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, 829 insertions, 0 deletions

diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
new file mode 100644
index 000000000..90c37f564
--- /dev/null
+++ b/drivers/hwmon/max6650.c
@@ -0,0 +1,829 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * max6650.c - Part of lm_sensors, Linux kernel modules for hardware
+ *             monitoring.
+ *
+ * (C) 2007 by Hans J. Koch <hjk@hansjkoch.de>
+ *
+ * based on code written by John Morris <john.morris@spirentcom.com>
+ * Copyright (c) 2003 Spirent Communications
+ * and Claus Gindhart <claus.gindhart@kontron.com>
+ *
+ * This module has only been tested with the MAX6650 chip. It should
+ * also work with the MAX6651. It does not distinguish max6650 and max6651
+ * chips.
+ *
+ * The datasheet was last seen at:
+ *
+ *        http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+
+/*
+ * Insmod parameters
+ */
+
+/* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */
+static int fan_voltage;
+/* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
+static int prescaler;
+/* clock: The clock frequency of the chip (max6651 can be clocked externally) */
+static int clock = 254000;
+
+module_param(fan_voltage, int, 0444);
+module_param(prescaler, int, 0444);
+module_param(clock, int, 0444);
+
+/*
+ * MAX 6650/6651 registers
+ */
+
+#define MAX6650_REG_SPEED	0x00
+#define MAX6650_REG_CONFIG	0x02
+#define MAX6650_REG_GPIO_DEF	0x04
+#define MAX6650_REG_DAC		0x06
+#define MAX6650_REG_ALARM_EN	0x08
+#define MAX6650_REG_ALARM	0x0A
+#define MAX6650_REG_TACH0	0x0C
+#define MAX6650_REG_TACH1	0x0E
+#define MAX6650_REG_TACH2	0x10
+#define MAX6650_REG_TACH3	0x12
+#define MAX6650_REG_GPIO_STAT	0x14
+#define MAX6650_REG_COUNT	0x16
+
+/*
+ * Config register bits
+ */
+
+#define MAX6650_CFG_V12			0x08
+#define MAX6650_CFG_PRESCALER_MASK	0x07
+#define MAX6650_CFG_PRESCALER_2		0x01
+#define MAX6650_CFG_PRESCALER_4		0x02
+#define MAX6650_CFG_PRESCALER_8		0x03
+#define MAX6650_CFG_PRESCALER_16	0x04
+#define MAX6650_CFG_MODE_MASK		0x30
+#define MAX6650_CFG_MODE_ON		0x00
+#define MAX6650_CFG_MODE_OFF		0x10
+#define MAX6650_CFG_MODE_CLOSED_LOOP	0x20
+#define MAX6650_CFG_MODE_OPEN_LOOP	0x30
+#define MAX6650_COUNT_MASK		0x03
+
+/*
+ * Alarm status register bits
+ */
+
+#define MAX6650_ALRM_MAX	0x01
+#define MAX6650_ALRM_MIN	0x02
+#define MAX6650_ALRM_TACH	0x04
+#define MAX6650_ALRM_GPIO1	0x08
+#define MAX6650_ALRM_GPIO2	0x10
+
+/* Minimum and maximum values of the FAN-RPM */
+#define FAN_RPM_MIN 240
+#define FAN_RPM_MAX 30000
+
+#define DIV_FROM_REG(reg)	(1 << ((reg) & 7))
+#define DAC_LIMIT(v12)		((v12) ? 180 : 76)
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct max6650_data {
+	struct i2c_client *client;
+	struct mutex update_lock; /* protect alarm register updates */
+	int nr_fans;
+	bool valid; /* false until following fields are valid */
+	unsigned long last_updated; /* in jiffies */
+
+	/* register values */
+	u8 speed;
+	u8 config;
+	u8 tach[4];
+	u8 count;
+	u8 dac;
+	u8 alarm;
+	u8 alarm_en;
+	unsigned long cooling_dev_state;
+};
+
+static const u8 tach_reg[] = {
+	MAX6650_REG_TACH0,
+	MAX6650_REG_TACH1,
+	MAX6650_REG_TACH2,
+	MAX6650_REG_TACH3,
+};
+
+static const struct of_device_id __maybe_unused max6650_dt_match[] = {
+	{
+		.compatible = "maxim,max6650",
+		.data = (void *)1
+	},
+	{
+		.compatible = "maxim,max6651",
+		.data = (void *)4
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, max6650_dt_match);
+
+static int dac_to_pwm(int dac, bool v12)
+{
+	/*
+	 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
+	 * Lower DAC values mean higher speeds.
+	 */
+	return clamp_val(255 - (255 * dac) / DAC_LIMIT(v12), 0, 255);
+}
+
+static u8 pwm_to_dac(unsigned int pwm, bool v12)
+{
+	int limit = DAC_LIMIT(v12);
+
+	return limit - (limit * pwm) / 255;
+}
+
+static struct max6650_data *max6650_update_device(struct device *dev)
+{
+	struct max6650_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	int reg, err = 0;
+	int i;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+		for (i = 0; i < data->nr_fans; i++) {
+			reg = i2c_smbus_read_byte_data(client, tach_reg[i]);
+			if (reg < 0) {
+				err = reg;
+				goto error;
+			}
+			data->tach[i] = reg;
+		}
+
+		/*
+		 * Alarms are cleared on read in case the condition that
+		 * caused the alarm is removed. Keep the value latched here
+		 * for providing the register through different alarm files.
+		 */
+		reg = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM);
+		if (reg < 0) {
+			err = reg;
+			goto error;
+		}
+		data->alarm |= reg;
+		data->last_updated = jiffies;
+		data->valid = true;
+	}
+
+error:
+	mutex_unlock(&data->update_lock);
+	if (err)
+		data = ERR_PTR(err);
+	return data;
+}
+
+/*
+ * Change the operating mode of the chip (if needed).
+ * mode is one of the MAX6650_CFG_MODE_* values.
+ */
+static int max6650_set_operating_mode(struct max6650_data *data, u8 mode)
+{
+	int result;
+	u8 config = data->config;
+
+	if (mode == (config & MAX6650_CFG_MODE_MASK))
+		return 0;
+
+	config = (config & ~MAX6650_CFG_MODE_MASK) | mode;
+
+	result = i2c_smbus_write_byte_data(data->client, MAX6650_REG_CONFIG,
+					   config);
+	if (result < 0)
+		return result;
+
+	data->config = config;
+
+	return 0;
+}
+
+/*
+ * Set the fan speed to the specified RPM (or read back the RPM setting).
+ * This works in closed loop mode only. Use pwm1 for open loop speed setting.
+ *
+ * The MAX6650/1 will automatically control fan speed when in closed loop
+ * mode.
+ *
+ * Assumptions:
+ *
+ * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use
+ *    the clock module parameter if you need to fine tune this.
+ *
+ * 2) The prescaler (low three bits of the config register) has already
+ *    been set to an appropriate value. Use the prescaler module parameter
+ *    if your BIOS doesn't initialize the chip properly.
+ *
+ * The relevant equations are given on pages 21 and 22 of the datasheet.
+ *
+ * From the datasheet, the relevant equation when in regulation is:
+ *
+ *    [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE
+ *
+ * where:
+ *
+ *    fCLK is the oscillator frequency (either the 254kHz internal
+ *         oscillator or the externally applied clock)
+ *
+ *    KTACH is the value in the speed register
+ *
+ *    FanSpeed is the speed of the fan in rps
+ *
+ *    KSCALE is the prescaler value (1, 2, 4, 8, or 16)
+ *
+ * When reading, we need to solve for FanSpeed. When writing, we need to
+ * solve for KTACH.
+ *
+ * Note: this tachometer is completely separate from the tachometers
+ * used to measure the fan speeds. Only one fan's speed (fan1) is
+ * controlled.
+ */
+
+static int max6650_set_target(struct max6650_data *data, unsigned long rpm)
+{
+	int kscale, ktach;
+
+	if (rpm == 0)
+		return max6650_set_operating_mode(data, MAX6650_CFG_MODE_OFF);
+
+	rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX);
+
+	/*
+	 * Divide the required speed by 60 to get from rpm to rps, then
+	 * use the datasheet equation:
+	 *
+	 *     KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1
+	 */
+
+	kscale = DIV_FROM_REG(data->config);
+	ktach = ((clock * kscale) / (256 * rpm / 60)) - 1;
+	if (ktach < 0)
+		ktach = 0;
+	if (ktach > 255)
+		ktach = 255;
+	data->speed = ktach;
+
+	return i2c_smbus_write_byte_data(data->client, MAX6650_REG_SPEED,
+					 data->speed);
+}
+
+/*
+ * Get gpio alarm status:
+ * Possible values:
+ * 0 = no alarm
+ * 1 = alarm
+ */
+
+static ssize_t alarm_show(struct device *dev,
+			  struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct max6650_data *data = max6650_update_device(dev);
+	bool alarm;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	alarm = data->alarm & attr->index;
+	if (alarm) {
+		mutex_lock(&data->update_lock);
+		data->alarm &= ~attr->index;
+		data->valid = false;
+		mutex_unlock(&data->update_lock);
+	}
+
+	return sysfs_emit(buf, "%d\n", alarm);
+}
+
+static SENSOR_DEVICE_ATTR_RO(gpio1_alarm, alarm, MAX6650_ALRM_GPIO1);
+static SENSOR_DEVICE_ATTR_RO(gpio2_alarm, alarm, MAX6650_ALRM_GPIO2);
+
+static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a,
+				     int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct max6650_data *data = dev_get_drvdata(dev);
+	struct device_attribute *devattr;
+
+	/*
+	 * Hide the alarms that have not been enabled by the firmware
+	 */
+
+	devattr = container_of(a, struct device_attribute, attr);
+	if (devattr == &sensor_dev_attr_gpio1_alarm.dev_attr ||
+	    devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) {
+		if (!(data->alarm_en & to_sensor_dev_attr(devattr)->index))
+			return 0;
+	}
+
+	return a->mode;
+}
+
+static struct attribute *max6650_attrs[] = {
+	&sensor_dev_attr_gpio1_alarm.dev_attr.attr,
+	&sensor_dev_attr_gpio2_alarm.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group max6650_group = {
+	.attrs = max6650_attrs,
+	.is_visible = max6650_attrs_visible,
+};
+
+static const struct attribute_group *max6650_groups[] = {
+	&max6650_group,
+	NULL
+};
+
+static int max6650_init_client(struct max6650_data *data,
+			       struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	int reg;
+	int err;
+	u32 voltage;
+	u32 prescale;
+	u32 target_rpm;
+
+	if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt",
+				 &voltage))
+		voltage = fan_voltage;
+	else
+		voltage /= 1000000; /* Microvolts to volts */
+	if (of_property_read_u32(dev->of_node, "maxim,fan-prescale",
+				 &prescale))
+		prescale = prescaler;
+
+	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
+	if (reg < 0) {
+		dev_err(dev, "Error reading config register, aborting.\n");
+		return reg;
+	}
+
+	switch (voltage) {
+	case 0:
+		break;
+	case 5:
+		reg &= ~MAX6650_CFG_V12;
+		break;
+	case 12:
+		reg |= MAX6650_CFG_V12;
+		break;
+	default:
+		dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage);
+	}
+
+	switch (prescale) {
+	case 0:
+		break;
+	case 1:
+		reg &= ~MAX6650_CFG_PRESCALER_MASK;
+		break;
+	case 2:
+		reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
+			 | MAX6650_CFG_PRESCALER_2;
+		break;
+	case  4:
+		reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
+			 | MAX6650_CFG_PRESCALER_4;
+		break;
+	case  8:
+		reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
+			 | MAX6650_CFG_PRESCALER_8;
+		break;
+	case 16:
+		reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
+			 | MAX6650_CFG_PRESCALER_16;
+		break;
+	default:
+		dev_err(dev, "illegal value for prescaler (%d)\n", prescale);
+	}
+
+	dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n",
+		 (reg & MAX6650_CFG_V12) ? 12 : 5,
+		 1 << (reg & MAX6650_CFG_PRESCALER_MASK));
+
+	err = i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, reg);
+	if (err) {
+		dev_err(dev, "Config write error, aborting.\n");
+		return err;
+	}
+	data->config = reg;
+
+	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_SPEED);
+	if (reg < 0) {
+		dev_err(dev, "Failed to read speed register, aborting.\n");
+		return reg;
+	}
+	data->speed = reg;
+
+	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
+	if (reg < 0) {
+		dev_err(dev, "Failed to read DAC register, aborting.\n");
+		return reg;
+	}
+	data->dac = reg;
+
+	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
+	if (reg < 0) {
+		dev_err(dev, "Failed to read count register, aborting.\n");
+		return reg;
+	}
+	data->count = reg;
+
+	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN);
+	if (reg < 0) {
+		dev_err(dev, "Failed to read alarm configuration, aborting.\n");
+		return reg;
+	}
+	data->alarm_en = reg;
+
+	if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm",
+				  &target_rpm)) {
+		max6650_set_target(data, target_rpm);
+		max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP);
+	}
+
+	return 0;
+}
+
+static int max6650_get_max_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	*state = 255;
+
+	return 0;
+}
+
+static int max6650_get_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	struct max6650_data *data = cdev->devdata;
+
+	*state = data->cooling_dev_state;
+
+	return 0;
+}
+
+static int max6650_set_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long state)
+{
+	struct max6650_data *data = cdev->devdata;
+	struct i2c_client *client = data->client;
+	int err;
+
+	state = clamp_val(state, 0, 255);
+
+	mutex_lock(&data->update_lock);
+
+	data->dac = pwm_to_dac(state, data->config & MAX6650_CFG_V12);
+	err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
+	if (!err) {
+		max6650_set_operating_mode(data, state ?
+					   MAX6650_CFG_MODE_OPEN_LOOP :
+					   MAX6650_CFG_MODE_OFF);
+		data->cooling_dev_state = state;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return err;
+}
+
+static const struct thermal_cooling_device_ops max6650_cooling_ops = {
+	.get_max_state = max6650_get_max_state,
+	.get_cur_state = max6650_get_cur_state,
+	.set_cur_state = max6650_set_cur_state,
+};
+
+static int max6650_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	struct max6650_data *data = max6650_update_device(dev);
+	int mode;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			*val = dac_to_pwm(data->dac,
+					  data->config & MAX6650_CFG_V12);
+			break;
+		case hwmon_pwm_enable:
+			/*
+			 * Possible values:
+			 * 0 = Fan always on
+			 * 1 = Open loop, Voltage is set according to speed,
+			 *     not regulated.
+			 * 2 = Closed loop, RPM for all fans regulated by fan1
+			 *     tachometer
+			 * 3 = Fan off
+			 */
+			mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4;
+			*val = (4 - mode) & 3; /* {0 1 2 3} -> {0 3 2 1} */
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			/*
+			 * Calculation details:
+			 *
+			 * Each tachometer counts over an interval given by the
+			 * "count" register (0.25, 0.5, 1 or 2 seconds).
+			 * The driver assumes that the fans produce two pulses
+			 * per revolution (this seems to be the most common).
+			 */
+			*val = DIV_ROUND_CLOSEST(data->tach[channel] * 120,
+						 DIV_FROM_REG(data->count));
+			break;
+		case hwmon_fan_div:
+			*val = DIV_FROM_REG(data->count);
+			break;
+		case hwmon_fan_target:
+			/*
+			 * Use the datasheet equation:
+			 *    FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)]
+			 * then multiply by 60 to give rpm.
+			 */
+			*val = 60 * DIV_FROM_REG(data->config) * clock /
+				(256 * (data->speed + 1));
+			break;
+		case hwmon_fan_min_alarm:
+			*val = !!(data->alarm & MAX6650_ALRM_MIN);
+			data->alarm &= ~MAX6650_ALRM_MIN;
+			data->valid = false;
+			break;
+		case hwmon_fan_max_alarm:
+			*val = !!(data->alarm & MAX6650_ALRM_MAX);
+			data->alarm &= ~MAX6650_ALRM_MAX;
+			data->valid = false;
+			break;
+		case hwmon_fan_fault:
+			*val = !!(data->alarm & MAX6650_ALRM_TACH);
+			data->alarm &= ~MAX6650_ALRM_TACH;
+			data->valid = false;
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static const u8 max6650_pwm_modes[] = {
+	MAX6650_CFG_MODE_ON,
+	MAX6650_CFG_MODE_OPEN_LOOP,
+	MAX6650_CFG_MODE_CLOSED_LOOP,
+	MAX6650_CFG_MODE_OFF,
+};
+
+static int max6650_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
+{
+	struct max6650_data *data = dev_get_drvdata(dev);
+	int ret = 0;
+	u8 reg;
+
+	mutex_lock(&data->update_lock);
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			reg = pwm_to_dac(clamp_val(val, 0, 255),
+					 data->config & MAX6650_CFG_V12);
+			ret = i2c_smbus_write_byte_data(data->client,
+							MAX6650_REG_DAC, reg);
+			if (ret)
+				break;
+			data->dac = reg;
+			break;
+		case hwmon_pwm_enable:
+			if (val < 0 || val >= ARRAY_SIZE(max6650_pwm_modes)) {
+				ret = -EINVAL;
+				break;
+			}
+			ret = max6650_set_operating_mode(data,
+						max6650_pwm_modes[val]);
+			break;
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+		break;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_div:
+			switch (val) {
+			case 1:
+				reg = 0;
+				break;
+			case 2:
+				reg = 1;
+				break;
+			case 4:
+				reg = 2;
+				break;
+			case 8:
+				reg = 3;
+				break;
+			default:
+				ret = -EINVAL;
+				goto error;
+			}
+			ret = i2c_smbus_write_byte_data(data->client,
+							MAX6650_REG_COUNT, reg);
+			if (ret)
+				break;
+			data->count = reg;
+			break;
+		case hwmon_fan_target:
+			if (val < 0) {
+				ret = -EINVAL;
+				break;
+			}
+			ret = max6650_set_target(data, val);
+			break;
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+error:
+	mutex_unlock(&data->update_lock);
+	return ret;
+}
+
+static umode_t max6650_is_visible(const void *_data,
+				  enum hwmon_sensor_types type, u32 attr,
+				  int channel)
+{
+	const struct max6650_data *data = _data;
+
+	if (channel && (channel >= data->nr_fans || type != hwmon_fan))
+		return 0;
+
+	switch (type) {
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			return 0444;
+		case hwmon_fan_target:
+		case hwmon_fan_div:
+			return 0644;
+		case hwmon_fan_min_alarm:
+			if (data->alarm_en & MAX6650_ALRM_MIN)
+				return 0444;
+			break;
+		case hwmon_fan_max_alarm:
+			if (data->alarm_en & MAX6650_ALRM_MAX)
+				return 0444;
+			break;
+		case hwmon_fan_fault:
+			if (data->alarm_en & MAX6650_ALRM_TACH)
+				return 0444;
+			break;
+		default:
+			break;
+		}
+		break;
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+		case hwmon_pwm_enable:
+			return 0644;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info * const max6650_info[] = {
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_DIV |
+			   HWMON_F_MIN_ALARM | HWMON_F_MAX_ALARM |
+			   HWMON_F_FAULT,
+			   HWMON_F_INPUT, HWMON_F_INPUT, HWMON_F_INPUT),
+	HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
+	NULL
+};
+
+static const struct hwmon_ops max6650_hwmon_ops = {
+	.read = max6650_read,
+	.write = max6650_write,
+	.is_visible = max6650_is_visible,
+};
+
+static const struct hwmon_chip_info max6650_chip_info = {
+	.ops = &max6650_hwmon_ops,
+	.info = max6650_info,
+};
+
+static const struct i2c_device_id max6650_id[];
+
+static int max6650_probe(struct i2c_client *client)
+{
+	struct thermal_cooling_device *cooling_dev;
+	struct device *dev = &client->dev;
+	struct max6650_data *data;
+	struct device *hwmon_dev;
+	int err;
+
+	data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+	i2c_set_clientdata(client, data);
+	mutex_init(&data->update_lock);
+
+	data->nr_fans = (uintptr_t)i2c_get_match_data(client);
+
+	/*
+	 * Initialize the max6650 chip
+	 */
+	err = max6650_init_client(data, client);
+	if (err)
+		return err;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev,
+							 client->name, data,
+							 &max6650_chip_info,
+							 max6650_groups);
+	err = PTR_ERR_OR_ZERO(hwmon_dev);
+	if (err)
+		return err;
+
+	if (IS_ENABLED(CONFIG_THERMAL)) {
+		cooling_dev = devm_thermal_of_child_cooling_device_register(dev, dev->of_node,
+									    client->name, data,
+									    &max6650_cooling_ops);
+		if (IS_ERR(cooling_dev)) {
+			dev_warn(dev, "thermal cooling device register failed: %ld\n",
+				 PTR_ERR(cooling_dev));
+		}
+	}
+
+	return 0;
+}
+
+static const struct i2c_device_id max6650_id[] = {
+	{ .name = "max6650", .driver_data = 1 },
+	{ .name = "max6651", .driver_data = 4 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max6650_id);
+
+static struct i2c_driver max6650_driver = {
+	.driver = {
+		.name	= "max6650",
+		.of_match_table = of_match_ptr(max6650_dt_match),
+	},
+	.probe		= max6650_probe,
+	.id_table	= max6650_id,
+};
+
+module_i2c_driver(max6650_driver);
+
+MODULE_AUTHOR("Hans J. Koch");
+MODULE_DESCRIPTION("MAX6650 sensor driver");
+MODULE_LICENSE("GPL");