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, 689 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
new file mode 100644
index 000000000..e6106e67e
--- /dev/null
+++ b/drivers/rtc/rtc-twl.c
@@ -0,0 +1,689 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * rtc-twl.c -- TWL Real Time Clock interface
+ *
+ * Copyright (C) 2007 MontaVista Software, Inc
+ * Author: Alexandre Rusev <source@mvista.com>
+ *
+ * Based on original TI driver twl4030-rtc.c
+ *   Copyright (C) 2006 Texas Instruments, Inc.
+ *
+ * Based on rtc-omap.c
+ *   Copyright (C) 2003 MontaVista Software, Inc.
+ *   Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
+ *   Copyright (C) 2006 David Brownell
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+
+#include <linux/mfd/twl.h>
+
+enum twl_class {
+	TWL_4030 = 0,
+	TWL_6030,
+};
+
+/*
+ * RTC block register offsets (use TWL_MODULE_RTC)
+ */
+enum {
+	REG_SECONDS_REG = 0,
+	REG_MINUTES_REG,
+	REG_HOURS_REG,
+	REG_DAYS_REG,
+	REG_MONTHS_REG,
+	REG_YEARS_REG,
+	REG_WEEKS_REG,
+
+	REG_ALARM_SECONDS_REG,
+	REG_ALARM_MINUTES_REG,
+	REG_ALARM_HOURS_REG,
+	REG_ALARM_DAYS_REG,
+	REG_ALARM_MONTHS_REG,
+	REG_ALARM_YEARS_REG,
+
+	REG_RTC_CTRL_REG,
+	REG_RTC_STATUS_REG,
+	REG_RTC_INTERRUPTS_REG,
+
+	REG_RTC_COMP_LSB_REG,
+	REG_RTC_COMP_MSB_REG,
+};
+static const u8 twl4030_rtc_reg_map[] = {
+	[REG_SECONDS_REG] = 0x00,
+	[REG_MINUTES_REG] = 0x01,
+	[REG_HOURS_REG] = 0x02,
+	[REG_DAYS_REG] = 0x03,
+	[REG_MONTHS_REG] = 0x04,
+	[REG_YEARS_REG] = 0x05,
+	[REG_WEEKS_REG] = 0x06,
+
+	[REG_ALARM_SECONDS_REG] = 0x07,
+	[REG_ALARM_MINUTES_REG] = 0x08,
+	[REG_ALARM_HOURS_REG] = 0x09,
+	[REG_ALARM_DAYS_REG] = 0x0A,
+	[REG_ALARM_MONTHS_REG] = 0x0B,
+	[REG_ALARM_YEARS_REG] = 0x0C,
+
+	[REG_RTC_CTRL_REG] = 0x0D,
+	[REG_RTC_STATUS_REG] = 0x0E,
+	[REG_RTC_INTERRUPTS_REG] = 0x0F,
+
+	[REG_RTC_COMP_LSB_REG] = 0x10,
+	[REG_RTC_COMP_MSB_REG] = 0x11,
+};
+static const u8 twl6030_rtc_reg_map[] = {
+	[REG_SECONDS_REG] = 0x00,
+	[REG_MINUTES_REG] = 0x01,
+	[REG_HOURS_REG] = 0x02,
+	[REG_DAYS_REG] = 0x03,
+	[REG_MONTHS_REG] = 0x04,
+	[REG_YEARS_REG] = 0x05,
+	[REG_WEEKS_REG] = 0x06,
+
+	[REG_ALARM_SECONDS_REG] = 0x08,
+	[REG_ALARM_MINUTES_REG] = 0x09,
+	[REG_ALARM_HOURS_REG] = 0x0A,
+	[REG_ALARM_DAYS_REG] = 0x0B,
+	[REG_ALARM_MONTHS_REG] = 0x0C,
+	[REG_ALARM_YEARS_REG] = 0x0D,
+
+	[REG_RTC_CTRL_REG] = 0x10,
+	[REG_RTC_STATUS_REG] = 0x11,
+	[REG_RTC_INTERRUPTS_REG] = 0x12,
+
+	[REG_RTC_COMP_LSB_REG] = 0x13,
+	[REG_RTC_COMP_MSB_REG] = 0x14,
+};
+
+/* RTC_CTRL_REG bitfields */
+#define BIT_RTC_CTRL_REG_STOP_RTC_M              0x01
+#define BIT_RTC_CTRL_REG_ROUND_30S_M             0x02
+#define BIT_RTC_CTRL_REG_AUTO_COMP_M             0x04
+#define BIT_RTC_CTRL_REG_MODE_12_24_M            0x08
+#define BIT_RTC_CTRL_REG_TEST_MODE_M             0x10
+#define BIT_RTC_CTRL_REG_SET_32_COUNTER_M        0x20
+#define BIT_RTC_CTRL_REG_GET_TIME_M              0x40
+#define BIT_RTC_CTRL_REG_RTC_V_OPT               0x80
+
+/* RTC_STATUS_REG bitfields */
+#define BIT_RTC_STATUS_REG_RUN_M                 0x02
+#define BIT_RTC_STATUS_REG_1S_EVENT_M            0x04
+#define BIT_RTC_STATUS_REG_1M_EVENT_M            0x08
+#define BIT_RTC_STATUS_REG_1H_EVENT_M            0x10
+#define BIT_RTC_STATUS_REG_1D_EVENT_M            0x20
+#define BIT_RTC_STATUS_REG_ALARM_M               0x40
+#define BIT_RTC_STATUS_REG_POWER_UP_M            0x80
+
+/* RTC_INTERRUPTS_REG bitfields */
+#define BIT_RTC_INTERRUPTS_REG_EVERY_M           0x03
+#define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M        0x04
+#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M        0x08
+
+
+/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
+#define ALL_TIME_REGS		6
+
+/*----------------------------------------------------------------------*/
+struct twl_rtc {
+	struct device *dev;
+	struct rtc_device *rtc;
+	u8 *reg_map;
+	/*
+	 * Cache the value for timer/alarm interrupts register; this is
+	 * only changed by callers holding rtc ops lock (or resume).
+	 */
+	unsigned char rtc_irq_bits;
+	bool wake_enabled;
+#ifdef CONFIG_PM_SLEEP
+	unsigned char irqstat;
+#endif
+	enum twl_class class;
+};
+
+/*
+ * Supports 1 byte read from TWL RTC register.
+ */
+static int twl_rtc_read_u8(struct twl_rtc *twl_rtc, u8 *data, u8 reg)
+{
+	int ret;
+
+	ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg]));
+	if (ret < 0)
+		pr_err("Could not read TWL register %X - error %d\n", reg, ret);
+	return ret;
+}
+
+/*
+ * Supports 1 byte write to TWL RTC registers.
+ */
+static int twl_rtc_write_u8(struct twl_rtc *twl_rtc, u8 data, u8 reg)
+{
+	int ret;
+
+	ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg]));
+	if (ret < 0)
+		pr_err("Could not write TWL register %X - error %d\n",
+		       reg, ret);
+	return ret;
+}
+
+/*
+ * Enable 1/second update and/or alarm interrupts.
+ */
+static int set_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit)
+{
+	unsigned char val;
+	int ret;
+
+	/* if the bit is set, return from here */
+	if (twl_rtc->rtc_irq_bits & bit)
+		return 0;
+
+	val = twl_rtc->rtc_irq_bits | bit;
+	val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
+	ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG);
+	if (ret == 0)
+		twl_rtc->rtc_irq_bits = val;
+
+	return ret;
+}
+
+/*
+ * Disable update and/or alarm interrupts.
+ */
+static int mask_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit)
+{
+	unsigned char val;
+	int ret;
+
+	/* if the bit is clear, return from here */
+	if (!(twl_rtc->rtc_irq_bits & bit))
+		return 0;
+
+	val = twl_rtc->rtc_irq_bits & ~bit;
+	ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG);
+	if (ret == 0)
+		twl_rtc->rtc_irq_bits = val;
+
+	return ret;
+}
+
+static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
+	int irq = platform_get_irq(pdev, 0);
+	int ret;
+
+	if (enabled) {
+		ret = set_rtc_irq_bit(twl_rtc,
+				      BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+		if (device_can_wakeup(dev) && !twl_rtc->wake_enabled) {
+			enable_irq_wake(irq);
+			twl_rtc->wake_enabled = true;
+		}
+	} else {
+		ret = mask_rtc_irq_bit(twl_rtc,
+				       BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+		if (twl_rtc->wake_enabled) {
+			disable_irq_wake(irq);
+			twl_rtc->wake_enabled = false;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Gets current TWL RTC time and date parameters.
+ *
+ * The RTC's time/alarm representation is not what gmtime(3) requires
+ * Linux to use:
+ *
+ *  - Months are 1..12 vs Linux 0-11
+ *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
+ */
+static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
+	unsigned char rtc_data[ALL_TIME_REGS];
+	int ret;
+	u8 save_control;
+	u8 rtc_control;
+
+	ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG);
+	if (ret < 0) {
+		dev_err(dev, "%s: reading CTRL_REG, error %d\n", __func__, ret);
+		return ret;
+	}
+	/* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */
+	if (twl_rtc->class == TWL_6030) {
+		if (save_control & BIT_RTC_CTRL_REG_GET_TIME_M) {
+			save_control &= ~BIT_RTC_CTRL_REG_GET_TIME_M;
+			ret = twl_rtc_write_u8(twl_rtc, save_control,
+					       REG_RTC_CTRL_REG);
+			if (ret < 0) {
+				dev_err(dev, "%s clr GET_TIME, error %d\n",
+					__func__, ret);
+				return ret;
+			}
+		}
+	}
+
+	/* Copy RTC counting registers to static registers or latches */
+	rtc_control = save_control | BIT_RTC_CTRL_REG_GET_TIME_M;
+
+	/* for twl6030/32 enable read access to static shadowed registers */
+	if (twl_rtc->class == TWL_6030)
+		rtc_control |= BIT_RTC_CTRL_REG_RTC_V_OPT;
+
+	ret = twl_rtc_write_u8(twl_rtc, rtc_control, REG_RTC_CTRL_REG);
+	if (ret < 0) {
+		dev_err(dev, "%s: writing CTRL_REG, error %d\n", __func__, ret);
+		return ret;
+	}
+
+	ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
+			(twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
+
+	if (ret < 0) {
+		dev_err(dev, "%s: reading data, error %d\n", __func__, ret);
+		return ret;
+	}
+
+	/* for twl6030 restore original state of rtc control register */
+	if (twl_rtc->class == TWL_6030) {
+		ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
+		if (ret < 0) {
+			dev_err(dev, "%s: restore CTRL_REG, error %d\n",
+				__func__, ret);
+			return ret;
+		}
+	}
+
+	tm->tm_sec = bcd2bin(rtc_data[0]);
+	tm->tm_min = bcd2bin(rtc_data[1]);
+	tm->tm_hour = bcd2bin(rtc_data[2]);
+	tm->tm_mday = bcd2bin(rtc_data[3]);
+	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
+	tm->tm_year = bcd2bin(rtc_data[5]) + 100;
+
+	return ret;
+}
+
+static int twl_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
+	unsigned char save_control;
+	unsigned char rtc_data[ALL_TIME_REGS];
+	int ret;
+
+	rtc_data[0] = bin2bcd(tm->tm_sec);
+	rtc_data[1] = bin2bcd(tm->tm_min);
+	rtc_data[2] = bin2bcd(tm->tm_hour);
+	rtc_data[3] = bin2bcd(tm->tm_mday);
+	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
+	rtc_data[5] = bin2bcd(tm->tm_year - 100);
+
+	/* Stop RTC while updating the TC registers */
+	ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG);
+	if (ret < 0)
+		goto out;
+
+	save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
+	ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
+	if (ret < 0)
+		goto out;
+
+	/* update all the time registers in one shot */
+	ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data,
+		(twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
+	if (ret < 0) {
+		dev_err(dev, "rtc_set_time error %d\n", ret);
+		goto out;
+	}
+
+	/* Start back RTC */
+	save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
+	ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
+
+out:
+	return ret;
+}
+
+/*
+ * Gets current TWL RTC alarm time.
+ */
+static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
+	unsigned char rtc_data[ALL_TIME_REGS];
+	int ret;
+
+	ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
+			twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS);
+	if (ret < 0) {
+		dev_err(dev, "rtc_read_alarm error %d\n", ret);
+		return ret;
+	}
+
+	/* some of these fields may be wildcard/"match all" */
+	alm->time.tm_sec = bcd2bin(rtc_data[0]);
+	alm->time.tm_min = bcd2bin(rtc_data[1]);
+	alm->time.tm_hour = bcd2bin(rtc_data[2]);
+	alm->time.tm_mday = bcd2bin(rtc_data[3]);
+	alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
+	alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
+
+	/* report cached alarm enable state */
+	if (twl_rtc->rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
+		alm->enabled = 1;
+
+	return ret;
+}
+
+static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
+
+	unsigned char alarm_data[ALL_TIME_REGS];
+	int ret;
+
+	ret = twl_rtc_alarm_irq_enable(dev, 0);
+	if (ret)
+		goto out;
+
+	alarm_data[0] = bin2bcd(alm->time.tm_sec);
+	alarm_data[1] = bin2bcd(alm->time.tm_min);
+	alarm_data[2] = bin2bcd(alm->time.tm_hour);
+	alarm_data[3] = bin2bcd(alm->time.tm_mday);
+	alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
+	alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
+
+	/* update all the alarm registers in one shot */
+	ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data,
+			twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS);
+	if (ret) {
+		dev_err(dev, "rtc_set_alarm error %d\n", ret);
+		goto out;
+	}
+
+	if (alm->enabled)
+		ret = twl_rtc_alarm_irq_enable(dev, 1);
+out:
+	return ret;
+}
+
+static irqreturn_t twl_rtc_interrupt(int irq, void *data)
+{
+	struct twl_rtc *twl_rtc = data;
+	unsigned long events;
+	int ret = IRQ_NONE;
+	int res;
+	u8 rd_reg;
+
+	res = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
+	if (res)
+		goto out;
+	/*
+	 * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
+	 * only one (ALARM or RTC) interrupt source may be enabled
+	 * at time, we also could check our results
+	 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
+	 */
+	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
+		events = RTC_IRQF | RTC_AF;
+	else
+		events = RTC_IRQF | RTC_PF;
+
+	res = twl_rtc_write_u8(twl_rtc, BIT_RTC_STATUS_REG_ALARM_M,
+			       REG_RTC_STATUS_REG);
+	if (res)
+		goto out;
+
+	if (twl_rtc->class == TWL_4030) {
+		/* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
+		 * needs 2 reads to clear the interrupt. One read is done in
+		 * do_twl_pwrirq(). Doing the second read, to clear
+		 * the bit.
+		 *
+		 * FIXME the reason PWR_ISR1 needs an extra read is that
+		 * RTC_IF retriggered until we cleared REG_ALARM_M above.
+		 * But re-reading like this is a bad hack; by doing so we
+		 * risk wrongly clearing status for some other IRQ (losing
+		 * the interrupt).  Be smarter about handling RTC_UF ...
+		 */
+		res = twl_i2c_read_u8(TWL4030_MODULE_INT,
+			&rd_reg, TWL4030_INT_PWR_ISR1);
+		if (res)
+			goto out;
+	}
+
+	/* Notify RTC core on event */
+	rtc_update_irq(twl_rtc->rtc, 1, events);
+
+	ret = IRQ_HANDLED;
+out:
+	return ret;
+}
+
+static const struct rtc_class_ops twl_rtc_ops = {
+	.read_time	= twl_rtc_read_time,
+	.set_time	= twl_rtc_set_time,
+	.read_alarm	= twl_rtc_read_alarm,
+	.set_alarm	= twl_rtc_set_alarm,
+	.alarm_irq_enable = twl_rtc_alarm_irq_enable,
+};
+
+static int twl_nvram_read(void *priv, unsigned int offset, void *val,
+			  size_t bytes)
+{
+	return twl_i2c_read((long)priv, val, offset, bytes);
+}
+
+static int twl_nvram_write(void *priv, unsigned int offset, void *val,
+			   size_t bytes)
+{
+	return twl_i2c_write((long)priv, val, offset, bytes);
+}
+
+/*----------------------------------------------------------------------*/
+
+static int twl_rtc_probe(struct platform_device *pdev)
+{
+	struct twl_rtc *twl_rtc;
+	struct nvmem_config nvmem_cfg;
+	struct device_node *np = pdev->dev.of_node;
+	int ret = -EINVAL;
+	int irq = platform_get_irq(pdev, 0);
+	u8 rd_reg;
+
+	if (!np) {
+		dev_err(&pdev->dev, "no DT info\n");
+		return -EINVAL;
+	}
+
+	if (irq <= 0)
+		return ret;
+
+	twl_rtc = devm_kzalloc(&pdev->dev, sizeof(*twl_rtc), GFP_KERNEL);
+	if (!twl_rtc)
+		return -ENOMEM;
+
+	if (twl_class_is_4030()) {
+		twl_rtc->class = TWL_4030;
+		twl_rtc->reg_map = (u8 *)twl4030_rtc_reg_map;
+	} else if (twl_class_is_6030()) {
+		twl_rtc->class = TWL_6030;
+		twl_rtc->reg_map = (u8 *)twl6030_rtc_reg_map;
+	} else {
+		dev_err(&pdev->dev, "TWL Class not supported.\n");
+		return -EINVAL;
+	}
+
+	ret = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
+	if (ret < 0)
+		return ret;
+
+	if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
+		dev_warn(&pdev->dev, "Power up reset detected.\n");
+
+	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
+		dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
+
+	/* Clear RTC Power up reset and pending alarm interrupts */
+	ret = twl_rtc_write_u8(twl_rtc, rd_reg, REG_RTC_STATUS_REG);
+	if (ret < 0)
+		return ret;
+
+	if (twl_rtc->class == TWL_6030) {
+		twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
+			REG_INT_MSK_LINE_A);
+		twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
+			REG_INT_MSK_STS_A);
+	}
+
+	ret = twl_rtc_write_u8(twl_rtc, BIT_RTC_CTRL_REG_STOP_RTC_M,
+			       REG_RTC_CTRL_REG);
+	if (ret < 0)
+		return ret;
+
+	/* ensure interrupts are disabled, bootloaders can be strange */
+	ret = twl_rtc_write_u8(twl_rtc, 0, REG_RTC_INTERRUPTS_REG);
+	if (ret < 0)
+		dev_warn(&pdev->dev, "unable to disable interrupt\n");
+
+	/* init cached IRQ enable bits */
+	ret = twl_rtc_read_u8(twl_rtc, &twl_rtc->rtc_irq_bits,
+			      REG_RTC_INTERRUPTS_REG);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, twl_rtc);
+	device_init_wakeup(&pdev->dev, true);
+
+	twl_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+					&twl_rtc_ops, THIS_MODULE);
+	if (IS_ERR(twl_rtc->rtc))
+		return PTR_ERR(twl_rtc->rtc);
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+					twl_rtc_interrupt,
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					dev_name(&twl_rtc->rtc->dev), twl_rtc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "IRQ is not free.\n");
+		return ret;
+	}
+
+	memset(&nvmem_cfg, 0, sizeof(nvmem_cfg));
+	nvmem_cfg.name = "twl-secured-";
+	nvmem_cfg.type = NVMEM_TYPE_BATTERY_BACKED;
+	nvmem_cfg.reg_read = twl_nvram_read;
+	nvmem_cfg.reg_write = twl_nvram_write;
+	nvmem_cfg.word_size = 1;
+	nvmem_cfg.stride = 1;
+	if (twl_class_is_4030()) {
+		/* 20 bytes SECURED_REG area */
+		nvmem_cfg.size = 20;
+		nvmem_cfg.priv = (void *)TWL_MODULE_SECURED_REG;
+		devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg);
+		/* 8 bytes BACKUP area */
+		nvmem_cfg.name = "twl-backup-";
+		nvmem_cfg.size = 8;
+		nvmem_cfg.priv = (void *)TWL4030_MODULE_BACKUP;
+		devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg);
+	} else {
+		/* 8 bytes SECURED_REG area */
+		nvmem_cfg.size = 8;
+		nvmem_cfg.priv = (void *)TWL_MODULE_SECURED_REG;
+		devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg);
+	}
+
+	return 0;
+}
+
+/*
+ * Disable all TWL RTC module interrupts.
+ * Sets status flag to free.
+ */
+static void twl_rtc_remove(struct platform_device *pdev)
+{
+	struct twl_rtc *twl_rtc = platform_get_drvdata(pdev);
+
+	/* leave rtc running, but disable irqs */
+	mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+	mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+	if (twl_rtc->class == TWL_6030) {
+		twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
+			REG_INT_MSK_LINE_A);
+		twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
+			REG_INT_MSK_STS_A);
+	}
+}
+
+static void twl_rtc_shutdown(struct platform_device *pdev)
+{
+	struct twl_rtc *twl_rtc = platform_get_drvdata(pdev);
+
+	/* mask timer interrupts, but leave alarm interrupts on to enable
+	   power-on when alarm is triggered */
+	mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int twl_rtc_suspend(struct device *dev)
+{
+	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
+
+	twl_rtc->irqstat = twl_rtc->rtc_irq_bits;
+
+	mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+	return 0;
+}
+
+static int twl_rtc_resume(struct device *dev)
+{
+	struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
+
+	set_rtc_irq_bit(twl_rtc, twl_rtc->irqstat);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(twl_rtc_pm_ops, twl_rtc_suspend, twl_rtc_resume);
+
+static const struct of_device_id twl_rtc_of_match[] = {
+	{.compatible = "ti,twl4030-rtc", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, twl_rtc_of_match);
+
+static struct platform_driver twl4030rtc_driver = {
+	.probe		= twl_rtc_probe,
+	.remove		= twl_rtc_remove,
+	.shutdown	= twl_rtc_shutdown,
+	.driver		= {
+		.name		= "twl_rtc",
+		.pm		= &twl_rtc_pm_ops,
+		.of_match_table = twl_rtc_of_match,
+	},
+};
+
+module_platform_driver(twl4030rtc_driver);
+
+MODULE_AUTHOR("Texas Instruments, MontaVista Software");
+MODULE_DESCRIPTION("TI TWL4030/TWL5030/TWL6030/TPS659x0 RTC driver");
+MODULE_LICENSE("GPL");