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