if (ret < 0)
+			break;
+		if (tmp != buf[i]) {
+			tmp = buf[i];
+			ret = regmap_write(rv3029->regmap, reg, tmp);
+			if (ret < 0)
+				break;
+		}
+		ret = rv3029_eeprom_busywait(rv3029);
+		if (ret < 0)
+			break;
+	}
+
+	err = rv3029_eeprom_exit(rv3029);
+	if (err < 0)
+		return err;
+
+	return ret;
+}
+
+static int rv3029_eeprom_update_bits(struct rv3029_data *rv3029,
+				     u8 reg, u8 mask, u8 set)
+{
+	u8 buf;
+	int ret;
+
+	ret = rv3029_eeprom_read(rv3029, reg, &buf, 1);
+	if (ret < 0)
+		return ret;
+	buf &= ~mask;
+	buf |= set & mask;
+	ret = rv3029_eeprom_write(rv3029, reg, &buf, 1);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
+{
+	struct device *dev = dev_id;
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	unsigned int flags, controls;
+	unsigned long events = 0;
+	int ret;
+
+	rtc_lock(rv3029->rtc);
+
+	ret = regmap_read(rv3029->regmap, RV3029_IRQ_CTRL, &controls);
+	if (ret) {
+		dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
+		rtc_unlock(rv3029->rtc);
+		return IRQ_NONE;
+	}
+
+	ret = regmap_read(rv3029->regmap, RV3029_IRQ_FLAGS, &flags);
+	if (ret) {
+		dev_warn(dev, "Read IRQ Flags Register error %d\n", ret);
+		rtc_unlock(rv3029->rtc);
+		return IRQ_NONE;
+	}
+
+	if (flags & RV3029_IRQ_FLAGS_AF) {
+		flags &= ~RV3029_IRQ_FLAGS_AF;
+		controls &= ~RV3029_IRQ_CTRL_AIE;
+		events |= RTC_AF;
+	}
+
+	if (events) {
+		rtc_update_irq(rv3029->rtc, 1, events);
+		regmap_write(rv3029->regmap, RV3029_IRQ_FLAGS, flags);
+		regmap_write(rv3029->regmap, RV3029_IRQ_CTRL, controls);
+	}
+	rtc_unlock(rv3029->rtc);
+
+	return IRQ_HANDLED;
+}
+
+static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	unsigned int sr;
+	int ret;
+	u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
+
+	ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
+	if (ret < 0)
+		return ret;
+
+	if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
+		return -EINVAL;
+
+	ret = regmap_bulk_read(rv3029->regmap, RV3029_W_SEC, regs,
+			       RV3029_WATCH_SECTION_LEN);
+	if (ret < 0)
+		return ret;
+
+	tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
+	tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
+
+	/* HR field has a more complex interpretation */
+	{
+		const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
+
+		if (_hr & RV3029_REG_HR_12_24) {
+			/* 12h format */
+			tm->tm_hour = bcd2bin(_hr & 0x1f);
+			if (_hr & RV3029_REG_HR_PM)	/* PM flag set */
+				tm->tm_hour += 12;
+		} else /* 24h format */
+			tm->tm_hour = bcd2bin(_hr & 0x3f);
+	}
+
+	tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
+	tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
+	tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 100;
+	tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
+
+	return 0;
+}
+
+static int rv3029_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	struct rtc_time *const tm = &alarm->time;
+	unsigned int controls, flags;
+	int ret;
+	u8 regs[8];
+
+	ret = regmap_bulk_read(rv3029->regmap, RV3029_A_SC, regs,
+			       RV3029_ALARM_SECTION_LEN);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_read(rv3029->regmap, RV3029_IRQ_CTRL, &controls);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(rv3029->regmap, RV3029_IRQ_FLAGS, &flags);
+	if (ret < 0)
+		return ret;
+
+	tm->tm_sec = bcd2bin(regs[RV3029_A_SC - RV3029_A_SC] & 0x7f);
+	tm->tm_min = bcd2bin(regs[RV3029_A_MN - RV3029_A_SC] & 0x7f);
+	tm->tm_hour = bcd2bin(regs[RV3029_A_HR - RV3029_A_SC] & 0x3f);
+	tm->tm_mday = bcd2bin(regs[RV3029_A_DT - RV3029_A_SC] & 0x3f);
+	tm->tm_mon = bcd2bin(regs[RV3029_A_MO - RV3029_A_SC] & 0x1f) - 1;
+	tm->tm_year = bcd2bin(regs[RV3029_A_YR - RV3029_A_SC] & 0x7f) + 100;
+	tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
+
+	alarm->enabled = !!(controls & RV3029_IRQ_CTRL_AIE);
+	alarm->pending = (flags & RV3029_IRQ_FLAGS_AF) && alarm->enabled;
+
+	return 0;
+}
+
+static int rv3029_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+
+	return regmap_update_bits(rv3029->regmap, RV3029_IRQ_CTRL,
+				  RV3029_IRQ_CTRL_AIE,
+				  enable ? RV3029_IRQ_CTRL_AIE : 0);
+}
+
+static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	struct rtc_time *const tm = &alarm->time;
+	int ret;
+	u8 regs[8];
+
+	/* Activate all the alarms with AE_x bit */
+	regs[RV3029_A_SC - RV3029_A_SC] = bin2bcd(tm->tm_sec) | RV3029_A_AE_X;
+	regs[RV3029_A_MN - RV3029_A_SC] = bin2bcd(tm->tm_min) | RV3029_A_AE_X;
+	regs[RV3029_A_HR - RV3029_A_SC] = (bin2bcd(tm->tm_hour) & 0x3f)
+		| RV3029_A_AE_X;
+	regs[RV3029_A_DT - RV3029_A_SC] = (bin2bcd(tm->tm_mday) & 0x3f)
+		| RV3029_A_AE_X;
+	regs[RV3029_A_MO - RV3029_A_SC] = (bin2bcd(tm->tm_mon + 1) & 0x1f)
+		| RV3029_A_AE_X;
+	regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)
+		| RV3029_A_AE_X;
+	regs[RV3029_A_YR - RV3029_A_SC] = (bin2bcd(tm->tm_year - 100))
+		| RV3029_A_AE_X;
+
+	/* Write the alarm */
+	ret = regmap_bulk_write(rv3029->regmap, RV3029_A_SC, regs,
+				RV3029_ALARM_SECTION_LEN);
+	if (ret < 0)
+		return ret;
+
+	return rv3029_alarm_irq_enable(dev, alarm->enabled);
+}
+
+static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	u8 regs[8];
+	int ret;
+
+	regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
+	regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
+	regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
+	regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
+	regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
+	regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
+	regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
+
+	ret = regmap_bulk_write(rv3029->regmap, RV3029_W_SEC, regs,
+				RV3029_WATCH_SECTION_LEN);
+	if (ret < 0)
+		return ret;
+
+	/* clear PON and VLOW2 bits */
+	return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
+				  RV3029_STATUS_PON | RV3029_STATUS_VLOW2, 0);
+}
+
+static int rv3029_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	unsigned long vl = 0;
+	int sr, ret = 0;
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
+		if (ret < 0)
+			return ret;
+
+		if (sr & RV3029_STATUS_VLOW1)
+			vl = RTC_VL_ACCURACY_LOW;
+
+		if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
+			vl |= RTC_VL_DATA_INVALID;
+
+		return put_user(vl, (unsigned int __user *)arg);
+
+	case RTC_VL_CLR:
+		return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
+					  RV3029_STATUS_VLOW1, 0);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static int rv3029_nvram_write(void *priv, unsigned int offset, void *val,
+			      size_t bytes)
+{
+	return regmap_bulk_write(priv, RV3029_RAM_PAGE + offset, val, bytes);
+}
+
+static int rv3029_nvram_read(void *priv, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	return regmap_bulk_read(priv, RV3029_RAM_PAGE + offset, val, bytes);
+}
+
+static const struct rv3029_trickle_tab_elem {
+	u32 r;		/* resistance in ohms */
+	u8 conf;	/* trickle config bits */
+} rv3029_trickle_tab[] = {
+	{
+		.r	= 1076,
+		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
+			  RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
+	}, {
+		.r	= 1091,
+		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
+			  RV3029_TRICKLE_20K,
+	}, {
+		.r	= 1137,
+		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
+			  RV3029_TRICKLE_80K,
+	}, {
+		.r	= 1154,
+		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
+	}, {
+		.r	= 1371,
+		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
+			  RV3029_TRICKLE_80K,
+	}, {
+		.r	= 1395,
+		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
+	}, {
+		.r	= 1472,
+		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
+	}, {
+		.r	= 1500,
+		.conf	= RV3029_TRICKLE_1K,
+	}, {
+		.r	= 3810,
+		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
+			  RV3029_TRICKLE_80K,
+	}, {
+		.r	= 4000,
+		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
+	}, {
+		.r	= 4706,
+		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
+	}, {
+		.r	= 5000,
+		.conf	= RV3029_TRICKLE_5K,
+	}, {
+		.r	= 16000,
+		.conf	= RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
+	}, {
+		.r	= 20000,
+		.conf	= RV3029_TRICKLE_20K,
+	}, {
+		.r	= 80000,
+		.conf	= RV3029_TRICKLE_80K,
+	},
+};
+
+static void rv3029_trickle_config(struct device *dev)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	struct device_node *of_node = dev->of_node;
+	const struct rv3029_trickle_tab_elem *elem;
+	int i, err;
+	u32 ohms;
+	u8 trickle_set_bits;
+
+	if (!of_node)
+		return;
+
+	/* Configure the trickle charger. */
+	err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
+	if (err) {
+		/* Disable trickle charger. */
+		trickle_set_bits = 0;
+	} else {
+		/* Enable trickle charger. */
+		for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
+			elem = &rv3029_trickle_tab[i];
+			if (elem->r >= ohms)
+				break;
+		}
+		trickle_set_bits = elem->conf;
+		dev_info(dev,
+			 "Trickle charger enabled at %d ohms resistance.\n",
+			 elem->r);
+	}
+	err = rv3029_eeprom_update_bits(rv3029, RV3029_CONTROL_E2P_EECTRL,
+					RV3029_TRICKLE_MASK,
+					trickle_set_bits);
+	if (err < 0)
+		dev_err(dev, "Failed to update trickle charger config\n");
+}
+
+#ifdef CONFIG_RTC_DRV_RV3029_HWMON
+
+static int rv3029_read_temp(struct rv3029_data *rv3029, int *temp_mC)
+{
+	unsigned int temp;
+	int ret;
+
+	ret = regmap_read(rv3029->regmap, RV3029_TEMP_PAGE, &temp);
+	if (ret < 0)
+		return ret;
+
+	*temp_mC = ((int)temp - 60) * 1000;
+
+	return 0;
+}
+
+static ssize_t rv3029_hwmon_show_temp(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	int ret, temp_mC;
+
+	ret = rv3029_read_temp(rv3029, &temp_mC);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d\n", temp_mC);
+}
+
+static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf,
+						size_t count)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	unsigned int th_set_bits = 0;
+	unsigned long interval_ms;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &interval_ms);
+	if (ret < 0)
+		return ret;
+
+	if (interval_ms != 0) {
+		th_set_bits |= RV3029_EECTRL_THE;
+		if (interval_ms >= 16000)
+			th_set_bits |= RV3029_EECTRL_THP;
+	}
+	ret = rv3029_eeprom_update_bits(rv3029, RV3029_CONTROL_E2P_EECTRL,
+					RV3029_EECTRL_THE | RV3029_EECTRL_THP,
+					th_set_bits);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
+						 struct device_attribute *attr,
+						 char *buf)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	int ret, interval_ms;
+	u8 eectrl;
+
+	ret = rv3029_eeprom_read(rv3029, RV3029_CONTROL_E2P_EECTRL,
+				 &eectrl, 1);
+	if (ret < 0)
+		return ret;
+
+	if (eectrl & RV3029_EECTRL_THE) {
+		if (eectrl & RV3029_EECTRL_THP)
+			interval_ms = 16000;
+		else
+			interval_ms = 1000;
+	} else {
+		interval_ms = 0;
+	}
+
+	return sprintf(buf, "%d\n", interval_ms);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
+			  NULL, 0);
+static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
+			  rv3029_hwmon_show_update_interval,
+			  rv3029_hwmon_set_update_interval, 0);
+
+static struct attribute *rv3029_hwmon_attrs[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_update_interval.dev_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(rv3029_hwmon);
+
+static void rv3029_hwmon_register(struct device *dev, const char *name)
+{
+	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	struct device *hwmon_dev;
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, rv3029,
+							   rv3029_hwmon_groups);
+	if (IS_ERR(hwmon_dev)) {
+		dev_warn(dev, "unable to register hwmon device %ld\n",
+			 PTR_ERR(hwmon_dev));
+	}
+}
+
+#else /* CONFIG_RTC_DRV_RV3029_HWMON */
+
+static void rv3029_hwmon_register(struct device *dev, const char *name)
+{
+}
+
+#endif /* CONFIG_RTC_DRV_RV3029_HWMON */
+
+static const struct rtc_class_ops rv3029_rtc_ops = {
+	.read_time	= rv3029_read_time,
+	.set_time	= rv3029_set_time,
+	.ioctl		= rv3029_ioctl,
+	.read_alarm	= rv3029_read_alarm,
+	.set_alarm	= rv3029_set_alarm,
+	.alarm_irq_enable = rv3029_alarm_irq_enable,
+};
+
+static int rv3029_probe(struct device *dev, struct regmap *regmap, int irq,
+			const char *name)
+{
+	struct rv3029_data *rv3029;
+	struct nvmem_config nvmem_cfg = {
+		.name = "rv3029_nvram",
+		.word_size = 1,
+		.stride = 1,
+		.size = RV3029_RAM_SECTION_LEN,
+		.type = NVMEM_TYPE_BATTERY_BACKED,
+		.reg_read = rv3029_nvram_read,
+		.reg_write = rv3029_nvram_write,
+	};
+	int rc = 0;
+
+	rv3029 = devm_kzalloc(dev, sizeof(*rv3029), GFP_KERNEL);
+	if (!rv3029)
+		return -ENOMEM;
+
+	rv3029->regmap = regmap;
+	rv3029->irq = irq;
+	rv3029->dev = dev;
+	dev_set_drvdata(dev, rv3029);
+
+	rv3029_trickle_config(dev);
+	rv3029_hwmon_register(dev, name);
+
+	rv3029->rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rv3029->rtc))
+		return PTR_ERR(rv3029->rtc);
+
+	if (rv3029->irq > 0) {
+		unsigned long irqflags = IRQF_TRIGGER_LOW;
+
+		if (dev_fwnode(dev))
+			irqflags = 0;
+
+		rc = devm_request_threaded_irq(dev, rv3029->irq,
+					       NULL, rv3029_handle_irq,
+					       irqflags | IRQF_ONESHOT,
+					       "rv3029", dev);
+		if (rc) {
+			dev_warn(dev, "unable to request IRQ, alarms disabled\n");
+			rv3029->irq = 0;
+		}
+	}
+	if (!rv3029->irq)
+		clear_bit(RTC_FEATURE_ALARM, rv3029->rtc->features);
+
+	rv3029->rtc->ops = &rv3029_rtc_ops;
+	rv3029->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rv3029->rtc->range_max = RTC_TIMESTAMP_END_2079;
+
+	rc = devm_rtc_register_device(rv3029->rtc);
+	if (rc)
+		return rc;
+
+	nvmem_cfg.priv = rv3029->regmap;
+	devm_rtc_nvmem_register(rv3029->rtc, &nvmem_cfg);
+
+	return 0;
+}
+
+static const struct regmap_range rv3029_holes_range[] = {
+	regmap_reg_range(0x05, 0x07),
+	regmap_reg_range(0x0f, 0x0f),
+	regmap_reg_range(0x17, 0x17),
+	regmap_reg_range(0x1a, 0x1f),
+	regmap_reg_range(0x21, 0x27),
+	regmap_reg_range(0x34, 0x37),
+};
+
+static const struct regmap_access_table rv3029_regs = {
+	.no_ranges =	rv3029_holes_range,
+	.n_no_ranges =	ARRAY_SIZE(rv3029_holes_range),
+};
+
+static const struct regmap_config config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.rd_table = &rv3029_regs,
+	.wr_table = &rv3029_regs,
+	.max_register = 0x3f,
+};
+
+#if IS_ENABLED(CONFIG_I2C)
+
+static int rv3029_i2c_probe(struct i2c_client *client)
+{
+	struct regmap *regmap;
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
+				     I2C_FUNC_SMBUS_BYTE)) {
+		dev_err(&client->dev, "Adapter does not support SMBUS_I2C_BLOCK or SMBUS_I2C_BYTE\n");
+		return -ENODEV;
+	}
+
+	regmap = devm_regmap_init_i2c(client, &config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	return rv3029_probe(&client->dev, regmap, client->irq, client->name);
+}
+
+static const struct i2c_device_id rv3029_id[] = {
+	{ .name = "rv3029" },
+	{ .name = "rv3029c2" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rv3029_id);
+
+static const __maybe_unused struct of_device_id rv3029_of_match[] = {
+	{ .compatible = "microcrystal,rv3029" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, rv3029_of_match);
+
+static struct i2c_driver rv3029_driver = {
+	.driver = {
+		.name = "rv3029",
+		.of_match_table = of_match_ptr(rv3029_of_match),
+	},
+	.probe		= rv3029_i2c_probe,
+	.id_table	= rv3029_id,
+};
+
+static int __init rv3029_register_driver(void)
+{
+	return i2c_add_driver(&rv3029_driver);
+}
+
+static void rv3029_unregister_driver(void)
+{
+	i2c_del_driver(&rv3029_driver);
+}
+
+#else
+
+static int __init rv3029_register_driver(void)
+{
+	return 0;
+}
+
+static void rv3029_unregister_driver(void)
+{
+}
+
+#endif
+
+#if IS_ENABLED(CONFIG_SPI_MASTER)
+
+static int rv3049_probe(struct spi_device *spi)
+{
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_spi(spi, &config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	return rv3029_probe(&spi->dev, regmap, spi->irq, "rv3049");
+}
+
+static struct spi_driver rv3049_driver = {
+	.driver = {
+		.name    = "rv3049",
+	},
+	.probe   = rv3049_probe,
+};
+
+static int __init rv3049_register_driver(void)
+{
+	return spi_register_driver(&rv3049_driver);
+}
+
+static void __exit rv3049_unregister_driver(void)
+{
+	spi_unregister_driver(&rv3049_driver);
+}
+
+#else
+
+static int __init rv3049_register_driver(void)
+{
+	return 0;
+}
+
+static void __exit rv3049_unregister_driver(void)
+{
+}
+
+#endif
+
+static int __init rv30x9_init(void)
+{
+	int ret;
+
+	ret = rv3029_register_driver();
+	if (ret)
+		return ret;
+
+	ret = rv3049_register_driver();
+	if (ret)
+		rv3029_unregister_driver();
+
+	return ret;
+}
+module_init(rv30x9_init)
+
+static void __exit rv30x9_exit(void)
+{
+	rv3049_unregister_driver();
+	rv3029_unregister_driver();
+}
+module_exit(rv30x9_exit)
+
+MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
+MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
+MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:rv3049");