mirror of https://gitee.com/openkylin/linux.git
129 lines
2.8 KiB
C
129 lines
2.8 KiB
C
/*
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* event.c - exporting ACPI events via procfs
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*
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* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
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* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
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*
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*/
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#include <linux/spinlock.h>
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#include <linux/proc_fs.h>
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#include <linux/init.h>
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#include <linux/poll.h>
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#include <acpi/acpi_drivers.h>
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#define _COMPONENT ACPI_SYSTEM_COMPONENT
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ACPI_MODULE_NAME("event")
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/* Global vars for handling event proc entry */
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static DEFINE_SPINLOCK(acpi_system_event_lock);
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int event_is_open = 0;
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extern struct list_head acpi_bus_event_list;
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extern wait_queue_head_t acpi_bus_event_queue;
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static int acpi_system_open_event(struct inode *inode, struct file *file)
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{
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spin_lock_irq(&acpi_system_event_lock);
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if (event_is_open)
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goto out_busy;
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event_is_open = 1;
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spin_unlock_irq(&acpi_system_event_lock);
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return 0;
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out_busy:
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spin_unlock_irq(&acpi_system_event_lock);
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return -EBUSY;
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}
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static ssize_t
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acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
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loff_t * ppos)
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{
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int result = 0;
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struct acpi_bus_event event;
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static char str[ACPI_MAX_STRING];
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static int chars_remaining = 0;
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static char *ptr;
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if (!chars_remaining) {
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memset(&event, 0, sizeof(struct acpi_bus_event));
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if ((file->f_flags & O_NONBLOCK)
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&& (list_empty(&acpi_bus_event_list)))
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return -EAGAIN;
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result = acpi_bus_receive_event(&event);
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if (result)
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return result;
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chars_remaining = sprintf(str, "%s %s %08x %08x\n",
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event.device_class ? event.
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device_class : "<unknown>",
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event.bus_id ? event.
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bus_id : "<unknown>", event.type,
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event.data);
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ptr = str;
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}
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if (chars_remaining < count) {
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count = chars_remaining;
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}
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if (copy_to_user(buffer, ptr, count))
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return -EFAULT;
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*ppos += count;
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chars_remaining -= count;
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ptr += count;
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return count;
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}
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static int acpi_system_close_event(struct inode *inode, struct file *file)
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{
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spin_lock_irq(&acpi_system_event_lock);
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event_is_open = 0;
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spin_unlock_irq(&acpi_system_event_lock);
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return 0;
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}
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static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
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{
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poll_wait(file, &acpi_bus_event_queue, wait);
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if (!list_empty(&acpi_bus_event_list))
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return POLLIN | POLLRDNORM;
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return 0;
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}
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static const struct file_operations acpi_system_event_ops = {
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.open = acpi_system_open_event,
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.read = acpi_system_read_event,
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.release = acpi_system_close_event,
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.poll = acpi_system_poll_event,
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};
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static int __init acpi_event_init(void)
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{
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struct proc_dir_entry *entry;
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int error = 0;
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if (acpi_disabled)
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return 0;
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/* 'event' [R] */
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entry = create_proc_entry("event", S_IRUSR, acpi_root_dir);
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if (entry)
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entry->proc_fops = &acpi_system_event_ops;
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else {
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error = -ENODEV;
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}
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return error;
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}
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subsys_initcall(acpi_event_init);
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