bus.c

Linux Kernel 2.6.9 for OMAP1710

/*
 *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
 *
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[e-mail]>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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/init.h>
#include <linux/ioport.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/proc_fs.h>
#ifdef CONFIG_X86
#include <asm/mpspec.h>
#endif
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>


#define _COMPONENT		ACPI_BUS_COMPONENT
ACPI_MODULE_NAME		("acpi_bus")

#ifdef	CONFIG_X86
extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
#endif

FADT_DESCRIPTOR			acpi_fadt;
struct acpi_device		*acpi_root;
struct proc_dir_entry		*acpi_root_dir;

#define STRUCT_TO_INT(s)	(*((int*)&s))

/* --------------------------------------------------------------------------
                                Device Management
   -------------------------------------------------------------------------- */

extern void acpi_bus_data_handler (
	acpi_handle		handle,
	u32			function,
	void			*context);
int
acpi_bus_get_device (
	acpi_handle		handle,
	struct acpi_device	**device)
{
	acpi_status		status = AE_OK;

	ACPI_FUNCTION_TRACE("acpi_bus_get_device");

	if (!device)
		return_VALUE(-EINVAL);

	/* TBD: Support fixed-feature devices */

	status = acpi_get_data(handle, acpi_bus_data_handler, (void**) device);
	if (ACPI_FAILURE(status) || !*device) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error getting context for object [%p]\n",
			handle));
		return_VALUE(-ENODEV);
	}

	return_VALUE(0);
}

int
acpi_bus_get_status (
	struct acpi_device	*device)
{
	acpi_status		status = AE_OK;
	unsigned long		sta = 0;
	
	ACPI_FUNCTION_TRACE("acpi_bus_get_status");

	if (!device)
		return_VALUE(-EINVAL);

	/*
	 * Evaluate _STA if present.
	 */
	if (device->flags.dynamic_status) {
		status = acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
		if (ACPI_FAILURE(status))
			return_VALUE(-ENODEV);
		STRUCT_TO_INT(device->status) = (int) sta;
	}

	/*
	 * Otherwise we assume the status of our parent (unless we don't
	 * have one, in which case status is implied).
	 */
	else if (device->parent)
		device->status = device->parent->status;
	else
		STRUCT_TO_INT(device->status) = 0x0F;

	if (device->status.functional && !device->status.present) {
		printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
			"functional but not present; setting present\n",
			device->pnp.bus_id,
			(u32) STRUCT_TO_INT(device->status));
		device->status.present = 1;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n", 
		device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status)));

	return_VALUE(0);
}


/* --------------------------------------------------------------------------
                                 Power Management
   -------------------------------------------------------------------------- */

int
acpi_bus_get_power (
	acpi_handle		handle,
	int			*state)
{
	int			result = 0;
	acpi_status             status = 0;
	struct acpi_device	*device = NULL;
	unsigned long		psc = 0;

	ACPI_FUNCTION_TRACE("acpi_bus_get_power");

	result = acpi_bus_get_device(handle, &device);
	if (result)
		return_VALUE(result);

	*state = ACPI_STATE_UNKNOWN;

	if (!device->flags.power_manageable) {
		/* TBD: Non-recursive algorithm for walking up hierarchy */
		if (device->parent)
			*state = device->parent->power.state;
		else
			*state = ACPI_STATE_D0;
	}
	else {
		/*
		 * Get the device's power state either directly (via _PSC) or 
		 * indirectly (via power resources).
		 */
		if (device->power.flags.explicit_get) {
			status = acpi_evaluate_integer(device->handle, "_PSC", 
				NULL, &psc);
			if (ACPI_FAILURE(status))
				return_VALUE(-ENODEV);
			device->power.state = (int) psc;
		}
		else if (device->power.flags.power_resources) {
			result = acpi_power_get_inferred_state(device);
			if (result)
				return_VALUE(result);
		}

		*state = device->power.state;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
		device->pnp.bus_id, device->power.state));

	return_VALUE(0);
}


int
acpi_bus_set_power (
	acpi_handle		handle,
	int			state)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	struct acpi_device	*device = NULL;
	char			object_name[5] = {'_','P','S','0'+state,'\0'};

	ACPI_FUNCTION_TRACE("acpi_bus_set_power");

	result = acpi_bus_get_device(handle, &device);
	if (result)
		return_VALUE(result);

	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
		return_VALUE(-EINVAL);

	/* Make sure this is a valid target state */

	if (!device->flags.power_manageable) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Device is not power manageable\n"));
		return_VALUE(-ENODEV);
	}
	if (state == device->power.state) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n", state));
		return_VALUE(0);
	}
	if (!device->power.states[state].flags.valid) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Device does not support D%d\n", state));
		return_VALUE(-ENODEV);
	}
	if (device->parent && (state < device->parent->power.state)) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Cannot set device to a higher-powered state than parent\n"));
		return_VALUE(-ENODEV);
	}

	/*
	 * Transition Power
	 * ----------------
	 * On transitions to a high-powered state we first apply power (via
	 * power resources) then evalute _PSx.  Conversly for transitions to
	 * a lower-powered state.
	 */ 
	if (state < device->power.state) {
		if (device->power.flags.power_resources) {
			result = acpi_power_transition(device, state);
			if (result)
				goto end;
		}
		if (device->power.states[state].flags.explicit_set) {
			status = acpi_evaluate_object(device->handle, 
				object_name, NULL, NULL);
			if (ACPI_FAILURE(status)) {
				result = -ENODEV;
				goto end;
			}
		}
	}
	else {
		if (device->power.states[state].flags.explicit_set) {
			status = acpi_evaluate_object(device->handle, 
				object_name, NULL, NULL);
			if (ACPI_FAILURE(status)) {
				result = -ENODEV;
				goto end;
			}
		}
		if (device->power.flags.power_resources) {
			result = acpi_power_transition(device, state);
			if (result)
				goto end;
		}
	}

end:
	if (result)
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error transitioning device [%s] to D%d\n",
			device->pnp.bus_id, state));
	else
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] transitioned to D%d\n",
			device->pnp.bus_id, state));

	return_VALUE(result);
}



/* --------------------------------------------------------------------------
                                Event Management
   -------------------------------------------------------------------------- */

static spinlock_t		acpi_bus_event_lock = SPIN_LOCK_UNLOCKED;

LIST_HEAD(acpi_bus_event_list);
DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);

extern int			event_is_open;

int
acpi_bus_generate_event (
	struct acpi_device	*device,
	u8			type,
	int			data)
{
	struct acpi_bus_event	*event = NULL;
	unsigned long		flags = 0;

	ACPI_FUNCTION_TRACE("acpi_bus_generate_event");

	if (!device)
		return_VALUE(-EINVAL);

	/* drop event on the floor if no one's listening */
	if (!event_is_open)
		return_VALUE(0);

	event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
	if (!event)
		return_VALUE(-ENOMEM);

	strcpy(event->device_class, device->pnp.device_class);
	strcpy(event->bus_id, device->pnp.bus_id);
	event->type = type;
	event->data = data;

	spin_lock_irqsave(&acpi_bus_event_lock, flags);
	list_add_tail(&event->node, &acpi_bus_event_list);
	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);

	wake_up_interruptible(&acpi_bus_event_queue);

	return_VALUE(0);
}

int
acpi_bus_receive_event (
	struct acpi_bus_event	*event)
{
	unsigned long		flags = 0;
	struct acpi_bus_event	*entry = NULL;

	DECLARE_WAITQUEUE(wait, current);

	ACPI_FUNCTION_TRACE("acpi_bus_receive_event");

	if (!event)
		return -EINVAL;

	if (list_empty(&acpi_bus_event_list)) {

		set_current_state(TASK_INTERRUPTIBLE);
		add_wait_queue(&acpi_bus_event_queue, &wait);

		if (list_empty(&acpi_bus_event_list))
			schedule();

		remove_wait_queue(&acpi_bus_event_queue, &wait);
		set_current_state(TASK_RUNNING);

		if (signal_pending(current))
			return_VALUE(-ERESTARTSYS);
	}

	spin_lock_irqsave(&acpi_bus_event_lock, flags);
	entry = list_entry(acpi_bus_event_list.next, struct acpi_bus_event, node);
	if (entry)
		list_del(&entry->node);
	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);

	if (!entry)
		return_VALUE(-ENODEV);

	memcpy(event, entry, sizeof(struct acpi_bus_event));

	kfree(entry);

	return_VALUE(0);
}


/* --------------------------------------------------------------------------
                             Notification Handling
   -------------------------------------------------------------------------- */

static int
acpi_bus_check_device (
	struct acpi_device	*device,
	int			*status_changed)
{
	acpi_status             status = 0;
	struct acpi_device_status old_status;

	ACPI_FUNCTION_TRACE("acpi_bus_check_device");

	if (!device)
		return_VALUE(-EINVAL);