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

Ilpo Järvinen
2024-12-04T13:41:22Z

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On Sun, 1 Dec 2024, Mario Limonciello wrote:

> 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>

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

--
i.

> ---
> 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);
>