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-rw-r--r--arch/sh/kernel/apm.c539
1 files changed, 539 insertions, 0 deletions
diff --git a/arch/sh/kernel/apm.c b/arch/sh/kernel/apm.c
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+/*
+ * bios-less APM driver for hp680
+ *
+ * Copyright 2005 (c) Andriy Skulysh <askulysh@gmail.com>
+ *
+ * based on ARM APM driver by
+ * 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/config.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/timer.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/miscdevice.h>
+#include <linux/apm_bios.h>
+#include <linux/pm.h>
+#include <linux/pm_legacy.h>
+#include <asm/apm.h>
+
+#define MODNAME "apm"
+
+/*
+ * The apm_bios device is one of the misc char devices.
+ * This is its minor number.
+ */
+#define APM_MINOR_DEV 134
+
+/*
+ * 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_DONE 4 /* suspend completed */
+
+ struct apm_queue queue;
+};
+
+/*
+ * Local variables
+ */
+static int suspends_pending;
+
+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 DECLARE_COMPLETION(kapmd_exit);
+static DEFINE_SPINLOCK(kapmd_queue_lock);
+static struct apm_queue kapmd_queue;
+
+int apm_suspended;
+EXPORT_SYMBOL(apm_suspended);
+
+/* Platform-specific apm_read_proc(). */
+int (*apm_get_info)(char *buf, char **start, off_t fpos, int length);
+EXPORT_SYMBOL(apm_get_info);
+
+/*
+ * 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_one_user(struct apm_user *as, apm_event_t event)
+{
+ if (as->suser && as->writer) {
+ switch (event) {
+ case APM_SYS_SUSPEND:
+ case APM_USER_SUSPEND:
+ /*
+ * If this user already has a suspend pending,
+ * don't queue another one.
+ */
+ if (as->suspend_state != SUSPEND_NONE)
+ return;
+
+ as->suspend_state = SUSPEND_PENDING;
+ suspends_pending++;
+ break;
+ }
+ }
+ queue_add_event(&as->queue, event);
+}
+
+static void queue_event(apm_event_t event, struct apm_user *sender)
+{
+ struct apm_user *as;
+
+ down_read(&user_list_lock);
+
+ list_for_each_entry(as, &apm_user_list, list)
+ if (as != sender && as->reader)
+ queue_event_one_user(as, event);
+
+ up_read(&user_list_lock);
+ wake_up_interruptible(&apm_waitqueue);
+}
+
+/**
+ * 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)
+{
+ spin_lock_irq(&kapmd_queue_lock);
+ queue_add_event(&kapmd_queue, event);
+ spin_unlock_irq(&kapmd_queue_lock);
+
+ wake_up_interruptible(&kapmd_wait);
+}
+EXPORT_SYMBOL(apm_queue_event);
+
+static void apm_suspend(void)
+{
+ struct apm_user *as;
+ int err;
+
+ apm_suspended = 1;
+ 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, NULL);
+
+ /*
+ * Finally, wake up anyone who is sleeping on the suspend.
+ */
+ down_read(&user_list_lock);
+ list_for_each_entry(as, &apm_user_list, list) {
+ as->suspend_result = err;
+ as->suspend_state = SUSPEND_DONE;
+ }
+ up_read(&user_list_lock);
+
+ wake_up(&apm_suspend_waitqueue);
+ apm_suspended = 0;
+}
+
+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;
+
+ if (event == APM_SYS_SUSPEND || event == APM_USER_SUSPEND)
+ as->suspend_state = SUSPEND_READ;
+
+ 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:
+ as->suspend_result = -EINTR;
+
+ if (as->suspend_state == SUSPEND_READ) {
+ /*
+ * 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--;
+ } else {
+ /*
+ * 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.
+ */
+ queue_event(APM_USER_SUSPEND, as);
+ }
+
+ /*
+ * If there are no further acknowledges required, suspend
+ * the system.
+ */
+ if (suspends_pending == 0)
+ apm_suspend();
+
+ /*
+ * Wait for the suspend/resume to complete. If there are
+ * pending acknowledges, we wait here for them.
+ *
+ * Note that 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;
+
+ /*
+ * Note: do not allow a thread which is acking the suspend
+ * to escape until the resume is complete.
+ */
+ if (as->suspend_state == SUSPEND_ACKED)
+ wait_event(apm_suspend_waitqueue,
+ as->suspend_state == SUSPEND_DONE);
+ else
+ wait_event_interruptible(apm_suspend_waitqueue,
+ as->suspend_state == SUSPEND_DONE);
+
+ current->flags = flags;
+ err = as->suspend_result;
+ as->suspend_state = SUSPEND_NONE;
+ break;
+ }
+
+ return err;
+}
+
+static int apm_release(struct inode * inode, struct file * filp)
+{
+ struct apm_user *as = filp->private_data;
+ 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.
+ */
+ if (as->suspend_state != SUSPEND_NONE) {
+ suspends_pending -= 1;
+ if (suspends_pending == 0)
+ 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_read_proc(char *buf, char **start, off_t fpos, int length)
+{
+ if (likely(apm_get_info))
+ return apm_get_info(buf, start, fpos, length);
+
+ return -EINVAL;
+}
+#endif
+
+static int kapmd(void *arg)
+{
+ daemonize("kapmd");
+ current->flags |= PF_NOFREEZE;
+
+ do {
+ apm_event_t event;
+
+ wait_event_interruptible(kapmd_wait,
+ !queue_empty(&kapmd_queue) || !pm_active);
+
+ if (!pm_active)
+ 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, NULL);
+ break;
+
+ case APM_USER_SUSPEND:
+ case APM_SYS_SUSPEND:
+ queue_event(event, NULL);
+ if (suspends_pending == 0)
+ apm_suspend();
+ break;
+
+ case APM_CRITICAL_SUSPEND:
+ apm_suspend();
+ break;
+ }
+ } while (1);
+
+ complete_and_exit(&kapmd_exit, 0);
+}
+
+static int __init apm_init(void)
+{
+ int ret;
+
+ pm_active = 1;
+
+ ret = kernel_thread(kapmd, NULL, CLONE_KERNEL);
+ if (unlikely(ret < 0)) {
+ pm_active = 0;
+ return ret;
+ }
+
+ create_proc_info_entry("apm", 0, NULL, apm_read_proc);
+
+ ret = misc_register(&apm_device);
+ if (unlikely(ret != 0)) {
+ remove_proc_entry("apm", NULL);
+
+ pm_active = 0;
+ wake_up(&kapmd_wait);
+ wait_for_completion(&kapmd_exit);
+ }
+
+ return ret;
+}
+
+static void __exit apm_exit(void)
+{
+ misc_deregister(&apm_device);
+ remove_proc_entry("apm", NULL);
+
+ pm_active = 0;
+ wake_up(&kapmd_wait);
+ wait_for_completion(&kapmd_exit);
+}
+
+module_init(apm_init);
+module_exit(apm_exit);
+
+MODULE_AUTHOR("Stephen Rothwell, Andriy Skulysh");
+MODULE_DESCRIPTION("Advanced Power Management");
+MODULE_LICENSE("GPL");