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, 764 insertions, 0 deletions

diff --git a/drivers/hwmon/tmp401.c b/drivers/hwmon/tmp401.c
new file mode 100644
index 000000000..83aafe4bd
--- /dev/null
+++ b/drivers/hwmon/tmp401.c
@@ -0,0 +1,764 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* tmp401.c
+ *
+ * Copyright (C) 2007,2008 Hans de Goede <hdegoede@redhat.com>
+ * Preliminary tmp411 support by:
+ * Gabriel Konat, Sander Leget, Wouter Willems
+ * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
+ *
+ * Cleanup and support for TMP431 and TMP432 by Guenter Roeck
+ * Copyright (c) 2013 Guenter Roeck <linux@roeck-us.net>
+ */
+
+/*
+ * Driver for the Texas Instruments TMP401 SMBUS temperature sensor IC.
+ *
+ * Note this IC is in some aspect similar to the LM90, but it has quite a
+ * few differences too, for example the local temp has a higher resolution
+ * and thus has 16 bits registers for its value and limit instead of 8 bits.
+ */
+
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c, 0x4d,
+	0x4e, 0x4f, I2C_CLIENT_END };
+
+enum chips { tmp401, tmp411, tmp431, tmp432, tmp435 };
+
+/*
+ * The TMP401 registers, note some registers have different addresses for
+ * reading and writing
+ */
+#define TMP401_STATUS				0x02
+#define TMP401_CONFIG				0x03
+#define TMP401_CONVERSION_RATE			0x04
+#define TMP4XX_N_FACTOR_REG			0x18
+#define TMP43X_BETA_RANGE			0x25
+#define TMP401_TEMP_CRIT_HYST			0x21
+#define TMP401_MANUFACTURER_ID_REG		0xFE
+#define TMP401_DEVICE_ID_REG			0xFF
+
+static const u8 TMP401_TEMP_MSB[7][3] = {
+	{ 0x00, 0x01, 0x23 },	/* temp */
+	{ 0x06, 0x08, 0x16 },	/* low limit */
+	{ 0x05, 0x07, 0x15 },	/* high limit */
+	{ 0x20, 0x19, 0x1a },	/* therm (crit) limit */
+	{ 0x30, 0x34, 0x00 },	/* lowest */
+	{ 0x32, 0xf6, 0x00 },	/* highest */
+};
+
+/* [0] = fault, [1] = low, [2] = high, [3] = therm/crit */
+static const u8 TMP432_STATUS_REG[] = {
+	0x1b, 0x36, 0x35, 0x37 };
+
+/* Flags */
+#define TMP401_CONFIG_RANGE			BIT(2)
+#define TMP401_CONFIG_SHUTDOWN			BIT(6)
+#define TMP401_STATUS_LOCAL_CRIT		BIT(0)
+#define TMP401_STATUS_REMOTE_CRIT		BIT(1)
+#define TMP401_STATUS_REMOTE_OPEN		BIT(2)
+#define TMP401_STATUS_REMOTE_LOW		BIT(3)
+#define TMP401_STATUS_REMOTE_HIGH		BIT(4)
+#define TMP401_STATUS_LOCAL_LOW			BIT(5)
+#define TMP401_STATUS_LOCAL_HIGH		BIT(6)
+
+/* On TMP432, each status has its own register */
+#define TMP432_STATUS_LOCAL			BIT(0)
+#define TMP432_STATUS_REMOTE1			BIT(1)
+#define TMP432_STATUS_REMOTE2			BIT(2)
+
+/* Manufacturer / Device ID's */
+#define TMP401_MANUFACTURER_ID			0x55
+#define TMP401_DEVICE_ID			0x11
+#define TMP411A_DEVICE_ID			0x12
+#define TMP411B_DEVICE_ID			0x13
+#define TMP411C_DEVICE_ID			0x10
+#define TMP431_DEVICE_ID			0x31
+#define TMP432_DEVICE_ID			0x32
+#define TMP435_DEVICE_ID			0x35
+
+/*
+ * Driver data (common to all clients)
+ */
+
+static const struct i2c_device_id tmp401_id[] = {
+	{ .name = "tmp401", .driver_data = tmp401 },
+	{ .name = "tmp411", .driver_data = tmp411 },
+	{ .name = "tmp431", .driver_data = tmp431 },
+	{ .name = "tmp432", .driver_data = tmp432 },
+	{ .name = "tmp435", .driver_data = tmp435 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tmp401_id);
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct tmp401_data {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	enum chips kind;
+
+	bool extended_range;
+
+	/* hwmon API configuration data */
+	u32 chip_channel_config[4];
+	struct hwmon_channel_info chip_info;
+	u32 temp_channel_config[4];
+	struct hwmon_channel_info temp_info;
+	const struct hwmon_channel_info *info[3];
+	struct hwmon_chip_info chip;
+};
+
+/* regmap */
+
+static bool tmp401_regmap_is_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case 0:			/* local temp msb */
+	case 1:			/* remote temp msb */
+	case 2:			/* status */
+	case 0x10:		/* remote temp lsb */
+	case 0x15:		/* local temp lsb */
+	case 0x1b:		/* status (tmp432) */
+	case 0x23 ... 0x24:	/* remote temp 2 msb / lsb */
+	case 0x30 ... 0x37:	/* lowest/highest temp; status (tmp432) */
+		return true;
+	default:
+		return false;
+	}
+}
+
+static int tmp401_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct tmp401_data *data = context;
+	struct i2c_client *client = data->client;
+	int regval;
+
+	switch (reg) {
+	case 0:			/* local temp msb */
+	case 1:			/* remote temp msb */
+	case 5:			/* local temp high limit msb */
+	case 6:			/* local temp low limit msb */
+	case 7:			/* remote temp ligh limit msb */
+	case 8:			/* remote temp low limit msb */
+	case 0x15:		/* remote temp 2 high limit msb */
+	case 0x16:		/* remote temp 2 low limit msb */
+	case 0x23:		/* remote temp 2 msb */
+	case 0x30:		/* local temp minimum, tmp411 */
+	case 0x32:		/* local temp maximum, tmp411 */
+	case 0x34:		/* remote temp minimum, tmp411 */
+	case 0xf6:		/* remote temp maximum, tmp411 (really 0x36) */
+		/* work around register overlap between TMP411 and TMP432 */
+		if (reg == 0xf6)
+			reg = 0x36;
+		regval = i2c_smbus_read_word_swapped(client, reg);
+		if (regval < 0)
+			return regval;
+		*val = regval;
+		break;
+	case 0x19:		/* critical limits, 8-bit registers */
+	case 0x1a:
+	case 0x20:
+		regval = i2c_smbus_read_byte_data(client, reg);
+		if (regval < 0)
+			return regval;
+		*val = regval << 8;
+		break;
+	case 0x1b:
+	case 0x35 ... 0x37:
+		if (data->kind == tmp432) {
+			regval = i2c_smbus_read_byte_data(client, reg);
+			if (regval < 0)
+				return regval;
+			*val = regval;
+			break;
+		}
+		/* simulate TMP432 status registers */
+		regval = i2c_smbus_read_byte_data(client, TMP401_STATUS);
+		if (regval < 0)
+			return regval;
+		*val = 0;
+		switch (reg) {
+		case 0x1b:	/* open / fault */
+			if (regval & TMP401_STATUS_REMOTE_OPEN)
+				*val |= BIT(1);
+			break;
+		case 0x35:	/* high limit */
+			if (regval & TMP401_STATUS_LOCAL_HIGH)
+				*val |= BIT(0);
+			if (regval & TMP401_STATUS_REMOTE_HIGH)
+				*val |= BIT(1);
+			break;
+		case 0x36:	/* low limit */
+			if (regval & TMP401_STATUS_LOCAL_LOW)
+				*val |= BIT(0);
+			if (regval & TMP401_STATUS_REMOTE_LOW)
+				*val |= BIT(1);
+			break;
+		case 0x37:	/* therm / crit limit */
+			if (regval & TMP401_STATUS_LOCAL_CRIT)
+				*val |= BIT(0);
+			if (regval & TMP401_STATUS_REMOTE_CRIT)
+				*val |= BIT(1);
+			break;
+		}
+		break;
+	default:
+		regval = i2c_smbus_read_byte_data(client, reg);
+		if (regval < 0)
+			return regval;
+		*val = regval;
+		break;
+	}
+	return 0;
+}
+
+static int tmp401_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct tmp401_data *data = context;
+	struct i2c_client *client = data->client;
+
+	switch (reg) {
+	case 0x05:		/* local temp high limit msb */
+	case 0x06:		/* local temp low limit msb */
+	case 0x07:		/* remote temp ligh limit msb */
+	case 0x08:		/* remote temp low limit msb */
+		reg += 6;	/* adjust for register write address */
+		fallthrough;
+	case 0x15:		/* remote temp 2 high limit msb */
+	case 0x16:		/* remote temp 2 low limit msb */
+		return i2c_smbus_write_word_swapped(client, reg, val);
+	case 0x19:		/* critical limits, 8-bit registers */
+	case 0x1a:
+	case 0x20:
+		return i2c_smbus_write_byte_data(client, reg, val >> 8);
+	case TMP401_CONVERSION_RATE:
+	case TMP401_CONFIG:
+		reg += 6;	/* adjust for register write address */
+		fallthrough;
+	default:
+		return i2c_smbus_write_byte_data(client, reg, val);
+	}
+}
+
+static const struct regmap_config tmp401_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.cache_type = REGCACHE_MAPLE,
+	.volatile_reg = tmp401_regmap_is_volatile,
+	.reg_read = tmp401_reg_read,
+	.reg_write = tmp401_reg_write,
+};
+
+/* temperature conversion */
+
+static int tmp401_register_to_temp(u16 reg, bool extended)
+{
+	int temp = reg;
+
+	if (extended)
+		temp -= 64 * 256;
+
+	return DIV_ROUND_CLOSEST(temp * 125, 32);
+}
+
+static u16 tmp401_temp_to_register(long temp, bool extended, int zbits)
+{
+	if (extended) {
+		temp = clamp_val(temp, -64000, 191000);
+		temp += 64000;
+	} else {
+		temp = clamp_val(temp, 0, 127000);
+	}
+
+	return DIV_ROUND_CLOSEST(temp * (1 << (8 - zbits)), 1000) << zbits;
+}
+
+/* hwmon API functions */
+
+static const u8 tmp401_temp_reg_index[] = {
+	[hwmon_temp_input] = 0,
+	[hwmon_temp_min] = 1,
+	[hwmon_temp_max] = 2,
+	[hwmon_temp_crit] = 3,
+	[hwmon_temp_lowest] = 4,
+	[hwmon_temp_highest] = 5,
+};
+
+static const u8 tmp401_status_reg_index[] = {
+	[hwmon_temp_fault] = 0,
+	[hwmon_temp_min_alarm] = 1,
+	[hwmon_temp_max_alarm] = 2,
+	[hwmon_temp_crit_alarm] = 3,
+};
+
+static int tmp401_temp_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct tmp401_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
+	unsigned int regs[2] = { TMP401_TEMP_MSB[3][channel], TMP401_TEMP_CRIT_HYST };
+	unsigned int regval;
+	u16 regvals[2];
+	int reg, ret;
+
+	switch (attr) {
+	case hwmon_temp_input:
+	case hwmon_temp_min:
+	case hwmon_temp_max:
+	case hwmon_temp_crit:
+	case hwmon_temp_lowest:
+	case hwmon_temp_highest:
+		reg = TMP401_TEMP_MSB[tmp401_temp_reg_index[attr]][channel];
+		ret = regmap_read(regmap, reg, &regval);
+		if (ret < 0)
+			return ret;
+		*val = tmp401_register_to_temp(regval, data->extended_range);
+		break;
+	case hwmon_temp_crit_hyst:
+		ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
+		if (ret < 0)
+			return ret;
+		*val = tmp401_register_to_temp(regvals[0], data->extended_range) -
+							(regvals[1] * 1000);
+		break;
+	case hwmon_temp_fault:
+	case hwmon_temp_min_alarm:
+	case hwmon_temp_max_alarm:
+	case hwmon_temp_crit_alarm:
+		reg = TMP432_STATUS_REG[tmp401_status_reg_index[attr]];
+		ret = regmap_read(regmap, reg, &regval);
+		if (ret < 0)
+			return ret;
+		*val = !!(regval & BIT(channel));
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int tmp401_temp_write(struct device *dev, u32 attr, int channel,
+			     long val)
+{
+	struct tmp401_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
+	unsigned int regval;
+	int reg, ret, temp;
+
+	switch (attr) {
+	case hwmon_temp_min:
+	case hwmon_temp_max:
+	case hwmon_temp_crit:
+		reg = TMP401_TEMP_MSB[tmp401_temp_reg_index[attr]][channel];
+		regval = tmp401_temp_to_register(val, data->extended_range,
+						 attr == hwmon_temp_crit ? 8 : 4);
+		ret = regmap_write(regmap, reg, regval);
+		break;
+	case hwmon_temp_crit_hyst:
+		if (data->extended_range)
+			val = clamp_val(val, -64000, 191000);
+		else
+			val = clamp_val(val, 0, 127000);
+
+		reg = TMP401_TEMP_MSB[3][channel];
+		ret = regmap_read(regmap, reg, &regval);
+		if (ret < 0)
+			break;
+		temp = tmp401_register_to_temp(regval, data->extended_range);
+		val = clamp_val(val, temp - 255000, temp);
+		regval = ((temp - val) + 500) / 1000;
+		ret = regmap_write(regmap, TMP401_TEMP_CRIT_HYST, regval);
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+	return ret;
+}
+
+static int tmp401_chip_read(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct tmp401_data *data = dev_get_drvdata(dev);
+	u32 regval;
+	int ret;
+
+	switch (attr) {
+	case hwmon_chip_update_interval:
+		ret = regmap_read(data->regmap, TMP401_CONVERSION_RATE, &regval);
+		if (ret < 0)
+			return ret;
+		*val = (1 << (7 - min(regval, 7))) * 125;
+		break;
+	case hwmon_chip_temp_reset_history:
+		*val = 0;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int tmp401_set_convrate(struct regmap *regmap, long val)
+{
+	int rate;
+
+	/*
+	 * For valid rates, interval can be calculated as
+	 *	interval = (1 << (7 - rate)) * 125;
+	 * Rounded rate is therefore
+	 *	rate = 7 - __fls(interval * 4 / (125 * 3));
+	 * Use clamp_val() to avoid overflows, and to ensure valid input
+	 * for __fls.
+	 */
+	val = clamp_val(val, 125, 16000);
+	rate = 7 - __fls(val * 4 / (125 * 3));
+	return regmap_write(regmap, TMP401_CONVERSION_RATE, rate);
+}
+
+static int tmp401_chip_write(struct device *dev, u32 attr, int channel, long val)
+{
+	struct tmp401_data *data = dev_get_drvdata(dev);
+	struct regmap *regmap = data->regmap;
+	int err;
+
+	switch (attr) {
+	case hwmon_chip_update_interval:
+		err = tmp401_set_convrate(regmap, val);
+		break;
+	case hwmon_chip_temp_reset_history:
+		if (val != 1) {
+			err = -EINVAL;
+			break;
+		}
+		/*
+		 * Reset history by writing any value to any of the
+		 * minimum/maximum registers (0x30-0x37).
+		 */
+		err = regmap_write(regmap, 0x30, 0);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+	return err;
+}
+
+static int tmp401_read(struct device *dev, enum hwmon_sensor_types type,
+		       u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_chip:
+		return tmp401_chip_read(dev, attr, channel, val);
+	case hwmon_temp:
+		return tmp401_temp_read(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int tmp401_write(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_chip:
+		return tmp401_chip_write(dev, attr, channel, val);
+	case hwmon_temp:
+		return tmp401_temp_write(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t tmp401_is_visible(const void *data, enum hwmon_sensor_types type,
+				 u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_update_interval:
+		case hwmon_chip_temp_reset_history:
+			return 0644;
+		default:
+			break;
+		}
+		break;
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+		case hwmon_temp_min_alarm:
+		case hwmon_temp_max_alarm:
+		case hwmon_temp_crit_alarm:
+		case hwmon_temp_fault:
+		case hwmon_temp_lowest:
+		case hwmon_temp_highest:
+			return 0444;
+		case hwmon_temp_min:
+		case hwmon_temp_max:
+		case hwmon_temp_crit:
+		case hwmon_temp_crit_hyst:
+			return 0644;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_ops tmp401_ops = {
+	.is_visible = tmp401_is_visible,
+	.read = tmp401_read,
+	.write = tmp401_write,
+};
+
+/* chip initialization, detect, probe */
+
+static int tmp401_init_client(struct tmp401_data *data)
+{
+	struct regmap *regmap = data->regmap;
+	u32 config, config_orig;
+	int ret;
+	u32 val = 0;
+	s32 nfactor = 0;
+
+	/* Set conversion rate to 2 Hz */
+	ret = regmap_write(regmap, TMP401_CONVERSION_RATE, 5);
+	if (ret < 0)
+		return ret;
+
+	/* Start conversions (disable shutdown if necessary) */
+	ret = regmap_read(regmap, TMP401_CONFIG, &config);
+	if (ret < 0)
+		return ret;
+
+	config_orig = config;
+	config &= ~TMP401_CONFIG_SHUTDOWN;
+
+	if (of_property_read_bool(data->client->dev.of_node, "ti,extended-range-enable")) {
+		/* Enable measurement over extended temperature range */
+		config |= TMP401_CONFIG_RANGE;
+	}
+
+	data->extended_range = !!(config & TMP401_CONFIG_RANGE);
+
+	if (config != config_orig) {
+		ret = regmap_write(regmap, TMP401_CONFIG, config);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = of_property_read_s32(data->client->dev.of_node, "ti,n-factor", &nfactor);
+	if (!ret) {
+		if (data->kind == tmp401) {
+			dev_err(&data->client->dev, "ti,tmp401 does not support n-factor correction\n");
+			return -EINVAL;
+		}
+		if (nfactor < -128 || nfactor > 127) {
+			dev_err(&data->client->dev, "n-factor is invalid (%d)\n", nfactor);
+			return -EINVAL;
+		}
+		ret = regmap_write(regmap, TMP4XX_N_FACTOR_REG, (unsigned int)nfactor);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = of_property_read_u32(data->client->dev.of_node, "ti,beta-compensation", &val);
+	if (!ret) {
+		if (data->kind == tmp401 || data->kind == tmp411) {
+			dev_err(&data->client->dev, "ti,tmp401 or ti,tmp411 does not support beta compensation\n");
+			return -EINVAL;
+		}
+		if (val > 15) {
+			dev_err(&data->client->dev, "beta-compensation is invalid (%u)\n", val);
+			return -EINVAL;
+		}
+		ret = regmap_write(regmap, TMP43X_BETA_RANGE, val);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int tmp401_detect(struct i2c_client *client,
+			 struct i2c_board_info *info)
+{
+	enum chips kind;
+	struct i2c_adapter *adapter = client->adapter;
+	u8 reg;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	/* Detect and identify the chip */
+	reg = i2c_smbus_read_byte_data(client, TMP401_MANUFACTURER_ID_REG);
+	if (reg != TMP401_MANUFACTURER_ID)
+		return -ENODEV;
+
+	reg = i2c_smbus_read_byte_data(client, TMP401_DEVICE_ID_REG);
+
+	switch (reg) {
+	case TMP401_DEVICE_ID:
+		if (client->addr != 0x4c)
+			return -ENODEV;
+		kind = tmp401;
+		break;
+	case TMP411A_DEVICE_ID:
+		if (client->addr != 0x4c)
+			return -ENODEV;
+		kind = tmp411;
+		break;
+	case TMP411B_DEVICE_ID:
+		if (client->addr != 0x4d)
+			return -ENODEV;
+		kind = tmp411;
+		break;
+	case TMP411C_DEVICE_ID:
+		if (client->addr != 0x4e)
+			return -ENODEV;
+		kind = tmp411;
+		break;
+	case TMP431_DEVICE_ID:
+		if (client->addr != 0x4c && client->addr != 0x4d)
+			return -ENODEV;
+		kind = tmp431;
+		break;
+	case TMP432_DEVICE_ID:
+		if (client->addr != 0x4c && client->addr != 0x4d)
+			return -ENODEV;
+		kind = tmp432;
+		break;
+	case TMP435_DEVICE_ID:
+		kind = tmp435;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	reg = i2c_smbus_read_byte_data(client, TMP401_CONFIG);
+	if (reg & 0x1b)
+		return -ENODEV;
+
+	reg = i2c_smbus_read_byte_data(client, TMP401_CONVERSION_RATE);
+	/* Datasheet says: 0x1-0x6 */
+	if (reg > 15)
+		return -ENODEV;
+
+	strscpy(info->type, tmp401_id[kind].name, I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static int tmp401_probe(struct i2c_client *client)
+{
+	static const char * const names[] = {
+		"TMP401", "TMP411", "TMP431", "TMP432", "TMP435"
+	};
+	struct device *dev = &client->dev;
+	struct hwmon_channel_info *info;
+	struct device *hwmon_dev;
+	struct tmp401_data *data;
+	int status;
+
+	data = devm_kzalloc(dev, sizeof(struct tmp401_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+	data->kind = (uintptr_t)i2c_get_match_data(client);
+
+	data->regmap = devm_regmap_init(dev, NULL, data, &tmp401_regmap_config);
+	if (IS_ERR(data->regmap))
+		return PTR_ERR(data->regmap);
+
+	/* initialize configuration data */
+	data->chip.ops = &tmp401_ops;
+	data->chip.info = data->info;
+
+	data->info[0] = &data->chip_info;
+	data->info[1] = &data->temp_info;
+
+	info = &data->chip_info;
+	info->type = hwmon_chip;
+	info->config = data->chip_channel_config;
+
+	data->chip_channel_config[0] = HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL;
+
+	info = &data->temp_info;
+	info->type = hwmon_temp;
+	info->config = data->temp_channel_config;
+
+	data->temp_channel_config[0] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+		HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
+		HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM;
+	data->temp_channel_config[1] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+		HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
+		HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT;
+
+	if (data->kind == tmp411) {
+		data->temp_channel_config[0] |= HWMON_T_HIGHEST | HWMON_T_LOWEST;
+		data->temp_channel_config[1] |= HWMON_T_HIGHEST | HWMON_T_LOWEST;
+		data->chip_channel_config[0] |= HWMON_C_TEMP_RESET_HISTORY;
+	}
+
+	if (data->kind == tmp432) {
+		data->temp_channel_config[2] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
+			HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT;
+	}
+
+	/* Initialize the TMP401 chip */
+	status = tmp401_init_client(data);
+	if (status < 0)
+		return status;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
+							 &data->chip, NULL);
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	dev_info(dev, "Detected TI %s chip\n", names[data->kind]);
+
+	return 0;
+}
+
+static const struct of_device_id __maybe_unused tmp4xx_of_match[] = {
+	{ .compatible = "ti,tmp401", },
+	{ .compatible = "ti,tmp411", },
+	{ .compatible = "ti,tmp431", },
+	{ .compatible = "ti,tmp432", },
+	{ .compatible = "ti,tmp435", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tmp4xx_of_match);
+
+static struct i2c_driver tmp401_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "tmp401",
+		.of_match_table = of_match_ptr(tmp4xx_of_match),
+	},
+	.probe		= tmp401_probe,
+	.id_table	= tmp401_id,
+	.detect		= tmp401_detect,
+	.address_list	= normal_i2c,
+};
+
+module_i2c_driver(tmp401_driver);
+
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_DESCRIPTION("Texas Instruments TMP401 temperature sensor driver");
+MODULE_LICENSE("GPL");