patch-2.4.22 linux-2.4.22/drivers/acpi/system.c

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diff -urN linux-2.4.21/drivers/acpi/system.c linux-2.4.22/drivers/acpi/system.c
@@ -0,0 +1,1327 @@
+/*
+ *  acpi_system.c - ACPI System Driver ($Revision: 57 $)
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/poll.h>
+#include <linux/delay.h>
+#include <linux/sysrq.h>
+#include <linux/compatmac.h>
+#include <linux/proc_fs.h>
+#include <linux/pm.h>
+#include <asm/uaccess.h>
+#include <asm/acpi.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+#ifdef CONFIG_X86
+#ifdef CONFIG_ACPI_SLEEP
+#include <linux/mc146818rtc.h>
+#include <linux/irq.h>
+#include <asm/hw_irq.h>
+#endif
+#endif
+
+
+#define _COMPONENT		ACPI_SYSTEM_COMPONENT
+ACPI_MODULE_NAME		("acpi_system")
+
+#define PREFIX			"ACPI: "
+
+extern FADT_DESCRIPTOR		acpi_fadt;
+
+static int acpi_system_add (struct acpi_device *device);
+static int acpi_system_remove (struct acpi_device *device, int type);
+
+acpi_status acpi_suspend (u32 state);
+
+static struct acpi_driver acpi_system_driver = {
+	.name =		ACPI_SYSTEM_DRIVER_NAME,
+	.class =	ACPI_SYSTEM_CLASS,
+	.ids =		ACPI_SYSTEM_HID,
+	.ops =		{
+				.add =		acpi_system_add,
+				.remove =	acpi_system_remove
+			},
+};
+
+struct acpi_system
+{
+	acpi_handle		handle;
+	u8			states[ACPI_S_STATE_COUNT];
+};
+
+/* Global vars for handling event proc entry */
+static spinlock_t		acpi_system_event_lock = SPIN_LOCK_UNLOCKED;
+int				event_is_open = 0;
+extern struct list_head		acpi_bus_event_list;
+extern wait_queue_head_t	acpi_bus_event_queue;
+
+/* --------------------------------------------------------------------------
+                                  System Sleep
+   -------------------------------------------------------------------------- */
+
+#ifdef CONFIG_PM
+
+static void
+acpi_power_off (void)
+{
+	acpi_suspend(ACPI_STATE_S5);
+}
+
+#endif /*CONFIG_PM*/
+
+
+#ifdef CONFIG_ACPI_SLEEP
+
+/**
+ * acpi_system_restore_state - OS-specific restoration of state
+ * @state:	sleep state we're exiting
+ *
+ * Note that if we're coming back from S4, the memory image should have
+ * already been loaded from the disk and is already in place.  (Otherwise how
+ * else would we be here?).
+ */
+acpi_status
+acpi_system_restore_state(
+	u32			state)
+{
+	/* 
+	 * We should only be here if we're coming back from STR or STD.
+	 * And, in the case of the latter, the memory image should have already
+	 * been loaded from disk.
+	 */
+	if (state > ACPI_STATE_S1) {
+		acpi_restore_state_mem();
+
+		/* Do _early_ resume for irqs.  Required by
+		 * ACPI specs.
+		 */
+		/* TBD: call arch dependant reinitialization of the 
+		 * interrupts.
+		 */
+#ifdef CONFIG_X86
+		init_8259A(0);
+#endif
+		/* wait for power to come back */
+		mdelay(1000);
+
+	}
+
+	/* Be really sure that irqs are disabled. */
+	ACPI_DISABLE_IRQS();
+
+	/* Wait a little again, just in case... */
+	mdelay(1000);
+
+	/* enable interrupts once again */
+	ACPI_ENABLE_IRQS();
+
+	/* turn all the devices back on */
+	if (state > ACPI_STATE_S1)
+		pm_send_all(PM_RESUME, (void *)0);
+
+	return AE_OK;
+}
+
+
+/**
+ * acpi_system_save_state - save OS specific state and power down devices
+ * @state:	sleep state we're entering.
+ *
+ * This handles saving all context to memory, and possibly disk.
+ * First, we call to the device driver layer to save device state.
+ * Once we have that, we save whatevery processor and kernel state we
+ * need to memory.
+ * If we're entering S4, we then write the memory image to disk.
+ *
+ * Only then it is safe for us to power down devices, since we may need
+ * the disks and upstream buses to write to.
+ */
+acpi_status
+acpi_system_save_state(
+	u32			state)
+{
+	int			error = 0;
+
+	/* Send notification to devices that they will be suspended.
+	 * If any device or driver cannot make the transition, either up
+	 * or down, we'll get an error back.
+	 */
+	if (state > ACPI_STATE_S1) {
+		error = pm_send_all(PM_SAVE_STATE, (void *)3);
+		if (error)
+			return AE_ERROR;
+	}
+
+	if (state <= ACPI_STATE_S5) {
+		/* Tell devices to stop I/O and actually save their state.
+		 * It is theoretically possible that something could fail,
+		 * so handle that gracefully..
+		 */
+		if (state > ACPI_STATE_S1 && state != ACPI_STATE_S5) {
+			error = pm_send_all(PM_SUSPEND, (void *)3);
+			if (error) {
+				/* Tell devices to restore state if they have
+				 * it saved and to start taking I/O requests.
+				 */
+				pm_send_all(PM_RESUME, (void *)0);
+				return error;
+			}
+		}
+		
+		/* flush caches */
+		ACPI_FLUSH_CPU_CACHE();
+
+		/* Do arch specific saving of state. */
+		if (state > ACPI_STATE_S1) {
+			error = acpi_save_state_mem();
+
+			/* TBD: if no s4bios, write codes for
+			 * acpi_save_state_disk()...
+			 */
+#if 0
+			if (!error && (state == ACPI_STATE_S4))
+				error = acpi_save_state_disk();
+#endif
+			if (error) {
+				pm_send_all(PM_RESUME, (void *)0);
+				return error;
+			}
+		}
+	}
+	/* disable interrupts
+	 * Note that acpi_suspend -- our caller -- will do this once we return.
+	 * But, we want it done early, so we don't get any suprises during
+	 * the device suspend sequence.
+	 */
+	ACPI_DISABLE_IRQS();
+
+	/* Unconditionally turn off devices.
+	 * Obvious if we enter a sleep state.
+	 * If entering S5 (soft off), this should put devices in a
+	 * quiescent state.
+	 */
+
+	if (state > ACPI_STATE_S1) {
+		error = pm_send_all(PM_SUSPEND, (void *)3);
+
+		/* We're pretty screwed if we got an error from this.
+		 * We try to recover by simply calling our own restore_state
+		 * function; see above for definition.
+		 *
+		 * If it's S5 though, go through with it anyway..
+		 */
+		if (error && state != ACPI_STATE_S5)
+			acpi_system_restore_state(state);
+	}
+	return error ? AE_ERROR : AE_OK;
+}
+
+
+/****************************************************************************
+ *
+ * FUNCTION:    acpi_system_suspend
+ *
+ * PARAMETERS:  %state: Sleep state to enter.
+ *
+ * RETURN:      acpi_status, whether or not we successfully entered and
+ *              exited sleep.
+ *
+ * DESCRIPTION: Perform OS-specific action to enter sleep state.
+ *              This is the final step in going to sleep, per spec.  If we
+ *              know we're coming back (i.e. not entering S5), we save the
+ *              processor flags. [ We'll have to save and restore them anyway,
+ *              so we use the arch-agnostic save_flags and restore_flags
+ *              here.]  We then set the place to return to in arch-specific
+ *              globals using arch_set_return_point. Finally, we call the
+ *              ACPI function to write the proper values to I/O ports.
+ *
+ ****************************************************************************/
+
+acpi_status
+acpi_system_suspend(
+	u32		state)
+{
+	acpi_status		status = AE_ERROR;
+	unsigned long		flags = 0;
+
+	local_irq_save(flags);
+	/* kernel_fpu_begin(); */
+
+	switch (state) {
+	case ACPI_STATE_S1:
+	case ACPI_STATE_S5:
+		barrier();
+		status = acpi_enter_sleep_state(state);
+		break;
+	case ACPI_STATE_S4:
+		do_suspend_lowlevel_s4bios(0);
+		break;
+	}
+
+	/* kernel_fpu_end(); */
+	local_irq_restore(flags);
+
+	return status;
+}
+
+
+
+/**
+ * acpi_suspend - OS-agnostic system suspend/resume support (S? states)
+ * @state:	state we're entering
+ *
+ */
+acpi_status
+acpi_suspend (
+	u32			state)
+{
+	acpi_status status;
+
+	/* only support S1 and S5 on kernel 2.4 */
+	if (state != ACPI_STATE_S1 && state != ACPI_STATE_S4
+	    && state != ACPI_STATE_S5)
+		return AE_ERROR;
+
+
+	if (ACPI_STATE_S4 == state) {
+		/* For s4bios, we need a wakeup address. */
+		if (1 == acpi_gbl_FACS->S4bios_f &&
+		    0 != acpi_gbl_FADT->smi_cmd) {
+			if (!acpi_wakeup_address)
+				return AE_ERROR;
+			acpi_set_firmware_waking_vector((acpi_physical_address) acpi_wakeup_address);
+		} else
+			/* We don't support S4 under 2.4.  Give up */
+			return AE_ERROR;
+	}
+
+	status = acpi_system_save_state(state);
+	if (!ACPI_SUCCESS(status) && state != ACPI_STATE_S5)
+		return status;
+
+	acpi_enter_sleep_state_prep(state);
+
+	/* disable interrupts and flush caches */
+	ACPI_DISABLE_IRQS();
+	ACPI_FLUSH_CPU_CACHE();
+
+	/* perform OS-specific sleep actions */
+	status = acpi_system_suspend(state);
+
+	/* Even if we failed to go to sleep, all of the devices are in an suspended
+	 * mode. So, we run these unconditionaly to make sure we have a usable system
+	 * no matter what.
+	 */
+	acpi_leave_sleep_state(state);
+	acpi_system_restore_state(state);
+
+	/* make sure interrupts are enabled */
+	ACPI_ENABLE_IRQS();
+
+	/* reset firmware waking vector */
+	acpi_set_firmware_waking_vector((acpi_physical_address) 0);
+
+	return status;
+}
+
+#endif /* CONFIG_ACPI_SLEEP */
+
+
+/* --------------------------------------------------------------------------
+                              FS Interface (/proc)
+   -------------------------------------------------------------------------- */
+
+static int
+acpi_system_read_info (
+	char			*page,
+	char			**start,
+	off_t			off,
+	int 			count,
+	int 			*eof,
+	void			*data)
+{
+	struct acpi_system	*system = (struct acpi_system *) data;
+	char			*p = page;
+	int			size = 0;
+	u32			i = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_system_read_info");
+
+	if (!system || (off != 0))
+		goto end;
+
+	p += sprintf(p, "version:                 %x\n", ACPI_CA_VERSION);
+
+	p += sprintf(p, "states:                  ");
+	for (i=0; i<ACPI_S_STATE_COUNT; i++) {
+		if (system->states[i]) {
+			p += sprintf(p, "S%d ", i);
+			if (i == ACPI_STATE_S4 &&
+			    acpi_gbl_FACS->S4bios_f &&
+			    0 != acpi_gbl_FADT->smi_cmd)
+				p += sprintf(p, "S4Bios ");
+		}
+	}
+	p += sprintf(p, "\n");
+
+end:
+	size = (p - page);
+	if (size <= off+count) *eof = 1;
+	*start = page + off;
+	size -= off;
+	if (size>count) size = count;
+	if (size<0) size = 0;
+
+	return_VALUE(size);
+}
+
+static int acpi_system_open_event(struct inode *inode, struct file *file);
+static ssize_t acpi_system_read_event (struct file*, char*, size_t, loff_t*);
+static int acpi_system_close_event(struct inode *inode, struct file *file);
+static unsigned int acpi_system_poll_event(struct file *file, poll_table *wait);
+
+
+static 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
+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			*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;
+
+
+	ACPI_FUNCTION_TRACE("acpi_system_read_event");
+
+	if (!chars_remaining) {
+		memset(&event, 0, sizeof(struct acpi_bus_event));
+
+		if ((file->f_flags & O_NONBLOCK)
+		    && (list_empty(&acpi_bus_event_list)))
+			return_VALUE(-EAGAIN);
+
+		result = acpi_bus_receive_event(&event);
+		if (result) {
+			return_VALUE(-EIO);
+		}
+
+		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_VALUE(-EFAULT);
+
+	*ppos += count;
+	chars_remaining -= count;
+	ptr += count;
+
+	return_VALUE(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 ssize_t acpi_system_read_dsdt (struct file*, char*, size_t, loff_t*);
+
+static struct file_operations acpi_system_dsdt_ops = {
+	.read =			acpi_system_read_dsdt,
+};
+
+static ssize_t
+acpi_system_read_dsdt (
+	struct file		*file,
+	char			*buffer,
+	size_t			count,
+	loff_t			*ppos)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_buffer	dsdt = {ACPI_ALLOCATE_BUFFER, NULL};
+	void			*data = 0;
+	size_t			size = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_system_read_dsdt");
+
+	status = acpi_get_table(ACPI_TABLE_DSDT, 1, &dsdt);
+	if (ACPI_FAILURE(status))
+		return_VALUE(-ENODEV);
+
+	if (*ppos < dsdt.length) {
+		data = dsdt.pointer + file->f_pos;
+		size = dsdt.length - file->f_pos;
+		if (size > count)
+			size = count;
+		if (copy_to_user(buffer, data, size)) {
+			acpi_os_free(dsdt.pointer);
+			return_VALUE(-EFAULT);
+		}
+	}
+
+	acpi_os_free(dsdt.pointer);
+
+	*ppos += size;
+
+	return_VALUE(size);
+}
+
+
+static ssize_t acpi_system_read_fadt (struct file*, char*, size_t, loff_t*);
+
+static struct file_operations acpi_system_fadt_ops = {
+	.read =			acpi_system_read_fadt,
+};
+
+static ssize_t
+acpi_system_read_fadt (
+	struct file		*file,
+	char			*buffer,
+	size_t			count,
+	loff_t			*ppos)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_buffer	fadt = {ACPI_ALLOCATE_BUFFER, NULL};
+	void			*data = 0;
+	size_t			size = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_system_read_fadt");
+
+	status = acpi_get_table(ACPI_TABLE_FADT, 1, &fadt);
+	if (ACPI_FAILURE(status))
+		return_VALUE(-ENODEV);
+
+	if (*ppos < fadt.length) {
+		data = fadt.pointer + file->f_pos;
+		size = fadt.length - file->f_pos;
+		if (size > count)
+			size = count;
+		if (copy_to_user(buffer, data, size)) {
+			acpi_os_free(fadt.pointer);
+			return_VALUE(-EFAULT);
+		}
+	}
+
+	acpi_os_free(fadt.pointer);
+
+	*ppos += size;
+
+	return_VALUE(size);
+}
+
+
+#ifdef ACPI_DEBUG_OUTPUT
+
+static int
+acpi_system_read_debug (
+	char			*page,
+	char			**start,
+	off_t			off,
+	int 			count,
+	int 			*eof,
+	void			*data)
+{
+	char			*p = page;
+	int 			size = 0;
+
+	if (off != 0)
+		goto end;
+
+	switch ((unsigned long) data) {
+	case 0:
+		p += sprintf(p, "0x%08x\n", acpi_dbg_layer);
+		break;
+	case 1:
+		p += sprintf(p, "0x%08x\n", acpi_dbg_level);
+		break;
+	default:
+		p += sprintf(p, "Invalid debug option\n");
+		break;
+	}
+	
+end:
+	size = (p - page);
+	if (size <= off+count) *eof = 1;
+	*start = page + off;
+	size -= off;
+	if (size>count) size = count;
+	if (size<0) size = 0;
+
+	return size;
+}
+
+
+static int
+acpi_system_write_debug (
+	struct file             *file,
+        const char              *buffer,
+	unsigned long           count,
+        void                    *data)
+{
+	char			debug_string[12] = {'\0'};
+
+	ACPI_FUNCTION_TRACE("acpi_system_write_debug");
+
+	if (count > sizeof(debug_string) - 1)
+		return_VALUE(-EINVAL);
+
+	if (copy_from_user(debug_string, buffer, count))
+		return_VALUE(-EFAULT);
+
+	debug_string[count] = '\0';
+
+	switch ((unsigned long) data) {
+	case 0:
+		acpi_dbg_layer = simple_strtoul(debug_string, NULL, 0);
+		break;
+	case 1:
+		acpi_dbg_level = simple_strtoul(debug_string, NULL, 0);
+		break;
+	default:
+		return_VALUE(-EINVAL);
+	}
+
+	return_VALUE(count);
+}
+
+#endif /* ACPI_DEBUG_OUTPUT */
+
+
+#ifdef CONFIG_ACPI_SLEEP
+
+static int
+acpi_system_read_sleep (
+        char                    *page,
+        char                    **start,
+        off_t                   off,
+        int                     count,
+        int                     *eof,
+        void                    *data)
+{
+	struct acpi_system	*system = (struct acpi_system *) data;
+	char			*p = page;
+	int			size;
+	int			i;
+
+	ACPI_FUNCTION_TRACE("acpi_system_read_sleep");
+
+	if (!system || (off != 0))
+		goto end;
+
+	for (i = 0; i <= ACPI_STATE_S5; i++) {
+		if (system->states[i]) {
+			p += sprintf(p,"S%d ", i);
+			if (i == ACPI_STATE_S4 && acpi_gbl_FACS->S4bios_f &&
+			    acpi_gbl_FADT->smi_cmd != 0)
+				p += sprintf(p, "S4Bios ");
+		}
+	}
+
+	p += sprintf(p, "\n");
+
+end:
+	size = (p - page);
+	if (size <= off+count) *eof = 1;
+	*start = page + off;
+	size -= off;
+	if (size>count) size = count;
+	if (size<0) size = 0;
+
+	return_VALUE(size);
+}
+
+
+static int
+acpi_system_write_sleep (
+	struct file		*file,
+	const char		*buffer,
+	unsigned long		count,
+	void			*data)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_system	*system = (struct acpi_system *) data;
+	char			state_string[12] = {'\0'};
+	u32			state = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_system_write_sleep");
+
+	if (!system || (count > sizeof(state_string) - 1))
+		return_VALUE(-EINVAL);
+
+	if (copy_from_user(state_string, buffer, count))
+		return_VALUE(-EFAULT);
+	
+	state_string[count] = '\0';
+	
+	state = simple_strtoul(state_string, NULL, 0);
+	
+	if (!system->states[state])
+		return_VALUE(-ENODEV);
+
+	/*
+	 * If S4 is supported by the OS, then we should assume that
+	 * echo 4b > /proc/acpi/sleep is for s4bios.
+	 * Since we have only s4bios, we assume that acpi_suspend failed
+	 * if no s4bios support.
+	 */
+	status = acpi_suspend(state);
+	if (ACPI_FAILURE(status))
+		return_VALUE(-ENODEV);
+	
+	return_VALUE(count);
+}
+
+
+static int
+acpi_system_read_alarm (
+	char                    *page,
+	char                    **start,
+	off_t                   off,
+	int                     count,
+	int                     *eof,
+	void                    *context)
+{
+	char			*p = page;
+	int			size = 0;
+	u32			sec, min, hr;
+	u32			day, mo, yr;
+
+	ACPI_FUNCTION_TRACE("acpi_system_read_alarm");
+
+	if (off != 0)
+		goto end;
+
+	spin_lock(&rtc_lock);
+
+	sec = CMOS_READ(RTC_SECONDS_ALARM);
+	min = CMOS_READ(RTC_MINUTES_ALARM);
+	hr = CMOS_READ(RTC_HOURS_ALARM);
+
+#if 0	/* If we ever get an FACP with proper values... */
+	if (acpi_gbl_FADT->day_alrm)
+		day = CMOS_READ(acpi_gbl_FADT->day_alrm);
+	else
+		day =  CMOS_READ(RTC_DAY_OF_MONTH);
+	if (acpi_gbl_FADT->mon_alrm)
+		mo = CMOS_READ(acpi_gbl_FADT->mon_alrm);
+	else
+		mo = CMOS_READ(RTC_MONTH);;
+	if (acpi_gbl_FADT->century)
+		yr = CMOS_READ(acpi_gbl_FADT->century) * 100 + CMOS_READ(RTC_YEAR);
+	else
+		yr = CMOS_READ(RTC_YEAR);
+#else
+	day = CMOS_READ(RTC_DAY_OF_MONTH);
+	mo = CMOS_READ(RTC_MONTH);
+	yr = CMOS_READ(RTC_YEAR);
+#endif
+
+	spin_unlock(&rtc_lock);
+
+	BCD_TO_BIN(sec);
+	BCD_TO_BIN(min);
+	BCD_TO_BIN(hr);
+	BCD_TO_BIN(day);
+	BCD_TO_BIN(mo);
+	BCD_TO_BIN(yr);
+
+#if 0
+	/* we're trusting the FADT (see above)*/
+#else
+	/* If we're not trusting the FADT, we should at least make it
+	 * right for _this_ century... ehm, what is _this_ century?
+	 *
+	 * TBD:
+	 *  ASAP: find piece of code in the kernel, e.g. star tracker driver,
+	 *        which we can trust to determine the century correctly. Atom
+	 *        watch driver would be nice, too...
+	 *
+	 *  if that has not happened, change for first release in 2050:
+ 	 *        if (yr<50)
+	 *                yr += 2100;
+	 *        else
+	 *                yr += 2000;   // current line of code
+	 *
+	 *  if that has not happened either, please do on 2099/12/31:23:59:59
+	 *        s/2000/2100
+	 *
+	 */
+	yr += 2000;
+#endif
+
+	p += sprintf(p,"%4.4u-", yr);
+	p += (mo > 12)  ? sprintf(p, "**-")  : sprintf(p, "%2.2u-", mo);
+	p += (day > 31) ? sprintf(p, "** ")  : sprintf(p, "%2.2u ", day);
+	p += (hr > 23)  ? sprintf(p, "**:")  : sprintf(p, "%2.2u:", hr);
+	p += (min > 59) ? sprintf(p, "**:")  : sprintf(p, "%2.2u:", min);
+	p += (sec > 59) ? sprintf(p, "**\n") : sprintf(p, "%2.2u\n", sec);
+
+ end:
+	size = p - page;
+	if (size < count) *eof = 1;
+	else if (size > count) size = count;
+	if (size < 0) size = 0;
+	*start = page;
+
+	return_VALUE(size);
+}
+
+
+static int
+get_date_field (
+	char			**p,
+	u32			*value)
+{
+	char			*next = NULL;
+	char			*string_end = NULL;
+	int			result = -EINVAL;
+
+	/*
+	 * Try to find delimeter, only to insert null.  The end of the
+	 * string won't have one, but is still valid.
+	 */
+	next = strpbrk(*p, "- :");
+	if (next)
+		*next++ = '\0';
+
+	*value = simple_strtoul(*p, &string_end, 10);
+
+	/* Signal success if we got a good digit */
+	if (string_end != *p)
+		result = 0;
+
+	if (next)
+		*p = next;
+
+	return result;
+}
+
+
+static int
+acpi_system_write_alarm (
+	struct file		*file,
+	const char		*buffer,
+	unsigned long		count,
+	void			*data)
+{
+	int			result = 0;
+	char			alarm_string[30] = {'\0'};
+	char			*p = alarm_string;
+	u32			sec, min, hr, day, mo, yr;
+	int			adjust = 0;
+	unsigned char		rtc_control = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_system_write_alarm");
+
+	if (count > sizeof(alarm_string) - 1)
+		return_VALUE(-EINVAL);
+	
+	if (copy_from_user(alarm_string, buffer, count))
+		return_VALUE(-EFAULT);
+
+	alarm_string[count] = '\0';
+
+	/* check for time adjustment */
+	if (alarm_string[0] == '+') {
+		p++;
+		adjust = 1;
+	}
+
+	if ((result = get_date_field(&p, &yr)))
+		goto end;
+	if ((result = get_date_field(&p, &mo)))
+		goto end;
+	if ((result = get_date_field(&p, &day)))
+		goto end;
+	if ((result = get_date_field(&p, &hr)))
+		goto end;
+	if ((result = get_date_field(&p, &min)))
+		goto end;
+	if ((result = get_date_field(&p, &sec)))
+		goto end;
+
+	if (sec > 59) {
+		min += 1;
+		sec -= 60;
+	}
+	if (min > 59) {
+		hr += 1;
+		min -= 60;
+	}
+	if (hr > 23) {
+		day += 1;
+		hr -= 24;
+	}
+	if (day > 31) {
+		mo += 1;
+		day -= 31;
+	}
+	if (mo > 12) {
+		yr += 1;
+		mo -= 12;
+	}
+
+	spin_lock_irq(&rtc_lock);
+
+	rtc_control = CMOS_READ(RTC_CONTROL);
+	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+		BIN_TO_BCD(yr);
+		BIN_TO_BCD(mo);
+		BIN_TO_BCD(day);
+		BIN_TO_BCD(hr);
+		BIN_TO_BCD(min);
+		BIN_TO_BCD(sec);
+	}
+
+	if (adjust) {
+		yr  += CMOS_READ(RTC_YEAR);
+		mo  += CMOS_READ(RTC_MONTH);
+		day += CMOS_READ(RTC_DAY_OF_MONTH);
+		hr  += CMOS_READ(RTC_HOURS);
+		min += CMOS_READ(RTC_MINUTES);
+		sec += CMOS_READ(RTC_SECONDS);
+	}
+
+	spin_unlock_irq(&rtc_lock);
+
+	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+		BCD_TO_BIN(yr);
+		BCD_TO_BIN(mo);
+		BCD_TO_BIN(day);
+		BCD_TO_BIN(hr);
+		BCD_TO_BIN(min);
+		BCD_TO_BIN(sec);
+	}
+
+	if (sec > 59) {
+		min++;
+		sec -= 60;
+	}
+	if (min > 59) {
+		hr++;
+		min -= 60;
+	}
+	if (hr > 23) {
+		day++;
+		hr -= 24;
+	}
+	if (day > 31) {
+		mo++;
+		day -= 31;
+	}
+	if (mo > 12) {
+		yr++;
+		mo -= 12;
+	}
+	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+		BIN_TO_BCD(yr);
+		BIN_TO_BCD(mo);
+		BIN_TO_BCD(day);
+		BIN_TO_BCD(hr);
+		BIN_TO_BCD(min);
+		BIN_TO_BCD(sec);
+	}
+
+	spin_lock_irq(&rtc_lock);
+
+	/* write the fields the rtc knows about */
+	CMOS_WRITE(hr, RTC_HOURS_ALARM);
+	CMOS_WRITE(min, RTC_MINUTES_ALARM);
+	CMOS_WRITE(sec, RTC_SECONDS_ALARM);
+
+	/*
+	 * If the system supports an enhanced alarm it will have non-zero
+	 * offsets into the CMOS RAM here -- which for some reason are pointing
+	 * to the RTC area of memory.
+	 */
+#if 0
+	if (acpi_gbl_FADT->day_alrm)
+		CMOS_WRITE(day, acpi_gbl_FADT->day_alrm);
+	if (acpi_gbl_FADT->mon_alrm)
+		CMOS_WRITE(mo, acpi_gbl_FADT->mon_alrm);
+	if (acpi_gbl_FADT->century)
+		CMOS_WRITE(yr/100, acpi_gbl_FADT->century);
+#endif
+	/* enable the rtc alarm interrupt */
+	if (!(rtc_control & RTC_AIE)) {
+		rtc_control |= RTC_AIE;
+		CMOS_WRITE(rtc_control,RTC_CONTROL);
+		CMOS_READ(RTC_INTR_FLAGS);
+	}
+
+	spin_unlock_irq(&rtc_lock);
+
+	acpi_set_register(ACPI_BITREG_RT_CLOCK_ENABLE, 1, ACPI_MTX_LOCK);
+
+	file->f_pos += count;
+
+	result = 0;
+end:
+	return_VALUE(result ? result : count);
+}
+
+#endif /*CONFIG_ACPI_SLEEP*/
+
+
+static int
+acpi_system_add_fs (
+	struct acpi_device	*device)
+{
+	struct proc_dir_entry	*entry = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_system_add_fs");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	/* 'info' [R] */
+	entry = create_proc_entry(ACPI_SYSTEM_FILE_INFO,
+		S_IRUGO, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create '%s' fs entry\n",
+			ACPI_SYSTEM_FILE_INFO));
+	else {
+		entry->read_proc = acpi_system_read_info;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'dsdt' [R] */
+	entry = create_proc_entry(ACPI_SYSTEM_FILE_DSDT,
+		S_IRUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create '%s' fs entry\n",
+			ACPI_SYSTEM_FILE_DSDT));
+	else
+		entry->proc_fops = &acpi_system_dsdt_ops;
+
+	/* 'fadt' [R] */
+	entry = create_proc_entry(ACPI_SYSTEM_FILE_FADT,
+		S_IRUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create '%s' fs entry\n",
+			ACPI_SYSTEM_FILE_FADT));
+	else
+		entry->proc_fops = &acpi_system_fadt_ops;
+
+	/* 'event' [R] */
+	entry = create_proc_entry(ACPI_SYSTEM_FILE_EVENT,
+		S_IRUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create '%s' fs entry\n",
+			ACPI_SYSTEM_FILE_EVENT));
+	else
+		entry->proc_fops = &acpi_system_event_ops;
+
+#ifdef CONFIG_ACPI_SLEEP
+
+	/* 'sleep' [R/W]*/
+	entry = create_proc_entry(ACPI_SYSTEM_FILE_SLEEP,
+		S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create '%s' fs entry\n",
+			ACPI_SYSTEM_FILE_SLEEP));
+	else {
+		entry->read_proc = acpi_system_read_sleep;
+		entry->write_proc = acpi_system_write_sleep;
+		entry->data = acpi_driver_data(device);
+	}
+
+	/* 'alarm' [R/W] */
+	entry = create_proc_entry(ACPI_SYSTEM_FILE_ALARM,
+		S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create '%s' fs entry\n",
+			ACPI_SYSTEM_FILE_ALARM));
+	else {
+		entry->read_proc = acpi_system_read_alarm;
+		entry->write_proc = acpi_system_write_alarm;
+		entry->data = acpi_driver_data(device);
+	}
+
+#endif /*CONFIG_ACPI_SLEEP*/
+
+#ifdef ACPI_DEBUG_OUTPUT
+
+	/* 'debug_layer' [R/W] */
+	entry = create_proc_entry(ACPI_SYSTEM_FILE_DEBUG_LAYER,
+		S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create '%s' fs entry\n",
+			ACPI_SYSTEM_FILE_DEBUG_LAYER));
+	else {
+		entry->read_proc  = acpi_system_read_debug;
+		entry->write_proc = acpi_system_write_debug;
+		entry->data = (void *) 0;
+	}
+
+	/* 'debug_level' [R/W] */
+	entry = create_proc_entry(ACPI_SYSTEM_FILE_DEBUG_LEVEL,
+		S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Unable to create '%s' fs entry\n",
+			ACPI_SYSTEM_FILE_DEBUG_LEVEL));
+	else {
+		entry->read_proc  = acpi_system_read_debug;
+		entry->write_proc = acpi_system_write_debug;
+		entry->data = (void *) 1;
+	}
+
+#endif /*ACPI_DEBUG_OUTPUT */
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_system_remove_fs (
+	struct acpi_device	*device)
+{
+	ACPI_FUNCTION_TRACE("acpi_system_remove_fs");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	remove_proc_entry(ACPI_SYSTEM_FILE_INFO, acpi_device_dir(device));
+	remove_proc_entry(ACPI_SYSTEM_FILE_DSDT, acpi_device_dir(device));
+	remove_proc_entry(ACPI_SYSTEM_FILE_EVENT, acpi_device_dir(device));
+#ifdef CONFIG_ACPI_SLEEP
+	remove_proc_entry(ACPI_SYSTEM_FILE_SLEEP, acpi_device_dir(device));
+	remove_proc_entry(ACPI_SYSTEM_FILE_ALARM, acpi_device_dir(device));
+#endif
+#ifdef ACPI_DEBUG_OUTPUT
+	remove_proc_entry(ACPI_SYSTEM_FILE_DEBUG_LAYER,
+		acpi_device_dir(device));
+	remove_proc_entry(ACPI_SYSTEM_FILE_DEBUG_LEVEL,
+		acpi_device_dir(device));
+#endif
+
+	return_VALUE(0);
+}
+
+
+/* --------------------------------------------------------------------------
+                                 Driver Interface
+   -------------------------------------------------------------------------- */
+
+#if defined(CONFIG_MAGIC_SYSRQ) && defined(CONFIG_PM)
+
+/* Simple wrapper calling power down function. */
+static void acpi_sysrq_power_off(int key, struct pt_regs *pt_regs,
+	struct kbd_struct *kbd, struct tty_struct *tty)
+{
+	acpi_power_off();
+}
+
+struct sysrq_key_op sysrq_acpi_poweroff_op = {
+	.handler =	&acpi_sysrq_power_off,
+	.help_msg =	"Off",
+	.action_msg =	"Power Off\n"
+};
+
+#endif  /* CONFIG_MAGIC_SYSRQ */
+
+static int
+acpi_system_add (
+	struct acpi_device	*device)
+{
+	int			result = 0;
+	acpi_status		status = AE_OK;
+	struct acpi_system	*system = NULL;
+	u8			i = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_system_add");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	system = kmalloc(sizeof(struct acpi_system), GFP_KERNEL);
+	if (!system)
+		return_VALUE(-ENOMEM);
+	memset(system, 0, sizeof(struct acpi_system));
+
+	system->handle = device->handle;
+	sprintf(acpi_device_name(device), "%s", ACPI_SYSTEM_DEVICE_NAME);
+	sprintf(acpi_device_class(device), "%s", ACPI_SYSTEM_CLASS);
+	acpi_driver_data(device) = system;
+
+	result = acpi_system_add_fs(device);
+	if (result)
+		goto end;
+
+	printk(KERN_INFO PREFIX "%s [%s] (supports", 
+		acpi_device_name(device), acpi_device_bid(device));
+	for (i=0; i<ACPI_S_STATE_COUNT; i++) {
+		u8 type_a, type_b;
+		status = acpi_get_sleep_type_data(i, &type_a, &type_b);
+		switch (i) {
+		case ACPI_STATE_S4:
+			if (acpi_gbl_FACS->S4bios_f &&
+			    0 != acpi_gbl_FADT->smi_cmd) {
+				printk(" S4bios");
+				system->states[i] = 1;
+			}
+			/* no break */
+		default: 
+			if (ACPI_SUCCESS(status)) {
+				system->states[i] = 1;
+				printk(" S%d", i);
+			}
+		}
+	}
+	printk(")\n");
+
+#ifdef CONFIG_PM
+	/* Install the soft-off (S5) handler. */
+	if (system->states[ACPI_STATE_S5]) {
+		pm_power_off = acpi_power_off;
+		register_sysrq_key('o', &sysrq_acpi_poweroff_op);
+	}
+#endif
+
+end:
+	if (result)
+		kfree(system);
+
+	return_VALUE(result);
+}
+
+
+static int
+acpi_system_remove (
+	struct acpi_device	*device,
+	int			type)
+{
+	struct acpi_system	*system = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_system_remove");
+
+	if (!device || !acpi_driver_data(device))
+		return_VALUE(-EINVAL);
+
+	system = (struct acpi_system *) acpi_driver_data(device);
+
+#ifdef CONFIG_PM
+	/* Remove the soft-off (S5) handler. */
+	if (system->states[ACPI_STATE_S5]) {
+		unregister_sysrq_key('o', &sysrq_acpi_poweroff_op);
+		pm_power_off = NULL;
+	}
+#endif
+
+	acpi_system_remove_fs(device);
+
+	kfree(system);
+
+	return 0;
+}
+
+
+int __init
+acpi_system_init (void)
+{
+	int			result = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_system_init");
+
+	result = acpi_bus_register_driver(&acpi_system_driver);
+	if (result < 0)
+		return_VALUE(-ENODEV);
+
+	return_VALUE(0);
+}
+
+
+void __exit
+acpi_system_exit (void)
+{
+	ACPI_FUNCTION_TRACE("acpi_system_exit");
+	acpi_bus_unregister_driver(&acpi_system_driver);
+	return_VOID;
+}
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)