53 lines
1.2 KiB
C
53 lines
1.2 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/* Firmware attributes class helper module */
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#include <linux/mutex.h>
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#include <linux/device/class.h>
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#include <linux/module.h>
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#include "firmware_attributes_class.h"
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static DEFINE_MUTEX(fw_attr_lock);
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static int fw_attr_inuse;
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static struct class firmware_attributes_class = {
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.name = "firmware-attributes",
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};
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int fw_attributes_class_get(struct class **fw_attr_class)
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{
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int err;
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mutex_lock(&fw_attr_lock);
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if (!fw_attr_inuse) { /*first time class is being used*/
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err = class_register(&firmware_attributes_class);
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if (err) {
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mutex_unlock(&fw_attr_lock);
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return err;
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}
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}
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fw_attr_inuse++;
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*fw_attr_class = &firmware_attributes_class;
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mutex_unlock(&fw_attr_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(fw_attributes_class_get);
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int fw_attributes_class_put(void)
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{
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mutex_lock(&fw_attr_lock);
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if (!fw_attr_inuse) {
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mutex_unlock(&fw_attr_lock);
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return -EINVAL;
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}
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fw_attr_inuse--;
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if (!fw_attr_inuse) /* No more consumers */
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class_unregister(&firmware_attributes_class);
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mutex_unlock(&fw_attr_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(fw_attributes_class_put);
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MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
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MODULE_LICENSE("GPL");
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