[PATCH v5 08/20] ACPI: platform_profile: Create class for ACPI platform profile

[Mario Limonciello <mario.limonciello@amd.com>]

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

Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v5:
 * Use ida instead of idr
 * Use device_unregister instead of device_destroy()
 * MKDEV (0, 0)
---
 drivers/acpi/platform_profile.c  | 50 +++++++++++++++++++++++++++++---
 include/linux/platform_profile.h |  2 ++
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index 0450bdae7c88b..652034b71ee9b 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)
@@ -113,6 +120,8 @@ void platform_profile_notify(void)
 {
 	if (!cur_profile)
 		return;
+	if (!class_is_registered(&platform_profile_class))
+		return;
 	sysfs_notify(acpi_kobj, NULL, "platform_profile");
 }
 EXPORT_SYMBOL_GPL(platform_profile_notify);
@@ -123,6 +132,9 @@ int platform_profile_cycle(void)
 	enum platform_profile_option next;
 	int err;
 
+	if (!class_is_registered(&platform_profile_class))
+		return -ENODEV;
+
 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
 		if (!cur_profile)
 			return -ENODEV;
@@ -163,20 +175,50 @@ 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;
+	if (!class_is_registered(&platform_profile_class)) {
+		/* class for individual handlers */
+		err = class_register(&platform_profile_class);
+		if (err)
+			return err;
+		/* legacy sysfs files */
+		err = sysfs_create_group(acpi_kobj, &platform_profile_group);
+		if (err)
+			goto cleanup_class;
+	}
+
+	/* create class interface for individual handler */
+	pprof->minor = ida_alloc(&platform_profile_ida, GFP_KERNEL);
+	pprof->class_dev = device_create(&platform_profile_class, NULL,
+					 MKDEV(0, 0), NULL, "platform-profile-%d",
+					 pprof->minor);
+	if (IS_ERR(pprof->class_dev)) {
+		err = PTR_ERR(pprof->class_dev);
+		goto cleanup_ida;
+	}
+	dev_set_drvdata(pprof->class_dev, pprof);
 
 	cur_profile = pprof;
 	return 0;
+
+cleanup_ida:
+	ida_free(&platform_profile_ida, pprof->minor);
+
+cleanup_class:
+	class_unregister(&platform_profile_class);
+
+	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);
+	id = pprof->minor;
+	device_unregister(pprof->class_dev);
+	ida_free(&platform_profile_ida, id);
+
 	cur_profile = NULL;
 	return 0;
 }
diff --git a/include/linux/platform_profile.h b/include/linux/platform_profile.h
index 58279b76d740e..d92a035e6ba6a 100644
--- a/include/linux/platform_profile.h
+++ b/include/linux/platform_profile.h
@@ -28,6 +28,8 @@ enum platform_profile_option {
 
 struct platform_profile_handler {
 	const char *name;
+	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