Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 593 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
new file mode 100644
index 000000000..7eebdb058
--- /dev/null
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -0,0 +1,593 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An I2C driver for the Philips PCF8563 RTC
+ * Copyright 2005-06 Tower Technologies
+ *
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ * Maintainers: http://www.nslu2-linux.org/
+ *
+ * based on the other drivers in this same directory.
+ *
+ * https://www.nxp.com/docs/en/data-sheet/PCF8563.pdf
+ */
+
+#include <linux/bcd.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+#define PCF8563_REG_ST1		0x00 /* status */
+#define PCF8563_REG_ST2		0x01
+#define PCF8563_BIT_AIE		BIT(1)
+#define PCF8563_BIT_AF		BIT(3)
+#define PCF8563_BITS_ST2_N	(7 << 5)
+
+#define PCF8563_REG_SC		0x02 /* datetime */
+#define PCF8563_REG_MN		0x03
+#define PCF8563_REG_HR		0x04
+#define PCF8563_REG_DM		0x05
+#define PCF8563_REG_DW		0x06
+#define PCF8563_REG_MO		0x07
+#define PCF8563_REG_YR		0x08
+
+#define PCF8563_REG_AMN		0x09 /* alarm */
+
+#define PCF8563_REG_CLKO		0x0D /* clock out */
+#define PCF8563_REG_CLKO_FE		0x80 /* clock out enabled */
+#define PCF8563_REG_CLKO_F_MASK		0x03 /* frequenc mask */
+#define PCF8563_REG_CLKO_F_32768HZ	0x00
+#define PCF8563_REG_CLKO_F_1024HZ	0x01
+#define PCF8563_REG_CLKO_F_32HZ		0x02
+#define PCF8563_REG_CLKO_F_1HZ		0x03
+
+#define PCF8563_REG_TMRC	0x0E /* timer control */
+#define PCF8563_TMRC_ENABLE	BIT(7)
+#define PCF8563_TMRC_4096	0
+#define PCF8563_TMRC_64		1
+#define PCF8563_TMRC_1		2
+#define PCF8563_TMRC_1_60	3
+#define PCF8563_TMRC_MASK	3
+
+#define PCF8563_REG_TMR		0x0F /* timer */
+
+#define PCF8563_SC_LV		0x80 /* low voltage */
+#define PCF8563_MO_C		0x80 /* century */
+
+static struct i2c_driver pcf8563_driver;
+
+struct pcf8563 {
+	struct rtc_device *rtc;
+	/*
+	 * The meaning of MO_C bit varies by the chip type.
+	 * From PCF8563 datasheet: this bit is toggled when the years
+	 * register overflows from 99 to 00
+	 *   0 indicates the century is 20xx
+	 *   1 indicates the century is 19xx
+	 * From RTC8564 datasheet: this bit indicates change of
+	 * century. When the year digit data overflows from 99 to 00,
+	 * this bit is set. By presetting it to 0 while still in the
+	 * 20th century, it will be set in year 2000, ...
+	 * There seems no reliable way to know how the system use this
+	 * bit.  So let's do it heuristically, assuming we are live in
+	 * 1970...2069.
+	 */
+	int c_polarity;	/* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
+
+	struct regmap *regmap;
+#ifdef CONFIG_COMMON_CLK
+	struct clk_hw		clkout_hw;
+#endif
+};
+
+static int pcf8563_set_alarm_mode(struct pcf8563 *pcf8563, bool on)
+{
+	u32 buf;
+	int err;
+
+	err = regmap_read(pcf8563->regmap, PCF8563_REG_ST2, &buf);
+	if (err < 0)
+		return err;
+
+	if (on)
+		buf |= PCF8563_BIT_AIE;
+	else
+		buf &= ~PCF8563_BIT_AIE;
+
+	buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
+
+	return regmap_write(pcf8563->regmap, PCF8563_REG_ST2, buf);
+}
+
+static int pcf8563_get_alarm_mode(struct pcf8563 *pcf8563, unsigned char *en,
+				  unsigned char *pen)
+{
+	u32 buf;
+	int err;
+
+	err = regmap_read(pcf8563->regmap, PCF8563_REG_ST2, &buf);
+	if (err < 0)
+		return err;
+
+	if (en)
+		*en = !!(buf & PCF8563_BIT_AIE);
+	if (pen)
+		*pen = !!(buf & PCF8563_BIT_AF);
+
+	return 0;
+}
+
+static irqreturn_t pcf8563_irq(int irq, void *dev_id)
+{
+	struct pcf8563 *pcf8563 = dev_id;
+	char pending;
+	int err;
+
+	err = pcf8563_get_alarm_mode(pcf8563, NULL, &pending);
+	if (err)
+		return IRQ_NONE;
+
+	if (pending) {
+		rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
+		pcf8563_set_alarm_mode(pcf8563, 1);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+/*
+ * In the routines that deal directly with the pcf8563 hardware, we use
+ * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
+ */
+static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
+	unsigned char buf[9];
+	int err;
+
+	err = regmap_bulk_read(pcf8563->regmap, PCF8563_REG_ST1, buf,
+			       sizeof(buf));
+	if (err < 0)
+		return err;
+
+	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
+		dev_err(dev,
+			"low voltage detected, date/time is not reliable.\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dev,
+		"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
+		"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
+		__func__,
+		buf[0], buf[1], buf[2], buf[3],
+		buf[4], buf[5], buf[6], buf[7],
+		buf[8]);
+
+	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
+	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
+	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
+	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
+	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
+	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
+	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]) + 100;
+	/* detect the polarity heuristically. see note above. */
+	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
+		(tm->tm_year >= 100) : (tm->tm_year < 100);
+
+	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+		"mday=%d, mon=%d, year=%d, wday=%d\n",
+		__func__,
+		tm->tm_sec, tm->tm_min, tm->tm_hour,
+		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+	return 0;
+}
+
+static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
+	unsigned char buf[9];
+
+	dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
+		"mday=%d, mon=%d, year=%d, wday=%d\n",
+		__func__,
+		tm->tm_sec, tm->tm_min, tm->tm_hour,
+		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+	/* hours, minutes and seconds */
+	buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
+	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
+	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
+
+	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
+
+	/* month, 1 - 12 */
+	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
+
+	/* year and century */
+	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year - 100);
+	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
+		buf[PCF8563_REG_MO] |= PCF8563_MO_C;
+
+	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
+
+	return regmap_bulk_write(pcf8563->regmap, PCF8563_REG_SC,
+				buf + PCF8563_REG_SC,
+				sizeof(buf) - PCF8563_REG_SC);
+}
+
+static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
+	int ret;
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		ret = regmap_test_bits(pcf8563->regmap, PCF8563_REG_SC,
+				       PCF8563_SC_LV);
+		if (ret < 0)
+			return ret;
+
+		return put_user(ret ? RTC_VL_DATA_INVALID : 0,
+				(unsigned int __user *)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
+{
+	struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
+	unsigned char buf[4];
+	int err;
+
+	err = regmap_bulk_read(pcf8563->regmap, PCF8563_REG_AMN, buf,
+			       sizeof(buf));
+	if (err < 0)
+		return err;
+
+	dev_dbg(dev,
+		"%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
+		__func__, buf[0], buf[1], buf[2], buf[3]);
+
+	tm->time.tm_sec = 0;
+	tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
+	tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
+	tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
+	tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
+
+	err = pcf8563_get_alarm_mode(pcf8563, &tm->enabled, &tm->pending);
+	if (err < 0)
+		return err;
+
+	dev_dbg(dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
+		" enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
+		tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
+		tm->enabled, tm->pending);
+
+	return 0;
+}
+
+static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
+{
+	struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
+	unsigned char buf[4];
+	int err;
+
+	buf[0] = bin2bcd(tm->time.tm_min);
+	buf[1] = bin2bcd(tm->time.tm_hour);
+	buf[2] = bin2bcd(tm->time.tm_mday);
+	buf[3] = tm->time.tm_wday & 0x07;
+
+	err = regmap_bulk_write(pcf8563->regmap, PCF8563_REG_AMN, buf,
+				sizeof(buf));
+	if (err)
+		return err;
+
+	return pcf8563_set_alarm_mode(pcf8563, !!tm->enabled);
+}
+
+static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
+	return pcf8563_set_alarm_mode(pcf8563, !!enabled);
+}
+
+#ifdef CONFIG_COMMON_CLK
+/*
+ * Handling of the clkout
+ */
+
+#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
+
+static const int clkout_rates[] = {
+	32768,
+	1024,
+	32,
+	1,
+};
+
+static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
+	u32 buf;
+	int ret;
+
+	ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf);
+	if (ret < 0)
+		return 0;
+
+	buf &= PCF8563_REG_CLKO_F_MASK;
+	return clkout_rates[buf];
+}
+
+static int pcf8563_clkout_determine_rate(struct clk_hw *hw,
+					 struct clk_rate_request *req)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
+		if (clkout_rates[i] <= req->rate) {
+			req->rate = clkout_rates[i];
+
+			return 0;
+		}
+
+	req->rate = clkout_rates[0];
+
+	return 0;
+}
+
+static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long parent_rate)
+{
+	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
+	int i, ret;
+	u32 buf;
+
+	ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
+		if (clkout_rates[i] == rate) {
+			buf &= ~PCF8563_REG_CLKO_F_MASK;
+			buf |= i;
+			return regmap_update_bits(pcf8563->regmap,
+					    PCF8563_REG_CLKO,
+					    PCF8563_REG_CLKO_F_MASK,
+					    buf);
+		}
+
+	return -EINVAL;
+}
+
+static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
+{
+	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
+	u32 buf;
+	int ret;
+
+	ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf);
+	if (ret < 0)
+		return ret;
+
+	if (enable)
+		buf |= PCF8563_REG_CLKO_FE;
+	else
+		buf &= ~PCF8563_REG_CLKO_FE;
+
+	return regmap_update_bits(pcf8563->regmap, PCF8563_REG_CLKO,
+				  PCF8563_REG_CLKO_FE, buf);
+}
+
+static int pcf8563_clkout_prepare(struct clk_hw *hw)
+{
+	return pcf8563_clkout_control(hw, 1);
+}
+
+static void pcf8563_clkout_unprepare(struct clk_hw *hw)
+{
+	pcf8563_clkout_control(hw, 0);
+}
+
+static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
+{
+	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
+	u32 buf;
+	int ret;
+
+	ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf);
+	if (ret < 0)
+		return ret;
+
+	return !!(buf & PCF8563_REG_CLKO_FE);
+}
+
+static const struct clk_ops pcf8563_clkout_ops = {
+	.prepare = pcf8563_clkout_prepare,
+	.unprepare = pcf8563_clkout_unprepare,
+	.is_prepared = pcf8563_clkout_is_prepared,
+	.recalc_rate = pcf8563_clkout_recalc_rate,
+	.determine_rate = pcf8563_clkout_determine_rate,
+	.set_rate = pcf8563_clkout_set_rate,
+};
+
+static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
+{
+	struct device_node *node = pcf8563->rtc->dev.parent->of_node;
+	struct clk_init_data init = {};
+	struct clk *clk;
+	int ret;
+
+	/* disable the clkout output */
+	ret = regmap_clear_bits(pcf8563->regmap, PCF8563_REG_CLKO,
+				PCF8563_REG_CLKO_FE);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	init.name = "pcf8563-clkout";
+	init.ops = &pcf8563_clkout_ops;
+	init.flags = 0;
+	init.parent_names = NULL;
+	init.num_parents = 0;
+	pcf8563->clkout_hw.init = &init;
+
+	/* optional override of the clockname */
+	of_property_read_string(node, "clock-output-names", &init.name);
+
+	/* register the clock */
+	clk = devm_clk_register(&pcf8563->rtc->dev, &pcf8563->clkout_hw);
+
+	if (!IS_ERR(clk))
+		devm_of_clk_add_hw_provider(pcf8563->rtc->dev.parent,
+					    of_clk_hw_simple_get,
+					    &pcf8563->clkout_hw);
+
+	return clk;
+}
+#endif
+
+static const struct rtc_class_ops pcf8563_rtc_ops = {
+	.ioctl		= pcf8563_rtc_ioctl,
+	.read_time	= pcf8563_rtc_read_time,
+	.set_time	= pcf8563_rtc_set_time,
+	.read_alarm	= pcf8563_rtc_read_alarm,
+	.set_alarm	= pcf8563_rtc_set_alarm,
+	.alarm_irq_enable = pcf8563_irq_enable,
+};
+
+static const struct regmap_config regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xF,
+};
+
+static int pcf8563_probe(struct i2c_client *client)
+{
+	struct pcf8563 *pcf8563;
+	int err;
+
+	dev_dbg(&client->dev, "%s\n", __func__);
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -ENODEV;
+
+	pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
+				GFP_KERNEL);
+	if (!pcf8563)
+		return -ENOMEM;
+
+	pcf8563->regmap = devm_regmap_init_i2c(client, &regmap_config);
+	if (IS_ERR(pcf8563->regmap))
+		return PTR_ERR(pcf8563->regmap);
+
+	i2c_set_clientdata(client, pcf8563);
+	device_set_wakeup_capable(&client->dev, 1);
+
+	/* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
+	err = regmap_set_bits(pcf8563->regmap, PCF8563_REG_TMRC,
+			      PCF8563_TMRC_1_60);
+	if (err < 0) {
+		dev_err(&client->dev, "%s: write error\n", __func__);
+		return err;
+	}
+
+	/* Clear flags and disable interrupts */
+	err = regmap_write(pcf8563->regmap, PCF8563_REG_ST2, 0);
+	if (err < 0) {
+		dev_err(&client->dev, "%s: write error\n", __func__);
+		return err;
+	}
+
+	pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
+	if (IS_ERR(pcf8563->rtc))
+		return PTR_ERR(pcf8563->rtc);
+
+	pcf8563->rtc->ops = &pcf8563_rtc_ops;
+	/* the pcf8563 alarm only supports a minute accuracy */
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, pcf8563->rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf8563->rtc->features);
+	clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);
+	pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
+	pcf8563->rtc->set_start_time = true;
+
+	if (client->irq > 0) {
+		unsigned long irqflags = IRQF_TRIGGER_LOW;
+
+		if (dev_fwnode(&client->dev))
+			irqflags = 0;
+
+		err = devm_request_threaded_irq(&client->dev, client->irq,
+				NULL, pcf8563_irq,
+				IRQF_SHARED | IRQF_ONESHOT | irqflags,
+				pcf8563_driver.driver.name, client);
+		if (err) {
+			dev_err(&client->dev, "unable to request IRQ %d\n",
+								client->irq);
+			return err;
+		}
+	} else {
+		client->irq = 0;
+	}
+
+	if (client->irq > 0 || device_property_read_bool(&client->dev, "wakeup-source")) {
+		device_init_wakeup(&client->dev, true);
+		set_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);
+	}
+
+	err = devm_rtc_register_device(pcf8563->rtc);
+	if (err)
+		return err;
+
+#ifdef CONFIG_COMMON_CLK
+	/* register clk in common clk framework */
+	pcf8563_clkout_register_clk(pcf8563);
+#endif
+
+	return 0;
+}
+
+static const struct i2c_device_id pcf8563_id[] = {
+	{ .name = "pcf8563" },
+	{ .name = "rtc8564" },
+	{ .name = "pca8565" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pcf8563_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id pcf8563_of_match[] = {
+	{ .compatible = "nxp,pcf8563" },
+	{ .compatible = "epson,rtc8564" },
+	{ .compatible = "microcrystal,rv8564" },
+	{ .compatible = "nxp,pca8565" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, pcf8563_of_match);
+#endif
+
+static struct i2c_driver pcf8563_driver = {
+	.driver		= {
+		.name	= "rtc-pcf8563",
+		.of_match_table = of_match_ptr(pcf8563_of_match),
+	},
+	.probe		= pcf8563_probe,
+	.id_table	= pcf8563_id,
+};
+
+module_i2c_driver(pcf8563_driver);
+
+MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
+MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
+MODULE_LICENSE("GPL");