[PATCH v2 0/9] hwmon: New hwmon registration API

[PATCH v2 0/9] hwmon: New hwmon registration API

[Guenter Roeck]

Up to now, each hwmon driver has to implement its own sysfs attributes.
This requires a lot of template code, and distracts from the driver's
core function to read and write chip registers.

To be able to reduce driver complexity, move sensor attribute handling
and thermal zone registration into the hwmon core. By using the new API,
driver size is typically reduced by 20-50% depending on driver complexity
and the number of sysfs attributes supported.

The first patch of the series is preparatory; it reorders include files
in the hwmon core to make it easier to add or remove individual include
files.

The secind patch of the series introduces the API as well as support
for temperature sensor attributes. Subsequent patches introduce support
for voltage, current, power, energy, humidity, fan speed, and basic pwm
attributes.

The series was tested by converting several drivers (lm75, lm90, tmp102,
tmp421, ltc4245, nct7904, max31790) to the new API. Testing was done with
real chips as well as with the hwmon driver module test code available
at https://github.com/groeck/module-tests.

v2:
- Add patch 1/9 (order include files alphabetically).
- Add patch 9/9 (pwm support).
- Document callback function parameters of struct hwmon_ops in
  include/linux/hwmon.h.
- Clarify that the is_visible() callback is mandatory.
- If an attribute has no template string, treat it as invisible, not as
  error. Affected are virtual attributes such as HWMON_C_REGISTER_TZ.
- Initialize device attribute read/write callback functions unconditionally.
- Cosmetic changes, including typo fixes and added newlines for readability.

[PATCH v2 1/9] hwmon: (core) Order include files alphabetically

[Guenter Roeck]

Ordering include files alphabetically makes it easier to add new ones.
Stop including linux/spinlock.h and linux/kdev_t.h since both are not
needed.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Added patch

 drivers/hwmon/hwmon.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index a26c385a435b..649a68d119b4 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -12,16 +12,14 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
-#include <linux/module.h>
 #include <linux/device.h>
 #include <linux/err.h>
-#include <linux/slab.h>
-#include <linux/kdev_t.h>
-#include <linux/idr.h>
-#include <linux/hwmon.h>
 #include <linux/gfp.h>
-#include <linux/spinlock.h>
+#include <linux/hwmon.h>
+#include <linux/idr.h>
+#include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/slab.h>
 #include <linux/string.h>
 
 #define HWMON_ID_PREFIX "hwmon"
-- 
2.5.0

[PATCH v2 2/9] hwmon: (core) New hwmon registration API

[Guenter Roeck]

Up to now, each hwmon driver has to implement its own sysfs attributes.
This requires a lot of template code, and distracts from the driver's core
function to read and write chip registers.

To be able to reduce driver complexity, move sensor attribute handling
and thermal zone registration into hwmon core. By using the new API,
driver code and data size is typically reduced by 20-70%, depending
on driver complexity and the number of sysfs attributes supported.

With this patch, the new API only supports thermal sensors. Support for
other sensor types will be added with subsequent patches.

Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2:
- Document callback function parameters of struct hwmon_ops in
  include/linux/hwmon.h.
- Clarify that the is_visible() callback is mandatory.
- Initialize device attribute read/write callback functions unconditionally.
- If an attribute has no template string, treat it as invisible, not as
  error. Affected are virtual attributes such as HWMON_C_REGISTER_TZ.
- Added newline to improve readability.

Review comments not addressed:
- Stick with u32 for attribute masks. We could use u64, but it is currently
  not needed, and changing it later would be straightforward.
- Do not use for_each_set_bit() to walk attribute masks.
  for_each_set_bit() expects a pointer to an unsigned long as argument,
  which would make it difficult to switch to u64 attribute masks if/when
  needed.

 drivers/hwmon/hwmon.c | 478 +++++++++++++++++++++++++++++++++++++++++++++++---
 include/linux/hwmon.h | 148 ++++++++++++++++
 2 files changed, 599 insertions(+), 27 deletions(-)

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 649a68d119b4..d780011cd063 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -12,6 +12,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/bitops.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/gfp.h>
@@ -21,6 +22,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/thermal.h>
 
 #define HWMON_ID_PREFIX "hwmon"
 #define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d"
@@ -28,9 +30,35 @@
 struct hwmon_device {
 	const char *name;
 	struct device dev;
+	const struct hwmon_chip_info *chip;
+
+	struct attribute_group group;
+	const struct attribute_group **groups;
 };
+
 #define to_hwmon_device(d) container_of(d, struct hwmon_device, dev)
 
+struct hwmon_device_attribute {
+	struct device_attribute dev_attr;
+	const struct hwmon_ops *ops;
+	enum hwmon_sensor_types type;
+	u32 attr;
+	int index;
+};
+
+#define to_hwmon_attr(d) \
+	container_of(d, struct hwmon_device_attribute, dev_attr)
+
+/*
+ * Thermal zone information
+ * In addition to the reference to the hwmon device,
+ * also provides the sensor index.
+ */
+struct hwmon_thermal_data {
+	struct hwmon_device *hwdev;	/* Reference to hwmon device */
+	int index;			/* sensor index */
+};
+
 static ssize_t
 show_name(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -78,25 +106,279 @@ static struct class hwmon_class = {
 
 static DEFINE_IDA(hwmon_ida);
 
-/**
- * hwmon_device_register_with_groups - register w/ hwmon
- * @dev: the parent device
- * @name: hwmon name attribute
- * @drvdata: driver data to attach to created device
- * @groups: List of attribute groups to create
- *
- * hwmon_device_unregister() must be called when the device is no
- * longer needed.
- *
- * Returns the pointer to the new device.
- */
-struct device *
-hwmon_device_register_with_groups(struct device *dev, const char *name,
-				  void *drvdata,
-				  const struct attribute_group **groups)
+/* Thermal zone handling */
+
+static int hwmon_thermal_get_temp(void *data, int *temp)
+{
+	struct hwmon_thermal_data *tdata = data;
+	struct hwmon_device *hwdev = tdata->hwdev;
+	int ret;
+	long t;
+
+	ret = hwdev->chip->ops->read(&hwdev->dev, hwmon_temp, hwmon_temp_input,
+				     tdata->index, &t);
+	if (ret < 0)
+		return ret;
+
+	*temp = t;
+
+	return 0;
+}
+
+static struct thermal_zone_of_device_ops hwmon_thermal_ops = {
+	.get_temp = hwmon_thermal_get_temp,
+};
+
+static int hwmon_thermal_add_sensor(struct device *dev,
+				    struct hwmon_device *hwdev,
+				    int index)
+{
+	struct hwmon_thermal_data *tdata;
+
+	tdata = devm_kzalloc(dev, sizeof(*tdata), GFP_KERNEL);
+	if (!tdata)
+		return -ENOMEM;
+
+	tdata->hwdev = hwdev;
+	tdata->index = index;
+
+	devm_thermal_zone_of_sensor_register(&hwdev->dev, index, tdata,
+					     &hwmon_thermal_ops);
+
+	return 0;
+}
+
+/* sysfs attribute management */
+
+static ssize_t hwmon_attr_show(struct device *dev,
+			       struct device_attribute *devattr, char *buf)
+{
+	struct hwmon_device_attribute *hattr = to_hwmon_attr(devattr);
+	long val;
+	int ret;
+
+	ret = hattr->ops->read(dev, hattr->type, hattr->attr, hattr->index,
+			       &val);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%ld\n", val);
+}
+
+static ssize_t hwmon_attr_store(struct device *dev,
+				struct device_attribute *devattr,
+				const char *buf, size_t count)
+{
+	struct hwmon_device_attribute *hattr = to_hwmon_attr(devattr);
+	long val;
+	int ret;
+
+	ret = kstrtol(buf, 10, &val);
+	if (ret < 0)
+		return ret;
+
+	ret = hattr->ops->write(dev, hattr->type, hattr->attr, hattr->index,
+				val);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static int hwmon_attr_base(enum hwmon_sensor_types type)
+{
+	if (type == hwmon_in)
+		return 0;
+	return 1;
+}
+
+static struct attribute *hwmon_genattr(struct device *dev,
+				       const void *drvdata,
+				       enum hwmon_sensor_types type,
+				       u32 attr,
+				       int index,
+				       const char *template,
+				       const struct hwmon_ops *ops)
+{
+	struct hwmon_device_attribute *hattr;
+	struct device_attribute *dattr;
+	struct attribute *a;
+	umode_t mode;
+	char *name;
+
+	/* The attribute is invisible if there is no template string */
+	if (!template)
+		return ERR_PTR(-ENOENT);
+
+	mode = ops->is_visible(drvdata, type, attr, index);
+	if (!mode)
+		return ERR_PTR(-ENOENT);
+
+	if ((mode & S_IRUGO) && !ops->read)
+		return ERR_PTR(-EINVAL);
+	if ((mode & S_IWUGO) && !ops->write)
+		return ERR_PTR(-EINVAL);
+
+	if (type == hwmon_chip) {
+		name = (char *)template;
+	} else {
+		name = devm_kzalloc(dev, strlen(template) + 16, GFP_KERNEL);
+		if (!name)
+			return ERR_PTR(-ENOMEM);
+		scnprintf(name, strlen(template) + 16, template,
+			  index + hwmon_attr_base(type));
+	}
+
+	hattr = devm_kzalloc(dev, sizeof(*hattr), GFP_KERNEL);
+	if (!hattr)
+		return ERR_PTR(-ENOMEM);
+
+	hattr->type = type;
+	hattr->attr = attr;
+	hattr->index = index;
+	hattr->ops = ops;
+
+	dattr = &hattr->dev_attr;
+	dattr->show = hwmon_attr_show;
+	dattr->store = hwmon_attr_store;
+
+	a = &dattr->attr;
+	sysfs_attr_init(a);
+	a->name = name;
+	a->mode = mode;
+
+	return a;
+}
+
+static const char * const hwmon_chip_attr_templates[] = {
+	[hwmon_chip_temp_reset_history] = "temp_reset_history",
+	[hwmon_chip_update_interval] = "update_interval",
+	[hwmon_chip_alarms] = "alarms",
+};
+
+static const char * const hwmon_temp_attr_templates[] = {
+	[hwmon_temp_input] = "temp%d_input",
+	[hwmon_temp_type] = "temp%d_type",
+	[hwmon_temp_lcrit] = "temp%d_lcrit",
+	[hwmon_temp_lcrit_hyst] = "temp%d_lcrit_hyst",
+	[hwmon_temp_min] = "temp%d_min",
+	[hwmon_temp_min_hyst] = "temp%d_min_hyst",
+	[hwmon_temp_max] = "temp%d_max",
+	[hwmon_temp_max_hyst] = "temp%d_max_hyst",
+	[hwmon_temp_crit] = "temp%d_crit",
+	[hwmon_temp_crit_hyst] = "temp%d_crit_hyst",
+	[hwmon_temp_emergency] = "temp%d_emergency",
+	[hwmon_temp_emergency_hyst] = "temp%d_emergency_hyst",
+	[hwmon_temp_alarm] = "temp%d_alarm",
+	[hwmon_temp_lcrit_alarm] = "temp%d_lcrit_alarm",
+	[hwmon_temp_min_alarm] = "temp%d_min_alarm",
+	[hwmon_temp_max_alarm] = "temp%d_max_alarm",
+	[hwmon_temp_crit_alarm] = "temp%d_crit_alarm",
+	[hwmon_temp_emergency_alarm] = "temp%d_emergency_alarm",
+	[hwmon_temp_fault] = "temp%d_fault",
+	[hwmon_temp_offset] = "temp%d_offset",
+	[hwmon_temp_label] = "temp%d_label",
+	[hwmon_temp_lowest] = "temp%d_lowest",
+	[hwmon_temp_highest] = "temp%d_highest",
+	[hwmon_temp_reset_history] = "temp%d_reset_history",
+};
+
+static const char * const *__templates[] = {
+	[hwmon_chip] = hwmon_chip_attr_templates,
+	[hwmon_temp] = hwmon_temp_attr_templates,
+};
+
+static const int __templates_size[] = {
+	[hwmon_chip] = ARRAY_SIZE(hwmon_chip_attr_templates),
+	[hwmon_temp] = ARRAY_SIZE(hwmon_temp_attr_templates),
+};
+
+static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
+{
+	int i, n;
+
+	for (i = n = 0; info->config[i]; i++)
+		n += hweight32(info->config[i]);
+
+	return n;
+}
+
+static int hwmon_genattrs(struct device *dev,
+			  const void *drvdata,
+			  struct attribute **attrs,
+			  const struct hwmon_ops *ops,
+			  const struct hwmon_channel_info *info)
+{
+	const char * const *templates;
+	int template_size;
+	int i, aindex = 0;
+
+	if (info->type >= ARRAY_SIZE(__templates))
+		return -EINVAL;
+
+	templates = __templates[info->type];
+	template_size = __templates_size[info->type];
+
+	for (i = 0; info->config[i]; i++) {
+		u32 attr_mask = info->config[i];
+		u32 attr;
+
+		while (attr_mask) {
+			struct attribute *a;
+
+			attr = __ffs(attr_mask);
+			attr_mask &= ~BIT(attr);
+			if (attr >= template_size)
+				return -EINVAL;
+			a = hwmon_genattr(dev, drvdata, info->type, attr, i,
+					  templates[attr], ops);
+			if (IS_ERR(a)) {
+				if (PTR_ERR(a) != -ENOENT)
+					return PTR_ERR(a);
+				continue;
+			}
+			attrs[aindex++] = a;
+		}
+	}
+	return aindex;
+}
+
+static struct attribute **
+__hwmon_create_attrs(struct device *dev, const void *drvdata,
+		     const struct hwmon_chip_info *chip)
+{
+	int ret, i, aindex = 0, nattrs = 0;
+	struct attribute **attrs;
+
+	for (i = 0; chip->info[i]; i++)
+		nattrs += hwmon_num_channel_attrs(chip->info[i]);
+
+	if (nattrs == 0)
+		return ERR_PTR(-EINVAL);
+
+	attrs = devm_kcalloc(dev, nattrs + 1, sizeof(*attrs), GFP_KERNEL);
+	if (!attrs)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; chip->info[i]; i++) {
+		ret = hwmon_genattrs(dev, drvdata, &attrs[aindex], chip->ops,
+				     chip->info[i]);
+		if (ret < 0)
+			return ERR_PTR(ret);
+		aindex += ret;
+	}
+
+	return attrs;
+}
+
+static struct device *
+__hwmon_device_register(struct device *dev, const char *name, void *drvdata,
+			const struct hwmon_chip_info *chip,
+			const struct attribute_group **groups)
 {
 	struct hwmon_device *hwdev;
-	int err, id;
+	struct device *hdev;
+	int i, j, err, id;
 
 	/* Do not accept invalid characters in hwmon name attribute */
 	if (name && (!strlen(name) || strpbrk(name, "-* \t\n")))
@@ -112,28 +394,128 @@ hwmon_device_register_with_groups(struct device *dev, const char *name,
 		goto ida_remove;
 	}
 
+	hdev = &hwdev->dev;
+
+	if (chip && chip->ops->is_visible) {
+		struct attribute **attrs;
+		int ngroups = 2;
+
+		if (groups)
+			for (i = 0; groups[i]; i++)
+				ngroups++;
+
+		hwdev->groups = devm_kcalloc(dev, ngroups, sizeof(*groups),
+					     GFP_KERNEL);
+		if (!hwdev->groups)
+			return ERR_PTR(-ENOMEM);
+
+		attrs = __hwmon_create_attrs(dev, drvdata, chip);
+		if (IS_ERR(attrs)) {
+			err = PTR_ERR(attrs);
+			goto free_hwmon;
+		}
+
+		hwdev->group.attrs = attrs;
+		ngroups = 0;
+		hwdev->groups[ngroups++] = &hwdev->group;
+
+		if (groups) {
+			for (i = 0; groups[i]; i++)
+				hwdev->groups[ngroups++] = groups[i];
+		}
+
+		hdev->groups = hwdev->groups;
+	} else {
+		hdev->groups = groups;
+	}
+
 	hwdev->name = name;
-	hwdev->dev.class = &hwmon_class;
-	hwdev->dev.parent = dev;
-	hwdev->dev.groups = groups;
-	hwdev->dev.of_node = dev ? dev->of_node : NULL;
-	dev_set_drvdata(&hwdev->dev, drvdata);
-	dev_set_name(&hwdev->dev, HWMON_ID_FORMAT, id);
-	err = device_register(&hwdev->dev);
+	hdev->class = &hwmon_class;
+	hdev->parent = dev;
+	hdev->of_node = dev ? dev->of_node : NULL;
+	hwdev->chip = chip;
+	dev_set_drvdata(hdev, drvdata);
+	dev_set_name(hdev, HWMON_ID_FORMAT, id);
+	err = device_register(hdev);
 	if (err)
-		goto free;
+		goto free_hwmon;
+
+	if (chip && chip->ops->is_visible && chip->ops->read &&
+	    chip->info[0]->type == hwmon_chip &&
+	    (chip->info[0]->config[0] & HWMON_C_REGISTER_TZ)) {
+		const struct hwmon_channel_info **info = chip->info;
+
+		for (i = 1; info[i]; i++) {
+			if (info[i]->type != hwmon_temp)
+				continue;
+
+			for (j = 0; info[i]->config[j]; j++) {
+				if (!chip->ops->is_visible(drvdata, hwmon_temp,
+							   hwmon_temp_input, j))
+					continue;
+				if (info[i]->config[j] & HWMON_T_INPUT)
+					hwmon_thermal_add_sensor(dev, hwdev, j);
+			}
+		}
+	}
 
-	return &hwdev->dev;
+	return hdev;
 
-free:
+free_hwmon:
 	kfree(hwdev);
 ida_remove:
 	ida_simple_remove(&hwmon_ida, id);
 	return ERR_PTR(err);
 }
+
+/**
+ * hwmon_device_register_with_groups - register w/ hwmon
+ * @dev: the parent device
+ * @name: hwmon name attribute
+ * @drvdata: driver data to attach to created device
+ * @groups: List of attribute groups to create
+ *
+ * hwmon_device_unregister() must be called when the device is no
+ * longer needed.
+ *
+ * Returns the pointer to the new device.
+ */
+struct device *
+hwmon_device_register_with_groups(struct device *dev, const char *name,
+				  void *drvdata,
+				  const struct attribute_group **groups)
+{
+	return __hwmon_device_register(dev, name, drvdata, NULL, groups);
+}
 EXPORT_SYMBOL_GPL(hwmon_device_register_with_groups);
 
 /**
+ * hwmon_device_register_with_info - register w/ hwmon
+ * @dev: the parent device
+ * @name: hwmon name attribute
+ * @drvdata: driver data to attach to created device
+ * @info: Pointer to hwmon chip information
+ * @groups - pointer to list of driver specific attribute groups
+ *
+ * hwmon_device_unregister() must be called when the device is no
+ * longer needed.
+ *
+ * Returns the pointer to the new device.
+ */
+struct device *
+hwmon_device_register_with_info(struct device *dev, const char *name,
+				void *drvdata,
+				const struct hwmon_chip_info *chip,
+				const struct attribute_group **groups)
+{
+	if (chip && (!chip->ops || !chip->info))
+		return ERR_PTR(-EINVAL);
+
+	return __hwmon_device_register(dev, name, drvdata, chip, groups);
+}
+EXPORT_SYMBOL_GPL(hwmon_device_register_with_info);
+
+/**
  * hwmon_device_register - register w/ hwmon
  * @dev: the device to register
  *
@@ -211,6 +593,48 @@ error:
 }
 EXPORT_SYMBOL_GPL(devm_hwmon_device_register_with_groups);
 
+/**
+ * devm_hwmon_device_register_with_info - register w/ hwmon
+ * @dev: the parent device
+ * @name: hwmon name attribute
+ * @drvdata: driver data to attach to created device
+ * @info: Pointer to hwmon chip information
+ * @groups - pointer to list of driver specific attribute groups
+ *
+ * Returns the pointer to the new device. The new device is automatically
+ * unregistered with the parent device.
+ */
+struct device *
+devm_hwmon_device_register_with_info(struct device *dev, const char *name,
+				     void *drvdata,
+				     const struct hwmon_chip_info *chip,
+				     const struct attribute_group **groups)
+{
+	struct device **ptr, *hwdev;
+
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
+	ptr = devres_alloc(devm_hwmon_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	hwdev = hwmon_device_register_with_info(dev, name, drvdata, chip,
+						groups);
+	if (IS_ERR(hwdev))
+		goto error;
+
+	*ptr = hwdev;
+	devres_add(dev, ptr);
+
+	return hwdev;
+
+error:
+	devres_free(ptr);
+	return hwdev;
+}
+EXPORT_SYMBOL_GPL(devm_hwmon_device_register_with_info);
+
 static int devm_hwmon_match(struct device *dev, void *res, void *data)
 {
 	struct device **hwdev = res;
diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
index 09354f6c1d63..52e56d71d742 100644
--- a/include/linux/hwmon.h
+++ b/include/linux/hwmon.h
@@ -14,9 +14,147 @@
 #ifndef _HWMON_H_
 #define _HWMON_H_
 
+#include <linux/bitops.h>
+
 struct device;
 struct attribute_group;
 
+enum hwmon_sensor_types {
+	hwmon_chip,
+	hwmon_temp,
+	hwmon_in,
+	hwmon_curr,
+	hwmon_power,
+	hwmon_energy,
+};
+
+enum hwmon_chip_attributes {
+	hwmon_chip_temp_reset_history,
+	hwmon_chip_register_tz,
+	hwmon_chip_update_interval,
+	hwmon_chip_alarms,
+};
+
+#define HWMON_C_TEMP_RESET_HISTORY	BIT(hwmon_chip_temp_reset_history)
+#define HWMON_C_IN_RESET_HISTORY	BIT(hwmon_chip_in_reset_history)
+#define HWMON_C_REGISTER_TZ		BIT(hwmon_chip_register_tz)
+#define HWMON_C_UPDATE_INTERVAL		BIT(hwmon_chip_update_interval)
+#define HWMON_C_ALARMS			BIT(hwmon_chip_alarms)
+
+enum hwmon_temp_attributes {
+	hwmon_temp_input = 0,
+	hwmon_temp_type,
+	hwmon_temp_lcrit,
+	hwmon_temp_lcrit_hyst,
+	hwmon_temp_min,
+	hwmon_temp_min_hyst,
+	hwmon_temp_max,
+	hwmon_temp_max_hyst,
+	hwmon_temp_crit,
+	hwmon_temp_crit_hyst,
+	hwmon_temp_emergency,
+	hwmon_temp_emergency_hyst,
+	hwmon_temp_alarm,
+	hwmon_temp_lcrit_alarm,
+	hwmon_temp_min_alarm,
+	hwmon_temp_max_alarm,
+	hwmon_temp_crit_alarm,
+	hwmon_temp_emergency_alarm,
+	hwmon_temp_fault,
+	hwmon_temp_offset,
+	hwmon_temp_label,
+	hwmon_temp_lowest,
+	hwmon_temp_highest,
+	hwmon_temp_reset_history,
+};
+
+#define HWMON_T_INPUT		BIT(hwmon_temp_input)
+#define HWMON_T_TYPE		BIT(hwmon_temp_type)
+#define HWMON_T_LCRIT		BIT(hwmon_temp_lcrit)
+#define HWMON_T_LCRIT_HYST	BIT(hwmon_temp_lcrit_hyst)
+#define HWMON_T_MIN		BIT(hwmon_temp_min)
+#define HWMON_T_MIN_HYST	BIT(hwmon_temp_min_hyst)
+#define HWMON_T_MAX		BIT(hwmon_temp_max)
+#define HWMON_T_MAX_HYST	BIT(hwmon_temp_max_hyst)
+#define HWMON_T_CRIT		BIT(hwmon_temp_crit)
+#define HWMON_T_CRIT_HYST	BIT(hwmon_temp_crit_hyst)
+#define HWMON_T_EMERGENCY	BIT(hwmon_temp_emergency)
+#define HWMON_T_EMERGENCY_HYST	BIT(hwmon_temp_emergency_hyst)
+#define HWMON_T_MIN_ALARM	BIT(hwmon_temp_min_alarm)
+#define HWMON_T_MAX_ALARM	BIT(hwmon_temp_max_alarm)
+#define HWMON_T_CRIT_ALARM	BIT(hwmon_temp_crit_alarm)
+#define HWMON_T_EMERGENCY_ALARM	BIT(hwmon_temp_emergency_alarm)
+#define HWMON_T_FAULT		BIT(hwmon_temp_fault)
+#define HWMON_T_OFFSET		BIT(hwmon_temp_offset)
+#define HWMON_T_LABEL		BIT(hwmon_temp_label)
+#define HWMON_T_LOWEST		BIT(hwmon_temp_lowest)
+#define HWMON_T_HIGHEST		BIT(hwmon_temp_highest)
+#define HWMON_T_RESET_HISTORY	BIT(hwmon_temp_reset_history)
+
+/**
+ * struct hwmon_ops - hwmon device operations
+ * @is_visible: Callback to return attribute visibility. Mandatory.
+ *		Parameters are:
+ *		@const void *drvdata:
+ *			Pointer to driver-private data structure passed
+ *			as argument to hwmon_device_register_with_info().
+ *		@type:	Sensor type
+ *		@attr:	Sensor attribute
+ *		@channel:
+ *			Channel number
+ *		The function returns the file permissions.
+ *		If the return value is 0, no attribute will be created.
+ * @read:       Read callback. Optional. If not provided, attributes
+ *		will not be readable.
+ *		Parameters are:
+ *		@dev:	Pointer to hardware monitoring device
+ *		@type:	Sensor type
+ *		@attr:	Sensor attribute
+ *		@channel:
+ *			Channel number
+ *		@val:	Pointer to returned value
+ *		The function returns 0 on success or a negative error number.
+ * @write:	Write callback. Optional. If not provided, attributes
+ *		will not be writable.
+ *		Parameters are:
+ *		@dev:	Pointer to hardware monitoring device
+ *		@type:	Sensor type
+ *		@attr:	Sensor attribute
+ *		@channel:
+ *			Channel number
+ *		@val:	Value to write
+ *		The function returns 0 on success or a negative error number.
+ */
+struct hwmon_ops {
+	umode_t (*is_visible)(const void *drvdata, enum hwmon_sensor_types type,
+			      u32 attr, int channel);
+	int (*read)(struct device *dev, enum hwmon_sensor_types type,
+		    u32 attr, int channel, long *val);
+	int (*write)(struct device *dev, enum hwmon_sensor_types type,
+		     u32 attr, int channel, long val);
+};
+
+/**
+ * Channel information
+ * @type:	Channel type.
+ * @config:	Pointer to NULL-terminated list of channel parameters.
+ *		Use for per-channel attributes.
+ */
+struct hwmon_channel_info {
+	enum hwmon_sensor_types type;
+	const u32 *config;
+};
+
+/**
+ * Chip configuration
+ * @ops:	Pointer to hwmon operations.
+ * @info:	Null-terminated list of channel information.
+ */
+struct hwmon_chip_info {
+	const struct hwmon_ops *ops;
+	const struct hwmon_channel_info **info;
+};
+
 struct device *hwmon_device_register(struct device *dev);
 struct device *
 hwmon_device_register_with_groups(struct device *dev, const char *name,
@@ -26,6 +164,16 @@ struct device *
 devm_hwmon_device_register_with_groups(struct device *dev, const char *name,
 				       void *drvdata,
 				       const struct attribute_group **groups);
+struct device *
+hwmon_device_register_with_info(struct device *dev,
+				const char *name, void *drvdata,
+				const struct hwmon_chip_info *info,
+				const struct attribute_group **groups);
+struct device *
+devm_hwmon_device_register_with_info(struct device *dev,
+				     const char *name, void *drvdata,
+				     const struct hwmon_chip_info *info,
+				     const struct attribute_group **groups);
 
 void hwmon_device_unregister(struct device *dev);
 void devm_hwmon_device_unregister(struct device *dev);
-- 
2.5.0

Re: [lkp] [PATCH v2 2/9] hwmon: (core) New hwmon registration API

[Fengguang Wu]

[-- Attachment #1: Type: text/plain, Size: 1890 bytes --]

Hi,

[auto build test ERROR on hwmon/hwmon-next]
[also build test ERROR on v4.7-rc7 next-20160719]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Guenter-Roeck/hwmon-New-hwmon-registration-API/20160717-133643
base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
config: arm-pxa_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 5.4.0-6) 5.4.0 20160609
reproduce:
         wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
         chmod +x ~/bin/make.cross
         # save the attached .config to linux build tree
         make.cross ARCH=arm 

All errors (new ones prefixed by >>):

    drivers/built-in.o: In function `hwmon_thermal_add_sensor':
>> drivers/hwmon/hwmon.c:145: undefined reference to `devm_thermal_zone_of_sensor_register'

git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 3c8e6fa53b772cd0950dbce3a803575ce7ffa8dc
vim +145 drivers/hwmon/hwmon.c

3c8e6fa5 Guenter Roeck 2016-07-16  139  	if (!tdata)
3c8e6fa5 Guenter Roeck 2016-07-16  140  		return -ENOMEM;
3c8e6fa5 Guenter Roeck 2016-07-16  141  
3c8e6fa5 Guenter Roeck 2016-07-16  142  	tdata->hwdev = hwdev;
3c8e6fa5 Guenter Roeck 2016-07-16  143  	tdata->index = index;
3c8e6fa5 Guenter Roeck 2016-07-16  144  
3c8e6fa5 Guenter Roeck 2016-07-16 @145  	devm_thermal_zone_of_sensor_register(&hwdev->dev, index, tdata,
3c8e6fa5 Guenter Roeck 2016-07-16  146  					     &hwmon_thermal_ops);
3c8e6fa5 Guenter Roeck 2016-07-16  147  
3c8e6fa5 Guenter Roeck 2016-07-16  148  	return 0;

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/octet-stream, Size: 30562 bytes --]

Re: [PATCH v2 2/9] hwmon: (core) New hwmon registration API

[Jonathan Cameron]

On 17/07/16 06:30, Guenter Roeck wrote:
> Up to now, each hwmon driver has to implement its own sysfs attributes.
> This requires a lot of template code, and distracts from the driver's core
> function to read and write chip registers.
> 
> To be able to reduce driver complexity, move sensor attribute handling
> and thermal zone registration into hwmon core. By using the new API,
> driver code and data size is typically reduced by 20-70%, depending
> on driver complexity and the number of sysfs attributes supported.
> 
> With this patch, the new API only supports thermal sensors. Support for
> other sensor types will be added with subsequent patches.
> 
Looks good to me which is pretty unusual for a V2 of anything ;)

> Acked-by: Punit Agrawal <punit.agrawal@arm.com>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
> ---
> v2:
> - Document callback function parameters of struct hwmon_ops in
>   include/linux/hwmon.h.
> - Clarify that the is_visible() callback is mandatory.
> - Initialize device attribute read/write callback functions unconditionally.
> - If an attribute has no template string, treat it as invisible, not as
>   error. Affected are virtual attributes such as HWMON_C_REGISTER_TZ.
> - Added newline to improve readability.
> 
> Review comments not addressed:
> - Stick with u32 for attribute masks. We could use u64, but it is currently
>   not needed, and changing it later would be straightforward.
> - Do not use for_each_set_bit() to walk attribute masks.
>   for_each_set_bit() expects a pointer to an unsigned long as argument,
>   which would make it difficult to switch to u64 attribute masks if/when
>   needed.
> 
>  drivers/hwmon/hwmon.c | 478 +++++++++++++++++++++++++++++++++++++++++++++++---
>  include/linux/hwmon.h | 148 ++++++++++++++++
>  2 files changed, 599 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
> index 649a68d119b4..d780011cd063 100644
> --- a/drivers/hwmon/hwmon.c
> +++ b/drivers/hwmon/hwmon.c
> @@ -12,6 +12,7 @@
>  
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>  
> +#include <linux/bitops.h>
>  #include <linux/device.h>
>  #include <linux/err.h>
>  #include <linux/gfp.h>
> @@ -21,6 +22,7 @@
>  #include <linux/pci.h>
>  #include <linux/slab.h>
>  #include <linux/string.h>
> +#include <linux/thermal.h>
>  
>  #define HWMON_ID_PREFIX "hwmon"
>  #define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d"
> @@ -28,9 +30,35 @@
>  struct hwmon_device {
>  	const char *name;
>  	struct device dev;
> +	const struct hwmon_chip_info *chip;
> +
> +	struct attribute_group group;
> +	const struct attribute_group **groups;
>  };
> +
>  #define to_hwmon_device(d) container_of(d, struct hwmon_device, dev)
>  
> +struct hwmon_device_attribute {
> +	struct device_attribute dev_attr;
> +	const struct hwmon_ops *ops;
> +	enum hwmon_sensor_types type;
> +	u32 attr;
> +	int index;
> +};
> +
> +#define to_hwmon_attr(d) \
> +	container_of(d, struct hwmon_device_attribute, dev_attr)
> +
> +/*
> + * Thermal zone information
> + * In addition to the reference to the hwmon device,
> + * also provides the sensor index.
> + */
> +struct hwmon_thermal_data {
> +	struct hwmon_device *hwdev;	/* Reference to hwmon device */
> +	int index;			/* sensor index */
> +};
> +
>  static ssize_t
>  show_name(struct device *dev, struct device_attribute *attr, char *buf)
>  {
> @@ -78,25 +106,279 @@ static struct class hwmon_class = {
>  
>  static DEFINE_IDA(hwmon_ida);
>  
> -/**
> - * hwmon_device_register_with_groups - register w/ hwmon
> - * @dev: the parent device
> - * @name: hwmon name attribute
> - * @drvdata: driver data to attach to created device
> - * @groups: List of attribute groups to create
> - *
> - * hwmon_device_unregister() must be called when the device is no
> - * longer needed.
> - *
> - * Returns the pointer to the new device.
> - */
> -struct device *
> -hwmon_device_register_with_groups(struct device *dev, const char *name,
> -				  void *drvdata,
> -				  const struct attribute_group **groups)
> +/* Thermal zone handling */
> +
> +static int hwmon_thermal_get_temp(void *data, int *temp)
> +{
> +	struct hwmon_thermal_data *tdata = data;
> +	struct hwmon_device *hwdev = tdata->hwdev;
> +	int ret;
> +	long t;
> +
> +	ret = hwdev->chip->ops->read(&hwdev->dev, hwmon_temp, hwmon_temp_input,
> +				     tdata->index, &t);
> +	if (ret < 0)
> +		return ret;
> +
> +	*temp = t;
> +
> +	return 0;
> +}
> +
> +static struct thermal_zone_of_device_ops hwmon_thermal_ops = {
> +	.get_temp = hwmon_thermal_get_temp,
> +};
> +
> +static int hwmon_thermal_add_sensor(struct device *dev,
> +				    struct hwmon_device *hwdev,
> +				    int index)
> +{
> +	struct hwmon_thermal_data *tdata;
> +
> +	tdata = devm_kzalloc(dev, sizeof(*tdata), GFP_KERNEL);
> +	if (!tdata)
> +		return -ENOMEM;
> +
> +	tdata->hwdev = hwdev;
> +	tdata->index = index;
> +
> +	devm_thermal_zone_of_sensor_register(&hwdev->dev, index, tdata,
> +					     &hwmon_thermal_ops);
> +
> +	return 0;
> +}
> +
> +/* sysfs attribute management */
> +
> +static ssize_t hwmon_attr_show(struct device *dev,
> +			       struct device_attribute *devattr, char *buf)
> +{
> +	struct hwmon_device_attribute *hattr = to_hwmon_attr(devattr);
> +	long val;
> +	int ret;
> +
> +	ret = hattr->ops->read(dev, hattr->type, hattr->attr, hattr->index,
> +			       &val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return sprintf(buf, "%ld\n", val);
> +}
> +
> +static ssize_t hwmon_attr_store(struct device *dev,
> +				struct device_attribute *devattr,
> +				const char *buf, size_t count)
> +{
> +	struct hwmon_device_attribute *hattr = to_hwmon_attr(devattr);
> +	long val;
> +	int ret;
> +
> +	ret = kstrtol(buf, 10, &val);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = hattr->ops->write(dev, hattr->type, hattr->attr, hattr->index,
> +				val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return count;
> +}
> +
> +static int hwmon_attr_base(enum hwmon_sensor_types type)
> +{
> +	if (type == hwmon_in)
> +		return 0;
> +	return 1;
> +}
> +
> +static struct attribute *hwmon_genattr(struct device *dev,
> +				       const void *drvdata,
> +				       enum hwmon_sensor_types type,
> +				       u32 attr,
> +				       int index,
> +				       const char *template,
> +				       const struct hwmon_ops *ops)
> +{
> +	struct hwmon_device_attribute *hattr;
> +	struct device_attribute *dattr;
> +	struct attribute *a;
> +	umode_t mode;
> +	char *name;
> +
> +	/* The attribute is invisible if there is no template string */
> +	if (!template)
> +		return ERR_PTR(-ENOENT);
> +
> +	mode = ops->is_visible(drvdata, type, attr, index);
> +	if (!mode)
> +		return ERR_PTR(-ENOENT);
> +
> +	if ((mode & S_IRUGO) && !ops->read)
> +		return ERR_PTR(-EINVAL);
> +	if ((mode & S_IWUGO) && !ops->write)
> +		return ERR_PTR(-EINVAL);
> +
> +	if (type == hwmon_chip) {
> +		name = (char *)template;
> +	} else {
> +		name = devm_kzalloc(dev, strlen(template) + 16, GFP_KERNEL);
> +		if (!name)
> +			return ERR_PTR(-ENOMEM);
> +		scnprintf(name, strlen(template) + 16, template,
> +			  index + hwmon_attr_base(type));
> +	}
> +
> +	hattr = devm_kzalloc(dev, sizeof(*hattr), GFP_KERNEL);
> +	if (!hattr)
> +		return ERR_PTR(-ENOMEM);
> +
> +	hattr->type = type;
> +	hattr->attr = attr;
> +	hattr->index = index;
> +	hattr->ops = ops;
> +
> +	dattr = &hattr->dev_attr;
> +	dattr->show = hwmon_attr_show;
> +	dattr->store = hwmon_attr_store;
> +
> +	a = &dattr->attr;
> +	sysfs_attr_init(a);
> +	a->name = name;
> +	a->mode = mode;
> +
> +	return a;
> +}
> +
> +static const char * const hwmon_chip_attr_templates[] = {
> +	[hwmon_chip_temp_reset_history] = "temp_reset_history",
> +	[hwmon_chip_update_interval] = "update_interval",
> +	[hwmon_chip_alarms] = "alarms",
> +};
> +
> +static const char * const hwmon_temp_attr_templates[] = {
> +	[hwmon_temp_input] = "temp%d_input",
> +	[hwmon_temp_type] = "temp%d_type",
> +	[hwmon_temp_lcrit] = "temp%d_lcrit",
> +	[hwmon_temp_lcrit_hyst] = "temp%d_lcrit_hyst",
> +	[hwmon_temp_min] = "temp%d_min",
> +	[hwmon_temp_min_hyst] = "temp%d_min_hyst",
> +	[hwmon_temp_max] = "temp%d_max",
> +	[hwmon_temp_max_hyst] = "temp%d_max_hyst",
> +	[hwmon_temp_crit] = "temp%d_crit",
> +	[hwmon_temp_crit_hyst] = "temp%d_crit_hyst",
> +	[hwmon_temp_emergency] = "temp%d_emergency",
> +	[hwmon_temp_emergency_hyst] = "temp%d_emergency_hyst",
> +	[hwmon_temp_alarm] = "temp%d_alarm",
> +	[hwmon_temp_lcrit_alarm] = "temp%d_lcrit_alarm",
> +	[hwmon_temp_min_alarm] = "temp%d_min_alarm",
> +	[hwmon_temp_max_alarm] = "temp%d_max_alarm",
> +	[hwmon_temp_crit_alarm] = "temp%d_crit_alarm",
> +	[hwmon_temp_emergency_alarm] = "temp%d_emergency_alarm",
> +	[hwmon_temp_fault] = "temp%d_fault",
> +	[hwmon_temp_offset] = "temp%d_offset",
> +	[hwmon_temp_label] = "temp%d_label",
> +	[hwmon_temp_lowest] = "temp%d_lowest",
> +	[hwmon_temp_highest] = "temp%d_highest",
> +	[hwmon_temp_reset_history] = "temp%d_reset_history",
> +};
> +
> +static const char * const *__templates[] = {
> +	[hwmon_chip] = hwmon_chip_attr_templates,
> +	[hwmon_temp] = hwmon_temp_attr_templates,
> +};
> +
> +static const int __templates_size[] = {
> +	[hwmon_chip] = ARRAY_SIZE(hwmon_chip_attr_templates),
> +	[hwmon_temp] = ARRAY_SIZE(hwmon_temp_attr_templates),
> +};
> +
> +static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
> +{
> +	int i, n;
> +
> +	for (i = n = 0; info->config[i]; i++)
> +		n += hweight32(info->config[i]);
> +
> +	return n;
> +}
> +
> +static int hwmon_genattrs(struct device *dev,
> +			  const void *drvdata,
> +			  struct attribute **attrs,
> +			  const struct hwmon_ops *ops,
> +			  const struct hwmon_channel_info *info)
> +{
> +	const char * const *templates;
> +	int template_size;
> +	int i, aindex = 0;
> +
> +	if (info->type >= ARRAY_SIZE(__templates))
> +		return -EINVAL;
> +
> +	templates = __templates[info->type];
> +	template_size = __templates_size[info->type];
> +
> +	for (i = 0; info->config[i]; i++) {
> +		u32 attr_mask = info->config[i];
> +		u32 attr;
> +
> +		while (attr_mask) {
> +			struct attribute *a;
> +
> +			attr = __ffs(attr_mask);
> +			attr_mask &= ~BIT(attr);
> +			if (attr >= template_size)
> +				return -EINVAL;
> +			a = hwmon_genattr(dev, drvdata, info->type, attr, i,
> +					  templates[attr], ops);
> +			if (IS_ERR(a)) {
> +				if (PTR_ERR(a) != -ENOENT)
> +					return PTR_ERR(a);
> +				continue;
> +			}
> +			attrs[aindex++] = a;
> +		}
> +	}
> +	return aindex;
> +}
> +
> +static struct attribute **
> +__hwmon_create_attrs(struct device *dev, const void *drvdata,
> +		     const struct hwmon_chip_info *chip)
> +{
> +	int ret, i, aindex = 0, nattrs = 0;
> +	struct attribute **attrs;
> +
> +	for (i = 0; chip->info[i]; i++)
> +		nattrs += hwmon_num_channel_attrs(chip->info[i]);
> +
> +	if (nattrs == 0)
> +		return ERR_PTR(-EINVAL);
> +
> +	attrs = devm_kcalloc(dev, nattrs + 1, sizeof(*attrs), GFP_KERNEL);
> +	if (!attrs)
> +		return ERR_PTR(-ENOMEM);
> +
> +	for (i = 0; chip->info[i]; i++) {
> +		ret = hwmon_genattrs(dev, drvdata, &attrs[aindex], chip->ops,
> +				     chip->info[i]);
> +		if (ret < 0)
> +			return ERR_PTR(ret);
> +		aindex += ret;
> +	}
> +
> +	return attrs;
> +}
> +
> +static struct device *
> +__hwmon_device_register(struct device *dev, const char *name, void *drvdata,
> +			const struct hwmon_chip_info *chip,
> +			const struct attribute_group **groups)
>  {
>  	struct hwmon_device *hwdev;
> -	int err, id;
> +	struct device *hdev;
> +	int i, j, err, id;
>  
>  	/* Do not accept invalid characters in hwmon name attribute */
>  	if (name && (!strlen(name) || strpbrk(name, "-* \t\n")))
> @@ -112,28 +394,128 @@ hwmon_device_register_with_groups(struct device *dev, const char *name,
>  		goto ida_remove;
>  	}
>  
> +	hdev = &hwdev->dev;
> +
> +	if (chip && chip->ops->is_visible) {
> +		struct attribute **attrs;
> +		int ngroups = 2;
> +
> +		if (groups)
> +			for (i = 0; groups[i]; i++)
> +				ngroups++;
> +
> +		hwdev->groups = devm_kcalloc(dev, ngroups, sizeof(*groups),
> +					     GFP_KERNEL);
> +		if (!hwdev->groups)
> +			return ERR_PTR(-ENOMEM);
> +
> +		attrs = __hwmon_create_attrs(dev, drvdata, chip);
> +		if (IS_ERR(attrs)) {
> +			err = PTR_ERR(attrs);
> +			goto free_hwmon;
> +		}
> +
> +		hwdev->group.attrs = attrs;
> +		ngroups = 0;
> +		hwdev->groups[ngroups++] = &hwdev->group;
> +
> +		if (groups) {
> +			for (i = 0; groups[i]; i++)
> +				hwdev->groups[ngroups++] = groups[i];
> +		}
> +
> +		hdev->groups = hwdev->groups;
> +	} else {
> +		hdev->groups = groups;
> +	}
> +
>  	hwdev->name = name;
> -	hwdev->dev.class = &hwmon_class;
> -	hwdev->dev.parent = dev;
> -	hwdev->dev.groups = groups;
> -	hwdev->dev.of_node = dev ? dev->of_node : NULL;
> -	dev_set_drvdata(&hwdev->dev, drvdata);
> -	dev_set_name(&hwdev->dev, HWMON_ID_FORMAT, id);
> -	err = device_register(&hwdev->dev);
> +	hdev->class = &hwmon_class;
> +	hdev->parent = dev;
> +	hdev->of_node = dev ? dev->of_node : NULL;
> +	hwdev->chip = chip;
> +	dev_set_drvdata(hdev, drvdata);
> +	dev_set_name(hdev, HWMON_ID_FORMAT, id);
> +	err = device_register(hdev);
>  	if (err)
> -		goto free;
> +		goto free_hwmon;
> +
> +	if (chip && chip->ops->is_visible && chip->ops->read &&
> +	    chip->info[0]->type == hwmon_chip &&
> +	    (chip->info[0]->config[0] & HWMON_C_REGISTER_TZ)) {
> +		const struct hwmon_channel_info **info = chip->info;
> +
> +		for (i = 1; info[i]; i++) {
> +			if (info[i]->type != hwmon_temp)
> +				continue;
> +
> +			for (j = 0; info[i]->config[j]; j++) {
> +				if (!chip->ops->is_visible(drvdata, hwmon_temp,
> +							   hwmon_temp_input, j))
> +					continue;
> +				if (info[i]->config[j] & HWMON_T_INPUT)
> +					hwmon_thermal_add_sensor(dev, hwdev, j);
> +			}
> +		}
> +	}
>  
> -	return &hwdev->dev;
> +	return hdev;
>  
> -free:
> +free_hwmon:
>  	kfree(hwdev);
>  ida_remove:
>  	ida_simple_remove(&hwmon_ida, id);
>  	return ERR_PTR(err);
>  }
> +
> +/**
> + * hwmon_device_register_with_groups - register w/ hwmon
> + * @dev: the parent device
> + * @name: hwmon name attribute
> + * @drvdata: driver data to attach to created device
> + * @groups: List of attribute groups to create
> + *
> + * hwmon_device_unregister() must be called when the device is no
> + * longer needed.
> + *
> + * Returns the pointer to the new device.
> + */
> +struct device *
> +hwmon_device_register_with_groups(struct device *dev, const char *name,
> +				  void *drvdata,
> +				  const struct attribute_group **groups)
> +{
> +	return __hwmon_device_register(dev, name, drvdata, NULL, groups);
> +}
>  EXPORT_SYMBOL_GPL(hwmon_device_register_with_groups);
>  
>  /**
> + * hwmon_device_register_with_info - register w/ hwmon
> + * @dev: the parent device
> + * @name: hwmon name attribute
> + * @drvdata: driver data to attach to created device
> + * @info: Pointer to hwmon chip information
> + * @groups - pointer to list of driver specific attribute groups
> + *
> + * hwmon_device_unregister() must be called when the device is no
> + * longer needed.
> + *
> + * Returns the pointer to the new device.
> + */
> +struct device *
> +hwmon_device_register_with_info(struct device *dev, const char *name,
> +				void *drvdata,
> +				const struct hwmon_chip_info *chip,
> +				const struct attribute_group **groups)
> +{
> +	if (chip && (!chip->ops || !chip->info))
> +		return ERR_PTR(-EINVAL);
> +
> +	return __hwmon_device_register(dev, name, drvdata, chip, groups);
> +}
> +EXPORT_SYMBOL_GPL(hwmon_device_register_with_info);
> +
> +/**
>   * hwmon_device_register - register w/ hwmon
>   * @dev: the device to register
>   *
> @@ -211,6 +593,48 @@ error:
>  }
>  EXPORT_SYMBOL_GPL(devm_hwmon_device_register_with_groups);
>  
> +/**
> + * devm_hwmon_device_register_with_info - register w/ hwmon
> + * @dev: the parent device
> + * @name: hwmon name attribute
> + * @drvdata: driver data to attach to created device
> + * @info: Pointer to hwmon chip information
> + * @groups - pointer to list of driver specific attribute groups
> + *
> + * Returns the pointer to the new device. The new device is automatically
> + * unregistered with the parent device.
> + */
> +struct device *
> +devm_hwmon_device_register_with_info(struct device *dev, const char *name,
> +				     void *drvdata,
> +				     const struct hwmon_chip_info *chip,
> +				     const struct attribute_group **groups)
> +{
> +	struct device **ptr, *hwdev;
> +
> +	if (!dev)
> +		return ERR_PTR(-EINVAL);
> +
> +	ptr = devres_alloc(devm_hwmon_release, sizeof(*ptr), GFP_KERNEL);
> +	if (!ptr)
> +		return ERR_PTR(-ENOMEM);
> +
> +	hwdev = hwmon_device_register_with_info(dev, name, drvdata, chip,
> +						groups);
> +	if (IS_ERR(hwdev))
> +		goto error;
> +
> +	*ptr = hwdev;
> +	devres_add(dev, ptr);
> +
> +	return hwdev;
> +
> +error:
> +	devres_free(ptr);
> +	return hwdev;
> +}
> +EXPORT_SYMBOL_GPL(devm_hwmon_device_register_with_info);
> +
>  static int devm_hwmon_match(struct device *dev, void *res, void *data)
>  {
>  	struct device **hwdev = res;
> diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
> index 09354f6c1d63..52e56d71d742 100644
> --- a/include/linux/hwmon.h
> +++ b/include/linux/hwmon.h
> @@ -14,9 +14,147 @@
>  #ifndef _HWMON_H_
>  #define _HWMON_H_
>  
> +#include <linux/bitops.h>
> +
>  struct device;
>  struct attribute_group;
>  
> +enum hwmon_sensor_types {
> +	hwmon_chip,
> +	hwmon_temp,
> +	hwmon_in,
> +	hwmon_curr,
> +	hwmon_power,
> +	hwmon_energy,
> +};
> +
> +enum hwmon_chip_attributes {
> +	hwmon_chip_temp_reset_history,
> +	hwmon_chip_register_tz,
> +	hwmon_chip_update_interval,
> +	hwmon_chip_alarms,
> +};
> +
> +#define HWMON_C_TEMP_RESET_HISTORY	BIT(hwmon_chip_temp_reset_history)
> +#define HWMON_C_IN_RESET_HISTORY	BIT(hwmon_chip_in_reset_history)
> +#define HWMON_C_REGISTER_TZ		BIT(hwmon_chip_register_tz)
> +#define HWMON_C_UPDATE_INTERVAL		BIT(hwmon_chip_update_interval)
> +#define HWMON_C_ALARMS			BIT(hwmon_chip_alarms)
> +
> +enum hwmon_temp_attributes {
> +	hwmon_temp_input = 0,
> +	hwmon_temp_type,
> +	hwmon_temp_lcrit,
> +	hwmon_temp_lcrit_hyst,
> +	hwmon_temp_min,
> +	hwmon_temp_min_hyst,
> +	hwmon_temp_max,
> +	hwmon_temp_max_hyst,
> +	hwmon_temp_crit,
> +	hwmon_temp_crit_hyst,
> +	hwmon_temp_emergency,
> +	hwmon_temp_emergency_hyst,
> +	hwmon_temp_alarm,
> +	hwmon_temp_lcrit_alarm,
> +	hwmon_temp_min_alarm,
> +	hwmon_temp_max_alarm,
> +	hwmon_temp_crit_alarm,
> +	hwmon_temp_emergency_alarm,
> +	hwmon_temp_fault,
> +	hwmon_temp_offset,
> +	hwmon_temp_label,
> +	hwmon_temp_lowest,
> +	hwmon_temp_highest,
> +	hwmon_temp_reset_history,
> +};
> +
> +#define HWMON_T_INPUT		BIT(hwmon_temp_input)
> +#define HWMON_T_TYPE		BIT(hwmon_temp_type)
> +#define HWMON_T_LCRIT		BIT(hwmon_temp_lcrit)
> +#define HWMON_T_LCRIT_HYST	BIT(hwmon_temp_lcrit_hyst)
> +#define HWMON_T_MIN		BIT(hwmon_temp_min)
> +#define HWMON_T_MIN_HYST	BIT(hwmon_temp_min_hyst)
> +#define HWMON_T_MAX		BIT(hwmon_temp_max)
> +#define HWMON_T_MAX_HYST	BIT(hwmon_temp_max_hyst)
> +#define HWMON_T_CRIT		BIT(hwmon_temp_crit)
> +#define HWMON_T_CRIT_HYST	BIT(hwmon_temp_crit_hyst)
> +#define HWMON_T_EMERGENCY	BIT(hwmon_temp_emergency)
> +#define HWMON_T_EMERGENCY_HYST	BIT(hwmon_temp_emergency_hyst)
> +#define HWMON_T_MIN_ALARM	BIT(hwmon_temp_min_alarm)
> +#define HWMON_T_MAX_ALARM	BIT(hwmon_temp_max_alarm)
> +#define HWMON_T_CRIT_ALARM	BIT(hwmon_temp_crit_alarm)
> +#define HWMON_T_EMERGENCY_ALARM	BIT(hwmon_temp_emergency_alarm)
> +#define HWMON_T_FAULT		BIT(hwmon_temp_fault)
> +#define HWMON_T_OFFSET		BIT(hwmon_temp_offset)
> +#define HWMON_T_LABEL		BIT(hwmon_temp_label)
> +#define HWMON_T_LOWEST		BIT(hwmon_temp_lowest)
> +#define HWMON_T_HIGHEST		BIT(hwmon_temp_highest)
> +#define HWMON_T_RESET_HISTORY	BIT(hwmon_temp_reset_history)
> +
> +/**
> + * struct hwmon_ops - hwmon device operations
> + * @is_visible: Callback to return attribute visibility. Mandatory.
> + *		Parameters are:
> + *		@const void *drvdata:
> + *			Pointer to driver-private data structure passed
> + *			as argument to hwmon_device_register_with_info().
> + *		@type:	Sensor type
> + *		@attr:	Sensor attribute
> + *		@channel:
> + *			Channel number
> + *		The function returns the file permissions.
> + *		If the return value is 0, no attribute will be created.
> + * @read:       Read callback. Optional. If not provided, attributes
> + *		will not be readable.
> + *		Parameters are:
> + *		@dev:	Pointer to hardware monitoring device
> + *		@type:	Sensor type
> + *		@attr:	Sensor attribute
> + *		@channel:
> + *			Channel number
> + *		@val:	Pointer to returned value
> + *		The function returns 0 on success or a negative error number.
> + * @write:	Write callback. Optional. If not provided, attributes
> + *		will not be writable.
> + *		Parameters are:
> + *		@dev:	Pointer to hardware monitoring device
> + *		@type:	Sensor type
> + *		@attr:	Sensor attribute
> + *		@channel:
> + *			Channel number
> + *		@val:	Value to write
> + *		The function returns 0 on success or a negative error number.
> + */
> +struct hwmon_ops {
> +	umode_t (*is_visible)(const void *drvdata, enum hwmon_sensor_types type,
> +			      u32 attr, int channel);
> +	int (*read)(struct device *dev, enum hwmon_sensor_types type,
> +		    u32 attr, int channel, long *val);
> +	int (*write)(struct device *dev, enum hwmon_sensor_types type,
> +		     u32 attr, int channel, long val);
> +};
> +
> +/**
> + * Channel information
> + * @type:	Channel type.
> + * @config:	Pointer to NULL-terminated list of channel parameters.
> + *		Use for per-channel attributes.
> + */
> +struct hwmon_channel_info {
> +	enum hwmon_sensor_types type;
> +	const u32 *config;
> +};
> +
> +/**
> + * Chip configuration
> + * @ops:	Pointer to hwmon operations.
> + * @info:	Null-terminated list of channel information.
> + */
> +struct hwmon_chip_info {
> +	const struct hwmon_ops *ops;
> +	const struct hwmon_channel_info **info;
> +};
> +
>  struct device *hwmon_device_register(struct device *dev);
>  struct device *
>  hwmon_device_register_with_groups(struct device *dev, const char *name,
> @@ -26,6 +164,16 @@ struct device *
>  devm_hwmon_device_register_with_groups(struct device *dev, const char *name,
>  				       void *drvdata,
>  				       const struct attribute_group **groups);
> +struct device *
> +hwmon_device_register_with_info(struct device *dev,
> +				const char *name, void *drvdata,
> +				const struct hwmon_chip_info *info,
> +				const struct attribute_group **groups);
> +struct device *
> +devm_hwmon_device_register_with_info(struct device *dev,
> +				     const char *name, void *drvdata,
> +				     const struct hwmon_chip_info *info,
> +				     const struct attribute_group **groups);
>  
>  void hwmon_device_unregister(struct device *dev);
>  void devm_hwmon_device_unregister(struct device *dev);
> 

Re: [PATCH v2 2/9] hwmon: (core) New hwmon registration API

[Guenter Roeck]

On 07/24/2016 12:08 PM, Jonathan Cameron wrote:
> On 17/07/16 06:30, Guenter Roeck wrote:
>> Up to now, each hwmon driver has to implement its own sysfs attributes.
>> This requires a lot of template code, and distracts from the driver's core
>> function to read and write chip registers.
>>
>> To be able to reduce driver complexity, move sensor attribute handling
>> and thermal zone registration into hwmon core. By using the new API,
>> driver code and data size is typically reduced by 20-70%, depending
>> on driver complexity and the number of sysfs attributes supported.
>>
>> With this patch, the new API only supports thermal sensors. Support for
>> other sensor types will be added with subsequent patches.
>>
> Looks good to me which is pretty unusual for a V2 of anything ;)
>

Thanks ... unfortunately, it wasn't perfect, so I'll have to send another version.
The thermal code needs to be surrounded with "#if IS_REACHABLE(CONFIG_THERMAL)
&& defined(CONFIG_THERMAL_OF)".

Guenter

[PATCH v2 3/9] hwmon: (core) Add voltage attribute support to new API

[Guenter Roeck]

Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: No change

 drivers/hwmon/hwmon.c | 21 +++++++++++++++++++++
 include/linux/hwmon.h | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index d780011cd063..5d88bf7f825a 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -252,6 +252,7 @@ static struct attribute *hwmon_genattr(struct device *dev,
 
 static const char * const hwmon_chip_attr_templates[] = {
 	[hwmon_chip_temp_reset_history] = "temp_reset_history",
+	[hwmon_chip_in_reset_history] = "in_reset_history",
 	[hwmon_chip_update_interval] = "update_interval",
 	[hwmon_chip_alarms] = "alarms",
 };
@@ -283,14 +284,34 @@ static const char * const hwmon_temp_attr_templates[] = {
 	[hwmon_temp_reset_history] = "temp%d_reset_history",
 };
 
+static const char * const hwmon_in_attr_templates[] = {
+	[hwmon_in_input] = "in%d_input",
+	[hwmon_in_min] = "in%d_min",
+	[hwmon_in_max] = "in%d_max",
+	[hwmon_in_lcrit] = "in%d_lcrit",
+	[hwmon_in_crit] = "in%d_crit",
+	[hwmon_in_average] = "in%d_average",
+	[hwmon_in_lowest] = "in%d_lowest",
+	[hwmon_in_highest] = "in%d_highest",
+	[hwmon_in_reset_history] = "in%d_reset_history",
+	[hwmon_in_label] = "in%d_label",
+	[hwmon_in_alarm] = "in%d_alarm",
+	[hwmon_in_min_alarm] = "in%d_min_alarm",
+	[hwmon_in_max_alarm] = "in%d_max_alarm",
+	[hwmon_in_lcrit_alarm] = "in%d_lcrit_alarm",
+	[hwmon_in_crit_alarm] = "in%d_crit_alarm",
+};
+
 static const char * const *__templates[] = {
 	[hwmon_chip] = hwmon_chip_attr_templates,
 	[hwmon_temp] = hwmon_temp_attr_templates,
+	[hwmon_in] = hwmon_in_attr_templates,
 };
 
 static const int __templates_size[] = {
 	[hwmon_chip] = ARRAY_SIZE(hwmon_chip_attr_templates),
 	[hwmon_temp] = ARRAY_SIZE(hwmon_temp_attr_templates),
+	[hwmon_in] = ARRAY_SIZE(hwmon_in_attr_templates),
 };
 
 static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
index 52e56d71d742..a01b8e3fc6f3 100644
--- a/include/linux/hwmon.h
+++ b/include/linux/hwmon.h
@@ -30,6 +30,7 @@ enum hwmon_sensor_types {
 
 enum hwmon_chip_attributes {
 	hwmon_chip_temp_reset_history,
+	hwmon_chip_in_reset_history,
 	hwmon_chip_register_tz,
 	hwmon_chip_update_interval,
 	hwmon_chip_alarms,
@@ -91,6 +92,40 @@ enum hwmon_temp_attributes {
 #define HWMON_T_HIGHEST		BIT(hwmon_temp_highest)
 #define HWMON_T_RESET_HISTORY	BIT(hwmon_temp_reset_history)
 
+enum hwmon_in_attributes {
+	hwmon_in_input,
+	hwmon_in_min,
+	hwmon_in_max,
+	hwmon_in_lcrit,
+	hwmon_in_crit,
+	hwmon_in_average,
+	hwmon_in_lowest,
+	hwmon_in_highest,
+	hwmon_in_reset_history,
+	hwmon_in_label,
+	hwmon_in_alarm,
+	hwmon_in_min_alarm,
+	hwmon_in_max_alarm,
+	hwmon_in_lcrit_alarm,
+	hwmon_in_crit_alarm,
+};
+
+#define HWMON_I_INPUT		BIT(hwmon_in_input)
+#define HWMON_I_MIN		BIT(hwmon_in_min)
+#define HWMON_I_MAX		BIT(hwmon_in_max)
+#define HWMON_I_LCRIT		BIT(hwmon_in_lcrit)
+#define HWMON_I_CRIT		BIT(hwmon_in_crit)
+#define HWMON_I_AVERAGE		BIT(hwmon_in_average)
+#define HWMON_I_LOWEST		BIT(hwmon_in_lowest)
+#define HWMON_I_HIGHEST		BIT(hwmon_in_highest)
+#define HWMON_I_RESET_HISTORY	BIT(hwmon_in_reset_history)
+#define HWMON_I_LABEL		BIT(hwmon_in_label)
+#define HWMON_I_ALARM		BIT(hwmon_in_alarm)
+#define HWMON_I_MIN_ALARM	BIT(hwmon_in_min_alarm)
+#define HWMON_I_MAX_ALARM	BIT(hwmon_in_max_alarm)
+#define HWMON_I_LCRIT_ALARM	BIT(hwmon_in_lcrit_alarm)
+#define HWMON_I_CRIT_ALARM	BIT(hwmon_in_crit_alarm)
+
 /**
  * struct hwmon_ops - hwmon device operations
  * @is_visible: Callback to return attribute visibility. Mandatory.
-- 
2.5.0

[PATCH v2 4/9] hwmon: (core) Add current attribute support to new API

[Guenter Roeck]

Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: No change

 drivers/hwmon/hwmon.c | 21 +++++++++++++++++++++
 include/linux/hwmon.h | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 5d88bf7f825a..bc5c1c95cc48 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -253,6 +253,7 @@ static struct attribute *hwmon_genattr(struct device *dev,
 static const char * const hwmon_chip_attr_templates[] = {
 	[hwmon_chip_temp_reset_history] = "temp_reset_history",
 	[hwmon_chip_in_reset_history] = "in_reset_history",
+	[hwmon_chip_curr_reset_history] = "curr_reset_history",
 	[hwmon_chip_update_interval] = "update_interval",
 	[hwmon_chip_alarms] = "alarms",
 };
@@ -302,16 +303,36 @@ static const char * const hwmon_in_attr_templates[] = {
 	[hwmon_in_crit_alarm] = "in%d_crit_alarm",
 };
 
+static const char * const hwmon_curr_attr_templates[] = {
+	[hwmon_curr_input] = "curr%d_input",
+	[hwmon_curr_min] = "curr%d_min",
+	[hwmon_curr_max] = "curr%d_max",
+	[hwmon_curr_lcrit] = "curr%d_lcrit",
+	[hwmon_curr_crit] = "curr%d_crit",
+	[hwmon_curr_average] = "curr%d_average",
+	[hwmon_curr_lowest] = "curr%d_lowest",
+	[hwmon_curr_highest] = "curr%d_highest",
+	[hwmon_curr_reset_history] = "curr%d_reset_history",
+	[hwmon_curr_label] = "curr%d_label",
+	[hwmon_curr_alarm] = "curr%d_alarm",
+	[hwmon_curr_min_alarm] = "curr%d_min_alarm",
+	[hwmon_curr_max_alarm] = "curr%d_max_alarm",
+	[hwmon_curr_lcrit_alarm] = "curr%d_lcrit_alarm",
+	[hwmon_curr_crit_alarm] = "curr%d_crit_alarm",
+};
+
 static const char * const *__templates[] = {
 	[hwmon_chip] = hwmon_chip_attr_templates,
 	[hwmon_temp] = hwmon_temp_attr_templates,
 	[hwmon_in] = hwmon_in_attr_templates,
+	[hwmon_curr] = hwmon_curr_attr_templates,
 };
 
 static const int __templates_size[] = {
 	[hwmon_chip] = ARRAY_SIZE(hwmon_chip_attr_templates),
 	[hwmon_temp] = ARRAY_SIZE(hwmon_temp_attr_templates),
 	[hwmon_in] = ARRAY_SIZE(hwmon_in_attr_templates),
+	[hwmon_curr] = ARRAY_SIZE(hwmon_curr_attr_templates),
 };
 
 static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
index a01b8e3fc6f3..8781c2253b1d 100644
--- a/include/linux/hwmon.h
+++ b/include/linux/hwmon.h
@@ -31,6 +31,7 @@ enum hwmon_sensor_types {
 enum hwmon_chip_attributes {
 	hwmon_chip_temp_reset_history,
 	hwmon_chip_in_reset_history,
+	hwmon_chip_curr_reset_history,
 	hwmon_chip_register_tz,
 	hwmon_chip_update_interval,
 	hwmon_chip_alarms,
@@ -38,6 +39,7 @@ enum hwmon_chip_attributes {
 
 #define HWMON_C_TEMP_RESET_HISTORY	BIT(hwmon_chip_temp_reset_history)
 #define HWMON_C_IN_RESET_HISTORY	BIT(hwmon_chip_in_reset_history)
+#define HWMON_C_CURR_RESET_HISTORY	BIT(hwmon_chip_curr_reset_history)
 #define HWMON_C_REGISTER_TZ		BIT(hwmon_chip_register_tz)
 #define HWMON_C_UPDATE_INTERVAL		BIT(hwmon_chip_update_interval)
 #define HWMON_C_ALARMS			BIT(hwmon_chip_alarms)
@@ -126,6 +128,40 @@ enum hwmon_in_attributes {
 #define HWMON_I_LCRIT_ALARM	BIT(hwmon_in_lcrit_alarm)
 #define HWMON_I_CRIT_ALARM	BIT(hwmon_in_crit_alarm)
 
+enum hwmon_curr_attributes {
+	hwmon_curr_input,
+	hwmon_curr_min,
+	hwmon_curr_max,
+	hwmon_curr_lcrit,
+	hwmon_curr_crit,
+	hwmon_curr_average,
+	hwmon_curr_lowest,
+	hwmon_curr_highest,
+	hwmon_curr_reset_history,
+	hwmon_curr_label,
+	hwmon_curr_alarm,
+	hwmon_curr_min_alarm,
+	hwmon_curr_max_alarm,
+	hwmon_curr_lcrit_alarm,
+	hwmon_curr_crit_alarm,
+};
+
+#define HWMON_C_INPUT		BIT(hwmon_curr_input)
+#define HWMON_C_MIN		BIT(hwmon_curr_min)
+#define HWMON_C_MAX		BIT(hwmon_curr_max)
+#define HWMON_C_LCRIT		BIT(hwmon_curr_lcrit)
+#define HWMON_C_CRIT		BIT(hwmon_curr_crit)
+#define HWMON_C_AVERAGE		BIT(hwmon_curr_average)
+#define HWMON_C_LOWEST		BIT(hwmon_curr_lowest)
+#define HWMON_C_HIGHEST		BIT(hwmon_curr_highest)
+#define HWMON_C_RESET_HISTORY	BIT(hwmon_curr_reset_history)
+#define HWMON_C_LABEL		BIT(hwmon_curr_label)
+#define HWMON_C_ALARM		BIT(hwmon_curr_alarm)
+#define HWMON_C_MIN_ALARM	BIT(hwmon_curr_min_alarm)
+#define HWMON_C_MAX_ALARM	BIT(hwmon_curr_max_alarm)
+#define HWMON_C_LCRIT_ALARM	BIT(hwmon_curr_lcrit_alarm)
+#define HWMON_C_CRIT_ALARM	BIT(hwmon_curr_crit_alarm)
+
 /**
  * struct hwmon_ops - hwmon device operations
  * @is_visible: Callback to return attribute visibility. Mandatory.
-- 
2.5.0

[PATCH v2 5/9] hwmon: (core) Add power attribute support to new API

[Guenter Roeck]

Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: No change

 drivers/hwmon/hwmon.c | 30 ++++++++++++++++++++++++++++
 include/linux/hwmon.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index bc5c1c95cc48..7a5c8bba7dc2 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -254,6 +254,7 @@ static const char * const hwmon_chip_attr_templates[] = {
 	[hwmon_chip_temp_reset_history] = "temp_reset_history",
 	[hwmon_chip_in_reset_history] = "in_reset_history",
 	[hwmon_chip_curr_reset_history] = "curr_reset_history",
+	[hwmon_chip_power_reset_history] = "power_reset_history",
 	[hwmon_chip_update_interval] = "update_interval",
 	[hwmon_chip_alarms] = "alarms",
 };
@@ -321,11 +322,39 @@ static const char * const hwmon_curr_attr_templates[] = {
 	[hwmon_curr_crit_alarm] = "curr%d_crit_alarm",
 };
 
+static const char * const hwmon_power_attr_templates[] = {
+	[hwmon_power_average] = "power%d_average",
+	[hwmon_power_average_interval] = "power%d_average_interval",
+	[hwmon_power_average_interval_max] = "power%d_interval_max",
+	[hwmon_power_average_interval_min] = "power%d_interval_min",
+	[hwmon_power_average_highest] = "power%d_average_highest",
+	[hwmon_power_average_lowest] = "power%d_average_lowest",
+	[hwmon_power_average_max] = "power%d_average_max",
+	[hwmon_power_average_min] = "power%d_average_min",
+	[hwmon_power_input] = "power%d_input",
+	[hwmon_power_input_highest] = "power%d_input_highest",
+	[hwmon_power_input_lowest] = "power%d_input_lowest",
+	[hwmon_power_reset_history] = "power%d_reset_history",
+	[hwmon_power_accuracy] = "power%d_accuracy",
+	[hwmon_power_cap] = "power%d_cap",
+	[hwmon_power_cap_hyst] = "power%d_cap_hyst",
+	[hwmon_power_cap_max] = "power%d_cap_max",
+	[hwmon_power_cap_min] = "power%d_cap_min",
+	[hwmon_power_max] = "power%d_max",
+	[hwmon_power_crit] = "power%d_crit",
+	[hwmon_power_label] = "power%d_label",
+	[hwmon_power_alarm] = "power%d_alarm",
+	[hwmon_power_cap_alarm] = "power%d_cap_alarm",
+	[hwmon_power_max_alarm] = "power%d_max_alarm",
+	[hwmon_power_crit_alarm] = "power%d_crit_alarm",
+};
+
 static const char * const *__templates[] = {
 	[hwmon_chip] = hwmon_chip_attr_templates,
 	[hwmon_temp] = hwmon_temp_attr_templates,
 	[hwmon_in] = hwmon_in_attr_templates,
 	[hwmon_curr] = hwmon_curr_attr_templates,
+	[hwmon_power] = hwmon_power_attr_templates,
 };
 
 static const int __templates_size[] = {
@@ -333,6 +362,7 @@ static const int __templates_size[] = {
 	[hwmon_temp] = ARRAY_SIZE(hwmon_temp_attr_templates),
 	[hwmon_in] = ARRAY_SIZE(hwmon_in_attr_templates),
 	[hwmon_curr] = ARRAY_SIZE(hwmon_curr_attr_templates),
+	[hwmon_power] = ARRAY_SIZE(hwmon_power_attr_templates),
 };
 
 static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
index 8781c2253b1d..d7e432ef7c2a 100644
--- a/include/linux/hwmon.h
+++ b/include/linux/hwmon.h
@@ -32,6 +32,7 @@ enum hwmon_chip_attributes {
 	hwmon_chip_temp_reset_history,
 	hwmon_chip_in_reset_history,
 	hwmon_chip_curr_reset_history,
+	hwmon_chip_power_reset_history,
 	hwmon_chip_register_tz,
 	hwmon_chip_update_interval,
 	hwmon_chip_alarms,
@@ -40,6 +41,7 @@ enum hwmon_chip_attributes {
 #define HWMON_C_TEMP_RESET_HISTORY	BIT(hwmon_chip_temp_reset_history)
 #define HWMON_C_IN_RESET_HISTORY	BIT(hwmon_chip_in_reset_history)
 #define HWMON_C_CURR_RESET_HISTORY	BIT(hwmon_chip_curr_reset_history)
+#define HWMON_C_POWER_RESET_HISTORY	BIT(hwmon_chip_power_reset_history)
 #define HWMON_C_REGISTER_TZ		BIT(hwmon_chip_register_tz)
 #define HWMON_C_UPDATE_INTERVAL		BIT(hwmon_chip_update_interval)
 #define HWMON_C_ALARMS			BIT(hwmon_chip_alarms)
@@ -162,6 +164,58 @@ enum hwmon_curr_attributes {
 #define HWMON_C_LCRIT_ALARM	BIT(hwmon_curr_lcrit_alarm)
 #define HWMON_C_CRIT_ALARM	BIT(hwmon_curr_crit_alarm)
 
+enum hwmon_power_attributes {
+	hwmon_power_average,
+	hwmon_power_average_interval,
+	hwmon_power_average_interval_max,
+	hwmon_power_average_interval_min,
+	hwmon_power_average_highest,
+	hwmon_power_average_lowest,
+	hwmon_power_average_max,
+	hwmon_power_average_min,
+	hwmon_power_input,
+	hwmon_power_input_highest,
+	hwmon_power_input_lowest,
+	hwmon_power_reset_history,
+	hwmon_power_accuracy,
+	hwmon_power_cap,
+	hwmon_power_cap_hyst,
+	hwmon_power_cap_max,
+	hwmon_power_cap_min,
+	hwmon_power_max,
+	hwmon_power_crit,
+	hwmon_power_label,
+	hwmon_power_alarm,
+	hwmon_power_cap_alarm,
+	hwmon_power_max_alarm,
+	hwmon_power_crit_alarm,
+};
+
+#define HWMON_P_AVERAGE			BIT(hwmon_power_average)
+#define HWMON_P_AVERAGE_INTERVAL	BIT(hwmon_power_average_interval)
+#define HWMON_P_AVERAGE_INTERVAL_MAX	BIT(hwmon_power_average_interval_max)
+#define HWMON_P_AVERAGE_INTERVAL_MIN	BIT(hwmon_power_average_interval_min)
+#define HWMON_P_AVERAGE_HIGHEST		BIT(hwmon_power_average_highest)
+#define HWMON_P_AVERAGE_LOWEST		BIT(hwmon_power_average_lowest)
+#define HWMON_P_AVERAGE_MAX		BIT(hwmon_power_average_max)
+#define HWMON_P_AVERAGE_MIN		BIT(hwmon_power_average_min)
+#define HWMON_P_INPUT			BIT(hwmon_power_input)
+#define HWMON_P_INPUT_HIGHEST		BIT(hwmon_power_input_highest)
+#define HWMON_P_INPUT_LOWEST		BIT(hwmon_power_input_lowest)
+#define HWMON_P_RESET_HISTORY		BIT(hwmon_power_reset_history)
+#define HWMON_P_ACCURACY		BIT(hwmon_power_accuracy)
+#define HWMON_P_CAP			BIT(hwmon_power_cap)
+#define HWMON_P_CAP_HYST		BIT(hwmon_power_cap_hyst)
+#define HWMON_P_CAP_MAX			BIT(hwmon_power_cap_max)
+#define HWMON_P_CAP_MIN			BIT(hwmon_power_cap_min)
+#define HWMON_P_MAX			BIT(hwmon_power_max)
+#define HWMON_P_CRIT			BIT(hwmon_power_crit)
+#define HWMON_P_LABEL			BIT(hwmon_power_label)
+#define HWMON_P_ALARM			BIT(hwmon_power_alarm)
+#define HWMON_P_CAP_ALARM		BIT(hwmon_power_cap_alarm)
+#define HWMON_P_MAX_ALARM		BIT(hwmon_power_max_alarm)
+#define HWMON_P_CRIT_ALARM		BIT(hwmon_power_crit_alarm)
+
 /**
  * struct hwmon_ops - hwmon device operations
  * @is_visible: Callback to return attribute visibility. Mandatory.
-- 
2.5.0

[PATCH v2 6/9] hwmon: (core) Add energy and humidity attribute support to new API

[Guenter Roeck]

Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: No change

 drivers/hwmon/hwmon.c | 20 ++++++++++++++++++++
 include/linux/hwmon.h | 29 +++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 7a5c8bba7dc2..f5de80a8bd1e 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -349,12 +349,30 @@ static const char * const hwmon_power_attr_templates[] = {
 	[hwmon_power_crit_alarm] = "power%d_crit_alarm",
 };
 
+static const char * const hwmon_energy_attr_templates[] = {
+	[hwmon_energy_input] = "energy%d_input",
+	[hwmon_energy_label] = "energy%d_label",
+};
+
+static const char * const hwmon_humidity_attr_templates[] = {
+	[hwmon_humidity_input] = "humidity%d_input",
+	[hwmon_humidity_label] = "humidity%d_label",
+	[hwmon_humidity_min] = "humidity%d_min",
+	[hwmon_humidity_min_hyst] = "humidity%d_min_hyst",
+	[hwmon_humidity_max] = "humidity%d_max",
+	[hwmon_humidity_max_hyst] = "humidity%d_max_hyst",
+	[hwmon_humidity_alarm] = "humidity%d_alarm",
+	[hwmon_humidity_fault] = "humidity%d_fault",
+};
+
 static const char * const *__templates[] = {
 	[hwmon_chip] = hwmon_chip_attr_templates,
 	[hwmon_temp] = hwmon_temp_attr_templates,
 	[hwmon_in] = hwmon_in_attr_templates,
 	[hwmon_curr] = hwmon_curr_attr_templates,
 	[hwmon_power] = hwmon_power_attr_templates,
+	[hwmon_energy] = hwmon_energy_attr_templates,
+	[hwmon_humidity] = hwmon_humidity_attr_templates,
 };
 
 static const int __templates_size[] = {
@@ -363,6 +381,8 @@ static const int __templates_size[] = {
 	[hwmon_in] = ARRAY_SIZE(hwmon_in_attr_templates),
 	[hwmon_curr] = ARRAY_SIZE(hwmon_curr_attr_templates),
 	[hwmon_power] = ARRAY_SIZE(hwmon_power_attr_templates),
+	[hwmon_energy] = ARRAY_SIZE(hwmon_energy_attr_templates),
+	[hwmon_humidity] = ARRAY_SIZE(hwmon_humidity_attr_templates),
 };
 
 static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
index d7e432ef7c2a..57d92f1d779b 100644
--- a/include/linux/hwmon.h
+++ b/include/linux/hwmon.h
@@ -26,6 +26,7 @@ enum hwmon_sensor_types {
 	hwmon_curr,
 	hwmon_power,
 	hwmon_energy,
+	hwmon_humidity,
 };
 
 enum hwmon_chip_attributes {
@@ -216,6 +217,34 @@ enum hwmon_power_attributes {
 #define HWMON_P_MAX_ALARM		BIT(hwmon_power_max_alarm)
 #define HWMON_P_CRIT_ALARM		BIT(hwmon_power_crit_alarm)
 
+enum hwmon_energy_attributes {
+	hwmon_energy_input,
+	hwmon_energy_label,
+};
+
+#define HWMON_E_INPUT			BIT(hwmon_energy_input)
+#define HWMON_E_LABEL			BIT(hwmon_energy_label)
+
+enum hwmon_humidity_attributes {
+	hwmon_humidity_input,
+	hwmon_humidity_label,
+	hwmon_humidity_min,
+	hwmon_humidity_min_hyst,
+	hwmon_humidity_max,
+	hwmon_humidity_max_hyst,
+	hwmon_humidity_alarm,
+	hwmon_humidity_fault,
+};
+
+#define HWMON_H_INPUT			BIT(hwmon_humidity_input)
+#define HWMON_H_LABEL			BIT(hwmon_humidity_label)
+#define HWMON_H_MIN			BIT(hwmon_humidity_min)
+#define HWMON_H_MIN_HYST		BIT(hwmon_humidity_min_hyst)
+#define HWMON_H_MAX			BIT(hwmon_humidity_max)
+#define HWMON_H_MAX_HYST		BIT(hwmon_humidity_max_hyst)
+#define HWMON_H_ALARM			BIT(hwmon_humidity_alarm)
+#define HWMON_H_FAULT			BIT(hwmon_humidity_fault)
+
 /**
  * struct hwmon_ops - hwmon device operations
  * @is_visible: Callback to return attribute visibility. Mandatory.
-- 
2.5.0

[PATCH v2 7/9] hwmon: (core) Add fan attribute support to new API

[Guenter Roeck]

Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: No change

 drivers/hwmon/hwmon.c | 16 ++++++++++++++++
 include/linux/hwmon.h | 27 +++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index f5de80a8bd1e..38c217e64d41 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -365,6 +365,20 @@ static const char * const hwmon_humidity_attr_templates[] = {
 	[hwmon_humidity_fault] = "humidity%d_fault",
 };
 
+static const char * const hwmon_fan_attr_templates[] = {
+	[hwmon_fan_input] = "fan%d_input",
+	[hwmon_fan_label] = "fan%d_label",
+	[hwmon_fan_min] = "fan%d_min",
+	[hwmon_fan_max] = "fan%d_max",
+	[hwmon_fan_div] = "fan%d_div",
+	[hwmon_fan_pulses] = "fan%d_pulses",
+	[hwmon_fan_target] = "fan%d_target",
+	[hwmon_fan_alarm] = "fan%d_alarm",
+	[hwmon_fan_min_alarm] = "fan%d_min_alarm",
+	[hwmon_fan_max_alarm] = "fan%d_max_alarm",
+	[hwmon_fan_fault] = "fan%d_fault",
+};
+
 static const char * const *__templates[] = {
 	[hwmon_chip] = hwmon_chip_attr_templates,
 	[hwmon_temp] = hwmon_temp_attr_templates,
@@ -373,6 +387,7 @@ static const char * const *__templates[] = {
 	[hwmon_power] = hwmon_power_attr_templates,
 	[hwmon_energy] = hwmon_energy_attr_templates,
 	[hwmon_humidity] = hwmon_humidity_attr_templates,
+	[hwmon_fan] = hwmon_fan_attr_templates,
 };
 
 static const int __templates_size[] = {
@@ -383,6 +398,7 @@ static const int __templates_size[] = {
 	[hwmon_power] = ARRAY_SIZE(hwmon_power_attr_templates),
 	[hwmon_energy] = ARRAY_SIZE(hwmon_energy_attr_templates),
 	[hwmon_humidity] = ARRAY_SIZE(hwmon_humidity_attr_templates),
+	[hwmon_fan] = ARRAY_SIZE(hwmon_fan_attr_templates),
 };
 
 static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
index 57d92f1d779b..74e89d45ff67 100644
--- a/include/linux/hwmon.h
+++ b/include/linux/hwmon.h
@@ -27,6 +27,7 @@ enum hwmon_sensor_types {
 	hwmon_power,
 	hwmon_energy,
 	hwmon_humidity,
+	hwmon_fan,
 };
 
 enum hwmon_chip_attributes {
@@ -245,6 +246,32 @@ enum hwmon_humidity_attributes {
 #define HWMON_H_ALARM			BIT(hwmon_humidity_alarm)
 #define HWMON_H_FAULT			BIT(hwmon_humidity_fault)
 
+enum hwmon_fan_attributes {
+	hwmon_fan_input,
+	hwmon_fan_label,
+	hwmon_fan_min,
+	hwmon_fan_max,
+	hwmon_fan_div,
+	hwmon_fan_pulses,
+	hwmon_fan_target,
+	hwmon_fan_alarm,
+	hwmon_fan_min_alarm,
+	hwmon_fan_max_alarm,
+	hwmon_fan_fault,
+};
+
+#define HWMON_F_INPUT			BIT(hwmon_fan_input)
+#define HWMON_F_LABEL			BIT(hwmon_fan_label)
+#define HWMON_F_MIN			BIT(hwmon_fan_min)
+#define HWMON_F_MAX			BIT(hwmon_fan_max)
+#define HWMON_F_DIV			BIT(hwmon_fan_div)
+#define HWMON_F_PULSES			BIT(hwmon_fan_pulses)
+#define HWMON_F_TARGET			BIT(hwmon_fan_target)
+#define HWMON_F_ALARM			BIT(hwmon_fan_alarm)
+#define HWMON_F_MIN_ALARM		BIT(hwmon_fan_min_alarm)
+#define HWMON_F_MAX_ALARM		BIT(hwmon_fan_max_alarm)
+#define HWMON_F_FAULT			BIT(hwmon_fan_fault)
+
 /**
  * struct hwmon_ops - hwmon device operations
  * @is_visible: Callback to return attribute visibility. Mandatory.
-- 
2.5.0

[PATCH v2 8/9] hwmon: (core) Document new kernel API

[Guenter Roeck]

Describe the new registration API function as well as the data
structures it requires.

Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Fixed typos

 Documentation/hwmon/hwmon-kernel-api.txt | 229 ++++++++++++++++++++++++++++++-
 1 file changed, 227 insertions(+), 2 deletions(-)

diff --git a/Documentation/hwmon/hwmon-kernel-api.txt b/Documentation/hwmon/hwmon-kernel-api.txt
index 2ecdbfc85ecf..f60a29ce7592 100644
--- a/Documentation/hwmon/hwmon-kernel-api.txt
+++ b/Documentation/hwmon/hwmon-kernel-api.txt
@@ -34,6 +34,19 @@ devm_hwmon_device_register_with_groups(struct device *dev,
 				       const char *name, void *drvdata,
 				       const struct attribute_group **groups);
 
+struct device *
+hwmon_device_register_with_info(struct device *dev,
+				const char *name, void *drvdata,
+				const struct hwmon_chip_info *info,
+				const struct attribute_group **groups);
+
+struct device *
+devm_hwmon_device_register_with_info(struct device *dev,
+				     const char *name,
+				     void *drvdata,
+				     const struct hwmon_chip_info *info,
+				     const struct attribute_group **groups);
+
 void hwmon_device_unregister(struct device *dev);
 void devm_hwmon_device_unregister(struct device *dev);
 
@@ -60,15 +73,227 @@ devm_hwmon_device_register_with_groups is similar to
 hwmon_device_register_with_groups. However, it is device managed, meaning the
 hwmon device does not have to be removed explicitly by the removal function.
 
+hwmon_device_register_with_info is the most comprehensive and preferred means
+to register a hardware monitoring device. It creates the standard sysfs
+attributes in the hardware monitoring core, letting the driver focus on reading
+from and writing to the chip instead of having to bother with sysfs attributes.
+Its parameters are described in more detail below.
+
+devm_hwmon_device_register_with_info is similar to
+hwmon_device_register_with_info. However, it is device managed, meaning the
+hwmon device does not have to be removed explicitly by the removal function.
+
 hwmon_device_unregister deregisters a registered hardware monitoring device.
 The parameter of this function is the pointer to the registered hardware
 monitoring device structure. This function must be called from the driver
 remove function if the hardware monitoring device was registered with
-hwmon_device_register or with hwmon_device_register_with_groups.
+hwmon_device_register, hwmon_device_register_with_groups, or
+hwmon_device_register_with_info.
 
 devm_hwmon_device_unregister does not normally have to be called. It is only
 needed for error handling, and only needed if the driver probe fails after
-the call to devm_hwmon_device_register_with_groups.
+the call to devm_hwmon_device_register_with_groups and if the automatic
+(device managed) removal would be too late.
+
+Using devm_hwmon_device_register_with_info()
+--------------------------------------------
+
+hwmon_device_register_with_info() registers a hardware monitoring device.
+The parameters to this function are
+
+struct device *dev	Pointer to parent device
+const char *name	Device name
+void *drvdata		Driver private data
+const struct hwmon_chip_info *info
+			Pointer to chip description.
+const struct attribute_group **groups
+			Null-terminated list of additional sysfs attribute
+			groups.
+
+This function returns a pointer to the created hardware monitoring device
+on success and a negative error code for failure.
+
+The hwmon_chip_info structure looks as follows.
+
+struct hwmon_chip_info {
+	const struct hwmon_ops *ops;
+	const struct hwmon_channel_info **info;
+};
+
+It contains the following fields:
+
+* ops:	Pointer to device operations.
+* info: NULL-terminated list of device channel descriptors.
+
+The list of hwmon operations is defined as:
+
+struct hwmon_ops {
+	umode_t (*is_visible)(const void *, enum hwmon_sensor_types type,
+			      u32 attr, int);
+	int (*read)(struct device *, enum hwmon_sensor_types type,
+		    u32 attr, int, long *);
+	int (*write)(struct device *, enum hwmon_sensor_types type,
+		     u32 attr, int, long);
+};
+
+It defines the following operations.
+
+* is_visible: Pointer to a function to return the file mode for each supported
+  attribute. This function is mandatory.
+
+* read: Pointer to a function for reading a value from the chip. This function
+  is optional, but must be provided if any readable attributes exist.
+
+* write: Pointer to a function for writing a value to the chip. This function is
+  optional, but must be provided if any writeable attributes exist.
+
+Each sensor channel is described with struct hwmon_channel_info, which is
+defined as follows.
+
+struct hwmon_channel_info {
+	enum hwmon_sensor_types type;
+	u32 *config;
+};
+
+It contains following fields:
+
+* type: The hardware monitoring sensor type.
+  Supported sensor types are
+  * hwmon_chip		A virtual sensor type, used to describe attributes
+			which apply to the entire chip.
+  * hwmon_temp		Temperature sensor
+  * hwmon_in		Voltage sensor
+  * hwmon_curr		Current sensor
+  * hwmon_power		Power sensor
+  * hwmon_energy	Energy sensor
+  * hwmon_humidity	Humidity sensor
+  * hwmon_fan		Fan speed sensor
+
+* config: Pointer to a 0-terminated list of configuration values for each
+  sensor of the given type. Each value is a combination of bit values
+  describing the attributes supposed by a single sensor.
+
+As an example, here is the complete description file for a LM75 compatible
+sensor chip. The chip has a single temperature sensor. The driver wants to
+register with the thermal subsystem (HWMON_C_REGISTER_TZ), and it supports
+the update_interval attribute (HWMON_C_UPDATE_INTERVAL). The chip supports
+reading the temperature (HWMON_T_INPUT), it has a maximum temperature
+register (HWMON_T_MAX) as well as a maximum temperature hysteresis register
+(HWMON_T_MAX_HYST).
+
+static const u32 lm75_chip_config[] = {
+	HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL,
+	0
+};
+
+static const struct hwmon_channel_info lm75_chip = {
+	.type = hwmon_chip,
+	.config = lm75_chip_config,
+};
+
+static const u32 lm75_temp_config[] = {
+	HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST,
+	0
+};
+
+static const struct hwmon_channel_info lm75_temp = {
+	.type = hwmon_temp,
+	.config = lm75_temp_config,
+};
+
+static const struct hwmon_channel_info *lm75_info[] = {
+	&lm75_chip,
+	&lm75_temp,
+	NULL
+};
+
+static const struct hwmon_ops lm75_hwmon_ops = {
+	.is_visible = lm75_is_visible,
+	.read = lm75_read,
+	.write = lm75_write,
+};
+
+static const struct hwmon_chip_info lm75_chip_info = {
+	.ops = &lm75_hwmon_ops,
+	.info = lm75_info,
+};
+
+A complete list of bit values indicating individual attribute support
+is defined in include/linux/hwmon.h. Definition prefixes are as follows.
+
+HWMON_C_xxxx	Chip attributes, for use with hwmon_chip.
+HWMON_T_xxxx	Temperature attributes, for use with hwmon_temp.
+HWMON_I_xxxx	Voltage attributes, for use with hwmon_in.
+HWMON_C_xxxx	Current attributes, for use with hwmon_curr.
+		Notice the prefix overlap with chip attributes.
+HWMON_P_xxxx	Power attributes, for use with hwmon_power.
+HWMON_E_xxxx	Energy attributes, for use with hwmon_energy.
+HWMON_H_xxxx	Humidity attributes, for use with hwmon_humidity.
+HWMON_F_xxxx	Fan speed attributes, for use with hwmon_fan.
+
+Driver callback functions
+-------------------------
+
+Each driver provides is_visible, read, and write functions. Parameters
+and return values for those functions are as follows.
+
+umode_t is_visible_func(const void *data, enum hwmon_sensor_types type,
+			u32 attr, int channel)
+
+Parameters:
+	data:	Pointer to device private data structure.
+	type:	The sensor type.
+	attr:	Attribute identifier associated with a specific attribute.
+		For example, the attribute value for HWMON_T_INPUT would be
+		hwmon_temp_input. For complete mappings of bit fields to
+		attribute values please see include/linux/hwmon.h.
+	channel:The sensor channel number.
+
+Return value:
+	The file mode for this attribute. Typically, this will be 0 (the
+	attribute will not be created), S_IRUGO, or 'S_IRUGO | S_IWUSR'.
+
+int read_func(struct device *dev, enum hwmon_sensor_types type,
+	      u32 attr, int channel, long *val)
+
+Parameters:
+	dev:	Pointer to the hardware monitoring device.
+	type:	The sensor type.
+	attr:	Attribute identifier associated with a specific attribute.
+		For example, the attribute value for HWMON_T_INPUT would be
+		hwmon_temp_input. For complete mappings please see
+		include/linux/hwmon.h.
+	channel:The sensor channel number.
+	val:	Pointer to attribute value.
+
+Return value:
+	0 on success, a negative error number otherwise.
+
+int write_func(struct device *dev, enum hwmon_sensor_types type,
+	       u32 attr, int channel, long val)
+
+Parameters:
+	dev:	Pointer to the hardware monitoring device.
+	type:	The sensor type.
+	attr:	Attribute identifier associated with a specific attribute.
+		For example, the attribute value for HWMON_T_INPUT would be
+		hwmon_temp_input. For complete mappings please see
+		include/linux/hwmon.h.
+	channel:The sensor channel number.
+	val:	The value to write to the chip.
+
+Return value:
+	0 on success, a negative error number otherwise.
+
+
+Driver-provided sysfs attributes
+--------------------------------
+
+If the hardware monitoring device is registered with
+hwmon_device_register_with_info or devm_hwmon_device_register_with_info,
+it is most likely not necessary to provide sysfs attributes. Only non-standard
+sysfs attributes need to be provided when one of those registration functions
+is used.
 
 The header file linux/hwmon-sysfs.h provides a number of useful macros to
 declare and use hardware monitoring sysfs attributes.
-- 
2.5.0

Re: [PATCH v2 8/9] hwmon: (core) Document new kernel API

[Jonathan Cameron]

On 17/07/16 06:30, Guenter Roeck wrote:
> Describe the new registration API function as well as the data
> structures it requires.
> 
> Acked-by: Punit Agrawal <punit.agrawal@arm.com>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Straight forward and clear.  Just what is wanted from documentation.

Reviewed-by: Jonathan Cameron <jic23@kernel.org>

Feel free to add reviewed by's for the other patches,
but seemed a bit superfluous given how simple they are :)

All seemed fine to me.  I should in theory get
around to converting over my one and only hwmon driver,
but to do that I'd feel I had to find the hardware so
might be a while.  Perhaps someone who has worked on it
more recently might do it *crosses fingers*
(sht15)

Hmm, could do iio-hwmon as well but you have touched that
more recently than I have *resorts to playground tactics*

Jonathan
> ---
> v2: Fixed typos
> 
>  Documentation/hwmon/hwmon-kernel-api.txt | 229 ++++++++++++++++++++++++++++++-
>  1 file changed, 227 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/hwmon/hwmon-kernel-api.txt b/Documentation/hwmon/hwmon-kernel-api.txt
> index 2ecdbfc85ecf..f60a29ce7592 100644
> --- a/Documentation/hwmon/hwmon-kernel-api.txt
> +++ b/Documentation/hwmon/hwmon-kernel-api.txt
> @@ -34,6 +34,19 @@ devm_hwmon_device_register_with_groups(struct device *dev,
>  				       const char *name, void *drvdata,
>  				       const struct attribute_group **groups);
>  
> +struct device *
> +hwmon_device_register_with_info(struct device *dev,
> +				const char *name, void *drvdata,
> +				const struct hwmon_chip_info *info,
> +				const struct attribute_group **groups);
> +
> +struct device *
> +devm_hwmon_device_register_with_info(struct device *dev,
> +				     const char *name,
> +				     void *drvdata,
> +				     const struct hwmon_chip_info *info,
> +				     const struct attribute_group **groups);
> +
>  void hwmon_device_unregister(struct device *dev);
>  void devm_hwmon_device_unregister(struct device *dev);
>  
> @@ -60,15 +73,227 @@ devm_hwmon_device_register_with_groups is similar to
>  hwmon_device_register_with_groups. However, it is device managed, meaning the
>  hwmon device does not have to be removed explicitly by the removal function.
>  
> +hwmon_device_register_with_info is the most comprehensive and preferred means
> +to register a hardware monitoring device. It creates the standard sysfs
> +attributes in the hardware monitoring core, letting the driver focus on reading
> +from and writing to the chip instead of having to bother with sysfs attributes.
> +Its parameters are described in more detail below.
> +
> +devm_hwmon_device_register_with_info is similar to
> +hwmon_device_register_with_info. However, it is device managed, meaning the
> +hwmon device does not have to be removed explicitly by the removal function.
> +
>  hwmon_device_unregister deregisters a registered hardware monitoring device.
>  The parameter of this function is the pointer to the registered hardware
>  monitoring device structure. This function must be called from the driver
>  remove function if the hardware monitoring device was registered with
> -hwmon_device_register or with hwmon_device_register_with_groups.
> +hwmon_device_register, hwmon_device_register_with_groups, or
> +hwmon_device_register_with_info.
>  
>  devm_hwmon_device_unregister does not normally have to be called. It is only
>  needed for error handling, and only needed if the driver probe fails after
> -the call to devm_hwmon_device_register_with_groups.
> +the call to devm_hwmon_device_register_with_groups and if the automatic
> +(device managed) removal would be too late.
> +
> +Using devm_hwmon_device_register_with_info()
> +--------------------------------------------
> +
> +hwmon_device_register_with_info() registers a hardware monitoring device.
> +The parameters to this function are
> +
> +struct device *dev	Pointer to parent device
> +const char *name	Device name
> +void *drvdata		Driver private data
> +const struct hwmon_chip_info *info
> +			Pointer to chip description.
> +const struct attribute_group **groups
> +			Null-terminated list of additional sysfs attribute
> +			groups.
> +
> +This function returns a pointer to the created hardware monitoring device
> +on success and a negative error code for failure.
> +
> +The hwmon_chip_info structure looks as follows.
> +
> +struct hwmon_chip_info {
> +	const struct hwmon_ops *ops;
> +	const struct hwmon_channel_info **info;
> +};
> +
> +It contains the following fields:
> +
> +* ops:	Pointer to device operations.
> +* info: NULL-terminated list of device channel descriptors.
> +
> +The list of hwmon operations is defined as:
> +
> +struct hwmon_ops {
> +	umode_t (*is_visible)(const void *, enum hwmon_sensor_types type,
> +			      u32 attr, int);
> +	int (*read)(struct device *, enum hwmon_sensor_types type,
> +		    u32 attr, int, long *);
> +	int (*write)(struct device *, enum hwmon_sensor_types type,
> +		     u32 attr, int, long);
> +};
> +
> +It defines the following operations.
> +
> +* is_visible: Pointer to a function to return the file mode for each supported
> +  attribute. This function is mandatory.
> +
> +* read: Pointer to a function for reading a value from the chip. This function
> +  is optional, but must be provided if any readable attributes exist.
> +
> +* write: Pointer to a function for writing a value to the chip. This function is
> +  optional, but must be provided if any writeable attributes exist.
> +
> +Each sensor channel is described with struct hwmon_channel_info, which is
> +defined as follows.
> +
> +struct hwmon_channel_info {
> +	enum hwmon_sensor_types type;
> +	u32 *config;
> +};
> +
> +It contains following fields:
> +
> +* type: The hardware monitoring sensor type.
> +  Supported sensor types are
> +  * hwmon_chip		A virtual sensor type, used to describe attributes
> +			which apply to the entire chip.
> +  * hwmon_temp		Temperature sensor
> +  * hwmon_in		Voltage sensor
> +  * hwmon_curr		Current sensor
> +  * hwmon_power		Power sensor
> +  * hwmon_energy	Energy sensor
> +  * hwmon_humidity	Humidity sensor
> +  * hwmon_fan		Fan speed sensor
> +
> +* config: Pointer to a 0-terminated list of configuration values for each
> +  sensor of the given type. Each value is a combination of bit values
> +  describing the attributes supposed by a single sensor.
> +
> +As an example, here is the complete description file for a LM75 compatible
> +sensor chip. The chip has a single temperature sensor. The driver wants to
> +register with the thermal subsystem (HWMON_C_REGISTER_TZ), and it supports
> +the update_interval attribute (HWMON_C_UPDATE_INTERVAL). The chip supports
> +reading the temperature (HWMON_T_INPUT), it has a maximum temperature
> +register (HWMON_T_MAX) as well as a maximum temperature hysteresis register
> +(HWMON_T_MAX_HYST).
> +
> +static const u32 lm75_chip_config[] = {
> +	HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL,
> +	0
> +};
> +
> +static const struct hwmon_channel_info lm75_chip = {
> +	.type = hwmon_chip,
> +	.config = lm75_chip_config,
> +};
> +
> +static const u32 lm75_temp_config[] = {
> +	HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST,
> +	0
> +};
> +
> +static const struct hwmon_channel_info lm75_temp = {
> +	.type = hwmon_temp,
> +	.config = lm75_temp_config,
> +};
> +
> +static const struct hwmon_channel_info *lm75_info[] = {
> +	&lm75_chip,
> +	&lm75_temp,
> +	NULL
> +};
> +
> +static const struct hwmon_ops lm75_hwmon_ops = {
> +	.is_visible = lm75_is_visible,
> +	.read = lm75_read,
> +	.write = lm75_write,
> +};
> +
> +static const struct hwmon_chip_info lm75_chip_info = {
> +	.ops = &lm75_hwmon_ops,
> +	.info = lm75_info,
> +};
> +
> +A complete list of bit values indicating individual attribute support
> +is defined in include/linux/hwmon.h. Definition prefixes are as follows.
> +
> +HWMON_C_xxxx	Chip attributes, for use with hwmon_chip.
> +HWMON_T_xxxx	Temperature attributes, for use with hwmon_temp.
> +HWMON_I_xxxx	Voltage attributes, for use with hwmon_in.
> +HWMON_C_xxxx	Current attributes, for use with hwmon_curr.
> +		Notice the prefix overlap with chip attributes.
> +HWMON_P_xxxx	Power attributes, for use with hwmon_power.
> +HWMON_E_xxxx	Energy attributes, for use with hwmon_energy.
> +HWMON_H_xxxx	Humidity attributes, for use with hwmon_humidity.
> +HWMON_F_xxxx	Fan speed attributes, for use with hwmon_fan.
> +
> +Driver callback functions
> +-------------------------
> +
> +Each driver provides is_visible, read, and write functions. Parameters
> +and return values for those functions are as follows.
> +
> +umode_t is_visible_func(const void *data, enum hwmon_sensor_types type,
> +			u32 attr, int channel)
> +
> +Parameters:
> +	data:	Pointer to device private data structure.
> +	type:	The sensor type.
> +	attr:	Attribute identifier associated with a specific attribute.
> +		For example, the attribute value for HWMON_T_INPUT would be
> +		hwmon_temp_input. For complete mappings of bit fields to
> +		attribute values please see include/linux/hwmon.h.
> +	channel:The sensor channel number.
> +
> +Return value:
> +	The file mode for this attribute. Typically, this will be 0 (the
> +	attribute will not be created), S_IRUGO, or 'S_IRUGO | S_IWUSR'.
> +
> +int read_func(struct device *dev, enum hwmon_sensor_types type,
> +	      u32 attr, int channel, long *val)
> +
> +Parameters:
> +	dev:	Pointer to the hardware monitoring device.
> +	type:	The sensor type.
> +	attr:	Attribute identifier associated with a specific attribute.
> +		For example, the attribute value for HWMON_T_INPUT would be
> +		hwmon_temp_input. For complete mappings please see
> +		include/linux/hwmon.h.
> +	channel:The sensor channel number.
> +	val:	Pointer to attribute value.
> +
> +Return value:
> +	0 on success, a negative error number otherwise.
> +
> +int write_func(struct device *dev, enum hwmon_sensor_types type,
> +	       u32 attr, int channel, long val)
> +
> +Parameters:
> +	dev:	Pointer to the hardware monitoring device.
> +	type:	The sensor type.
> +	attr:	Attribute identifier associated with a specific attribute.
> +		For example, the attribute value for HWMON_T_INPUT would be
> +		hwmon_temp_input. For complete mappings please see
> +		include/linux/hwmon.h.
> +	channel:The sensor channel number.
> +	val:	The value to write to the chip.
> +
> +Return value:
> +	0 on success, a negative error number otherwise.
> +
> +
> +Driver-provided sysfs attributes
> +--------------------------------
> +
> +If the hardware monitoring device is registered with
> +hwmon_device_register_with_info or devm_hwmon_device_register_with_info,
> +it is most likely not necessary to provide sysfs attributes. Only non-standard
> +sysfs attributes need to be provided when one of those registration functions
> +is used.
>  
>  The header file linux/hwmon-sysfs.h provides a number of useful macros to
>  declare and use hardware monitoring sysfs attributes.
> 

[PATCH v2 9/9] hwmon: (core) Add basic pwm attribute support to new API

[Guenter Roeck]

Add basic pwm attribute support (no auto attributes) to new API.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Added patch

 Documentation/hwmon/hwmon-kernel-api.txt |  2 ++
 drivers/hwmon/hwmon.c                    |  9 +++++++++
 include/linux/hwmon.h                    | 13 +++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/Documentation/hwmon/hwmon-kernel-api.txt b/Documentation/hwmon/hwmon-kernel-api.txt
index f60a29ce7592..ef9d74947f5c 100644
--- a/Documentation/hwmon/hwmon-kernel-api.txt
+++ b/Documentation/hwmon/hwmon-kernel-api.txt
@@ -168,6 +168,7 @@ It contains following fields:
   * hwmon_energy	Energy sensor
   * hwmon_humidity	Humidity sensor
   * hwmon_fan		Fan speed sensor
+  * hwmon_pwm		PWM control
 
 * config: Pointer to a 0-terminated list of configuration values for each
   sensor of the given type. Each value is a combination of bit values
@@ -230,6 +231,7 @@ HWMON_P_xxxx	Power attributes, for use with hwmon_power.
 HWMON_E_xxxx	Energy attributes, for use with hwmon_energy.
 HWMON_H_xxxx	Humidity attributes, for use with hwmon_humidity.
 HWMON_F_xxxx	Fan speed attributes, for use with hwmon_fan.
+HWMON_PWM_xxxx	PWM control attributes, for use with hwmon_pwm.
 
 Driver callback functions
 -------------------------
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 38c217e64d41..bd99732e415b 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -379,6 +379,13 @@ static const char * const hwmon_fan_attr_templates[] = {
 	[hwmon_fan_fault] = "fan%d_fault",
 };
 
+static const char * const hwmon_pwm_attr_templates[] = {
+	[hwmon_pwm_input] = "pwm%d",
+	[hwmon_pwm_enable] = "pwm%d_enable",
+	[hwmon_pwm_mode] = "pwm%d_mode",
+	[hwmon_pwm_freq] = "pwm%d_freq",
+};
+
 static const char * const *__templates[] = {
 	[hwmon_chip] = hwmon_chip_attr_templates,
 	[hwmon_temp] = hwmon_temp_attr_templates,
@@ -388,6 +395,7 @@ static const char * const *__templates[] = {
 	[hwmon_energy] = hwmon_energy_attr_templates,
 	[hwmon_humidity] = hwmon_humidity_attr_templates,
 	[hwmon_fan] = hwmon_fan_attr_templates,
+	[hwmon_pwm] = hwmon_pwm_attr_templates,
 };
 
 static const int __templates_size[] = {
@@ -399,6 +407,7 @@ static const int __templates_size[] = {
 	[hwmon_energy] = ARRAY_SIZE(hwmon_energy_attr_templates),
 	[hwmon_humidity] = ARRAY_SIZE(hwmon_humidity_attr_templates),
 	[hwmon_fan] = ARRAY_SIZE(hwmon_fan_attr_templates),
+	[hwmon_pwm] = ARRAY_SIZE(hwmon_pwm_attr_templates),
 };
 
 static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
index 74e89d45ff67..9d2f8bde7d12 100644
--- a/include/linux/hwmon.h
+++ b/include/linux/hwmon.h
@@ -28,6 +28,7 @@ enum hwmon_sensor_types {
 	hwmon_energy,
 	hwmon_humidity,
 	hwmon_fan,
+	hwmon_pwm,
 };
 
 enum hwmon_chip_attributes {
@@ -272,6 +273,18 @@ enum hwmon_fan_attributes {
 #define HWMON_F_MAX_ALARM		BIT(hwmon_fan_max_alarm)
 #define HWMON_F_FAULT			BIT(hwmon_fan_fault)
 
+enum hwmon_pwm_attributes {
+	hwmon_pwm_input,
+	hwmon_pwm_enable,
+	hwmon_pwm_mode,
+	hwmon_pwm_freq,
+};
+
+#define HWMON_PWM_INPUT			BIT(hwmon_pwm_input)
+#define HWMON_PWM_ENABLE		BIT(hwmon_pwm_enable)
+#define HWMON_PWM_MODE			BIT(hwmon_pwm_mode)
+#define HWMON_PWM_FREQ			BIT(hwmon_pwm_freq)
+
 /**
  * struct hwmon_ops - hwmon device operations
  * @is_visible: Callback to return attribute visibility. Mandatory.
-- 
2.5.0