[PATCH v9 10/22] ACPI: platform_profile: Create class for ACPI platform profile

Mario Limonciello
2024-12-02T05:51:51Z

When registering a platform profile handler create a class device
that will allow changing a single platform profile handler.

The class and sysfs group are no longer needed when the platform profile
core is a module and unloaded, so remove them at that time as well.

Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v8:
* Use attr->mode
---
drivers/acpi/platform_profile.c | 82 ++++++++++++++++++++++++++++++--
include/linux/platform_profile.h | 2 +
2 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index a1f0378f15e62..11eb60b09bac4 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -5,6 +5,7 @@
#include <linux/acpi.h>
#include <linux/bits.h>
#include <linux/init.h>
+#include <linux/kdev_t.h>
#include <linux/mutex.h>
#include <linux/platform_profile.h>
#include <linux/sysfs.h>
@@ -22,6 +23,12 @@ static const char * const profile_names[] = {
};
static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);

+static DEFINE_IDA(platform_profile_ida);
+
+static const struct class platform_profile_class = {
+ .name = "platform-profile",
+};
+
static ssize_t platform_profile_choices_show(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -101,8 +108,21 @@ static struct attribute *platform_profile_attrs[] = {
NULL
};

+static int profile_class_registered(struct device *dev, const void *data)
+{
+ return 1;
+}
+
+static umode_t profile_class_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
+{
+ if (!class_find_device(&platform_profile_class, NULL, NULL, profile_class_registered))
+ return 0;
+ return attr->mode;
+}
+
static const struct attribute_group platform_profile_group = {
- .attrs = platform_profile_attrs
+ .attrs = platform_profile_attrs,
+ .is_visible = profile_class_is_visible,
};

void platform_profile_notify(struct platform_profile_handler *pprof)
@@ -160,25 +180,77 @@ int platform_profile_register(struct platform_profile_handler *pprof)
if (cur_profile)
return -EEXIST;

- err = sysfs_create_group(acpi_kobj, &platform_profile_group);
- if (err)
- return err;
+ /* create class interface for individual handler */
+ pprof->minor = ida_alloc(&platform_profile_ida, GFP_KERNEL);
+ if (pprof->minor < 0)
+ return pprof->minor;
+ pprof->class_dev = device_create(&platform_profile_class, pprof->dev,
+ MKDEV(0, 0), pprof, "platform-profile-%d",
+ pprof->minor);
+ if (IS_ERR(pprof->class_dev)) {
+ err = PTR_ERR(pprof->class_dev);
+ goto cleanup_ida;
+ }

cur_profile = pprof;
+
+ err = sysfs_update_group(acpi_kobj, &platform_profile_group);
+ if (err)
+ goto cleanup_cur;
+
return 0;
+
+cleanup_cur:
+ cur_profile = NULL;
+ device_unregister(pprof->class_dev);
+
+cleanup_ida:
+ ida_free(&platform_profile_ida, pprof->minor);
+
+ return err;
}
EXPORT_SYMBOL_GPL(platform_profile_register);

int platform_profile_remove(struct platform_profile_handler *pprof)
{
+ int id;
guard(mutex)(&profile_lock);

- sysfs_remove_group(acpi_kobj, &platform_profile_group);
cur_profile = NULL;
+
+ id = pprof->minor;
+ device_unregister(pprof->class_dev);
+ ida_free(&platform_profile_ida, id);
+
+ sysfs_update_group(acpi_kobj, &platform_profile_group);
+
return 0;
}
EXPORT_SYMBOL_GPL(platform_profile_remove);

+static int __init platform_profile_init(void)
+{
+ int err;
+
+ err = class_register(&platform_profile_class);
+ if (err)
+ return err;
+
+ err = sysfs_create_group(acpi_kobj, &platform_profile_group);
+ if (err)
+ class_unregister(&platform_profile_class);
+
+ return err;
+}
+
+static void __exit platform_profile_exit(void)
+{
+ sysfs_remove_group(acpi_kobj, &platform_profile_group);
+ class_unregister(&platform_profile_class);
+}
+module_init(platform_profile_init);
+module_exit(platform_profile_exit);
+
MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
MODULE_DESCRIPTION("ACPI platform profile sysfs interface");
MODULE_LICENSE("GPL");
diff --git a/include/linux/platform_profile.h b/include/linux/platform_profile.h
index 8ec0b8da56db5..a888fd085c513 100644
--- a/include/linux/platform_profile.h
+++ b/include/linux/platform_profile.h
@@ -29,6 +29,8 @@ enum platform_profile_option {
struct platform_profile_handler {
const char *name;
struct device *dev;
+ struct device *class_dev;
+ int minor;
unsigned long choices[BITS_TO_LONGS(PLATFORM_PROFILE_LAST)];
int (*profile_get)(struct platform_profile_handler *pprof,
enum platform_profile_option *profile);
--
2.43.0