+++ /dev/null
-/*
- * bios-less APM driver for ARM Linux
- * Jamey Hicks <jamey@crl.dec.com>
- * adapted from the APM BIOS driver for Linux by Stephen Rothwell (sfr@linuxcare.com)
- *
- * APM 1.2 Reference:
- * Intel Corporation, Microsoft Corporation. Advanced Power Management
- * (APM) BIOS Interface Specification, Revision 1.2, February 1996.
- *
- * [This document is available from Microsoft at:
- * http://www.microsoft.com/hwdev/busbios/amp_12.htm]
- */
-#include <linux/module.h>
-#include <linux/poll.h>
-#include <linux/slab.h>
-#include <linux/proc_fs.h>
-#include <linux/miscdevice.h>
-#include <linux/apm_bios.h>
-#include <linux/capability.h>
-#include <linux/sched.h>
-#include <linux/pm.h>
-#include <linux/device.h>
-#include <linux/kernel.h>
-#include <linux/list.h>
-#include <linux/init.h>
-#include <linux/completion.h>
-#include <linux/kthread.h>
-#include <linux/delay.h>
-
-#include <asm/apm.h> /* apm_power_info */
-#include <asm/system.h>
-
-/*
- * The apm_bios device is one of the misc char devices.
- * This is its minor number.
- */
-#define APM_MINOR_DEV 134
-
-/*
- * See Documentation/Config.help for the configuration options.
- *
- * Various options can be changed at boot time as follows:
- * (We allow underscores for compatibility with the modules code)
- * apm=on/off enable/disable APM
- */
-
-/*
- * Maximum number of events stored
- */
-#define APM_MAX_EVENTS 16
-
-struct apm_queue {
- unsigned int event_head;
- unsigned int event_tail;
- apm_event_t events[APM_MAX_EVENTS];
-};
-
-/*
- * The per-file APM data
- */
-struct apm_user {
- struct list_head list;
-
- unsigned int suser: 1;
- unsigned int writer: 1;
- unsigned int reader: 1;
-
- int suspend_result;
- unsigned int suspend_state;
-#define SUSPEND_NONE 0 /* no suspend pending */
-#define SUSPEND_PENDING 1 /* suspend pending read */
-#define SUSPEND_READ 2 /* suspend read, pending ack */
-#define SUSPEND_ACKED 3 /* suspend acked */
-#define SUSPEND_WAIT 4 /* waiting for suspend */
-#define SUSPEND_DONE 5 /* suspend completed */
-
- struct apm_queue queue;
-};
-
-/*
- * Local variables
- */
-static int suspends_pending;
-static int apm_disabled;
-static struct task_struct *kapmd_tsk;
-
-static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
-static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
-
-/*
- * This is a list of everyone who has opened /dev/apm_bios
- */
-static DECLARE_RWSEM(user_list_lock);
-static LIST_HEAD(apm_user_list);
-
-/*
- * kapmd info. kapmd provides us a process context to handle
- * "APM" events within - specifically necessary if we're going
- * to be suspending the system.
- */
-static DECLARE_WAIT_QUEUE_HEAD(kapmd_wait);
-static DEFINE_SPINLOCK(kapmd_queue_lock);
-static struct apm_queue kapmd_queue;
-
-static DEFINE_MUTEX(state_lock);
-
-static const char driver_version[] = "1.13"; /* no spaces */
-
-
-
-/*
- * Compatibility cruft until the IPAQ people move over to the new
- * interface.
- */
-static void __apm_get_power_status(struct apm_power_info *info)
-{
-}
-
-/*
- * This allows machines to provide their own "apm get power status" function.
- */
-void (*apm_get_power_status)(struct apm_power_info *) = __apm_get_power_status;
-EXPORT_SYMBOL(apm_get_power_status);
-
-
-/*
- * APM event queue management.
- */
-static inline int queue_empty(struct apm_queue *q)
-{
- return q->event_head == q->event_tail;
-}
-
-static inline apm_event_t queue_get_event(struct apm_queue *q)
-{
- q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS;
- return q->events[q->event_tail];
-}
-
-static void queue_add_event(struct apm_queue *q, apm_event_t event)
-{
- q->event_head = (q->event_head + 1) % APM_MAX_EVENTS;
- if (q->event_head == q->event_tail) {
- static int notified;
-
- if (notified++ == 0)
- printk(KERN_ERR "apm: an event queue overflowed\n");
- q->event_tail = (q->event_tail + 1) % APM_MAX_EVENTS;
- }
- q->events[q->event_head] = event;
-}
-
-static void queue_event(apm_event_t event)
-{
- struct apm_user *as;
-
- down_read(&user_list_lock);
- list_for_each_entry(as, &apm_user_list, list) {
- if (as->reader)
- queue_add_event(&as->queue, event);
- }
- up_read(&user_list_lock);
- wake_up_interruptible(&apm_waitqueue);
-}
-
-/*
- * queue_suspend_event - queue an APM suspend event.
- *
- * Check that we're in a state where we can suspend. If not,
- * return -EBUSY. Otherwise, queue an event to all "writer"
- * users. If there are no "writer" users, return '1' to
- * indicate that we can immediately suspend.
- */
-static int queue_suspend_event(apm_event_t event, struct apm_user *sender)
-{
- struct apm_user *as;
- int ret = 1;
-
- mutex_lock(&state_lock);
- down_read(&user_list_lock);
-
- /*
- * If a thread is still processing, we can't suspend, so reject
- * the request.
- */
- list_for_each_entry(as, &apm_user_list, list) {
- if (as != sender && as->reader && as->writer && as->suser &&
- as->suspend_state != SUSPEND_NONE) {
- ret = -EBUSY;
- goto out;
- }
- }
-
- list_for_each_entry(as, &apm_user_list, list) {
- if (as != sender && as->reader && as->writer && as->suser) {
- as->suspend_state = SUSPEND_PENDING;
- suspends_pending++;
- queue_add_event(&as->queue, event);
- ret = 0;
- }
- }
- out:
- up_read(&user_list_lock);
- mutex_unlock(&state_lock);
- wake_up_interruptible(&apm_waitqueue);
- return ret;
-}
-
-static void apm_suspend(void)
-{
- struct apm_user *as;
- int err = pm_suspend(PM_SUSPEND_MEM);
-
- /*
- * Anyone on the APM queues will think we're still suspended.
- * Send a message so everyone knows we're now awake again.
- */
- queue_event(APM_NORMAL_RESUME);
-
- /*
- * Finally, wake up anyone who is sleeping on the suspend.
- */
- mutex_lock(&state_lock);
- down_read(&user_list_lock);
- list_for_each_entry(as, &apm_user_list, list) {
- if (as->suspend_state == SUSPEND_WAIT ||
- as->suspend_state == SUSPEND_ACKED) {
- as->suspend_result = err;
- as->suspend_state = SUSPEND_DONE;
- }
- }
- up_read(&user_list_lock);
- mutex_unlock(&state_lock);
-
- wake_up(&apm_suspend_waitqueue);
-}
-
-static ssize_t apm_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
-{
- struct apm_user *as = fp->private_data;
- apm_event_t event;
- int i = count, ret = 0;
-
- if (count < sizeof(apm_event_t))
- return -EINVAL;
-
- if (queue_empty(&as->queue) && fp->f_flags & O_NONBLOCK)
- return -EAGAIN;
-
- wait_event_interruptible(apm_waitqueue, !queue_empty(&as->queue));
-
- while ((i >= sizeof(event)) && !queue_empty(&as->queue)) {
- event = queue_get_event(&as->queue);
-
- ret = -EFAULT;
- if (copy_to_user(buf, &event, sizeof(event)))
- break;
-
- mutex_lock(&state_lock);
- if (as->suspend_state == SUSPEND_PENDING &&
- (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND))
- as->suspend_state = SUSPEND_READ;
- mutex_unlock(&state_lock);
-
- buf += sizeof(event);
- i -= sizeof(event);
- }
-
- if (i < count)
- ret = count - i;
-
- return ret;
-}
-
-static unsigned int apm_poll(struct file *fp, poll_table * wait)
-{
- struct apm_user *as = fp->private_data;
-
- poll_wait(fp, &apm_waitqueue, wait);
- return queue_empty(&as->queue) ? 0 : POLLIN | POLLRDNORM;
-}
-
-/*
- * apm_ioctl - handle APM ioctl
- *
- * APM_IOC_SUSPEND
- * This IOCTL is overloaded, and performs two functions. It is used to:
- * - initiate a suspend
- * - acknowledge a suspend read from /dev/apm_bios.
- * Only when everyone who has opened /dev/apm_bios with write permission
- * has acknowledge does the actual suspend happen.
- */
-static int
-apm_ioctl(struct inode * inode, struct file *filp, u_int cmd, u_long arg)
-{
- struct apm_user *as = filp->private_data;
- unsigned long flags;
- int err = -EINVAL;
-
- if (!as->suser || !as->writer)
- return -EPERM;
-
- switch (cmd) {
- case APM_IOC_SUSPEND:
- mutex_lock(&state_lock);
-
- as->suspend_result = -EINTR;
-
- if (as->suspend_state == SUSPEND_READ) {
- int pending;
-
- /*
- * If we read a suspend command from /dev/apm_bios,
- * then the corresponding APM_IOC_SUSPEND ioctl is
- * interpreted as an acknowledge.
- */
- as->suspend_state = SUSPEND_ACKED;
- suspends_pending--;
- pending = suspends_pending == 0;
- mutex_unlock(&state_lock);
-
- /*
- * If there are no further acknowledges required,
- * suspend the system.
- */
- if (pending)
- apm_suspend();
-
- /*
- * Wait for the suspend/resume to complete. If there
- * are pending acknowledges, we wait here for them.
- *
- * Note: we need to ensure that the PM subsystem does
- * not kick us out of the wait when it suspends the
- * threads.
- */
- flags = current->flags;
- current->flags |= PF_NOFREEZE;
-
- wait_event(apm_suspend_waitqueue,
- as->suspend_state == SUSPEND_DONE);
- } else {
- as->suspend_state = SUSPEND_WAIT;
- mutex_unlock(&state_lock);
-
- /*
- * Otherwise it is a request to suspend the system.
- * Queue an event for all readers, and expect an
- * acknowledge from all writers who haven't already
- * acknowledged.
- */
- err = queue_suspend_event(APM_USER_SUSPEND, as);
- if (err < 0) {
- /*
- * Avoid taking the lock here - this
- * should be fine.
- */
- as->suspend_state = SUSPEND_NONE;
- break;
- }
-
- if (err > 0)
- apm_suspend();
-
- /*
- * Wait for the suspend/resume to complete. If there
- * are pending acknowledges, we wait here for them.
- *
- * Note: we need to ensure that the PM subsystem does
- * not kick us out of the wait when it suspends the
- * threads.
- */
- flags = current->flags;
- current->flags |= PF_NOFREEZE;
-
- wait_event_interruptible(apm_suspend_waitqueue,
- as->suspend_state == SUSPEND_DONE);
- }
-
- current->flags = flags;
-
- mutex_lock(&state_lock);
- err = as->suspend_result;
- as->suspend_state = SUSPEND_NONE;
- mutex_unlock(&state_lock);
- break;
- }
-
- return err;
-}
-
-static int apm_release(struct inode * inode, struct file * filp)
-{
- struct apm_user *as = filp->private_data;
- int pending = 0;
-
- filp->private_data = NULL;
-
- down_write(&user_list_lock);
- list_del(&as->list);
- up_write(&user_list_lock);
-
- /*
- * We are now unhooked from the chain. As far as new
- * events are concerned, we no longer exist. However, we
- * need to balance suspends_pending, which means the
- * possibility of sleeping.
- */
- mutex_lock(&state_lock);
- if (as->suspend_state != SUSPEND_NONE) {
- suspends_pending -= 1;
- pending = suspends_pending == 0;
- }
- mutex_unlock(&state_lock);
- if (pending)
- apm_suspend();
-
- kfree(as);
- return 0;
-}
-
-static int apm_open(struct inode * inode, struct file * filp)
-{
- struct apm_user *as;
-
- as = kzalloc(sizeof(*as), GFP_KERNEL);
- if (as) {
- /*
- * XXX - this is a tiny bit broken, when we consider BSD
- * process accounting. If the device is opened by root, we
- * instantly flag that we used superuser privs. Who knows,
- * we might close the device immediately without doing a
- * privileged operation -- cevans
- */
- as->suser = capable(CAP_SYS_ADMIN);
- as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
- as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
-
- down_write(&user_list_lock);
- list_add(&as->list, &apm_user_list);
- up_write(&user_list_lock);
-
- filp->private_data = as;
- }
-
- return as ? 0 : -ENOMEM;
-}
-
-static struct file_operations apm_bios_fops = {
- .owner = THIS_MODULE,
- .read = apm_read,
- .poll = apm_poll,
- .ioctl = apm_ioctl,
- .open = apm_open,
- .release = apm_release,
-};
-
-static struct miscdevice apm_device = {
- .minor = APM_MINOR_DEV,
- .name = "apm_bios",
- .fops = &apm_bios_fops
-};
-
-
-#ifdef CONFIG_PROC_FS
-/*
- * Arguments, with symbols from linux/apm_bios.h.
- *
- * 0) Linux driver version (this will change if format changes)
- * 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
- * 2) APM flags from APM Installation Check (0x00):
- * bit 0: APM_16_BIT_SUPPORT
- * bit 1: APM_32_BIT_SUPPORT
- * bit 2: APM_IDLE_SLOWS_CLOCK
- * bit 3: APM_BIOS_DISABLED
- * bit 4: APM_BIOS_DISENGAGED
- * 3) AC line status
- * 0x00: Off-line
- * 0x01: On-line
- * 0x02: On backup power (BIOS >= 1.1 only)
- * 0xff: Unknown
- * 4) Battery status
- * 0x00: High
- * 0x01: Low
- * 0x02: Critical
- * 0x03: Charging
- * 0x04: Selected battery not present (BIOS >= 1.2 only)
- * 0xff: Unknown
- * 5) Battery flag
- * bit 0: High
- * bit 1: Low
- * bit 2: Critical
- * bit 3: Charging
- * bit 7: No system battery
- * 0xff: Unknown
- * 6) Remaining battery life (percentage of charge):
- * 0-100: valid
- * -1: Unknown
- * 7) Remaining battery life (time units):
- * Number of remaining minutes or seconds
- * -1: Unknown
- * 8) min = minutes; sec = seconds
- */
-static int apm_get_info(char *buf, char **start, off_t fpos, int length)
-{
- struct apm_power_info info;
- char *units;
- int ret;
-
- info.ac_line_status = 0xff;
- info.battery_status = 0xff;
- info.battery_flag = 0xff;
- info.battery_life = -1;
- info.time = -1;
- info.units = -1;
-
- if (apm_get_power_status)
- apm_get_power_status(&info);
-
- switch (info.units) {
- default: units = "?"; break;
- case 0: units = "min"; break;
- case 1: units = "sec"; break;
- }
-
- ret = sprintf(buf, "%s 1.2 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
- driver_version, APM_32_BIT_SUPPORT,
- info.ac_line_status, info.battery_status,
- info.battery_flag, info.battery_life,
- info.time, units);
-
- return ret;
-}
-#endif
-
-static int kapmd(void *arg)
-{
- do {
- apm_event_t event;
- int ret;
-
- wait_event_interruptible(kapmd_wait,
- !queue_empty(&kapmd_queue) || kthread_should_stop());
-
- if (kthread_should_stop())
- break;
-
- spin_lock_irq(&kapmd_queue_lock);
- event = 0;
- if (!queue_empty(&kapmd_queue))
- event = queue_get_event(&kapmd_queue);
- spin_unlock_irq(&kapmd_queue_lock);
-
- switch (event) {
- case 0:
- break;
-
- case APM_LOW_BATTERY:
- case APM_POWER_STATUS_CHANGE:
- queue_event(event);
- break;
-
- case APM_USER_SUSPEND:
- case APM_SYS_SUSPEND:
- ret = queue_suspend_event(event, NULL);
- if (ret < 0) {
- /*
- * We were busy. Try again in 50ms.
- */
- queue_add_event(&kapmd_queue, event);
- msleep(50);
- }
- if (ret > 0)
- apm_suspend();
- break;
-
- case APM_CRITICAL_SUSPEND:
- apm_suspend();
- break;
- }
- } while (1);
-
- return 0;
-}
-
-static int __init apm_init(void)
-{
- int ret;
-
- if (apm_disabled) {
- printk(KERN_NOTICE "apm: disabled on user request.\n");
- return -ENODEV;
- }
-
- kapmd_tsk = kthread_create(kapmd, NULL, "kapmd");
- if (IS_ERR(kapmd_tsk)) {
- ret = PTR_ERR(kapmd_tsk);
- kapmd_tsk = NULL;
- return ret;
- }
- kapmd_tsk->flags |= PF_NOFREEZE;
- wake_up_process(kapmd_tsk);
-
-#ifdef CONFIG_PROC_FS
- create_proc_info_entry("apm", 0, NULL, apm_get_info);
-#endif
-
- ret = misc_register(&apm_device);
- if (ret != 0) {
- remove_proc_entry("apm", NULL);
- kthread_stop(kapmd_tsk);
- }
-
- return ret;
-}
-
-static void __exit apm_exit(void)
-{
- misc_deregister(&apm_device);
- remove_proc_entry("apm", NULL);
-
- kthread_stop(kapmd_tsk);
-}
-
-module_init(apm_init);
-module_exit(apm_exit);
-
-MODULE_AUTHOR("Stephen Rothwell");
-MODULE_DESCRIPTION("Advanced Power Management");
-MODULE_LICENSE("GPL");
-
-#ifndef MODULE
-static int __init apm_setup(char *str)
-{
- while ((str != NULL) && (*str != '\0')) {
- if (strncmp(str, "off", 3) == 0)
- apm_disabled = 1;
- if (strncmp(str, "on", 2) == 0)
- apm_disabled = 0;
- str = strchr(str, ',');
- if (str != NULL)
- str += strspn(str, ", \t");
- }
- return 1;
-}
-
-__setup("apm=", apm_setup);
-#endif
-
-/**
- * apm_queue_event - queue an APM event for kapmd
- * @event: APM event
- *
- * Queue an APM event for kapmd to process and ultimately take the
- * appropriate action. Only a subset of events are handled:
- * %APM_LOW_BATTERY
- * %APM_POWER_STATUS_CHANGE
- * %APM_USER_SUSPEND
- * %APM_SYS_SUSPEND
- * %APM_CRITICAL_SUSPEND
- */
-void apm_queue_event(apm_event_t event)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&kapmd_queue_lock, flags);
- queue_add_event(&kapmd_queue, event);
- spin_unlock_irqrestore(&kapmd_queue_lock, flags);
-
- wake_up_interruptible(&kapmd_wait);
-}
-EXPORT_SYMBOL(apm_queue_event);
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