diff options
Diffstat (limited to 'drivers/platform/x86/firmware_attributes_class.c')
-rw-r--r-- | drivers/platform/x86/firmware_attributes_class.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/platform/x86/firmware_attributes_class.c b/drivers/platform/x86/firmware_attributes_class.c new file mode 100644 index 000000000000..d62ec3d71ede --- /dev/null +++ b/drivers/platform/x86/firmware_attributes_class.c @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +/* Firmware attributes class helper module */ + +#include <linux/mutex.h> +#include <linux/device/class.h> +#include <linux/module.h> +#include "firmware_attributes_class.h" + +static DEFINE_MUTEX(fw_attr_lock); +int fw_attr_inuse; + +static struct class firmware_attributes_class = { + .name = "firmware-attributes", +}; + +int fw_attributes_class_get(struct class **fw_attr_class) +{ + int err; + + mutex_lock(&fw_attr_lock); + if (!fw_attr_inuse) { /*first time class is being used*/ + err = class_register(&firmware_attributes_class); + if (err) { + mutex_unlock(&fw_attr_lock); + return err; + } + } + fw_attr_inuse++; + *fw_attr_class = &firmware_attributes_class; + mutex_unlock(&fw_attr_lock); + return 0; +} +EXPORT_SYMBOL_GPL(fw_attributes_class_get); + +int fw_attributes_class_put(void) +{ + mutex_lock(&fw_attr_lock); + if (!fw_attr_inuse) { + mutex_unlock(&fw_attr_lock); + return -EINVAL; + } + fw_attr_inuse--; + if (!fw_attr_inuse) /* No more consumers */ + class_unregister(&firmware_attributes_class); + mutex_unlock(&fw_attr_lock); + return 0; +} +EXPORT_SYMBOL_GPL(fw_attributes_class_put); + +MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>"); +MODULE_LICENSE("GPL"); |