ec.c

/*
 *  acpi_ec.c - ACPI Embedded Controller Driver ($Revision: 38 $)
 *
 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
 *  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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <acpi/actypes.h>

#define _COMPONENT		ACPI_EC_COMPONENT
ACPI_MODULE_NAME		("acpi_ec")

#define ACPI_EC_COMPONENT		0x00100000
#define ACPI_EC_CLASS			"embedded_controller"
#define ACPI_EC_HID			"PNP0C09"
#define ACPI_EC_DRIVER_NAME		"ACPI Embedded Controller Driver"
#define ACPI_EC_DEVICE_NAME		"Embedded Controller"
#define ACPI_EC_FILE_INFO		"info"


#define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
#define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
#define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
#define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */

#define ACPI_EC_EVENT_OBF	0x01	/* Output buffer full */
#define ACPI_EC_EVENT_IBE	0x02	/* Input buffer empty */

#define ACPI_EC_DELAY		50	/* Wait 50ms max. during EC ops */
#define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */

#define ACPI_EC_UDELAY         100     /* Poll @ 100us increments */
#define ACPI_EC_UDELAY_COUNT   1000    /* Wait 10ms max. during EC ops */

#define ACPI_EC_COMMAND_READ	0x80
#define ACPI_EC_COMMAND_WRITE	0x81
#define ACPI_EC_BURST_ENABLE	0x82
#define ACPI_EC_BURST_DISABLE	0x83
#define ACPI_EC_COMMAND_QUERY	0x84

#define EC_POLLING		0xFF
#define EC_BURST		0x00


static int acpi_ec_remove (struct acpi_device *device, int type);
static int acpi_ec_start (struct acpi_device *device);
static int acpi_ec_stop (struct acpi_device *device, int type);
static int acpi_ec_burst_add ( struct acpi_device *device);
static int acpi_ec_polling_add ( struct acpi_device	*device);

static struct acpi_driver acpi_ec_driver = {
	.name =		ACPI_EC_DRIVER_NAME,
	.class =	ACPI_EC_CLASS,
	.ids =		ACPI_EC_HID,
	.ops =		{
				.add =		acpi_ec_polling_add,
				.remove =	acpi_ec_remove,
				.start =	acpi_ec_start,
				.stop =		acpi_ec_stop,
			},
};
union acpi_ec {
	struct {
		u32				mode;
		acpi_handle			handle;
		unsigned long			uid;
		unsigned long			gpe_bit;
		struct acpi_generic_address	status_addr;
		struct acpi_generic_address	command_addr;
		struct acpi_generic_address	data_addr;
		unsigned long			global_lock;
	} common;

	struct {
		u32				mode;
		acpi_handle			handle;
		unsigned long			uid;
		unsigned long			gpe_bit;
		struct acpi_generic_address	status_addr;
		struct acpi_generic_address	command_addr;
		struct acpi_generic_address	data_addr;
		unsigned long			global_lock;
		unsigned int			expect_event;
		atomic_t			leaving_burst; /* 0 : No, 1 : Yes, 2: abort*/
		atomic_t			pending_gpe;
		struct semaphore		sem;
		wait_queue_head_t		wait;
	}burst;

	struct {
		u32				mode;
		acpi_handle			handle;
		unsigned long			uid;
		unsigned long			gpe_bit;
		struct acpi_generic_address	status_addr;
		struct acpi_generic_address	command_addr;
		struct acpi_generic_address	data_addr;
		unsigned long			global_lock;
       		spinlock_t                      lock;
	}polling;
};

static int acpi_ec_polling_wait ( union acpi_ec *ec, u8 event); 
static int acpi_ec_burst_wait(union acpi_ec *ec, unsigned int event);
static int acpi_ec_polling_read ( union acpi_ec *ec, u8 address, u32 *data);
static int acpi_ec_burst_read( union acpi_ec *ec, u8 address, u32 *data);
static int acpi_ec_polling_write ( union acpi_ec *ec, u8 address, u8 data);
static int acpi_ec_burst_write ( union acpi_ec *ec, u8 address, u8 data);
static int acpi_ec_polling_query ( union acpi_ec *ec, u32 *data);
static int acpi_ec_burst_query ( union acpi_ec *ec, u32 *data);
static void acpi_ec_gpe_polling_query ( void *ec_cxt);
static void acpi_ec_gpe_burst_query ( void *ec_cxt);
static u32 acpi_ec_gpe_polling_handler ( void *data);
static u32 acpi_ec_gpe_burst_handler ( void *data);
static acpi_status __init
acpi_fake_ecdt_polling_callback (
	acpi_handle	handle,
	u32		Level,
	void		*context,
	void		**retval);

static acpi_status __init
acpi_fake_ecdt_burst_callback (
	acpi_handle	handle,
	u32		Level,
	void		*context,
	void		**retval);

static int __init
acpi_ec_polling_get_real_ecdt(void);
static int __init
acpi_ec_burst_get_real_ecdt(void);
/* If we find an EC via the ECDT, we need to keep a ptr to its context */
static union acpi_ec	*ec_ecdt;

/* External interfaces use first EC only, so remember */
static struct acpi_device *first_ec;
static int acpi_ec_polling_mode = EC_POLLING;

/* --------------------------------------------------------------------------
                             Transaction Management
   -------------------------------------------------------------------------- */

static inline u32 acpi_ec_read_status(union acpi_ec *ec)
{
	u32	status = 0;

	acpi_hw_low_level_read(8, &status, &ec->common.status_addr);
	return status;
}

static int
acpi_ec_wait (
	union acpi_ec		*ec,
	u8			event)
{
	if (acpi_ec_polling_mode) 
		return acpi_ec_polling_wait (ec, event);
	else
		return acpi_ec_burst_wait (ec, event);
}

static int
acpi_ec_polling_wait (
	union acpi_ec		*ec,
	u8			event)
{
	u32			acpi_ec_status = 0;
	u32			i = ACPI_EC_UDELAY_COUNT;

	if (!ec)
		return -EINVAL;

	/* Poll the EC status register waiting for the event to occur. */
	switch (event) {
	case ACPI_EC_EVENT_OBF:
		do {
			acpi_hw_low_level_read(8, &acpi_ec_status, &ec->common.status_addr);
			if (acpi_ec_status & ACPI_EC_FLAG_OBF)
				return 0;
			udelay(ACPI_EC_UDELAY);
		} while (--i>0);
		break;
	case ACPI_EC_EVENT_IBE:
		do {
			acpi_hw_low_level_read(8, &acpi_ec_status, &ec->common.status_addr);
			if (!(acpi_ec_status & ACPI_EC_FLAG_IBF))
				return 0;
			udelay(ACPI_EC_UDELAY);
		} while (--i>0);
		break;
	default:
		return -EINVAL;
	}

	return -ETIME;
}
static int acpi_ec_burst_wait(union acpi_ec *ec, unsigned int event)
{
	int	result = 0;

	ACPI_FUNCTION_TRACE("acpi_ec_wait");

	ec->burst.expect_event = event;
	smp_mb();

	switch (event) {
	case ACPI_EC_EVENT_OBF:
		if (acpi_ec_read_status(ec) & event) {
			ec->burst.expect_event = 0;
			return_VALUE(0);
		}
		break;

	case ACPI_EC_EVENT_IBE:
		if (~acpi_ec_read_status(ec) & event) {
			ec->burst.expect_event = 0;
			return_VALUE(0);
		}
		break;
	}

	result = wait_event_timeout(ec->burst.wait,
					!ec->burst.expect_event,
					msecs_to_jiffies(ACPI_EC_DELAY));
	
	ec->burst.expect_event = 0;
	smp_mb();

	/*
	 * Verify that the event in question has actually happened by
	 * querying EC status. Do the check even if operation timed-out
	 * to make sure that we did not miss interrupt.
	 */
	switch (event) {
	case ACPI_EC_EVENT_OBF:
		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
			return_VALUE(0);
		break;

	case ACPI_EC_EVENT_IBE:
		if (~acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
			return_VALUE(0);
		break;
	}

	return_VALUE(-ETIME);
}



static int
acpi_ec_enter_burst_mode (
	union acpi_ec		*ec)
{
	u32			tmp = 0;
	int			status = 0;

	ACPI_FUNCTION_TRACE("acpi_ec_enter_burst_mode");

	status = acpi_ec_read_status(ec);
	if (status != -EINVAL &&
		!(status & ACPI_EC_FLAG_BURST)){
		status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
		if(status)
			goto end;
		acpi_hw_low_level_write(8, ACPI_EC_BURST_ENABLE, &ec->common.command_addr);
		status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
		if (status)
			return_VALUE(-EINVAL);
		acpi_hw_low_level_read(8, &tmp, &ec->common.data_addr);
		if(tmp != 0x90 ) {/* Burst ACK byte*/
			return_VALUE(-EINVAL);
		}
	}

	atomic_set(&ec->burst.leaving_burst , 0);
	return_VALUE(0);
end:
	printk("Error in acpi_ec_wait\n");
	return_VALUE(-1);
}

static int
acpi_ec_leave_burst_mode (
	union acpi_ec		*ec)
{

	ACPI_FUNCTION_TRACE("acpi_ec_leave_burst_mode");

	atomic_set(&ec->burst.leaving_burst, 1);
	return_VALUE(0);
}

static int
acpi_ec_read (
	union acpi_ec		*ec,
	u8			address,
	u32			*data)
{
	if (acpi_ec_polling_mode) 
		return acpi_ec_polling_read(ec, address, data);
	else
		return acpi_ec_burst_read(ec, address, data);
}
static int
acpi_ec_write (
	union acpi_ec		*ec,
	u8			address,
	u8			data)
{
	if (acpi_ec_polling_mode) 
		return acpi_ec_polling_write(ec, address, data);
	else
		return acpi_ec_burst_write(ec, address, data);
}
static int
acpi_ec_polling_read (
	union acpi_ec		*ec,
	u8			address,
	u32			*data)
{
	acpi_status		status = AE_OK;
	int			result = 0;
	unsigned long		flags = 0;
	u32			glk = 0;

	ACPI_FUNCTION_TRACE("acpi_ec_read");

	if (!ec || !data)
		return_VALUE(-EINVAL);

	*data = 0;

	if (ec->common.global_lock) {
		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
		if (ACPI_FAILURE(status))
			return_VALUE(-ENODEV);
	}

	spin_lock_irqsave(&ec->polling.lock, flags);

	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->common.command_addr);
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (result)
		goto end;

	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
	if (result)
		goto end;

	acpi_hw_low_level_read(8, data, &ec->common.data_addr);

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
		*data, address));
	
end:
	spin_unlock_irqrestore(&ec->polling.lock, flags);

	if (ec->common.global_lock)
		acpi_release_global_lock(glk);

	return_VALUE(result);
}


static int
acpi_ec_polling_write (
	union acpi_ec		*ec,
	u8			address,
	u8			data)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	unsigned long		flags = 0;
	u32			glk = 0;

	ACPI_FUNCTION_TRACE("acpi_ec_write");

	if (!ec)
		return_VALUE(-EINVAL);

	if (ec->common.global_lock) {
		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
		if (ACPI_FAILURE(status))
			return_VALUE(-ENODEV);
	}

	spin_lock_irqsave(&ec->polling.lock, flags);

	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->common.command_addr);
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (result)
		goto end;

	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (result)
		goto end;

	acpi_hw_low_level_write(8, data, &ec->common.data_addr);
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (result)
		goto end;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",
		data, address));

end:
	spin_unlock_irqrestore(&ec->polling.lock, flags);

	if (ec->common.global_lock)
		acpi_release_global_lock(glk);

	return_VALUE(result);
}

static int
acpi_ec_burst_read (
	union acpi_ec		*ec,
	u8			address,
	u32			*data)
{
	int			status = 0;
	u32			glk;

	ACPI_FUNCTION_TRACE("acpi_ec_read");

	if (!ec || !data)
		return_VALUE(-EINVAL);

	*data = 0;

	if (ec->common.global_lock) {
		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
		if (ACPI_FAILURE(status))
			return_VALUE(-ENODEV);
	}

	WARN_ON(in_interrupt());
	down(&ec->burst.sem);

	acpi_ec_enter_burst_mode(ec);
	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (status) {
		printk("read EC, IB not empty\n");
		goto end;
	}
	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->common.command_addr);
	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (status) {
		printk("read EC, IB not empty\n");
	}

	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
	status= acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
	if (status){
		printk("read EC, OB not full\n");
		goto end;
	}
	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
		*data, address));
	
end:
	acpi_ec_leave_burst_mode(ec);
	up(&ec->burst.sem);

	if (ec->common.global_lock)
		acpi_release_global_lock(glk);

	return_VALUE(status);
}


static int
acpi_ec_burst_write (
	union acpi_ec		*ec,
	u8			address,
	u8			data)
{
	int			status = 0;
	u32			glk;

	ACPI_FUNCTION_TRACE("acpi_ec_write");

	if (!ec)
		return_VALUE(-EINVAL);

	if (ec->common.global_lock) {
		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
		if (ACPI_FAILURE(status))
			return_VALUE(-ENODEV);
	}

	WARN_ON(in_interrupt());
	down(&ec->burst.sem);

	acpi_ec_enter_burst_mode(ec);

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if ( status) {
		printk("write EC, IB not empty\n");
	}
	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->common.command_addr);
	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (status) {
		printk ("write EC, IB not empty\n");
	}

	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (status){
		printk("write EC, IB not empty\n");
	}

	acpi_hw_low_level_write(8, data, &ec->common.data_addr);

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",
		data, address));

	acpi_ec_leave_burst_mode(ec);
	up(&ec->burst.sem);

	if (ec->common.global_lock)
		acpi_release_global_lock(glk);

	return_VALUE(status);
}

/*
 * Externally callable EC access functions. For now, assume 1 EC only
 */
int
ec_read(u8 addr, u8 *val)
{
	union acpi_ec *ec;
	int err;
	u32 temp_data;

	if (!first_ec)
		return -ENODEV;

	ec = acpi_driver_data(first_ec);

	err = acpi_ec_read(ec, addr, &temp_data);

	if (!err) {
		*val = temp_data;
		return 0;
	}
	else
		return err;
}
EXPORT_SYMBOL(ec_read);

int
ec_write(u8 addr, u8 val)
{
	union acpi_ec *ec;
	int err;

	if (!first_ec)
		return -ENODEV;

	ec = acpi_driver_data(first_ec);

	err = acpi_ec_write(ec, addr, val);

	return err;
}
EXPORT_SYMBOL(ec_write);

static int
acpi_ec_query (
	union acpi_ec		*ec,
	u32			*data)
{
	if (acpi_ec_polling_mode) 
		return acpi_ec_polling_query(ec, data);
	else
		return acpi_ec_burst_query(ec, data);
}
static int
acpi_ec_polling_query (
	union acpi_ec		*ec,
	u32			*data)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	unsigned long		flags = 0;
	u32			glk = 0;

	ACPI_FUNCTION_TRACE("acpi_ec_query");

	if (!ec || !data)
		return_VALUE(-EINVAL);

	*data = 0;

	if (ec->common.global_lock) {
		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
		if (ACPI_FAILURE(status))
			return_VALUE(-ENODEV);
	}

	/*
	 * Query the EC to find out which _Qxx method we need to evaluate.
	 * Note that successful completion of the query causes the ACPI_EC_SCI
	 * bit to be cleared (and thus clearing the interrupt source).
	 */
	spin_lock_irqsave(&ec->polling.lock, flags);

	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY, &ec->common.command_addr);
	result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
	if (result)
		goto end;

	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
	if (!*data)
		result = -ENODATA;

end:
	spin_unlock_irqrestore(&ec->polling.lock, flags);

	if (ec->common.global_lock)
		acpi_release_global_lock(glk);

	return_VALUE(result);
}
static int
acpi_ec_burst_query (
	union acpi_ec		*ec,
	u32			*data)
{
	int			status = 0;
	u32			glk;

	ACPI_FUNCTION_TRACE("acpi_ec_query");

	if (!ec || !data)
		return_VALUE(-EINVAL);
	*data = 0;

	if (ec->common.global_lock) {
		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
		if (ACPI_FAILURE(status))
			return_VALUE(-ENODEV);
	}

	down(&ec->burst.sem);

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
	if (status) {
		printk("query EC, IB not empty\n");
		goto end;
	}
	/*
	 * Query the EC to find out which _Qxx method we need to evaluate.
	 * Note that successful completion of the query causes the ACPI_EC_SCI
	 * bit to be cleared (and thus clearing the interrupt source).
	 */
	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY, &ec->common.command_addr);
	status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
	if (status){
		printk("query EC, OB not full\n");
		goto end;
	}

	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
	if (!*data)
		status = -ENODATA;

end:
	up(&ec->burst.sem);

	if (ec->common.global_lock)
		acpi_release_global_lock(glk);

	return_VALUE(status);
}


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

union acpi_ec_query_data {
	acpi_handle		handle;
	u8			data;
};

static void
acpi_ec_gpe_query (
	void			*ec_cxt)
{
	if (acpi_ec_polling_mode) 
		acpi_ec_gpe_polling_query(ec_cxt);
	else
		acpi_ec_gpe_burst_query(ec_cxt);
}

static void
acpi_ec_gpe_polling_query (
	void			*ec_cxt)
{
	union acpi_ec		*ec = (union acpi_ec *) ec_cxt;
	u32			value = 0;
	unsigned long		flags = 0;
	static char		object_name[5] = {'_','Q','0','0','\0'};
	const char		hex[] = {'0','1','2','3','4','5','6','7',
				         '8','9','A','B','C','D','E','F'};

	ACPI_FUNCTION_TRACE("acpi_ec_gpe_query");

	if (!ec_cxt)
		goto end;

	spin_lock_irqsave(&ec->polling.lock, flags);
	acpi_hw_low_level_read(8, &value, &ec->common.command_addr);
	spin_unlock_irqrestore(&ec->polling.lock, flags);

	/* TBD: Implement asynch events!
	 * NOTE: All we care about are EC-SCI's.  Other EC events are
	 * handled via polling (yuck!).  This is because some systems
	 * treat EC-SCIs as level (versus EDGE!) triggered, preventing
	 *  a purely interrupt-driven approach (grumble, grumble).
	 */
	if (!(value & ACPI_EC_FLAG_SCI))
		goto end;

	if (acpi_ec_query(ec, &value))
		goto end;

	object_name[2] = hex[((value >> 4) & 0x0F)];
	object_name[3] = hex[(value & 0x0F)];

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s\n", object_name));

	acpi_evaluate_object(ec->common.handle, object_name, NULL, NULL);

end:	
	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
}
static void
acpi_ec_gpe_burst_query (
	void			*ec_cxt)
{
	union acpi_ec		*ec = (union acpi_ec *) ec_cxt;
	u32			value;
	int			result = -ENODATA;
	static char		object_name[5] = {'_','Q','0','0','\0'};
	const char		hex[] = {'0','1','2','3','4','5','6','7',
				         '8','9','A','B','C','D','E','F'};

	ACPI_FUNCTION_TRACE("acpi_ec_gpe_query");

	if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI)
		result = acpi_ec_query(ec, &value);

	if (result)
		goto end;

	object_name[2] = hex[((value >> 4) & 0x0F)];
	object_name[3] = hex[(value & 0x0F)];

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s\n", object_name));

	acpi_evaluate_object(ec->common.handle, object_name, NULL, NULL);
end:	
	atomic_dec(&ec->burst.pending_gpe);
	return;
}

static u32
acpi_ec_gpe_handler (
	void			*data)
{
	if (acpi_ec_polling_mode) 
		return acpi_ec_gpe_polling_handler(data);
	else
		return acpi_ec_gpe_burst_handler(data);	
}
static u32
acpi_ec_gpe_polling_handler (
	void			*data)
{
	acpi_status		status = AE_OK;
	union acpi_ec		*ec = (union acpi_ec *) data;

	if (!ec)
		return ACPI_INTERRUPT_NOT_HANDLED;

	acpi_disable_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);

	status = acpi_os_queue_for_execution(OSD_PRIORITY_GPE,
		acpi_ec_gpe_query, ec);

	if (status == AE_OK)
		return ACPI_INTERRUPT_HANDLED;
	else
		return ACPI_INTERRUPT_NOT_HANDLED;
}
static u32
acpi_ec_gpe_burst_handler (
	void			*data)
{
	acpi_status		status = AE_OK;
	u32			value;
	union acpi_ec		*ec = (union acpi_ec *) data;

	if (!ec)
		return ACPI_INTERRUPT_NOT_HANDLED;

	acpi_clear_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);
	value = acpi_ec_read_status(ec);

	switch ( ec->burst.expect_event) {
	case ACPI_EC_EVENT_OBF:
		if (!(value & ACPI_EC_FLAG_OBF))
			break;
	case ACPI_EC_EVENT_IBE:
		if ((value & ACPI_EC_FLAG_IBF))
			break;
		ec->burst.expect_event = 0;
		wake_up(&ec->burst.wait);
		return ACPI_INTERRUPT_HANDLED;
	default:
		break;
	}

	if (value & ACPI_EC_FLAG_SCI){
		atomic_add(1, &ec->burst.pending_gpe) ;
		status = acpi_os_queue_for_execution(OSD_PRIORITY_GPE,
						acpi_ec_gpe_query, ec);
		return status == AE_OK ?
		ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
	} 
	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);
	return status == AE_OK ?
		ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
}

/* --------------------------------------------------------------------------
                             Address Space Management
   -------------------------------------------------------------------------- */

static acpi_status
acpi_ec_space_setup (
	acpi_handle		region_handle,
	u32			function,
	void			*handler_context,
	void			**return_context)
{
	/*
	 * The EC object is in the handler context and is needed
	 * when calling the acpi_ec_space_handler.
	 */
	*return_context  = (function != ACPI_REGION_DEACTIVATE) ?
						handler_context : NULL;

	return AE_OK;
}


static acpi_status
acpi_ec_space_handler (
	u32			function,
	acpi_physical_address	address,
	u32			bit_width,
	acpi_integer		*value,
	void			*handler_context,
	void			*region_context)
{
	int			result = 0;
	union acpi_ec		*ec = NULL;
	u64			temp = *value;
	acpi_integer		f_v = 0;
	int 			i = 0;

	ACPI_FUNCTION_TRACE("acpi_ec_space_handler");

	if ((address > 0xFF) || !value || !handler_context)
		return_VALUE(AE_BAD_PARAMETER);

	if (bit_width != 8 && acpi_strict) {
		printk(KERN_WARNING PREFIX "acpi_ec_space_handler: bit_width should be 8\n");
		return_VALUE(AE_BAD_PARAMETER);
	}

	ec = (union acpi_ec *) handler_context;

next_byte:
	switch (function) {
	case ACPI_READ:
		temp = 0;
		result = acpi_ec_read(ec, (u8) address, (u32 *)&temp);
		break;
	case ACPI_WRITE:
		result = acpi_ec_write(ec, (u8) address, (u8) temp);
		break;
	default:
		result = -EINVAL;
		goto out;
		break;
	}

	bit_width -= 8;
	if (bit_width) {
		if (function == ACPI_READ)
			f_v |= temp << 8 * i;
		if (function == ACPI_WRITE)
			temp >>= 8;
		i++;
		address++;
		goto next_byte;
	}

	if (function == ACPI_READ) {
		f_v |= temp << 8 * i;
		*value = f_v;
	}

		
out:
	switch (result) {
	case -EINVAL:
		return_VALUE(AE_BAD_PARAMETER);
		break;
	case -ENODEV:
		return_VALUE(AE_NOT_FOUND);
		break;
	case -ETIME:
		return_VALUE(AE_TIME);
		break;
	default:
		return_VALUE(AE_OK);
	}
}


/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

static struct proc_dir_entry	*acpi_ec_dir;


static int
acpi_ec_read_info (struct seq_file *seq, void *offset)
{
	union acpi_ec		*ec = (union acpi_ec *) seq->private;

	ACPI_FUNCTION_TRACE("acpi_ec_read_info");

	if (!ec)
		goto end;

	seq_printf(seq, "gpe bit:                 0x%02x\n",
		(u32) ec->common.gpe_bit);
	seq_printf(seq, "ports:                   0x%02x, 0x%02x\n",
		(u32) ec->common.status_addr.address, (u32) ec->common.data_addr.address);
	seq_printf(seq, "use global lock:         %s\n",
		ec->common.global_lock?"yes":"no");
	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

end:
	return_VALUE(0);
}