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, 969 insertions, 0 deletions

diff --git a/drivers/hwmon/ltc2992.c b/drivers/hwmon/ltc2992.c
new file mode 100644
index 000000000..43b6029c0
--- /dev/null
+++ b/drivers/hwmon/ltc2992.c
@@ -0,0 +1,969 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/*
+ * LTC2992 - Dual Wide Range Power Monitor
+ *
+ * Copyright 2020 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#define LTC2992_CTRLB			0x01
+#define LTC2992_FAULT1			0x03
+#define LTC2992_POWER1			0x05
+#define LTC2992_POWER1_MAX		0x08
+#define LTC2992_POWER1_MIN		0x0B
+#define LTC2992_POWER1_MAX_THRESH	0x0E
+#define LTC2992_POWER1_MIN_THRESH	0x11
+#define LTC2992_DSENSE1			0x14
+#define LTC2992_DSENSE1_MAX		0x16
+#define LTC2992_DSENSE1_MIN		0x18
+#define LTC2992_DSENSE1_MAX_THRESH	0x1A
+#define LTC2992_DSENSE1_MIN_THRESH	0x1C
+#define LTC2992_SENSE1			0x1E
+#define LTC2992_SENSE1_MAX		0x20
+#define LTC2992_SENSE1_MIN		0x22
+#define LTC2992_SENSE1_MAX_THRESH	0x24
+#define LTC2992_SENSE1_MIN_THRESH	0x26
+#define LTC2992_G1			0x28
+#define LTC2992_G1_MAX			0x2A
+#define LTC2992_G1_MIN			0x2C
+#define LTC2992_G1_MAX_THRESH		0x2E
+#define LTC2992_G1_MIN_THRESH		0x30
+#define LTC2992_FAULT2			0x35
+#define LTC2992_G2			0x5A
+#define LTC2992_G2_MAX			0x5C
+#define LTC2992_G2_MIN			0x5E
+#define LTC2992_G2_MAX_THRESH		0x60
+#define LTC2992_G2_MIN_THRESH		0x62
+#define LTC2992_G3			0x64
+#define LTC2992_G3_MAX			0x66
+#define LTC2992_G3_MIN			0x68
+#define LTC2992_G3_MAX_THRESH		0x6A
+#define LTC2992_G3_MIN_THRESH		0x6C
+#define LTC2992_G4			0x6E
+#define LTC2992_G4_MAX			0x70
+#define LTC2992_G4_MIN			0x72
+#define LTC2992_G4_MAX_THRESH		0x74
+#define LTC2992_G4_MIN_THRESH		0x76
+#define LTC2992_FAULT3			0x92
+#define LTC2992_GPIO_STATUS		0x95
+#define LTC2992_GPIO_IO_CTRL		0x96
+#define LTC2992_GPIO_CTRL		0x97
+
+#define LTC2992_POWER(x)		(LTC2992_POWER1 + ((x) * 0x32))
+#define LTC2992_POWER_MAX(x)		(LTC2992_POWER1_MAX + ((x) * 0x32))
+#define LTC2992_POWER_MIN(x)		(LTC2992_POWER1_MIN + ((x) * 0x32))
+#define LTC2992_POWER_MAX_THRESH(x)	(LTC2992_POWER1_MAX_THRESH + ((x) * 0x32))
+#define LTC2992_POWER_MIN_THRESH(x)	(LTC2992_POWER1_MIN_THRESH + ((x) * 0x32))
+#define LTC2992_DSENSE(x)		(LTC2992_DSENSE1 + ((x) * 0x32))
+#define LTC2992_DSENSE_MAX(x)		(LTC2992_DSENSE1_MAX + ((x) * 0x32))
+#define LTC2992_DSENSE_MIN(x)		(LTC2992_DSENSE1_MIN + ((x) * 0x32))
+#define LTC2992_DSENSE_MAX_THRESH(x)	(LTC2992_DSENSE1_MAX_THRESH + ((x) * 0x32))
+#define LTC2992_DSENSE_MIN_THRESH(x)	(LTC2992_DSENSE1_MIN_THRESH + ((x) * 0x32))
+#define LTC2992_SENSE(x)		(LTC2992_SENSE1 + ((x) * 0x32))
+#define LTC2992_SENSE_MAX(x)		(LTC2992_SENSE1_MAX + ((x) * 0x32))
+#define LTC2992_SENSE_MIN(x)		(LTC2992_SENSE1_MIN + ((x) * 0x32))
+#define LTC2992_SENSE_MAX_THRESH(x)	(LTC2992_SENSE1_MAX_THRESH + ((x) * 0x32))
+#define LTC2992_SENSE_MIN_THRESH(x)	(LTC2992_SENSE1_MIN_THRESH + ((x) * 0x32))
+#define LTC2992_POWER_FAULT(x)		(LTC2992_FAULT1 + ((x) * 0x32))
+#define LTC2992_SENSE_FAULT(x)		(LTC2992_FAULT1 + ((x) * 0x32))
+#define LTC2992_DSENSE_FAULT(x)		(LTC2992_FAULT1 + ((x) * 0x32))
+
+/* CTRLB register bitfields */
+#define LTC2992_RESET_HISTORY		BIT(3)
+
+/* FAULT1 FAULT2 registers common bitfields */
+#define LTC2992_POWER_FAULT_MSK(x)	(BIT(6) << (x))
+#define LTC2992_DSENSE_FAULT_MSK(x)	(BIT(4) << (x))
+#define LTC2992_SENSE_FAULT_MSK(x)	(BIT(2) << (x))
+
+/* FAULT1 bitfields */
+#define LTC2992_GPIO1_FAULT_MSK(x)	(BIT(0) << (x))
+
+/* FAULT2 bitfields */
+#define LTC2992_GPIO2_FAULT_MSK(x)	(BIT(0) << (x))
+
+/* FAULT3 bitfields */
+#define LTC2992_GPIO3_FAULT_MSK(x)	(BIT(6) << (x))
+#define LTC2992_GPIO4_FAULT_MSK(x)	(BIT(4) << (x))
+
+#define LTC2992_IADC_NANOV_LSB		12500
+#define LTC2992_VADC_UV_LSB		25000
+#define LTC2992_VADC_GPIO_UV_LSB	500
+
+#define LTC2992_GPIO_NR		4
+#define LTC2992_GPIO1_BIT	7
+#define LTC2992_GPIO2_BIT	6
+#define LTC2992_GPIO3_BIT	0
+#define LTC2992_GPIO4_BIT	6
+#define LTC2992_GPIO_BIT(x)	(LTC2992_GPIO_NR - (x) - 1)
+
+struct ltc2992_state {
+	struct i2c_client		*client;
+	struct gpio_chip		gc;
+	struct mutex			gpio_mutex; /* lock for gpio access */
+	const char			*gpio_names[LTC2992_GPIO_NR];
+	struct regmap			*regmap;
+	u32				r_sense_uohm[2];
+};
+
+struct ltc2992_gpio_regs {
+	u8	data;
+	u8	max;
+	u8	min;
+	u8	max_thresh;
+	u8	min_thresh;
+	u8	alarm;
+	u8	min_alarm_msk;
+	u8	max_alarm_msk;
+	u8	ctrl;
+	u8	ctrl_bit;
+};
+
+static const struct ltc2992_gpio_regs ltc2992_gpio_addr_map[] = {
+	{
+		.data = LTC2992_G1,
+		.max = LTC2992_G1_MAX,
+		.min = LTC2992_G1_MIN,
+		.max_thresh = LTC2992_G1_MAX_THRESH,
+		.min_thresh = LTC2992_G1_MIN_THRESH,
+		.alarm = LTC2992_FAULT1,
+		.min_alarm_msk = LTC2992_GPIO1_FAULT_MSK(0),
+		.max_alarm_msk = LTC2992_GPIO1_FAULT_MSK(1),
+		.ctrl = LTC2992_GPIO_IO_CTRL,
+		.ctrl_bit = LTC2992_GPIO1_BIT,
+	},
+	{
+		.data = LTC2992_G2,
+		.max = LTC2992_G2_MAX,
+		.min = LTC2992_G2_MIN,
+		.max_thresh = LTC2992_G2_MAX_THRESH,
+		.min_thresh = LTC2992_G2_MIN_THRESH,
+		.alarm = LTC2992_FAULT2,
+		.min_alarm_msk = LTC2992_GPIO2_FAULT_MSK(0),
+		.max_alarm_msk = LTC2992_GPIO2_FAULT_MSK(1),
+		.ctrl = LTC2992_GPIO_IO_CTRL,
+		.ctrl_bit = LTC2992_GPIO2_BIT,
+	},
+	{
+		.data = LTC2992_G3,
+		.max = LTC2992_G3_MAX,
+		.min = LTC2992_G3_MIN,
+		.max_thresh = LTC2992_G3_MAX_THRESH,
+		.min_thresh = LTC2992_G3_MIN_THRESH,
+		.alarm = LTC2992_FAULT3,
+		.min_alarm_msk = LTC2992_GPIO3_FAULT_MSK(0),
+		.max_alarm_msk = LTC2992_GPIO3_FAULT_MSK(1),
+		.ctrl = LTC2992_GPIO_IO_CTRL,
+		.ctrl_bit = LTC2992_GPIO3_BIT,
+	},
+	{
+		.data = LTC2992_G4,
+		.max = LTC2992_G4_MAX,
+		.min = LTC2992_G4_MIN,
+		.max_thresh = LTC2992_G4_MAX_THRESH,
+		.min_thresh = LTC2992_G4_MIN_THRESH,
+		.alarm = LTC2992_FAULT3,
+		.min_alarm_msk = LTC2992_GPIO4_FAULT_MSK(0),
+		.max_alarm_msk = LTC2992_GPIO4_FAULT_MSK(1),
+		.ctrl = LTC2992_GPIO_CTRL,
+		.ctrl_bit = LTC2992_GPIO4_BIT,
+	},
+};
+
+static const char *ltc2992_gpio_names[LTC2992_GPIO_NR] = {
+	"GPIO1", "GPIO2", "GPIO3", "GPIO4",
+};
+
+static int ltc2992_read_reg(struct ltc2992_state *st, u8 addr, const u8 reg_len)
+{
+	u8 regvals[4];
+	int val;
+	int ret;
+	int i;
+
+	ret = regmap_bulk_read(st->regmap, addr, regvals, reg_len);
+	if (ret < 0)
+		return ret;
+
+	val = 0;
+	for (i = 0; i < reg_len; i++)
+		val |= regvals[reg_len - i - 1] << (i * 8);
+
+	return val;
+}
+
+static int ltc2992_write_reg(struct ltc2992_state *st, u8 addr, const u8 reg_len, u32 val)
+{
+	u8 regvals[4];
+	int i;
+
+	for (i = 0; i < reg_len; i++)
+		regvals[reg_len - i - 1] = (val >> (i * 8)) & 0xFF;
+
+	return regmap_bulk_write(st->regmap, addr, regvals, reg_len);
+}
+
+static int ltc2992_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct ltc2992_state *st = gpiochip_get_data(chip);
+	unsigned long gpio_status;
+	int reg;
+
+	mutex_lock(&st->gpio_mutex);
+	reg = ltc2992_read_reg(st, LTC2992_GPIO_STATUS, 1);
+	mutex_unlock(&st->gpio_mutex);
+
+	if (reg < 0)
+		return reg;
+
+	gpio_status = reg;
+
+	return !test_bit(LTC2992_GPIO_BIT(offset), &gpio_status);
+}
+
+static int ltc2992_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+				     unsigned long *bits)
+{
+	struct ltc2992_state *st = gpiochip_get_data(chip);
+	unsigned long gpio_status;
+	unsigned int gpio_nr;
+	int reg;
+
+	mutex_lock(&st->gpio_mutex);
+	reg = ltc2992_read_reg(st, LTC2992_GPIO_STATUS, 1);
+	mutex_unlock(&st->gpio_mutex);
+
+	if (reg < 0)
+		return reg;
+
+	gpio_status = reg;
+
+	for_each_set_bit(gpio_nr, mask, LTC2992_GPIO_NR) {
+		if (test_bit(LTC2992_GPIO_BIT(gpio_nr), &gpio_status))
+			set_bit(gpio_nr, bits);
+	}
+
+	return 0;
+}
+
+static int ltc2992_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			    int value)
+{
+	struct ltc2992_state *st = gpiochip_get_data(chip);
+	unsigned long gpio_ctrl;
+	int reg, ret;
+
+	mutex_lock(&st->gpio_mutex);
+	reg = ltc2992_read_reg(st, ltc2992_gpio_addr_map[offset].ctrl, 1);
+	if (reg < 0) {
+		mutex_unlock(&st->gpio_mutex);
+		return reg;
+	}
+
+	gpio_ctrl = reg;
+	assign_bit(ltc2992_gpio_addr_map[offset].ctrl_bit, &gpio_ctrl, value);
+
+	ret = ltc2992_write_reg(st, ltc2992_gpio_addr_map[offset].ctrl, 1,
+				gpio_ctrl);
+	mutex_unlock(&st->gpio_mutex);
+
+	return ret;
+}
+
+static int ltc2992_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask,
+				     unsigned long *bits)
+{
+	struct ltc2992_state *st = gpiochip_get_data(chip);
+	unsigned long gpio_ctrl_io = 0;
+	unsigned long gpio_ctrl = 0;
+	unsigned int gpio_nr;
+	int ret;
+
+	for_each_set_bit(gpio_nr, mask, LTC2992_GPIO_NR) {
+		if (gpio_nr < 3)
+			assign_bit(ltc2992_gpio_addr_map[gpio_nr].ctrl_bit, &gpio_ctrl_io, true);
+
+		if (gpio_nr == 3)
+			assign_bit(ltc2992_gpio_addr_map[gpio_nr].ctrl_bit, &gpio_ctrl, true);
+	}
+
+	mutex_lock(&st->gpio_mutex);
+	ret = ltc2992_write_reg(st, LTC2992_GPIO_IO_CTRL, 1, gpio_ctrl_io);
+	if (ret)
+		goto out;
+
+	ret = ltc2992_write_reg(st, LTC2992_GPIO_CTRL, 1, gpio_ctrl);
+out:
+	mutex_unlock(&st->gpio_mutex);
+	return ret;
+}
+
+static int ltc2992_config_gpio(struct ltc2992_state *st)
+{
+	const char *name = dev_name(&st->client->dev);
+	char *gpio_name;
+	int ret;
+	int i;
+
+	ret = ltc2992_write_reg(st, LTC2992_GPIO_IO_CTRL, 1, 0);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&st->gpio_mutex);
+
+	for (i = 0; i < ARRAY_SIZE(st->gpio_names); i++) {
+		gpio_name = devm_kasprintf(&st->client->dev, GFP_KERNEL, "ltc2992-%x-%s",
+					   st->client->addr, ltc2992_gpio_names[i]);
+		if (!gpio_name)
+			return -ENOMEM;
+
+		st->gpio_names[i] = gpio_name;
+	}
+
+	st->gc.label = name;
+	st->gc.parent = &st->client->dev;
+	st->gc.owner = THIS_MODULE;
+	st->gc.can_sleep = true;
+	st->gc.base = -1;
+	st->gc.names = st->gpio_names;
+	st->gc.ngpio = ARRAY_SIZE(st->gpio_names);
+	st->gc.get = ltc2992_gpio_get;
+	st->gc.get_multiple = ltc2992_gpio_get_multiple;
+	st->gc.set = ltc2992_gpio_set;
+	st->gc.set_multiple = ltc2992_gpio_set_multiple;
+
+	ret = devm_gpiochip_add_data(&st->client->dev, &st->gc, st);
+	if (ret)
+		dev_err(&st->client->dev, "GPIO registering failed (%d)\n", ret);
+
+	return ret;
+}
+
+static umode_t ltc2992_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
+				  int channel)
+{
+	const struct ltc2992_state *st = data;
+
+	switch (type) {
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_in_reset_history:
+			return 0200;
+		}
+		break;
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+		case hwmon_in_lowest:
+		case hwmon_in_highest:
+		case hwmon_in_min_alarm:
+		case hwmon_in_max_alarm:
+			return 0444;
+		case hwmon_in_min:
+		case hwmon_in_max:
+			return 0644;
+		}
+		break;
+	case hwmon_curr:
+		switch (attr) {
+		case hwmon_curr_input:
+		case hwmon_curr_lowest:
+		case hwmon_curr_highest:
+		case hwmon_curr_min_alarm:
+		case hwmon_curr_max_alarm:
+			if (st->r_sense_uohm[channel])
+				return 0444;
+			break;
+		case hwmon_curr_min:
+		case hwmon_curr_max:
+			if (st->r_sense_uohm[channel])
+				return 0644;
+			break;
+		}
+		break;
+	case hwmon_power:
+		switch (attr) {
+		case hwmon_power_input:
+		case hwmon_power_input_lowest:
+		case hwmon_power_input_highest:
+		case hwmon_power_min_alarm:
+		case hwmon_power_max_alarm:
+			if (st->r_sense_uohm[channel])
+				return 0444;
+			break;
+		case hwmon_power_min:
+		case hwmon_power_max:
+			if (st->r_sense_uohm[channel])
+				return 0644;
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int ltc2992_get_voltage(struct ltc2992_state *st, u32 reg, u32 scale, long *val)
+{
+	int reg_val;
+
+	reg_val = ltc2992_read_reg(st, reg, 2);
+	if (reg_val < 0)
+		return reg_val;
+
+	reg_val = reg_val >> 4;
+	*val = DIV_ROUND_CLOSEST(reg_val * scale, 1000);
+
+	return 0;
+}
+
+static int ltc2992_set_voltage(struct ltc2992_state *st, u32 reg, u32 scale, long val)
+{
+	u32 reg_val;
+	long vmax;
+
+	vmax = DIV_ROUND_CLOSEST_ULL(0xFFFULL * scale, 1000);
+	val = max(val, 0L);
+	val = min(val, vmax);
+	reg_val = min(DIV_ROUND_CLOSEST_ULL((u64)val * 1000, scale),
+		      0xFFFULL) << 4;
+
+	return ltc2992_write_reg(st, reg, 2, reg_val);
+}
+
+static int ltc2992_read_gpio_alarm(struct ltc2992_state *st, int nr_gpio, u32 attr, long *val)
+{
+	int reg_val;
+	u32 mask;
+
+	if (attr == hwmon_in_max_alarm)
+		mask = ltc2992_gpio_addr_map[nr_gpio].max_alarm_msk;
+	else
+		mask = ltc2992_gpio_addr_map[nr_gpio].min_alarm_msk;
+
+	reg_val = ltc2992_read_reg(st, ltc2992_gpio_addr_map[nr_gpio].alarm, 1);
+	if (reg_val < 0)
+		return reg_val;
+
+	*val = !!(reg_val & mask);
+	reg_val &= ~mask;
+
+	return ltc2992_write_reg(st, ltc2992_gpio_addr_map[nr_gpio].alarm, 1, reg_val);
+}
+
+static int ltc2992_read_gpios_in(struct device *dev, u32 attr, int nr_gpio, long *val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_in_input:
+		reg = ltc2992_gpio_addr_map[nr_gpio].data;
+		break;
+	case hwmon_in_lowest:
+		reg = ltc2992_gpio_addr_map[nr_gpio].min;
+		break;
+	case hwmon_in_highest:
+		reg = ltc2992_gpio_addr_map[nr_gpio].max;
+		break;
+	case hwmon_in_min:
+		reg = ltc2992_gpio_addr_map[nr_gpio].min_thresh;
+		break;
+	case hwmon_in_max:
+		reg = ltc2992_gpio_addr_map[nr_gpio].max_thresh;
+		break;
+	case hwmon_in_min_alarm:
+	case hwmon_in_max_alarm:
+		return ltc2992_read_gpio_alarm(st, nr_gpio, attr, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ltc2992_get_voltage(st, reg, LTC2992_VADC_GPIO_UV_LSB, val);
+}
+
+static int ltc2992_read_in_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
+{
+	int reg_val;
+	u32 mask;
+
+	if (attr == hwmon_in_max_alarm)
+		mask = LTC2992_SENSE_FAULT_MSK(1);
+	else
+		mask = LTC2992_SENSE_FAULT_MSK(0);
+
+	reg_val = ltc2992_read_reg(st, LTC2992_SENSE_FAULT(channel), 1);
+	if (reg_val < 0)
+		return reg_val;
+
+	*val = !!(reg_val & mask);
+	reg_val &= ~mask;
+
+	return ltc2992_write_reg(st, LTC2992_SENSE_FAULT(channel), 1, reg_val);
+}
+
+static int ltc2992_read_in(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	if (channel > 1)
+		return ltc2992_read_gpios_in(dev, attr, channel - 2, val);
+
+	switch (attr) {
+	case hwmon_in_input:
+		reg = LTC2992_SENSE(channel);
+		break;
+	case hwmon_in_lowest:
+		reg = LTC2992_SENSE_MIN(channel);
+		break;
+	case hwmon_in_highest:
+		reg = LTC2992_SENSE_MAX(channel);
+		break;
+	case hwmon_in_min:
+		reg = LTC2992_SENSE_MIN_THRESH(channel);
+		break;
+	case hwmon_in_max:
+		reg = LTC2992_SENSE_MAX_THRESH(channel);
+		break;
+	case hwmon_in_min_alarm:
+	case hwmon_in_max_alarm:
+		return ltc2992_read_in_alarm(st, channel, val, attr);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ltc2992_get_voltage(st, reg, LTC2992_VADC_UV_LSB, val);
+}
+
+static int ltc2992_get_current(struct ltc2992_state *st, u32 reg, u32 channel, long *val)
+{
+	int reg_val;
+
+	reg_val = ltc2992_read_reg(st, reg, 2);
+	if (reg_val < 0)
+		return reg_val;
+
+	reg_val = reg_val >> 4;
+	*val = DIV_ROUND_CLOSEST(reg_val * LTC2992_IADC_NANOV_LSB, st->r_sense_uohm[channel]);
+
+	return 0;
+}
+
+static int ltc2992_set_current(struct ltc2992_state *st, u32 reg, u32 channel, long val)
+{
+	u32 reg_val;
+	long cmax;
+
+	cmax = DIV_ROUND_CLOSEST_ULL(0xFFFULL * LTC2992_IADC_NANOV_LSB,
+				     st->r_sense_uohm[channel]);
+	val = max(val, 0L);
+	val = min(val, cmax);
+	reg_val = min(DIV_ROUND_CLOSEST_ULL((u64)val * st->r_sense_uohm[channel],
+					    LTC2992_IADC_NANOV_LSB),
+		      0xFFFULL) << 4;
+
+	return ltc2992_write_reg(st, reg, 2, reg_val);
+}
+
+static int ltc2992_read_curr_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
+{
+	int reg_val;
+	u32 mask;
+
+	if (attr == hwmon_curr_max_alarm)
+		mask = LTC2992_DSENSE_FAULT_MSK(1);
+	else
+		mask = LTC2992_DSENSE_FAULT_MSK(0);
+
+	reg_val = ltc2992_read_reg(st, LTC2992_DSENSE_FAULT(channel), 1);
+	if (reg_val < 0)
+		return reg_val;
+
+	*val = !!(reg_val & mask);
+
+	reg_val &= ~mask;
+	return ltc2992_write_reg(st, LTC2992_DSENSE_FAULT(channel), 1, reg_val);
+}
+
+static int ltc2992_read_curr(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_curr_input:
+		reg = LTC2992_DSENSE(channel);
+		break;
+	case hwmon_curr_lowest:
+		reg = LTC2992_DSENSE_MIN(channel);
+		break;
+	case hwmon_curr_highest:
+		reg = LTC2992_DSENSE_MAX(channel);
+		break;
+	case hwmon_curr_min:
+		reg = LTC2992_DSENSE_MIN_THRESH(channel);
+		break;
+	case hwmon_curr_max:
+		reg = LTC2992_DSENSE_MAX_THRESH(channel);
+		break;
+	case hwmon_curr_min_alarm:
+	case hwmon_curr_max_alarm:
+		return ltc2992_read_curr_alarm(st, channel, val, attr);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ltc2992_get_current(st, reg, channel, val);
+}
+
+static int ltc2992_get_power(struct ltc2992_state *st, u32 reg, u32 channel, long *val)
+{
+	int reg_val;
+
+	reg_val = ltc2992_read_reg(st, reg, 3);
+	if (reg_val < 0)
+		return reg_val;
+
+	*val = mul_u64_u32_div(reg_val,
+			       LTC2992_VADC_UV_LSB / 1000 *
+			       LTC2992_IADC_NANOV_LSB,
+			       st->r_sense_uohm[channel]);
+
+	return 0;
+}
+
+static int ltc2992_set_power(struct ltc2992_state *st, u32 reg, u32 channel, long val)
+{
+	u32 reg_val;
+	u64 pmax, uval;
+
+	uval = max(val, 0L);
+	pmax = mul_u64_u32_div(0xFFFFFFULL,
+			       LTC2992_VADC_UV_LSB / 1000 *
+			       LTC2992_IADC_NANOV_LSB,
+			       st->r_sense_uohm[channel]);
+	uval = min(uval, pmax);
+	reg_val = min(mul_u64_u32_div(uval, st->r_sense_uohm[channel],
+				      LTC2992_VADC_UV_LSB / 1000 *
+				      LTC2992_IADC_NANOV_LSB),
+		      0xFFFFFFULL);
+
+	return ltc2992_write_reg(st, reg, 3, reg_val);
+}
+
+static int ltc2992_read_power_alarm(struct ltc2992_state *st, int channel, long *val, u32 attr)
+{
+	int reg_val;
+	u32 mask;
+
+	if (attr == hwmon_power_max_alarm)
+		mask = LTC2992_POWER_FAULT_MSK(1);
+	else
+		mask = LTC2992_POWER_FAULT_MSK(0);
+
+	reg_val = ltc2992_read_reg(st, LTC2992_POWER_FAULT(channel), 1);
+	if (reg_val < 0)
+		return reg_val;
+
+	*val = !!(reg_val & mask);
+	reg_val &= ~mask;
+
+	return ltc2992_write_reg(st, LTC2992_POWER_FAULT(channel), 1, reg_val);
+}
+
+static int ltc2992_read_power(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_power_input:
+		reg = LTC2992_POWER(channel);
+		break;
+	case hwmon_power_input_lowest:
+		reg = LTC2992_POWER_MIN(channel);
+		break;
+	case hwmon_power_input_highest:
+		reg = LTC2992_POWER_MAX(channel);
+		break;
+	case hwmon_power_min:
+		reg = LTC2992_POWER_MIN_THRESH(channel);
+		break;
+	case hwmon_power_max:
+		reg = LTC2992_POWER_MAX_THRESH(channel);
+		break;
+	case hwmon_power_min_alarm:
+	case hwmon_power_max_alarm:
+		return ltc2992_read_power_alarm(st, channel, val, attr);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ltc2992_get_power(st, reg, channel, val);
+}
+
+static int ltc2992_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
+			long *val)
+{
+	switch (type) {
+	case hwmon_in:
+		return ltc2992_read_in(dev, attr, channel, val);
+	case hwmon_curr:
+		return ltc2992_read_curr(dev, attr, channel, val);
+	case hwmon_power:
+		return ltc2992_read_power(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc2992_write_curr(struct device *dev, u32 attr, int channel, long val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_curr_min:
+		reg = LTC2992_DSENSE_MIN_THRESH(channel);
+		break;
+	case hwmon_curr_max:
+		reg = LTC2992_DSENSE_MAX_THRESH(channel);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ltc2992_set_current(st, reg, channel, val);
+}
+
+static int ltc2992_write_gpios_in(struct device *dev, u32 attr, int nr_gpio, long val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_in_min:
+		reg = ltc2992_gpio_addr_map[nr_gpio].min_thresh;
+		break;
+	case hwmon_in_max:
+		reg = ltc2992_gpio_addr_map[nr_gpio].max_thresh;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ltc2992_set_voltage(st, reg, LTC2992_VADC_GPIO_UV_LSB, val);
+}
+
+static int ltc2992_write_in(struct device *dev, u32 attr, int channel, long val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	if (channel > 1)
+		return ltc2992_write_gpios_in(dev, attr, channel - 2, val);
+
+	switch (attr) {
+	case hwmon_in_min:
+		reg = LTC2992_SENSE_MIN_THRESH(channel);
+		break;
+	case hwmon_in_max:
+		reg = LTC2992_SENSE_MAX_THRESH(channel);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ltc2992_set_voltage(st, reg, LTC2992_VADC_UV_LSB, val);
+}
+
+static int ltc2992_write_power(struct device *dev, u32 attr, int channel, long val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+	u32 reg;
+
+	switch (attr) {
+	case hwmon_power_min:
+		reg = LTC2992_POWER_MIN_THRESH(channel);
+		break;
+	case hwmon_power_max:
+		reg = LTC2992_POWER_MAX_THRESH(channel);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ltc2992_set_power(st, reg, channel, val);
+}
+
+static int ltc2992_write_chip(struct device *dev, u32 attr, int channel, long val)
+{
+	struct ltc2992_state *st = dev_get_drvdata(dev);
+
+	switch (attr) {
+	case hwmon_chip_in_reset_history:
+		return regmap_update_bits(st->regmap, LTC2992_CTRLB, LTC2992_RESET_HISTORY,
+					  LTC2992_RESET_HISTORY);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc2992_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
+			 long val)
+{
+	switch (type) {
+	case hwmon_chip:
+		return ltc2992_write_chip(dev, attr, channel, val);
+	case hwmon_in:
+		return ltc2992_write_in(dev, attr, channel, val);
+	case hwmon_curr:
+		return ltc2992_write_curr(dev, attr, channel, val);
+	case hwmon_power:
+		return ltc2992_write_power(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const struct hwmon_ops ltc2992_hwmon_ops = {
+	.is_visible = ltc2992_is_visible,
+	.read = ltc2992_read,
+	.write = ltc2992_write,
+};
+
+static const struct hwmon_channel_info * const ltc2992_info[] = {
+	HWMON_CHANNEL_INFO(chip,
+			   HWMON_C_IN_RESET_HISTORY),
+	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
+			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
+			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
+			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
+			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
+			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | HWMON_I_MIN |
+			   HWMON_I_MAX | HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM),
+	HWMON_CHANNEL_INFO(curr,
+			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | HWMON_C_MIN |
+			   HWMON_C_MAX | HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM,
+			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | HWMON_C_MIN |
+			   HWMON_C_MAX | HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM),
+	HWMON_CHANNEL_INFO(power,
+			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | HWMON_P_INPUT_HIGHEST |
+			   HWMON_P_MIN | HWMON_P_MAX | HWMON_P_MIN_ALARM | HWMON_P_MAX_ALARM,
+			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | HWMON_P_INPUT_HIGHEST |
+			   HWMON_P_MIN | HWMON_P_MAX | HWMON_P_MIN_ALARM | HWMON_P_MAX_ALARM),
+	NULL
+};
+
+static const struct hwmon_chip_info ltc2992_chip_info = {
+	.ops = &ltc2992_hwmon_ops,
+	.info = ltc2992_info,
+};
+
+static const struct regmap_config ltc2992_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xE8,
+};
+
+static int ltc2992_parse_dt(struct ltc2992_state *st)
+{
+	u32 addr;
+	u32 val;
+	int ret;
+
+	device_for_each_child_node_scoped(&st->client->dev, child) {
+		ret = fwnode_property_read_u32(child, "reg", &addr);
+		if (ret < 0)
+			return ret;
+
+		if (addr > 1)
+			return -EINVAL;
+
+		ret = fwnode_property_read_u32(child, "shunt-resistor-micro-ohms", &val);
+		if (!ret) {
+			if (!val)
+				return dev_err_probe(&st->client->dev, -EINVAL,
+						     "shunt resistor value cannot be zero\n");
+
+			st->r_sense_uohm[addr] = val;
+		}
+	}
+
+	return 0;
+}
+
+static int ltc2992_i2c_probe(struct i2c_client *client)
+{
+	struct device *hwmon_dev;
+	struct ltc2992_state *st;
+	int ret;
+
+	st = devm_kzalloc(&client->dev, sizeof(*st), GFP_KERNEL);
+	if (!st)
+		return -ENOMEM;
+
+	st->client = client;
+	st->regmap = devm_regmap_init_i2c(client, &ltc2992_regmap_config);
+	if (IS_ERR(st->regmap))
+		return PTR_ERR(st->regmap);
+
+	ret = ltc2992_parse_dt(st);
+	if (ret < 0)
+		return ret;
+
+	ret = ltc2992_config_gpio(st);
+	if (ret < 0)
+		return ret;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev, client->name, st,
+							 &ltc2992_chip_info, NULL);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct of_device_id ltc2992_of_match[] = {
+	{ .compatible = "adi,ltc2992" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ltc2992_of_match);
+
+static const struct i2c_device_id ltc2992_i2c_id[] = {
+	{ .name = "ltc2992" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ltc2992_i2c_id);
+
+static struct i2c_driver ltc2992_i2c_driver = {
+	.driver = {
+		.name = "ltc2992",
+		.of_match_table = ltc2992_of_match,
+	},
+	.probe = ltc2992_i2c_probe,
+	.id_table = ltc2992_i2c_id,
+};
+
+module_i2c_driver(ltc2992_i2c_driver);
+
+MODULE_AUTHOR("Alexandru Tachici <alexandru.tachici@analog.com>");
+MODULE_DESCRIPTION("Hwmon driver for Linear Technology 2992");
+MODULE_LICENSE("Dual BSD/GPL");