[PATCH v6 0/6] platform/x86: firmware_attributes_class: Add a high level API

[PATCH v6 0/6] platform/x86: firmware_attributes_class: Add a high level API

[Kurt Borja]

Hi all,

After my discussion with Joshua on v2, I realized the API I made was not
ergonomic at all and it didn't exactly respond to driver needs. In this
version I tried a completely different approach and IMO it's much much
better now.

First of all I adopted standard sysfs terminology for everything. A
"firmware attribute" is just an attribute_group under the attributes/
directory so everything related to this concept is just called "group"
now. Everything refered as properties in the previous patch are now just
plain "attributes".

This new API revolves around the `fwat_{bool,enum,int,str}_data`
structs. These hold all the metadata a "firmware_attribute" of that
given type needs.

These structs also hold `read` and `write` callbacks for the
current_value attribute, because obviously that value is always dynamic.
However the rest of attributes (default_value, display_name, min, max,
etc) are constant.

In the simple case this metadata structs can be defined statically with
DEFINE_FWAT_{BOOL,ENUM,INT,STR}_GROUP() macros. However most users of
this class obtain this values dynamically so you can also define this
structs dynamically.

In the end all groups (static and dynamic) will be created using
fwat_create_group() after registering the class device.

Let me know what you think, your feedback is very appreciated :)

I do have one question for anyone interested. Should constraints over
the current_value (such as min, max, increment, etc.) be enforced at the
show/store level? i.e. before values reach read/write callbacks.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
Changes in v6:
  [Patch 1]
    - Add put_device() if device_register() fails
    - Drop sysfs_remove_groups() in fwat_device_unregister()
    - Didn't drop kset_unregister() because I think it's required
  [Patch 2]
    - Introduce FWAT_GROUP_ATTR() macro to avoid errors when creating
      default ktype attributes.
    - Fix typos in firmware_attributes_class.h
    - Constify struct fwat_attribute in callbacks
    - Drop DEFINE_SYSFS_GROUP_VISIBLE() and pass the visibility callback
      directly
    - Drop <linux/list.h> in firmware_attributes_class.h
    - Rename enum fwat_group_type members
    - Move fwat_*_current_value assertions to firmware_attributes_class.c
    - Add a '__' prefix to fwat_create_*_group() functions
    - Some style improvements
    - Didn't drop fwat_remove_auto_groups() because I think it's
      required
  [Patch 4]
    - Don't drop mutex initialization
    - Lock fw_attrs_lock on *_write() callbacks

  - Link to v5: https://lore.kernel.org/r/20250705-fw-attrs-api-v5-0-60b6d51d93eb@gmail.com

Changes in v5:
  - Fix kernel test robot warning
  - Link to v4: https://lore.kernel.org/r/20250630-fw-attrs-api-v4-0-1a04952b255f@gmail.com

Changes in v4:
  [Patch 1]
    - Embbed a device in fwat_device instead of a kobject.
    - Instead of an attrs_kobj root kobj, create a kset with the same
      name.
  [Patch 2]
    - Add a (*show_override) callback in fwat_group_data.
    - Instead of allocating and filling sysfs groups and attributes
      manually, I defined custom ktypes for each fwat type. All groups are
      now statically defined and added through default_groups.
  
      I think this is a BIG optimization in terms of memory at least. Also
      fwat_group memory is now managed by a kobject which is allocated one
      time. This is also a less impactful performance optimization (less
      individual allocations).
    - No changes to API :) (I take suggestions though)

  I might have lost some of the changelog. Sorry for that!
  
  - Link to v3: https://lore.kernel.org/r/20250621-fw-attrs-api-v3-0-3dd55e463396@gmail.com

Changes in v3:
  [Patch 1]
  - Fixed UAF in fwat_device_unregister(). Device was unregistered after
    freeing fadev.
  [Patch 2]
  - Patch 2 was completely replaced. A new approach for the API is taken,
    based on Joshua's suggestions.
  
  - Link to v2: https://lore.kernel.org/r/20250517-fw-attrs-api-v2-0-fa1ab045a01c@gmail.com

Changes in v2:
  [Patch 1]
   - Include kdev_t.h header
  [Patch 2]
   - Use one line comments in fwat_create_attrs()
   - Check propagate errors in fwat_create_attrs()
   - Add `mode` to fwat_attr_config and related macros to let users
     configure the `current_value` attribute mode
   - Use defined structs in fwat_attr_ops instead of anonymous ones
   - Move fwat_attr_type from config to ops
  [Patch 5]
   - Just transition to new API without chaing ABI
  
  - Link to v1: https://lore.kernel.org/r/20250509-fw-attrs-api-v1-0-258afed65bfa@gmail.com

---
Kurt Borja (5):
      platform/x86: firmware_attributes_class: Add high level API for the attributes interface
      platform/x86: firmware_attributes_class: Move header to include directory
      platform/x86: samsung-galaxybook: Transition new firmware_attributes API
      Documentation: ABI: Update sysfs-class-firmware-attributes documentation
      MAINTAINERS: Add FIRMWARE ATTRIBUTES CLASS entry

Thomas Weißschuh (1):
      platform/x86: firmware_attributes_class: Add device initialization methods

 .../ABI/testing/sysfs-class-firmware-attributes    |   1 +
 MAINTAINERS                                        |   8 +
 drivers/platform/x86/dell/dell-wmi-sysman/sysman.c |   2 +-
 drivers/platform/x86/firmware_attributes_class.c   | 667 ++++++++++++++++++++-
 drivers/platform/x86/firmware_attributes_class.h   |  12 -
 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c       |   2 +-
 drivers/platform/x86/lenovo/think-lmi.c            |   2 +-
 drivers/platform/x86/samsung-galaxybook.c          | 240 ++------
 include/linux/firmware_attributes_class.h          | 369 ++++++++++++
 9 files changed, 1111 insertions(+), 192 deletions(-)
---
base-commit: 428f6f3a56ac85f37a07a3fe5149b593185d5c4c
change-id: 20250326-fw-attrs-api-0eea7c0225b6
-- 
 ~ Kurt

[PATCH v6 1/6] platform/x86: firmware_attributes_class: Add device initialization methods

[Kurt Borja]

From: Thomas Weißschuh <linux@weissschuh.net>

Currently each user of firmware_attributes_class has to manually set up
kobjects, devices, etc.

Provide this infrastructure out-of-the-box through the newly introduced
fwat_device_register().

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Kurt Borja <kuurtb@gmail.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/platform/x86/firmware_attributes_class.c | 126 +++++++++++++++++++++++
 drivers/platform/x86/firmware_attributes_class.h |  28 +++++
 2 files changed, 154 insertions(+)

diff --git a/drivers/platform/x86/firmware_attributes_class.c b/drivers/platform/x86/firmware_attributes_class.c
index 736e96c186d9dc6d945517f090e9af903e93bbf4..084e66481a4a29bfd801d9e5bbb4067ac25b8437 100644
--- a/drivers/platform/x86/firmware_attributes_class.c
+++ b/drivers/platform/x86/firmware_attributes_class.c
@@ -2,7 +2,14 @@
 
 /* Firmware attributes class helper module */
 
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/device/class.h>
+#include <linux/kdev_t.h>
+#include <linux/kobject.h>
 #include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
 #include "firmware_attributes_class.h"
 
 const struct class firmware_attributes_class = {
@@ -10,6 +17,123 @@ const struct class firmware_attributes_class = {
 };
 EXPORT_SYMBOL_GPL(firmware_attributes_class);
 
+static void fwat_device_release(struct device *dev)
+{
+	struct fwat_device *fadev = to_fwat_device(dev);
+
+	kfree(fadev);
+}
+
+/**
+ * fwat_device_register - Create and register a firmware-attributes class
+ *			  device
+ * @parent: Parent device
+ * @name: Name of the class device
+ * @drvdata: Drvdata of the class device
+ * @groups: Extra groups for the "attributes" directory
+ *
+ * Return: pointer to the new fwat_device on success, ERR_PTR on failure
+ */
+struct fwat_device *
+fwat_device_register(struct device *parent, const char *name, void *drvdata,
+		     const struct attribute_group **groups)
+{
+	struct fwat_device *fadev;
+	int ret;
+
+	if (!parent || !name)
+		return ERR_PTR(-EINVAL);
+
+	fadev = kzalloc(sizeof(*fadev), GFP_KERNEL);
+	if (!fadev)
+		return ERR_PTR(-ENOMEM);
+
+	fadev->groups = groups;
+	fadev->dev.class = &firmware_attributes_class;
+	fadev->dev.parent = parent;
+	fadev->dev.release = fwat_device_release;
+	dev_set_drvdata(&fadev->dev, drvdata);
+	ret = dev_set_name(&fadev->dev, "%s", name);
+	if (ret) {
+		kfree(fadev);
+		return ERR_PTR(ret);
+	}
+	ret = device_register(&fadev->dev);
+	if (ret) {
+		put_device(&fadev->dev);
+		return ERR_PTR(ret);
+	}
+
+	fadev->attrs_kset = kset_create_and_add("attributes", NULL, &fadev->dev.kobj);
+	if (!fadev->attrs_kset) {
+		ret = -ENOMEM;
+		goto out_device_unregister;
+	}
+
+	ret = sysfs_create_groups(&fadev->attrs_kset->kobj, groups);
+	if (ret)
+		goto out_kset_unregister;
+
+	return fadev;
+
+out_kset_unregister:
+	kset_unregister(fadev->attrs_kset);
+
+out_device_unregister:
+	device_unregister(&fadev->dev);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(fwat_device_register);
+
+void fwat_device_unregister(struct fwat_device *fadev)
+{
+	if (!fadev)
+		return;
+
+	kset_unregister(fadev->attrs_kset);
+	device_unregister(&fadev->dev);
+}
+EXPORT_SYMBOL_GPL(fwat_device_unregister);
+
+static void devm_fwat_device_release(void *data)
+{
+	struct fwat_device *fadev = data;
+
+	fwat_device_unregister(fadev);
+}
+
+/**
+ * devm_fwat_device_register - Create and register a firmware-attributes class
+ *			       device
+ * @parent: Parent device
+ * @name: Name of the class device
+ * @data: Drvdata of the class device
+ * @groups: Extra groups for the class device (Optional)
+ *
+ * Device managed version of fwat_device_register().
+ *
+ * Return: pointer to the new fwat_device on success, ERR_PTR on failure
+ */
+struct fwat_device *
+devm_fwat_device_register(struct device *parent, const char *name, void *data,
+			  const struct attribute_group **groups)
+{
+	struct fwat_device *fadev;
+	int ret;
+
+	fadev = fwat_device_register(parent, name, data, groups);
+	if (IS_ERR(fadev))
+		return fadev;
+
+	ret = devm_add_action_or_reset(parent, devm_fwat_device_release, fadev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return fadev;
+}
+EXPORT_SYMBOL_GPL(devm_fwat_device_register);
+
 static __init int fw_attributes_class_init(void)
 {
 	return class_register(&firmware_attributes_class);
@@ -23,5 +147,7 @@ static __exit void fw_attributes_class_exit(void)
 module_exit(fw_attributes_class_exit);
 
 MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
+MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net>");
+MODULE_AUTHOR("Kurt Borja <kuurtb@gmail.com>");
 MODULE_DESCRIPTION("Firmware attributes class helper module");
 MODULE_LICENSE("GPL");
diff --git a/drivers/platform/x86/firmware_attributes_class.h b/drivers/platform/x86/firmware_attributes_class.h
index d27abe54fcf9812a2f0868eec5426bbc8e7eb21c..048fd0904f767357ef856e687ec4cf3260016ec6 100644
--- a/drivers/platform/x86/firmware_attributes_class.h
+++ b/drivers/platform/x86/firmware_attributes_class.h
@@ -5,8 +5,36 @@
 #ifndef FW_ATTR_CLASS_H
 #define FW_ATTR_CLASS_H
 
+#include <linux/container_of.h>
+#include <linux/device.h>
 #include <linux/device/class.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
 
 extern const struct class firmware_attributes_class;
 
+/**
+ * struct fwat_device - The firmware-attributes device
+ * @dev: The class device.
+ * @attrs_kobj: The "attributes" root kobject.
+ * @groups: Sysfs groups attached to the @attrs_kobj.
+ */
+struct fwat_device {
+	struct device dev;
+	struct kset *attrs_kset;
+	const struct attribute_group **groups;
+};
+
+#define to_fwat_device(_d)	container_of_const(_d, struct fwat_device, dev)
+
+struct fwat_device * __must_check
+fwat_device_register(struct device *parent, const char *name, void *drvdata,
+		     const struct attribute_group **groups);
+
+void fwat_device_unregister(struct fwat_device *fwadev);
+
+struct fwat_device * __must_check
+devm_fwat_device_register(struct device *parent, const char *name, void *data,
+			  const struct attribute_group **groups);
+
 #endif /* FW_ATTR_CLASS_H */

-- 
2.50.0

[PATCH v6 2/6] platform/x86: firmware_attributes_class: Add high level API for the attributes interface

[Kurt Borja]

Add high level API to aid in the creation of attribute groups attached
to the `attrs_kobj` (per ABI specification).

This new API lets users configure each group, either statically or
dynamically through a (per type) data struct and then create this group
through the generic fwat_create_group() macro.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/platform/x86/firmware_attributes_class.c | 539 +++++++++++++++++++++++
 drivers/platform/x86/firmware_attributes_class.h | 329 ++++++++++++++
 2 files changed, 868 insertions(+)

diff --git a/drivers/platform/x86/firmware_attributes_class.c b/drivers/platform/x86/firmware_attributes_class.c
index 084e66481a4a29bfd801d9e5bbb4067ac25b8437..40469586cbb4f011e3f03f6ccb8dea643f319ab3 100644
--- a/drivers/platform/x86/firmware_attributes_class.c
+++ b/drivers/platform/x86/firmware_attributes_class.c
@@ -10,13 +10,65 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/string_choices.h>
 #include "firmware_attributes_class.h"
 
+#define to_fwat_bool_data(_c) \
+	container_of_const(_c, struct fwat_bool_data, group)
+#define to_fwat_enum_data(_c) \
+	container_of_const(_c, struct fwat_enum_data, group)
+#define to_fwat_int_data(_c) \
+	container_of_const(_c, struct fwat_int_data, group)
+#define to_fwat_str_data(_c) \
+	container_of_const(_c, struct fwat_str_data, group)
+
+#define __FWAT_ATTR(_name, _mode, _show, _store, _type) {		\
+		.attr = { .name = __stringify(_name), .mode = _mode },	\
+		.show = _show, .store = _store, .type = _type,		\
+	}
+
+#define FWAT_ATTR_RO(_prefix, _name, _show, _type)			\
+	static struct fwat_attribute fwat_##_prefix##_##_name##_attr =	\
+		__FWAT_ATTR(_name, 0444, _show, NULL, _type)
+
+#define FWAT_GROUP_ATTR(_type, _mode, _name)					\
+	static struct fwat_attribute fwat_##_type##_##_name##_attr =		\
+		__FWAT_ATTR(_name, _mode, _type##_group_show,			\
+			    _type##_group_store, fwat_##_type##_##_name)
+
+struct fwat_group {
+	const struct fwat_group_data *data;
+	struct device *dev;
+	struct kobject kobj;
+};
+
+#define kobj_to_fwat_group(_k) \
+	container_of_const(_k, struct fwat_group, kobj)
+
+struct fwat_attribute {
+	struct attribute attr;
+	ssize_t (*show)(struct kobject *kobj, const struct fwat_attribute *attr,
+			char *buf);
+	ssize_t (*store)(struct kobject *kobj, const struct fwat_attribute *attr,
+			 const char *buf, size_t count);
+	int type;
+};
+
+#define to_fwat_attribute(_a) \
+	container_of_const(_a, struct fwat_attribute, attr)
+
 const struct class firmware_attributes_class = {
 	.name = "firmware-attributes",
 };
 EXPORT_SYMBOL_GPL(firmware_attributes_class);
 
+static const char * const fwat_type_labels[] = {
+	[fwat_group_type_boolean]			= "boolean",
+	[fwat_group_type_enumeration]			= "enumeration",
+	[fwat_group_type_integer]			= "integer",
+	[fwat_group_type_string]			= "string",
+};
+
 static void fwat_device_release(struct device *dev)
 {
 	struct fwat_device *fadev = to_fwat_device(dev);
@@ -24,6 +76,492 @@ static void fwat_device_release(struct device *dev)
 	kfree(fadev);
 }
 
+static ssize_t
+type_show(struct kobject *kobj, const struct fwat_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%s\n", fwat_type_labels[attr->type]);
+}
+
+static ssize_t
+display_name_show(struct kobject *kobj, const struct fwat_attribute *attr,
+		  char *buf)
+{
+	struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const char *disp_name = group->data->display_name;
+
+	if (!disp_name)
+		return -EOPNOTSUPP;
+
+	return sysfs_emit(buf, "%s\n", disp_name);
+}
+
+static ssize_t
+display_name_language_code_show(struct kobject *kobj, const struct fwat_attribute *attr,
+				char *buf)
+{
+	struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const char *lang_code = group->data->language_code;
+
+	if (!lang_code)
+		return -EOPNOTSUPP;
+
+	return sysfs_emit(buf, "%s\n", lang_code);
+}
+
+static ssize_t
+bool_group_show(struct kobject *kobj, const struct fwat_attribute *attr, char *buf)
+{
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_bool_data *data = to_fwat_bool_data(group->data);
+	bool val;
+	int ret;
+
+	/* show_override does not affect current_value */
+	if (data->group.show_override && attr->type != fwat_bool_current_value)
+		return data->group.show_override(group->dev, attr->type, buf);
+
+	switch (attr->type) {
+	case fwat_bool_current_value:
+		ret = data->read(group->dev, data->group.id, &val);
+		if (ret < 0)
+			return ret;
+		break;
+	case fwat_bool_default_value:
+		val = data->default_val;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return sysfs_emit(buf, "%s\n", str_yes_no(val));
+}
+
+static ssize_t
+bool_group_store(struct kobject *kobj, const struct fwat_attribute *attr,
+		 const char *buf, size_t count)
+{
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_bool_data *data = to_fwat_bool_data(group->data);
+	bool val;
+	int ret;
+
+	ret = kstrtobool(buf, &val);
+	if (ret)
+		return ret;
+
+	ret = data->write(group->dev, data->group.id, val);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t
+enum_group_show(struct kobject *kobj, const struct fwat_attribute *attr, char *buf)
+{
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_enum_data *data = to_fwat_enum_data(group->data);
+	int val_idx, sz;
+	int ret;
+
+	/* show_override does not affect current_value */
+	if (data->group.show_override && attr->type != fwat_enum_current_value)
+		return data->group.show_override(group->dev, attr->type, buf);
+
+	switch (attr->type) {
+	case fwat_enum_current_value:
+		ret = data->read(group->dev, data->group.id, &val_idx);
+		if (ret < 0)
+			return ret;
+		break;
+	case fwat_enum_default_value:
+		val_idx = data->default_idx;
+		break;
+	case fwat_enum_possible_values:
+		if (!data->possible_vals || !data->possible_vals[0])
+			return -EOPNOTSUPP;
+
+		sz = sysfs_emit_at(buf, 0, "%s", data->possible_vals[0]);
+		for (unsigned int i = 1; data->possible_vals[i]; i++)
+			sz += sysfs_emit_at(buf, sz, ";%s", data->possible_vals[i]);
+		sz += sysfs_emit_at(buf, sz, "\n");
+
+		return sz;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return sysfs_emit(buf, "%s\n", data->possible_vals[val_idx]);
+}
+
+static ssize_t
+enum_group_store(struct kobject *kobj, const struct fwat_attribute *attr,
+		 const char *buf, size_t count)
+{
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_enum_data *data = to_fwat_enum_data(group->data);
+	int val_idx;
+	int ret;
+
+	val_idx = __sysfs_match_string(data->possible_vals, -1, buf);
+	if (val_idx < 0)
+		return val_idx;
+
+	ret = data->write(group->dev, data->group.id, val_idx);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t
+int_group_show(struct kobject *kobj, const struct fwat_attribute *attr, char *buf)
+{
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_int_data *data = to_fwat_int_data(group->data);
+	long val;
+	int ret;
+
+	/* show_override does not affect current_value */
+	if (data->group.show_override && attr->type != fwat_int_current_value)
+		return data->group.show_override(group->dev, attr->type, buf);
+
+	switch (attr->type) {
+	case fwat_int_current_value:
+		ret = data->read(group->dev, data->group.id, &val);
+		if (ret < 0)
+			return ret;
+		break;
+	case fwat_int_default_value:
+		val = data->default_val;
+		break;
+	case fwat_int_min_value:
+		val = data->min_val;
+		break;
+	case fwat_int_max_value:
+		val = data->max_val;
+		break;
+	case fwat_int_scalar_increment:
+		val = data->increment;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return sysfs_emit(buf, "%ld\n", val);
+}
+
+static ssize_t
+int_group_store(struct kobject *kobj, const struct fwat_attribute *attr,
+		const char *buf, size_t count)
+{
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_int_data *data = to_fwat_int_data(group->data);
+	long val;
+	int ret;
+
+	ret = kstrtol(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = data->write(group->dev, data->group.id, val);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t
+str_group_show(struct kobject *kobj, const struct fwat_attribute *attr, char *buf)
+{
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_str_data *data = to_fwat_str_data(group->data);
+	const char *val;
+	long len;
+	int ret;
+
+	/* show_override does not affect current_value */
+	if (data->group.show_override && attr->type != fwat_str_current_value)
+		return data->group.show_override(group->dev, attr->type, buf);
+
+	switch (attr->type) {
+	case fwat_str_current_value:
+		ret = data->read(group->dev, data->group.id, &val);
+		if (ret < 0)
+			return ret;
+		break;
+	case fwat_str_default_value:
+		val = data->default_val;
+		break;
+	case fwat_str_min_length:
+		len = data->min_len;
+		return sysfs_emit(buf, "%ld\n", len);
+	case fwat_str_max_length:
+		len = data->max_len;
+		return sysfs_emit(buf, "%ld\n", len);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return sysfs_emit(buf, "%s\n", val);
+}
+
+static ssize_t
+str_group_store(struct kobject *kobj, const struct fwat_attribute *attr,
+		const char *buf, size_t count)
+{
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_str_data *data = to_fwat_str_data(group->data);
+	int ret;
+
+	ret = data->write(group->dev, data->group.id, buf);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+#define __FWAT_TYPE_NONE	(-1) /* Dummy value, never evaluated. */
+
+FWAT_ATTR_RO(all, display_name, display_name_show, __FWAT_TYPE_NONE);
+FWAT_ATTR_RO(all, display_name_language_code, display_name_language_code_show,
+	     __FWAT_TYPE_NONE);
+
+FWAT_ATTR_RO(bool, type, type_show, fwat_group_type_boolean);
+FWAT_GROUP_ATTR(bool, 0644, current_value);
+FWAT_GROUP_ATTR(bool, 0444, default_value);
+
+FWAT_ATTR_RO(enum, type, type_show, fwat_group_type_enumeration);
+FWAT_GROUP_ATTR(enum, 0644, current_value);
+FWAT_GROUP_ATTR(enum, 0444, default_value);
+FWAT_GROUP_ATTR(enum, 0444, possible_values);
+
+FWAT_ATTR_RO(int, type, type_show, fwat_group_type_integer);
+FWAT_GROUP_ATTR(int, 0644, current_value);
+FWAT_GROUP_ATTR(int, 0444, default_value);
+FWAT_GROUP_ATTR(int, 0444, min_value);
+FWAT_GROUP_ATTR(int, 0444, max_value);
+FWAT_GROUP_ATTR(int, 0444, scalar_increment);
+
+FWAT_ATTR_RO(str, type, type_show, fwat_group_type_string);
+FWAT_GROUP_ATTR(str, 0644, current_value);
+FWAT_GROUP_ATTR(str, 0444, default_value);
+FWAT_GROUP_ATTR(str, 0444, min_length);
+FWAT_GROUP_ATTR(str, 0444, max_length);
+
+static struct attribute *fwat_bool_attrs[] = {
+	&fwat_bool_type_attr.attr,
+	&fwat_all_display_name_attr.attr,
+	&fwat_all_display_name_language_code_attr.attr,
+	&fwat_bool_current_value_attr.attr,
+	&fwat_bool_default_value_attr.attr,
+	NULL
+};
+
+static struct attribute *fwat_enum_attrs[] = {
+	&fwat_enum_type_attr.attr,
+	&fwat_all_display_name_attr.attr,
+	&fwat_all_display_name_language_code_attr.attr,
+	&fwat_enum_current_value_attr.attr,
+	&fwat_enum_default_value_attr.attr,
+	&fwat_enum_possible_values_attr.attr,
+	NULL
+};
+
+static struct attribute *fwat_int_attrs[] = {
+	&fwat_int_type_attr.attr,
+	&fwat_all_display_name_attr.attr,
+	&fwat_all_display_name_language_code_attr.attr,
+	&fwat_int_current_value_attr.attr,
+	&fwat_int_default_value_attr.attr,
+	&fwat_int_min_value_attr.attr,
+	&fwat_int_max_value_attr.attr,
+	&fwat_int_scalar_increment_attr.attr,
+	NULL
+};
+
+static struct attribute *fwat_str_attrs[] = {
+	&fwat_str_type_attr.attr,
+	&fwat_all_display_name_attr.attr,
+	&fwat_all_display_name_language_code_attr.attr,
+	&fwat_str_current_value_attr.attr,
+	&fwat_str_default_value_attr.attr,
+	&fwat_str_min_length_attr.attr,
+	&fwat_str_max_length_attr.attr,
+	NULL
+};
+
+static_assert(fwat_bool_current_value == 0);
+static_assert(fwat_enum_current_value == 0);
+static_assert(fwat_int_current_value == 0);
+static_assert(fwat_str_current_value == 0);
+
+static umode_t fwat_attr_visible(struct kobject *kobj, struct attribute *attr, int n)
+{
+	const struct fwat_attribute *fwat_attr = to_fwat_attribute(attr);
+	const struct fwat_group *group = kobj_to_fwat_group(kobj);
+	const struct fwat_group_data *data = group->data;
+
+	/* The `type` attribute is always first */
+	if (n == 0)
+		return attr->mode;
+
+	if (attr == &fwat_all_display_name_attr.attr)
+		return data->display_name ? attr->mode : 0;
+
+	if (attr == &fwat_all_display_name_language_code_attr.attr)
+		return data->language_code ? attr->mode : 0;
+
+	if (!fwat_attr->type)
+		return data->mode;
+
+	return test_bit(fwat_attr->type, &data->fattrs) ? attr->mode : 0;
+}
+
+static const struct attribute_group fwat_bool_group = {
+	.attrs = fwat_bool_attrs,
+	.is_visible = fwat_attr_visible,
+};
+__ATTRIBUTE_GROUPS(fwat_bool);
+
+static const struct attribute_group fwat_enum_group = {
+	.attrs = fwat_enum_attrs,
+	.is_visible = fwat_attr_visible,
+};
+__ATTRIBUTE_GROUPS(fwat_enum);
+
+static const struct attribute_group fwat_int_group = {
+	.attrs = fwat_int_attrs,
+	.is_visible = fwat_attr_visible,
+};
+__ATTRIBUTE_GROUPS(fwat_int);
+
+static const struct attribute_group fwat_str_group = {
+	.attrs = fwat_str_attrs,
+	.is_visible = fwat_attr_visible,
+};
+__ATTRIBUTE_GROUPS(fwat_str);
+
+static ssize_t
+fwat_attr_sysfs_show(struct kobject *kobj, struct attribute *attr, char *buf)
+{
+	const struct fwat_attribute *fwat_attr = to_fwat_attribute(attr);
+
+	if (!fwat_attr->show)
+		return -EOPNOTSUPP;
+
+	return fwat_attr->show(kobj, fwat_attr, buf);
+}
+
+static ssize_t
+fwat_attr_sysfs_store(struct kobject *kobj, struct attribute *attr, const char *buf,
+		      size_t count)
+{
+	const struct fwat_attribute *fwat_attr = to_fwat_attribute(attr);
+
+	if (!fwat_attr->store)
+		return -EOPNOTSUPP;
+
+	return fwat_attr->store(kobj, fwat_attr, buf, count);
+}
+
+static void fwat_group_release(struct kobject *kobj)
+{
+	struct fwat_group *group = kobj_to_fwat_group(kobj);
+
+	kfree(group);
+}
+
+static const struct sysfs_ops fwat_attr_sysfs_ops = {
+	.show = fwat_attr_sysfs_show,
+	.store = fwat_attr_sysfs_store,
+};
+
+static const struct kobj_type fwat_boolean_ktype = {
+	.sysfs_ops = &fwat_attr_sysfs_ops,
+	.release = fwat_group_release,
+	.default_groups = fwat_bool_groups,
+};
+
+static const struct kobj_type fwat_enumeration_ktype = {
+	.sysfs_ops = &fwat_attr_sysfs_ops,
+	.release = fwat_group_release,
+	.default_groups = fwat_enum_groups,
+};
+
+static const struct kobj_type fwat_integer_ktype = {
+	.sysfs_ops = &fwat_attr_sysfs_ops,
+	.release = fwat_group_release,
+	.default_groups = fwat_int_groups,
+};
+
+static const struct kobj_type fwat_string_ktype = {
+	.sysfs_ops = &fwat_attr_sysfs_ops,
+	.release = fwat_group_release,
+	.default_groups = fwat_str_groups,
+};
+
+static int __fwat_create_group(struct fwat_device *fadev, const struct kobj_type *ktype,
+			       const struct fwat_group_data *data)
+{
+	struct fwat_group *group;
+	int ret;
+
+	group = kzalloc(sizeof(*group), GFP_KERNEL);
+	if (!group)
+		return -ENOMEM;
+
+	group->dev = &fadev->dev;
+	group->data = data;
+
+	group->kobj.kset = fadev->attrs_kset;
+	ret = kobject_init_and_add(&group->kobj, ktype, NULL, "%s", data->name);
+	if (ret) {
+		kobject_put(&group->kobj);
+		return ret;
+	}
+
+	kobject_uevent(&group->kobj, KOBJ_ADD);
+
+	return 0;
+}
+
+static void fwat_remove_auto_groups(struct fwat_device *fadev)
+{
+	struct kobject *pos, *n;
+
+	list_for_each_entry_safe(pos, n, &fadev->attrs_kset->list, entry)
+		kobject_put(pos);
+}
+
+int __fwat_create_bool_group(struct fwat_device *fadev,
+			     const struct fwat_bool_data *data)
+{
+	return __fwat_create_group(fadev, &fwat_boolean_ktype, &data->group);
+}
+EXPORT_SYMBOL_GPL(__fwat_create_bool_group);
+
+int __fwat_create_enum_group(struct fwat_device *fadev,
+			     const struct fwat_enum_data *data)
+{
+	return __fwat_create_group(fadev, &fwat_enumeration_ktype, &data->group);
+}
+EXPORT_SYMBOL_GPL(__fwat_create_enum_group);
+
+int __fwat_create_int_group(struct fwat_device *fadev,
+			    const struct fwat_int_data *data)
+{
+	return __fwat_create_group(fadev, &fwat_integer_ktype, &data->group);
+}
+EXPORT_SYMBOL_GPL(__fwat_create_int_group);
+
+int __fwat_create_str_group(struct fwat_device *fadev,
+			    const struct fwat_str_data *data)
+{
+	return __fwat_create_group(fadev, &fwat_string_ktype, &data->group);
+}
+EXPORT_SYMBOL_GPL(__fwat_create_str_group);
+
 /**
  * fwat_device_register - Create and register a firmware-attributes class
  *			  device
@@ -91,6 +629,7 @@ void fwat_device_unregister(struct fwat_device *fadev)
 	if (!fadev)
 		return;
 
+	fwat_remove_auto_groups(fadev);
 	kset_unregister(fadev->attrs_kset);
 	device_unregister(&fadev->dev);
 }
diff --git a/drivers/platform/x86/firmware_attributes_class.h b/drivers/platform/x86/firmware_attributes_class.h
index 048fd0904f767357ef856e687ec4cf3260016ec6..2af79d1d66fc83a9c1b8e564138c8dfff67c9e78 100644
--- a/drivers/platform/x86/firmware_attributes_class.h
+++ b/drivers/platform/x86/firmware_attributes_class.h
@@ -27,6 +27,335 @@ struct fwat_device {
 
 #define to_fwat_device(_d)	container_of_const(_d, struct fwat_device, dev)
 
+enum fwat_group_type {
+	fwat_group_type_boolean,
+	fwat_group_type_enumeration,
+	fwat_group_type_integer,
+	fwat_group_type_string,
+};
+
+enum fwat_bool_attrs {
+	fwat_bool_current_value,
+	fwat_bool_default_value,
+	fwat_bool_attrs_last
+};
+
+#define FWAT_BOOL_CURRENT_VALUE			BIT(fwat_bool_current_value)
+#define FWAT_BOOL_DEFAULT_VALUE			BIT(fwat_bool_default_value)
+#define FWAT_BOOL_ALL_ATTRS			GENMASK(fwat_bool_attrs_last, 0)
+
+enum fwat_enum_attrs {
+	fwat_enum_current_value,
+	fwat_enum_default_value,
+	fwat_enum_possible_values,
+	fwat_enum_attrs_last
+};
+
+#define FWAT_ENUM_CURRENT_VALUE			BIT(fwat_enum_current_value)
+#define FWAT_ENUM_DEFAULT_VALUE			BIT(fwat_enum_default_value)
+#define FWAT_ENUM_POSSIBLE_VALUES		BIT(fwat_enum_possible_values)
+#define FWAT_ENUM_ALL_ATTRS			GENMASK(fwat_enum_attrs_last, 0)
+
+enum fwat_int_attrs {
+	fwat_int_current_value,
+	fwat_int_default_value,
+	fwat_int_min_value,
+	fwat_int_max_value,
+	fwat_int_scalar_increment,
+	fwat_int_attrs_last
+};
+
+#define FWAT_INT_CURRENT_VALUE			BIT(fwat_int_current_value)
+#define FWAT_INT_DEFAULT_VALUE			BIT(fwat_int_default_value)
+#define FWAT_INT_MIN_VALUE			BIT(fwat_int_min_value)
+#define FWAT_INT_MAX_VALUE			BIT(fwat_int_max_value)
+#define FWAT_INT_SCALAR_INCREMENT		BIT(fwat_int_scalar_increment)
+#define FWAT_INT_ALL_ATTRS			GENMASK(fwat_int_attrs_last, 0)
+
+enum fwat_str_attrs {
+	fwat_str_current_value,
+	fwat_str_default_value,
+	fwat_str_min_length,
+	fwat_str_max_length,
+	fwat_str_attrs_last
+};
+
+#define FWAT_STR_CURRENT_VALUE			BIT(fwat_str_current_value)
+#define FWAT_STR_DEFAULT_VALUE			BIT(fwat_str_default_value)
+#define FWAT_STR_MIN_LENGTH			BIT(fwat_str_min_length)
+#define FWAT_STR_MAX_LENGTH			BIT(fwat_str_max_length)
+#define FWAT_STR_ALL_ATTRS			GENMASK(fwat_str_attrs_last, 0)
+
+/**
+ * struct fwat_group_data - Data struct common between group types
+ * @id: Group ID defined by the user.
+ * @name: Name of the group.
+ * @display_name: Name shown in the display_name attribute. (Optional)
+ * @language_code: Language code shown in the display_name_language_code
+ *                 attribute. (Optional)
+ * @mode: Mode for the current_value attribute. All other attributes will have
+ *        0444 permissions.
+ * @fattrs: Bitmap of selected attributes for this group type.
+ * @show_override: Custom show method for attributes in this group, except for
+ *		   the current_value attribute, for which the a `read` callback
+ *		   will still be used. (Optional)
+ *
+ * NOTE: This struct is not meant to be defined directly. It is supposed to be
+ * embedded and defined as part of fwat_[type]_data structs.
+ */
+struct fwat_group_data {
+	long id;
+	umode_t mode;
+	const char *name;
+	const char *display_name;
+	const char *language_code;
+	unsigned long fattrs;
+	ssize_t (*show_override)(struct device *dev, int type, char *buf);
+};
+
+/**
+ * struct fwat_bool_data - Data struct for the boolean group type
+ * @read: Read callback for the current_value attribute.
+ * @write: Write callback for the current_value attribute.
+ * @default_val: Default value.
+ * @group: Group data.
+ */
+struct fwat_bool_data {
+	int (*read)(struct device *dev, long id, bool *val);
+	int (*write)(struct device *dev, long id, bool val);
+	bool default_val;
+	struct fwat_group_data group;
+};
+
+/**
+ * struct fwat_enum_data - Data struct for the enumeration group type
+ * @read: Read callback for the current_value attribute.
+ * @write: Write callback for the current_value attribute.
+ * @default_idx: Index of the default value in the @possible_vals array.
+ * @possible_vals: Array of possible value strings for this group type.
+ * @group: Group data.
+ *
+ * NOTE: The `val_idx` argument in the @write callback is guaranteed to be a
+ *       valid (within bounds) index. However, the user is in charge of writing
+ *       valid indexes to the `*val_idx` argument of the @read callback.
+ *       Failing to do so may result in an OOB access.
+ */
+struct fwat_enum_data {
+	int (*read)(struct device *dev, long id, int *val_idx);
+	int (*write)(struct device *dev, long id, int val_idx);
+	int default_idx;
+	const char * const *possible_vals;
+	struct fwat_group_data group;
+};
+
+/**
+ * struct fwat_int_data - Data struct for the integer group type
+ * @read: Read callback for the current_value attribute.
+ * @write: Write callback for the current_value attribute.
+ * @default_val: Default value.
+ * @min_val: Minimum value.
+ * @max_val: Maximum value.
+ * @increment: Scalar increment for this value.
+ * @group: Group data.
+ *
+ * NOTE: The @min_val, @max_val, @increment constraints are merely informative.
+ *       These values are not enforced in any of the callbacks.
+ */
+struct fwat_int_data {
+	int (*read)(struct device *dev, long id, long *val);
+	int (*write)(struct device *dev, long id, long val);
+	long default_val;
+	long min_val;
+	long max_val;
+	long increment;
+	struct fwat_group_data group;
+};
+
+/**
+ * struct fwat_str_data - Data struct for the string group type
+ * @read: Read callback for the current_value attribute.
+ * @write: Write callback for the current_value attribute.
+ * @default_val: Default value.
+ * @min_len: Minimum string length.
+ * @max_len: Maximum string length.
+ * @group: Group data.
+ *
+ * NOTE: The @min_len, @max_len constraints are merely informative. These
+ *       values are not enforced in any of the callbacks.
+ */
+struct fwat_str_data {
+	int (*read)(struct device *dev, long id, const char **buf);
+	int (*write)(struct device *dev, long id, const char *buf);
+	const char *default_val;
+	long min_len;
+	long max_len;
+	struct fwat_group_data group;
+};
+
+#define __FWAT_GROUP(_name, _disp_name, _mode, _fattrs) \
+	{ .name = __stringify(_name), .display_name = _disp_name, .mode = _mode, .fattrs = _fattrs }
+
+/**
+ * DEFINE_FWAT_BOOL_GROUP - Convenience macro to quickly define a static
+ *                          struct fwat_bool_data instance
+ * @_name: Name of the group.
+ * @_disp_name: Name shown in the display_name attribute. (Optional)
+ * @_def_val: Default value.
+ * @_mode: Mode for the current_value attribute. All other attributes will have
+ *         0444 permissions.
+ * @_fattrs: Bitmap of selected attributes for this group type.
+ *
+ * `read` and `write` callbacks are required to be already defined as
+ * `_name##_read` and `_name##_write` respectively.
+ */
+#define DEFINE_FWAT_BOOL_GROUP(_name, _disp_name, _def_val, _mode, _fattrs) \
+	static const struct fwat_bool_data _name##_group_data = {	\
+		.read = _name##_read,					\
+		.write = _name##_write,					\
+		.default_val = _def_val,				\
+		.group = __FWAT_GROUP(_name, _disp_name, _mode, _fattrs), \
+	}
+
+/**
+ * DEFINE_FWAT_ENUM_GROUP - Convenience macro to quickly define a static
+ *                          struct fwat_enum_data instance
+ * @_name: Name of the group.
+ * @_disp_name: Name shown in the display_name attribute. (Optional)
+ * @_def_idx: Index of the default value in the @_poss_vals array.
+ * @_poss_vals: Array of possible value strings for this group type.
+ * @_mode: Mode for the current_value attribute. All other attributes will have
+ *         0444 permissions.
+ * @_fattrs: Bitmap of selected attributes for this group type.
+ *
+ * `read` and `write` callbacks are required to be already defined as
+ * `_name##_read` and `_name##_write` respectively.
+ *
+ * NOTE: The `val_idx` argument in the `write` callback is guaranteed to be a
+ *       valid (within bounds) index. However, the user is in charge of writing
+ *       valid indexes to the `*val_idx` argument of the `read` callback.
+ *       Failing to do so may result in an OOB access.
+ */
+#define DEFINE_FWAT_ENUM_GROUP(_name, _disp_name, _poss_vals, _def_idx, _mode, _fattrs) \
+	static const struct fwat_enum_data _name##_group_data = {	\
+		.read = _name##_read,					\
+		.write = _name##_write,					\
+		.default_idx = _def_idx,				\
+		.possible_vals = _poss_vals,				\
+		.group = __FWAT_GROUP(_name, _disp_name, _mode, _fattrs), \
+	}
+
+/**
+ * DEFINE_FWAT_INT_GROUP - Convenience macro to quickly define a static
+ *                         struct fwat_int_data instance
+ * @_name: Name of the group.
+ * @_disp_name: Name shown in the display_name attribute. (Optional)
+ * @_def_val: Default value.
+ * @_min: Minimum value.
+ * @_max: Maximum value.
+ * @_inc: Scalar increment for this value.
+ * @_mode: Mode for the current_value attribute. All other attributes will have
+ *         0444 permissions.
+ * @_fattrs: Bitmap of selected attributes for this group type.
+ *
+ * `read` and `write` callbacks are required to be already defined as
+ * `_name##_read` and `_name##_write` respectively.
+ *
+ * NOTE: The @_min, @_max, @_inc constraints are merely informative. These
+ *       values are not enforced in any of the callbacks.
+ */
+#define DEFINE_FWAT_INT_GROUP(_name, _disp_name, _def_val, _min, _max, _inc, _mode, _fattrs) \
+	static const struct fwat_int_data _name##_group_data = {	\
+		.read = _name##_read,					\
+		.write = _name##_write,					\
+		.default_val = _def_val,				\
+		.min_val = _min,					\
+		.max_val = _max,					\
+		.increment = _inc,					\
+		.group = __FWAT_GROUP(_name, _disp_name, _mode, _fattrs), \
+	}
+
+/**
+ * DEFINE_FWAT_STR_GROUP - Convenience macro to quickly define a static
+ *                         struct fwat_str_data instance
+ * @_name: Name of the group.
+ * @_disp_name: Name shown in the display_name attribute. (Optional)
+ * @_def_val: Default value.
+ * @_min: Minimum string length.
+ * @_max: Maximum string length.
+ * @_mode: Mode for the current_value attribute. All other attributes will have
+ *         0444 permissions.
+ * @_fattrs: Bitmap of selected attributes for this group type.
+ *
+ * `read` and `write` callbacks are required to be already defined as
+ * `_name##_read` and `_name##_write` respectively.
+ *
+ * NOTE: The @_min, @_max constraints are merely informative. These values are
+ *       not enforced in any of the callbacks.
+ */
+#define DEFINE_FWAT_STR_GROUP(_name, _disp_name, _def_val, _min, _max, _mode, _fattrs) \
+	static const struct fwat_str_data _name##_group_data = {	\
+		.read = _name##_read,					\
+		.write = _name##_write,					\
+		.default_val = _def_val,				\
+		.min_len = _min,					\
+		.max_len = _max,					\
+		.group = __FWAT_GROUP(_name, _disp_name, _mode, _fattrs), \
+	}
+
+int __fwat_create_bool_group(struct fwat_device *fadev,
+			     const struct fwat_bool_data *data);
+int __fwat_create_enum_group(struct fwat_device *fadev,
+			     const struct fwat_enum_data *data);
+int __fwat_create_int_group(struct fwat_device *fadev,
+			    const struct fwat_int_data *data);
+int __fwat_create_str_group(struct fwat_device *fadev,
+			    const struct fwat_str_data *data);
+
+/**
+ * fwat_create_group - Convenience generic macro to create a group
+ * @_dev: fwat_device
+ * @_data: One of fwat_{bool,enum,int,str}_data instance
+ *
+ * This macro (and associated functions) creates a sysfs group under the
+ * 'attributes' directory, which is located in the class device root directory.
+ *
+ * See Documentation/ABI/testing/sysfs-class-firmware-attributes for details.
+ *
+ * The @_data associated with this group may be created either statically,
+ * through DEFINE_FWAT_*_GROUP macros or dynamically, in which case the user
+ * would have allocate and fill the struct manually. The dynamic approach should
+ * be preferred when group constraints and/or visibility is decided dynamically.
+ *
+ * Example:
+ *
+ * static int stat_read(...){...};
+ * static int stat_write(...){...};
+ *
+ * DEFINE_FWAT_(BOOL|ENUM|INT|STR)_GROUP(stat, ...);
+ *
+ * static int create_groups(struct fwat_device *fadev)
+ * {
+ *	struct fwat_enum_data *dyn_group_data;
+ *
+ *	dyn_group_data = kzalloc(...);
+ *	// Fill the data
+ *	...
+ *	fwat_create_group(fadev, &stat_group_data);
+ *	fwat_create_group(fadev, &dyn_group_data);
+ *	fwat_create_group(...);
+ *	...
+ * }
+ *
+ * Return: 0 on success, -errno on failure
+ */
+#define fwat_create_group(_dev, _data) \
+	_Generic((_data),							\
+		 const struct fwat_bool_data * : __fwat_create_bool_group,	\
+		 const struct fwat_enum_data * : __fwat_create_enum_group,	\
+		 const struct fwat_int_data * : __fwat_create_int_group,	\
+		 const struct fwat_str_data * : __fwat_create_str_group)	\
+		(_dev, _data)
+
 struct fwat_device * __must_check
 fwat_device_register(struct device *parent, const char *name, void *drvdata,
 		     const struct attribute_group **groups);

-- 
2.50.0

[PATCH v6 3/6] platform/x86: firmware_attributes_class: Move header to include directory

[Kurt Borja]

Move firmware_attributes_class.h to include/linux/ to avoid hardcoding
paths inside drivers/platform/x86/.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/platform/x86/dell/dell-wmi-sysman/sysman.c                  | 2 +-
 drivers/platform/x86/firmware_attributes_class.c                    | 2 +-
 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c                        | 2 +-
 drivers/platform/x86/lenovo/think-lmi.c                             | 2 +-
 drivers/platform/x86/samsung-galaxybook.c                           | 2 +-
 {drivers/platform/x86 => include/linux}/firmware_attributes_class.h | 0
 6 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
index f5402b714657297e0ab4bb52a988fcc4c787a5fb..a93189f48dbb79aff39b4b1c254c637dc8e8ef35 100644
--- a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
@@ -12,8 +12,8 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/wmi.h>
+#include <linux/firmware_attributes_class.h>
 #include "dell-wmi-sysman.h"
-#include "../../firmware_attributes_class.h"
 
 #define MAX_TYPES  4
 #include <linux/nls.h>
diff --git a/drivers/platform/x86/firmware_attributes_class.c b/drivers/platform/x86/firmware_attributes_class.c
index 40469586cbb4f011e3f03f6ccb8dea643f319ab3..4652637de9bc279ef2030503efb18223fe64a657 100644
--- a/drivers/platform/x86/firmware_attributes_class.c
+++ b/drivers/platform/x86/firmware_attributes_class.c
@@ -11,7 +11,7 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/string_choices.h>
-#include "firmware_attributes_class.h"
+#include <linux/firmware_attributes_class.h>
 
 #define to_fwat_bool_data(_c) \
 	container_of_const(_c, struct fwat_bool_data, group)
diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
index 5bfa7159f5bcd57385a20fe9ac646597b320a378..c002f72b6ac083db8106e9bd044e8a8fc1d3f310 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
@@ -12,7 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/wmi.h>
 #include "bioscfg.h"
-#include "../../firmware_attributes_class.h"
+#include <linux/firmware_attributes_class.h>
 #include <linux/nls.h>
 #include <linux/errno.h>
 
diff --git a/drivers/platform/x86/lenovo/think-lmi.c b/drivers/platform/x86/lenovo/think-lmi.c
index 0992b41b6221da77db2186f0ec8cda6c10a4f689..ecda54c26a6f01b77e061346ff8d99ba657e4b56 100644
--- a/drivers/platform/x86/lenovo/think-lmi.c
+++ b/drivers/platform/x86/lenovo/think-lmi.c
@@ -20,7 +20,7 @@
 #include <linux/types.h>
 #include <linux/dmi.h>
 #include <linux/wmi.h>
-#include "../firmware_attributes_class.h"
+#include <linux/firmware_attributes_class.h>
 #include "think-lmi.h"
 
 static bool debug_support;
diff --git a/drivers/platform/x86/samsung-galaxybook.c b/drivers/platform/x86/samsung-galaxybook.c
index 3c13e13d488584300c9765132861be5c2aeca269..28046bb941c4b4947e10931690a290d80e909922 100644
--- a/drivers/platform/x86/samsung-galaxybook.c
+++ b/drivers/platform/x86/samsung-galaxybook.c
@@ -28,7 +28,7 @@
 #include <linux/uuid.h>
 #include <linux/workqueue.h>
 #include <acpi/battery.h>
-#include "firmware_attributes_class.h"
+#include <linux/firmware_attributes_class.h>
 
 #define DRIVER_NAME "samsung-galaxybook"
 
diff --git a/drivers/platform/x86/firmware_attributes_class.h b/include/linux/firmware_attributes_class.h
similarity index 100%
rename from drivers/platform/x86/firmware_attributes_class.h
rename to include/linux/firmware_attributes_class.h

-- 
2.50.0

[PATCH v6 4/6] platform/x86: samsung-galaxybook: Transition new firmware_attributes API

[Kurt Borja]

Transition to new firmware_attributes API.

Defining firmware_attributes groups statically through
DEFINE_FWAT_ENUM_GROUP() incurs in a minor ABI change. In particular the
display_name_language_code attribute is no longer created. Fortunately,
this doesn't break user-space compatibility, because this attribute is
not required, neither by the ABI specification nor by user-space tools.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/platform/x86/samsung-galaxybook.c | 238 ++++++++----------------------
 1 file changed, 63 insertions(+), 175 deletions(-)

diff --git a/drivers/platform/x86/samsung-galaxybook.c b/drivers/platform/x86/samsung-galaxybook.c
index 28046bb941c4b4947e10931690a290d80e909922..0bf736c02a1870342a024507dd6b9f6d8e7d0f82 100644
--- a/drivers/platform/x86/samsung-galaxybook.c
+++ b/drivers/platform/x86/samsung-galaxybook.c
@@ -36,8 +36,6 @@ struct samsung_galaxybook {
 	struct platform_device *platform;
 	struct acpi_device *acpi;
 
-	struct device *fw_attrs_dev;
-	struct kset *fw_attrs_kset;
 	/* block in case firmware attributes are updated in multiple threads */
 	struct mutex fw_attr_lock;
 
@@ -60,36 +58,6 @@ struct samsung_galaxybook {
 	u8 profile_performance_modes[PLATFORM_PROFILE_LAST];
 };
 
-enum galaxybook_fw_attr_id {
-	GB_ATTR_POWER_ON_LID_OPEN,
-	GB_ATTR_USB_CHARGING,
-	GB_ATTR_BLOCK_RECORDING,
-};
-
-static const char * const galaxybook_fw_attr_name[] = {
-	[GB_ATTR_POWER_ON_LID_OPEN] = "power_on_lid_open",
-	[GB_ATTR_USB_CHARGING]      = "usb_charging",
-	[GB_ATTR_BLOCK_RECORDING]   = "block_recording",
-};
-
-static const char * const galaxybook_fw_attr_desc[] = {
-	[GB_ATTR_POWER_ON_LID_OPEN] = "Power On Lid Open",
-	[GB_ATTR_USB_CHARGING]      = "USB Charging",
-	[GB_ATTR_BLOCK_RECORDING]   = "Block Recording",
-};
-
-#define GB_ATTR_LANGUAGE_CODE "en_US.UTF-8"
-
-struct galaxybook_fw_attr {
-	struct samsung_galaxybook *galaxybook;
-	enum galaxybook_fw_attr_id fw_attr_id;
-	struct attribute_group attr_group;
-	struct kobj_attribute display_name;
-	struct kobj_attribute current_value;
-	int (*get_value)(struct samsung_galaxybook *galaxybook, bool *value);
-	int (*set_value)(struct samsung_galaxybook *galaxybook, const bool value);
-};
-
 struct sawb {
 	u16 safn;
 	u16 sasb;
@@ -908,150 +876,95 @@ static int galaxybook_block_recording_init(struct samsung_galaxybook *galaxybook
 
 /* Firmware Attributes setup */
 
-static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+static const char * const galaxybook_possible_vals[] = {
+	[false] = "0", [true] = "1", NULL
+};
+
+static int power_on_lid_open_read(struct device *dev, long id, int *val_idx)
 {
-	return sysfs_emit(buf, "enumeration\n");
-}
-
-static struct kobj_attribute fw_attr_type = __ATTR_RO(type);
-
-static ssize_t default_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
-{
-	return sysfs_emit(buf, "0\n");
-}
-
-static struct kobj_attribute fw_attr_default_value = __ATTR_RO(default_value);
-
-static ssize_t possible_values_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
-{
-	return sysfs_emit(buf, "0;1\n");
-}
-
-static struct kobj_attribute fw_attr_possible_values = __ATTR_RO(possible_values);
-
-static ssize_t display_name_language_code_show(struct kobject *kobj, struct kobj_attribute *attr,
-					       char *buf)
-{
-	return sysfs_emit(buf, "%s\n", GB_ATTR_LANGUAGE_CODE);
-}
-
-static struct kobj_attribute fw_attr_display_name_language_code =
-	__ATTR_RO(display_name_language_code);
-
-static ssize_t display_name_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
-{
-	struct galaxybook_fw_attr *fw_attr =
-		container_of(attr, struct galaxybook_fw_attr, display_name);
-
-	return sysfs_emit(buf, "%s\n", galaxybook_fw_attr_desc[fw_attr->fw_attr_id]);
-}
-
-static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
-{
-	struct galaxybook_fw_attr *fw_attr =
-		container_of(attr, struct galaxybook_fw_attr, current_value);
-	bool value;
+	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
+	bool val;
 	int err;
 
-	err = fw_attr->get_value(fw_attr->galaxybook, &value);
+	err = power_on_lid_open_acpi_get(galaxybook, &val);
 	if (err)
 		return err;
 
-	return sysfs_emit(buf, "%u\n", value);
+	*val_idx = val;
+
+	return 0;
 }
 
-static ssize_t current_value_store(struct kobject *kobj, struct kobj_attribute *attr,
-				   const char *buf, size_t count)
+static int power_on_lid_open_write(struct device *dev, long id, int val_idx)
 {
-	struct galaxybook_fw_attr *fw_attr =
-		container_of(attr, struct galaxybook_fw_attr, current_value);
-	struct samsung_galaxybook *galaxybook = fw_attr->galaxybook;
-	bool value;
-	int err;
-
-	if (!count)
-		return -EINVAL;
-
-	err = kstrtobool(buf, &value);
-	if (err)
-		return err;
+	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
 
 	guard(mutex)(&galaxybook->fw_attr_lock);
 
-	err = fw_attr->set_value(galaxybook, value);
+	return power_on_lid_open_acpi_set(galaxybook, val_idx ? true : false);
+}
+
+DEFINE_FWAT_ENUM_GROUP(power_on_lid_open, "Power On Lid Open", galaxybook_possible_vals,
+		       false, 0644, FWAT_ENUM_ALL_ATTRS);
+
+static int usb_charging_read(struct device *dev, long id, int *val_idx)
+{
+	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
+	bool val;
+	int err;
+
+	err = usb_charging_acpi_get(galaxybook, &val);
 	if (err)
 		return err;
 
-	return count;
+	*val_idx = val;
+
+	return 0;
 }
 
-#define NUM_FW_ATTR_ENUM_ATTRS  6
-
-static int galaxybook_fw_attr_init(struct samsung_galaxybook *galaxybook,
-				   const enum galaxybook_fw_attr_id fw_attr_id,
-				   int (*get_value)(struct samsung_galaxybook *galaxybook,
-						    bool *value),
-				   int (*set_value)(struct samsung_galaxybook *galaxybook,
-						    const bool value))
+static int usb_charging_write(struct device *dev, long id, int val_idx)
 {
-	struct galaxybook_fw_attr *fw_attr;
-	struct attribute **attrs;
+	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
 
-	fw_attr = devm_kzalloc(&galaxybook->platform->dev, sizeof(*fw_attr), GFP_KERNEL);
-	if (!fw_attr)
-		return -ENOMEM;
+	guard(mutex)(&galaxybook->fw_attr_lock);
 
-	attrs = devm_kcalloc(&galaxybook->platform->dev, NUM_FW_ATTR_ENUM_ATTRS + 1,
-			     sizeof(*attrs), GFP_KERNEL);
-	if (!attrs)
-		return -ENOMEM;
-
-	attrs[0] = &fw_attr_type.attr;
-	attrs[1] = &fw_attr_default_value.attr;
-	attrs[2] = &fw_attr_possible_values.attr;
-	attrs[3] = &fw_attr_display_name_language_code.attr;
-
-	sysfs_attr_init(&fw_attr->display_name.attr);
-	fw_attr->display_name.attr.name = "display_name";
-	fw_attr->display_name.attr.mode = 0444;
-	fw_attr->display_name.show = display_name_show;
-	attrs[4] = &fw_attr->display_name.attr;
-
-	sysfs_attr_init(&fw_attr->current_value.attr);
-	fw_attr->current_value.attr.name = "current_value";
-	fw_attr->current_value.attr.mode = 0644;
-	fw_attr->current_value.show = current_value_show;
-	fw_attr->current_value.store = current_value_store;
-	attrs[5] = &fw_attr->current_value.attr;
-
-	attrs[6] = NULL;
-
-	fw_attr->galaxybook = galaxybook;
-	fw_attr->fw_attr_id = fw_attr_id;
-	fw_attr->attr_group.name = galaxybook_fw_attr_name[fw_attr_id];
-	fw_attr->attr_group.attrs = attrs;
-	fw_attr->get_value = get_value;
-	fw_attr->set_value = set_value;
-
-	return sysfs_create_group(&galaxybook->fw_attrs_kset->kobj, &fw_attr->attr_group);
+	return usb_charging_acpi_set(galaxybook, val_idx ? true : false);
 }
 
-static void galaxybook_kset_unregister(void *data)
+DEFINE_FWAT_ENUM_GROUP(usb_charging, "USB Charging", galaxybook_possible_vals,
+		       false, 0644, FWAT_ENUM_ALL_ATTRS);
+
+static int block_recording_read(struct device *dev, long id, int *val_idx)
 {
-	struct kset *kset = data;
+	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
+	bool val;
+	int err;
 
-	kset_unregister(kset);
+	err = block_recording_acpi_get(galaxybook, &val);
+	if (err)
+		return err;
+
+	*val_idx = val;
+
+	return 0;
 }
 
-static void galaxybook_fw_attrs_dev_unregister(void *data)
+static int block_recording_write(struct device *dev, long id, int val_idx)
 {
-	struct device *fw_attrs_dev = data;
 
-	device_unregister(fw_attrs_dev);
+	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
+
+	guard(mutex)(&galaxybook->fw_attr_lock);
+
+	return block_recording_acpi_set(galaxybook, val_idx ? true : false);
 }
 
+DEFINE_FWAT_ENUM_GROUP(block_recording, "Block Recording", galaxybook_possible_vals,
+		       false, 0644, FWAT_ENUM_ALL_ATTRS);
+
 static int galaxybook_fw_attrs_init(struct samsung_galaxybook *galaxybook)
 {
+	struct fwat_device *fdev;
 	bool value;
 	int err;
 
@@ -1059,42 +972,20 @@ static int galaxybook_fw_attrs_init(struct samsung_galaxybook *galaxybook)
 	if (err)
 		return err;
 
-	galaxybook->fw_attrs_dev = device_create(&firmware_attributes_class, NULL, MKDEV(0, 0),
-						 NULL, "%s", DRIVER_NAME);
-	if (IS_ERR(galaxybook->fw_attrs_dev))
-		return PTR_ERR(galaxybook->fw_attrs_dev);
-
-	err = devm_add_action_or_reset(&galaxybook->platform->dev,
-				       galaxybook_fw_attrs_dev_unregister,
-				       galaxybook->fw_attrs_dev);
-	if (err)
-		return err;
-
-	galaxybook->fw_attrs_kset = kset_create_and_add("attributes", NULL,
-							&galaxybook->fw_attrs_dev->kobj);
-	if (!galaxybook->fw_attrs_kset)
-		return -ENOMEM;
-	err = devm_add_action_or_reset(&galaxybook->platform->dev,
-				       galaxybook_kset_unregister, galaxybook->fw_attrs_kset);
-	if (err)
-		return err;
+	fdev = devm_fwat_device_register(&galaxybook->platform->dev, DRIVER_NAME, galaxybook, NULL);
+	if (IS_ERR(fdev))
+		return PTR_ERR(fdev);
 
 	err = power_on_lid_open_acpi_get(galaxybook, &value);
 	if (!err) {
-		err = galaxybook_fw_attr_init(galaxybook,
-					      GB_ATTR_POWER_ON_LID_OPEN,
-					      &power_on_lid_open_acpi_get,
-					      &power_on_lid_open_acpi_set);
+		err = fwat_create_group(fdev, &power_on_lid_open_group_data);
 		if (err)
 			return err;
 	}
 
 	err = usb_charging_acpi_get(galaxybook, &value);
 	if (!err) {
-		err = galaxybook_fw_attr_init(galaxybook,
-					      GB_ATTR_USB_CHARGING,
-					      &usb_charging_acpi_get,
-					      &usb_charging_acpi_set);
+		err = fwat_create_group(fdev, &usb_charging_group_data);
 		if (err)
 			return err;
 	}
@@ -1107,10 +998,7 @@ static int galaxybook_fw_attrs_init(struct samsung_galaxybook *galaxybook)
 
 	galaxybook->has_block_recording = true;
 
-	return galaxybook_fw_attr_init(galaxybook,
-				       GB_ATTR_BLOCK_RECORDING,
-				       &block_recording_acpi_get,
-				       &block_recording_acpi_set);
+	return fwat_create_group(fdev, &block_recording_group_data);
 }
 
 /*

-- 
2.50.0

[PATCH v6 5/6] Documentation: ABI: Update sysfs-class-firmware-attributes documentation

[Kurt Borja]

Add a simple boolean type.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 Documentation/ABI/testing/sysfs-class-firmware-attributes | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes b/Documentation/ABI/testing/sysfs-class-firmware-attributes
index 2713efa509b465a39bf014180794bf487e5b42d6..64b8d5d49716e8387fee26e3e56910862f6a4f5c 100644
--- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
+++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
@@ -18,6 +18,7 @@ Description:
 
 		The following are known types:
 
+			- boolean
 			- enumeration: a set of pre-defined valid values
 			- integer: a range of numerical values
 			- string

-- 
2.50.0

[PATCH v6 6/6] MAINTAINERS: Add FIRMWARE ATTRIBUTES CLASS entry

[Kurt Borja]

Add entry for the FIRMWARE ATTRIBUTES CLASS.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 MAINTAINERS | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 0a5309abba307992d4bf5b05ef8a65c839fb7606..9ef3dcadc2d6adfcdb6832026681691586c613ce 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9352,6 +9352,14 @@ F:	include/linux/firewire.h
 F:	include/uapi/linux/firewire*.h
 F:	tools/firewire/
 
+FIRMWARE ATTRIBUTES CLASS
+M:	Kurt Borja <kuurtb@gmail.com>
+L:	platform-driver-x86@vger.kernel.org
+S:	Maintained
+F:	drivers/platform/x86/firmware_attributes_class.c
+F:	include/linux/firmware_attributes_class.h
+K:	(devm_)?fwat_device_(un)?register
+
 FIRMWARE FRAMEWORK FOR ARMV8-A
 M:	Sudeep Holla <sudeep.holla@arm.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

-- 
2.50.0

Re: [PATCH v6 3/6] platform/x86: firmware_attributes_class: Move header to include directory

[kernel test robot]

Hi Kurt,

kernel test robot noticed the following build errors:

[auto build test ERROR on 428f6f3a56ac85f37a07a3fe5149b593185d5c4c]

url:    https://github.com/intel-lab-lkp/linux/commits/Kurt-Borja/platform-x86-firmware_attributes_class-Add-device-initialization-methods/20250710-110641
base:   428f6f3a56ac85f37a07a3fe5149b593185d5c4c
patch link:    https://lore.kernel.org/r/20250710-fw-attrs-api-v6-3-9959ef759771%40gmail.com
patch subject: [PATCH v6 3/6] platform/x86: firmware_attributes_class: Move header to include directory
config: i386-randconfig-002-20250714 (https://download.01.org/0day-ci/archive/20250714/202507142344.HcDxuqCC-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250714/202507142344.HcDxuqCC-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202507142344.HcDxuqCC-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/platform/x86/lenovo/wmi-other.c:42:10: fatal error: ../firmware_attributes_class.h: No such file or directory
      42 | #include "../firmware_attributes_class.h"
         |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   compilation terminated.


vim +42 drivers/platform/x86/lenovo/wmi-other.c

edc4b183b794ba Derek J. Clark 2025-07-01  36  
edc4b183b794ba Derek J. Clark 2025-07-01  37  #include "wmi-capdata01.h"
edc4b183b794ba Derek J. Clark 2025-07-01  38  #include "wmi-events.h"
edc4b183b794ba Derek J. Clark 2025-07-01  39  #include "wmi-gamezone.h"
edc4b183b794ba Derek J. Clark 2025-07-01  40  #include "wmi-helpers.h"
edc4b183b794ba Derek J. Clark 2025-07-01  41  #include "wmi-other.h"
edc4b183b794ba Derek J. Clark 2025-07-01 @42  #include "../firmware_attributes_class.h"
edc4b183b794ba Derek J. Clark 2025-07-01  43  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki