[ACPI] Add "ec_polling" boot option

EC burst mode benefits many machines, some of
them significantly.  However, our current
implementation fails on some machines such
as Rafael's Asus L5D.

This patch restores the alternative EC polling code,
which can be enabled at boot time via "ec_polling"

http://bugzilla.kernel.org/show_bug.cgi?id=4665

Signed-off-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 722 insertions, 171 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index fca4140a50a9..2dadb7f63269 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -59,76 +59,185 @@ ACPI_MODULE_NAME		("acpi_ec")
 #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
 
-static int acpi_ec_add (struct acpi_device *device);
+#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 struct acpi_driver acpi_ec_driver = {
 	.name =		ACPI_EC_DRIVER_NAME,
 	.class =	ACPI_EC_CLASS,
 	.ids =		ACPI_EC_HID,
 	.ops =		{
-				.add =		acpi_ec_add,
+				.add =		acpi_ec_burst_add,
 				.remove =	acpi_ec_remove,
 				.start =	acpi_ec_start,
 				.stop =		acpi_ec_stop,
 			},
 };
-
-struct acpi_ec {
-	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;
+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 struct acpi_ec	*ec_ecdt;
+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;
 
 /* --------------------------------------------------------------------------
                              Transaction Management
    -------------------------------------------------------------------------- */
 
-static inline u32 acpi_ec_read_status(struct acpi_ec *ec)
+static inline u32 acpi_ec_read_status(union acpi_ec *ec)
 {
 	u32	status = 0;
 
-	acpi_hw_low_level_read(8, &status, &ec->status_addr);
+	acpi_hw_low_level_read(8, &status, &ec->common.status_addr);
 	return status;
 }
 
-static int acpi_ec_wait(struct acpi_ec *ec, unsigned int event)
+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->expect_event = event;
+	ec->burst.expect_event = event;
 	smp_mb();
 
-	result = wait_event_interruptible_timeout(ec->wait,
-					!ec->expect_event,
+	result = wait_event_interruptible_timeout(ec->burst.wait,
+					!ec->burst.expect_event,
 					msecs_to_jiffies(ACPI_EC_DELAY));
 	
-	ec->expect_event = 0;
+	ec->burst.expect_event = 0;
 	smp_mb();
 
 	if (result < 0){
@@ -160,7 +269,7 @@ static int acpi_ec_wait(struct acpi_ec *ec, unsigned int event)
 
 static int
 acpi_ec_enter_burst_mode (
-	struct acpi_ec		*ec)
+	union acpi_ec		*ec)
 {
 	u32			tmp = 0;
 	int			status = 0;
@@ -170,43 +279,43 @@ acpi_ec_enter_burst_mode (
 	status = acpi_ec_read_status(ec);
 	if (status != -EINVAL &&
 		!(status & ACPI_EC_FLAG_BURST)){
-		acpi_hw_low_level_write(8, ACPI_EC_BURST_ENABLE, &ec->command_addr);
+		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){
-			acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+			acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 			return_VALUE(-EINVAL);
 		}
-		acpi_hw_low_level_read(8, &tmp, &ec->data_addr);
-		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		acpi_hw_low_level_read(8, &tmp, &ec->common.data_addr);
+		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 		if(tmp != 0x90 ) {/* Burst ACK byte*/
 			return_VALUE(-EINVAL);
 		}
 	}
 
-	atomic_set(&ec->leaving_burst , 0);
+	atomic_set(&ec->burst.leaving_burst , 0);
 	return_VALUE(0);
 }
 
 static int
 acpi_ec_leave_burst_mode (
-	struct acpi_ec		*ec)
+	union acpi_ec		*ec)
 {
 	int			status =0;
 
 	ACPI_FUNCTION_TRACE("acpi_ec_leave_burst_mode");
 
-	atomic_set(&ec->leaving_burst , 1);
+	atomic_set(&ec->burst.leaving_burst , 1);
 	status = acpi_ec_read_status(ec);
 	if (status != -EINVAL &&
 		(status & ACPI_EC_FLAG_BURST)){
-		acpi_hw_low_level_write(8, ACPI_EC_BURST_DISABLE, &ec->command_addr);
+		acpi_hw_low_level_write(8, ACPI_EC_BURST_DISABLE, &ec->common.command_addr);
 		status = acpi_ec_wait(ec, ACPI_EC_FLAG_IBF);
 		if (status){
-			acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+			acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,"------->wait fail\n"));
 			return_VALUE(-EINVAL);
 		}
-		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 		status = acpi_ec_read_status(ec);
 	}
 
@@ -215,7 +324,131 @@ acpi_ec_leave_burst_mode (
 
 static int
 acpi_ec_read (
-	struct acpi_ec		*ec,
+	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)
 {
@@ -230,51 +463,51 @@ acpi_ec_read (
 retry:
 	*data = 0;
 
-	if (ec->global_lock) {
+	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->sem);
+	down(&ec->burst.sem);
 
 	if(acpi_ec_enter_burst_mode(ec))
 		goto end;
 
-	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->command_addr);
+	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->common.command_addr);
 	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 	if (status) {
 		goto end;
 	}
 
-	acpi_hw_low_level_write(8, address, &ec->data_addr);
+	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
 	status= acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
 	if (status){
-		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 		goto end;
 	}
 
-	acpi_hw_low_level_read(8, data, &ec->data_addr);
-	acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
+	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
 		*data, address));
 	
 end:
 	acpi_ec_leave_burst_mode(ec);
-	up(&ec->sem);
+	up(&ec->burst.sem);
 
-	if (ec->global_lock)
+	if (ec->common.global_lock)
 		acpi_release_global_lock(glk);
 
-	if(atomic_read(&ec->leaving_burst) == 2){
+	if(atomic_read(&ec->burst.leaving_burst) == 2){
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
-		while(atomic_read(&ec->pending_gpe)){
+		while(atomic_read(&ec->burst.pending_gpe)){
 			msleep(1);	
 		}
-		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 		goto retry;
 	}
 
@@ -283,8 +516,8 @@ end:
 
 
 static int
-acpi_ec_write (
-	struct acpi_ec		*ec,
+acpi_ec_burst_write (
+	union acpi_ec		*ec,
 	u8			address,
 	u8			data)
 {
@@ -297,14 +530,14 @@ acpi_ec_write (
 	if (!ec)
 		return_VALUE(-EINVAL);
 retry:
-	if (ec->global_lock) {
+	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->sem);
+	down(&ec->burst.sem);
 
 	if(acpi_ec_enter_burst_mode(ec))
 		goto end;
@@ -312,33 +545,33 @@ retry:
 	status = acpi_ec_read_status(ec);
 	if (status != -EINVAL &&
 		!(status & ACPI_EC_FLAG_BURST)){
-		acpi_hw_low_level_write(8, ACPI_EC_BURST_ENABLE, &ec->command_addr);
+		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)
 			goto end;
-		acpi_hw_low_level_read(8, &tmp, &ec->data_addr);
+		acpi_hw_low_level_read(8, &tmp, &ec->common.data_addr);
 		if(tmp != 0x90 ) /* Burst ACK byte*/
 			goto end;
 	}
 	/*Now we are in burst mode*/
 
-	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->command_addr);
+	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->common.command_addr);
 	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 	if (status){
 		goto end;
 	}
 
-	acpi_hw_low_level_write(8, address, &ec->data_addr);
+	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
 	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
 	if (status){
-		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 		goto end;
 	}
 
-	acpi_hw_low_level_write(8, data, &ec->data_addr);
+	acpi_hw_low_level_write(8, data, &ec->common.data_addr);
 	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 	if (status)
 		goto end;
 
@@ -347,17 +580,17 @@ retry:
 
 end:
 	acpi_ec_leave_burst_mode(ec);
-	up(&ec->sem);
+	up(&ec->burst.sem);
 
-	if (ec->global_lock)
+	if (ec->common.global_lock)
 		acpi_release_global_lock(glk);
 
-	if(atomic_read(&ec->leaving_burst) == 2){
+	if(atomic_read(&ec->burst.leaving_burst) == 2){
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
-		while(atomic_read(&ec->pending_gpe)){
+		while(atomic_read(&ec->burst.pending_gpe)){
 			msleep(1);	
 		}
-		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 		goto retry;
 	}
 
@@ -370,7 +603,7 @@ end:
 int
 ec_read(u8 addr, u8 *val)
 {
-	struct acpi_ec *ec;
+	union acpi_ec *ec;
 	int err;
 	u32 temp_data;
 
@@ -393,7 +626,7 @@ EXPORT_SYMBOL(ec_read);
 int
 ec_write(u8 addr, u8 val)
 {
-	struct acpi_ec *ec;
+	union acpi_ec *ec;
 	int err;
 
 	if (!first_ec)
@@ -407,10 +640,66 @@ ec_write(u8 addr, u8 val)
 }
 EXPORT_SYMBOL(ec_write);
 
-
 static int
 acpi_ec_query (
-	struct acpi_ec		*ec,
+	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;
@@ -422,13 +711,13 @@ acpi_ec_query (
 		return_VALUE(-EINVAL);
 	*data = 0;
 
-	if (ec->global_lock) {
+	if (ec->common.global_lock) {
 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 		if (ACPI_FAILURE(status))
 			return_VALUE(-ENODEV);
 	}
 
-	down(&ec->sem);
+	down(&ec->burst.sem);
 	if(acpi_ec_enter_burst_mode(ec))
 		goto end;
 	/*
@@ -436,28 +725,28 @@ acpi_ec_query (
 	 * 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->command_addr);
+	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){
-		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 		goto end;
 	}
 
-	acpi_hw_low_level_read(8, data, &ec->data_addr);
-	acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
+	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 	if (!*data)
 		status = -ENODATA;
 
 end:
 	acpi_ec_leave_burst_mode(ec);
-	up(&ec->sem);
+	up(&ec->burst.sem);
 
-	if (ec->global_lock)
+	if (ec->common.global_lock)
 		acpi_release_global_lock(glk);
 
-	if(atomic_read(&ec->leaving_burst) == 2){
+	if(atomic_read(&ec->burst.leaving_burst) == 2){
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));
-		acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 		status = -ENODATA;
 	}
 	return_VALUE(status);
@@ -468,7 +757,7 @@ end:
                                 Event Management
    -------------------------------------------------------------------------- */
 
-struct acpi_ec_query_data {
+union acpi_ec_query_data {
 	acpi_handle		handle;
 	u8			data;
 };
@@ -477,7 +766,59 @@ static void
 acpi_ec_gpe_query (
 	void			*ec_cxt)
 {
-	struct acpi_ec		*ec = (struct acpi_ec *) 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'};
@@ -497,9 +838,9 @@ acpi_ec_gpe_query (
 
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s\n", object_name));
 
-	acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
+	acpi_evaluate_object(ec->common.handle, object_name, NULL, NULL);
 end:	
-	atomic_dec(&ec->pending_gpe);
+	atomic_dec(&ec->burst.pending_gpe);
 	return;
 }
 
@@ -507,48 +848,77 @@ 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;
-	struct acpi_ec		*ec = (struct acpi_ec *) data;
+	union acpi_ec		*ec = (union acpi_ec *) data;
 
 	if (!ec)
 		return ACPI_INTERRUPT_NOT_HANDLED;
 
-	acpi_disable_gpe(NULL, ec->gpe_bit, ACPI_ISR);
+	acpi_disable_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);
 
 	value = acpi_ec_read_status(ec);
 
 	if((value & ACPI_EC_FLAG_IBF) &&
 		!(value & ACPI_EC_FLAG_BURST) &&
-			(atomic_read(&ec->leaving_burst) == 0)) { 
+			(atomic_read(&ec->burst.leaving_burst) == 0)) { 
 	/*
 	 * the embedded controller disables 
 	 * burst mode for any reason other 
 	 * than the burst disable command
 	 * to process critical event.
 	 */
-		atomic_set(&ec->leaving_burst , 2); /* block current pending transaction
+		atomic_set(&ec->burst.leaving_burst , 2); /* block current pending transaction
 					and retry */
-		wake_up(&ec->wait);
+		wake_up(&ec->burst.wait);
 	}else {
-		if ((ec->expect_event == ACPI_EC_EVENT_OBF &&
+		if ((ec->burst.expect_event == ACPI_EC_EVENT_OBF &&
 				(value & ACPI_EC_FLAG_OBF)) ||
-	    			(ec->expect_event == ACPI_EC_EVENT_IBE &&
+	    			(ec->burst.expect_event == ACPI_EC_EVENT_IBE &&
 				!(value & ACPI_EC_FLAG_IBF))) {
-			ec->expect_event = 0;
-			wake_up(&ec->wait);
+			ec->burst.expect_event = 0;
+			wake_up(&ec->burst.wait);
 			return ACPI_INTERRUPT_HANDLED;
 		}
 	}
 
 	if (value & ACPI_EC_FLAG_SCI){
-		atomic_add(1, &ec->pending_gpe) ;
+		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->gpe_bit, ACPI_ISR);
+	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);
 	return status == AE_OK ?
 		ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 }
@@ -585,7 +955,7 @@ acpi_ec_space_handler (
 	void			*region_context)
 {
 	int			result = 0;
-	struct acpi_ec		*ec = NULL;
+	union acpi_ec		*ec = NULL;
 	u64			temp = *value;
 	acpi_integer		f_v = 0;
 	int 			i = 0;
@@ -600,7 +970,7 @@ acpi_ec_space_handler (
 		return_VALUE(AE_BAD_PARAMETER);
 	}
 
-	ec = (struct acpi_ec *) handler_context;
+	ec = (union acpi_ec *) handler_context;
 
 next_byte:
 	switch (function) {
@@ -661,7 +1031,7 @@ static struct proc_dir_entry	*acpi_ec_dir;
 static int
 acpi_ec_read_info (struct seq_file *seq, void *offset)
 {
-	struct acpi_ec		*ec = (struct acpi_ec *) seq->private;
+	union acpi_ec		*ec = (union acpi_ec *) seq->private;
 
 	ACPI_FUNCTION_TRACE("acpi_ec_read_info");
 
@@ -669,12 +1039,12 @@ acpi_ec_read_info (struct seq_file *seq, void *offset)
 		goto end;
 
 	seq_printf(seq, "gpe bit:                 0x%02x\n",
-		(u32) ec->gpe_bit);
+		(u32) ec->common.gpe_bit);
 	seq_printf(seq, "ports:                   0x%02x, 0x%02x\n",
-		(u32) ec->status_addr.address, (u32) ec->data_addr.address);
+		(u32) ec->common.status_addr.address, (u32) ec->common.data_addr.address);
 	seq_printf(seq, "use global lock:         %s\n",
-		ec->global_lock?"yes":"no");
-	acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+		ec->common.global_lock?"yes":"no");
+	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 
 end:
 	return_VALUE(0);
@@ -697,7 +1067,7 @@ static int
 acpi_ec_add_fs (
 	struct acpi_device	*device)
 {
-	struct proc_dir_entry	*entry;
+	struct proc_dir_entry	*entry = NULL;
 
 	ACPI_FUNCTION_TRACE("acpi_ec_add_fs");
 
@@ -744,13 +1114,82 @@ acpi_ec_remove_fs (
                                Driver Interface
    -------------------------------------------------------------------------- */
 
+
 static int
-acpi_ec_add (
+acpi_ec_polling_add (
 	struct acpi_device	*device)
 {
-	int			result;
-	acpi_status		status;
-	struct acpi_ec		*ec;
+	int			result = 0;
+	acpi_status		status = AE_OK;
+	union acpi_ec		*ec = NULL;
+	unsigned long		uid;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_add");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	ec = kmalloc(sizeof(union acpi_ec), GFP_KERNEL);
+	if (!ec)
+		return_VALUE(-ENOMEM);
+	memset(ec, 0, sizeof(union acpi_ec));
+
+	ec->common.handle = device->handle;
+	ec->common.uid = -1;
+	spin_lock_init(&ec->polling.lock);
+	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
+	acpi_driver_data(device) = ec;
+
+	/* Use the global lock for all EC transactions? */
+	acpi_evaluate_integer(ec->common.handle, "_GLK", NULL, &ec->common.global_lock);
+
+	/* If our UID matches the UID for the ECDT-enumerated EC,
+	   we now have the *real* EC info, so kill the makeshift one.*/
+	acpi_evaluate_integer(ec->common.handle, "_UID", NULL, &uid);
+	if (ec_ecdt && ec_ecdt->common.uid == uid) {
+		acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
+			ACPI_ADR_SPACE_EC, &acpi_ec_space_handler);
+	
+		acpi_remove_gpe_handler(NULL, ec_ecdt->common.gpe_bit, &acpi_ec_gpe_handler);
+
+		kfree(ec_ecdt);
+	}
+
+	/* Get GPE bit assignment (EC events). */
+	/* TODO: Add support for _GPE returning a package */
+	status = acpi_evaluate_integer(ec->common.handle, "_GPE", NULL, &ec->common.gpe_bit);
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Error obtaining GPE bit assignment\n"));
+		result = -ENODEV;
+		goto end;
+	}
+
+	result = acpi_ec_add_fs(device);
+	if (result)
+		goto end;
+
+	printk(KERN_INFO PREFIX "%s [%s] (gpe %d)\n",
+		acpi_device_name(device), acpi_device_bid(device),
+		(u32) ec->common.gpe_bit);
+
+	if (!first_ec)
+		first_ec = device;
+
+end:
+	if (result)
+		kfree(ec);
+
+	return_VALUE(result);
+}
+static int
+acpi_ec_burst_add (
+	struct acpi_device	*device)
+{
+	int			result = 0;
+	acpi_status		status = AE_OK;
+	union acpi_ec		*ec = NULL;
 	unsigned long		uid;
 
 	ACPI_FUNCTION_TRACE("acpi_ec_add");
@@ -758,39 +1197,39 @@ acpi_ec_add (
 	if (!device)
 		return_VALUE(-EINVAL);
 
-	ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
+	ec = kmalloc(sizeof(union acpi_ec), GFP_KERNEL);
 	if (!ec)
 		return_VALUE(-ENOMEM);
-	memset(ec, 0, sizeof(struct acpi_ec));
-
-	ec->handle = device->handle;
-	ec->uid = -1;
- 	atomic_set(&ec->pending_gpe, 0);
- 	atomic_set(&ec->leaving_burst , 1);
- 	init_MUTEX(&ec->sem);
- 	init_waitqueue_head(&ec->wait);
+	memset(ec, 0, sizeof(union acpi_ec));
+
+	ec->common.handle = device->handle;
+	ec->common.uid = -1;
+ 	atomic_set(&ec->burst.pending_gpe, 0);
+ 	atomic_set(&ec->burst.leaving_burst , 1);
+ 	init_MUTEX(&ec->burst.sem);
+ 	init_waitqueue_head(&ec->burst.wait);
 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 	acpi_driver_data(device) = ec;
 
 	/* Use the global lock for all EC transactions? */
-	acpi_evaluate_integer(ec->handle, "_GLK", NULL, &ec->global_lock);
+	acpi_evaluate_integer(ec->common.handle, "_GLK", NULL, &ec->common.global_lock);
 
 	/* If our UID matches the UID for the ECDT-enumerated EC,
 	   we now have the *real* EC info, so kill the makeshift one.*/
-	acpi_evaluate_integer(ec->handle, "_UID", NULL, &uid);
-	if (ec_ecdt && ec_ecdt->uid == uid) {
+	acpi_evaluate_integer(ec->common.handle, "_UID", NULL, &uid);
+	if (ec_ecdt && ec_ecdt->common.uid == uid) {
 		acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
 			ACPI_ADR_SPACE_EC, &acpi_ec_space_handler);
 
-		acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit, &acpi_ec_gpe_handler);
+		acpi_remove_gpe_handler(NULL, ec_ecdt->common.gpe_bit, &acpi_ec_gpe_handler);
 
 		kfree(ec_ecdt);
 	}
 
 	/* Get GPE bit assignment (EC events). */
 	/* TODO: Add support for _GPE returning a package */
-	status = acpi_evaluate_integer(ec->handle, "_GPE", NULL, &ec->gpe_bit);
+	status = acpi_evaluate_integer(ec->common.handle, "_GPE", NULL, &ec->common.gpe_bit);
 	if (ACPI_FAILURE(status)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 			"Error obtaining GPE bit assignment\n"));
@@ -804,7 +1243,7 @@ acpi_ec_add (
 
 	printk(KERN_INFO PREFIX "%s [%s] (gpe %d)\n",
 		acpi_device_name(device), acpi_device_bid(device),
-		(u32) ec->gpe_bit);
+		(u32) ec->common.gpe_bit);
 
 	if (!first_ec)
 		first_ec = device;
@@ -822,7 +1261,7 @@ acpi_ec_remove (
 	struct acpi_device	*device,
 	int			type)
 {
-	struct acpi_ec		*ec;
+	union acpi_ec		*ec = NULL;
 
 	ACPI_FUNCTION_TRACE("acpi_ec_remove");
 
@@ -844,7 +1283,7 @@ acpi_ec_io_ports (
 	struct acpi_resource	*resource,
 	void			*context)
 {
-	struct acpi_ec		*ec = (struct acpi_ec *) context;
+	union acpi_ec		*ec = (union acpi_ec *) context;
 	struct acpi_generic_address *addr;
 
 	if (resource->id != ACPI_RSTYPE_IO) {
@@ -856,10 +1295,10 @@ acpi_ec_io_ports (
 	 * the second address region returned is the status/command
 	 * port.
 	 */
-	if (ec->data_addr.register_bit_width == 0) {
-		addr = &ec->data_addr;
-	} else if (ec->command_addr.register_bit_width == 0) {
-		addr = &ec->command_addr;
+	if (ec->common.data_addr.register_bit_width == 0) {
+		addr = &ec->common.data_addr;
+	} else if (ec->common.command_addr.register_bit_width == 0) {
+		addr = &ec->common.command_addr;
 	} else {
 		return AE_CTRL_TERMINATE;
 	}
@@ -877,8 +1316,8 @@ static int
 acpi_ec_start (
 	struct acpi_device	*device)
 {
-	acpi_status		status;
-	struct acpi_ec		*ec;
+	acpi_status		status = AE_OK;
+	union acpi_ec		*ec = NULL;
 
 	ACPI_FUNCTION_TRACE("acpi_ec_start");
 
@@ -893,35 +1332,36 @@ acpi_ec_start (
 	/*
 	 * Get I/O port addresses. Convert to GAS format.
 	 */
-	status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
+	status = acpi_walk_resources(ec->common.handle, METHOD_NAME__CRS,
 		acpi_ec_io_ports, ec);
-	if (ACPI_FAILURE(status) || ec->command_addr.register_bit_width == 0) {
+	if (ACPI_FAILURE(status) || ec->common.command_addr.register_bit_width == 0) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error getting I/O port addresses"));
 		return_VALUE(-ENODEV);
 	}
 
-	ec->status_addr = ec->command_addr;
+	ec->common.status_addr = ec->common.command_addr;
 
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02x, ports=0x%2x,0x%2x\n",
-		(u32) ec->gpe_bit, (u32) ec->command_addr.address,
-		(u32) ec->data_addr.address));
+		(u32) ec->common.gpe_bit, (u32) ec->common.command_addr.address,
+		(u32) ec->common.data_addr.address));
+
 
 	/*
 	 * Install GPE handler
 	 */
-	status = acpi_install_gpe_handler(NULL, ec->gpe_bit,
+	status = acpi_install_gpe_handler(NULL, ec->common.gpe_bit,
 		ACPI_GPE_EDGE_TRIGGERED, &acpi_ec_gpe_handler, ec);
 	if (ACPI_FAILURE(status)) {
 		return_VALUE(-ENODEV);
 	}
-	acpi_set_gpe_type (NULL, ec->gpe_bit, ACPI_GPE_TYPE_RUNTIME);
-	acpi_enable_gpe (NULL, ec->gpe_bit, ACPI_NOT_ISR);
+	acpi_set_gpe_type (NULL, ec->common.gpe_bit, ACPI_GPE_TYPE_RUNTIME);
+	acpi_enable_gpe (NULL, ec->common.gpe_bit, ACPI_NOT_ISR);
 
-	status = acpi_install_address_space_handler (ec->handle,
+	status = acpi_install_address_space_handler (ec->common.handle,
 			ACPI_ADR_SPACE_EC, &acpi_ec_space_handler,
 			&acpi_ec_space_setup, ec);
 	if (ACPI_FAILURE(status)) {
-		acpi_remove_gpe_handler(NULL, ec->gpe_bit, &acpi_ec_gpe_handler);
+		acpi_remove_gpe_handler(NULL, ec->common.gpe_bit, &acpi_ec_gpe_handler);
 		return_VALUE(-ENODEV);
 	}
 
@@ -934,8 +1374,8 @@ acpi_ec_stop (
 	struct acpi_device	*device,
 	int			type)
 {
-	acpi_status		status;
-	struct acpi_ec		*ec;
+	acpi_status		status = AE_OK;
+	union acpi_ec		*ec = NULL;
 
 	ACPI_FUNCTION_TRACE("acpi_ec_stop");
 
@@ -944,12 +1384,12 @@ acpi_ec_stop (
 
 	ec = acpi_driver_data(device);
 
-	status = acpi_remove_address_space_handler(ec->handle,
+	status = acpi_remove_address_space_handler(ec->common.handle,
 		ACPI_ADR_SPACE_EC, &acpi_ec_space_handler);
 	if (ACPI_FAILURE(status))
 		return_VALUE(-ENODEV);
 
-	status = acpi_remove_gpe_handler(NULL, ec->gpe_bit, &acpi_ec_gpe_handler);
+	status = acpi_remove_gpe_handler(NULL, ec->common.gpe_bit, &acpi_ec_gpe_handler);
 	if (ACPI_FAILURE(status))
 		return_VALUE(-ENODEV);
 
@@ -963,26 +1403,76 @@ acpi_fake_ecdt_callback (
 	void		*context,
 	void		**retval)
 {
+
+	if (acpi_ec_polling_mode)
+		return acpi_fake_ecdt_polling_callback(handle,
+			Level, context, retval);
+	else
+		return acpi_fake_ecdt_burst_callback(handle,
+			Level, context, retval);
+}
+
+static acpi_status __init
+acpi_fake_ecdt_polling_callback (
+	acpi_handle	handle,
+	u32		Level,
+	void		*context,
+	void		**retval)
+{
+	acpi_status	status;
+
+	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+		acpi_ec_io_ports, ec_ecdt);
+	if (ACPI_FAILURE(status))
+		return status;
+	ec_ecdt->common.status_addr = ec_ecdt->common.command_addr;
+
+	ec_ecdt->common.uid = -1;
+	acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->common.uid);
+
+	status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec_ecdt->common.gpe_bit);
+	if (ACPI_FAILURE(status))
+		return status;
+	spin_lock_init(&ec_ecdt->polling.lock);
+	ec_ecdt->common.global_lock = TRUE;
+	ec_ecdt->common.handle = handle;
+
+	printk(KERN_INFO PREFIX  "GPE=0x%02x, ports=0x%2x, 0x%2x\n",
+		(u32) ec_ecdt->common.gpe_bit, (u32) ec_ecdt->common.command_addr.address,
+		(u32) ec_ecdt->common.data_addr.address);
+
+	return AE_CTRL_TERMINATE;
+}
+
+static acpi_status __init
+acpi_fake_ecdt_burst_callback (
+	acpi_handle	handle,
+	u32		Level,
+	void		*context,
+	void		**retval)
+{
 	acpi_status	status;
 
+	init_MUTEX(&ec_ecdt->burst.sem);
+	init_waitqueue_head(&ec_ecdt->burst.wait);
 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 		acpi_ec_io_ports, ec_ecdt);
 	if (ACPI_FAILURE(status))
 		return status;
-	ec_ecdt->status_addr = ec_ecdt->command_addr;
+	ec_ecdt->common.status_addr = ec_ecdt->common.command_addr;
 
-	ec_ecdt->uid = -1;
-	acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->uid);
+	ec_ecdt->common.uid = -1;
+	acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->common.uid);
 
-	status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec_ecdt->gpe_bit);
+	status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec_ecdt->common.gpe_bit);
 	if (ACPI_FAILURE(status))
 		return status;
-	ec_ecdt->global_lock = TRUE;
-	ec_ecdt->handle = handle;
+	ec_ecdt->common.global_lock = TRUE;
+	ec_ecdt->common.handle = handle;
 
 	printk(KERN_INFO PREFIX  "GPE=0x%02x, ports=0x%2x, 0x%2x\n",
-		(u32) ec_ecdt->gpe_bit, (u32) ec_ecdt->command_addr.address,
-		(u32) ec_ecdt->data_addr.address);
+		(u32) ec_ecdt->common.gpe_bit, (u32) ec_ecdt->common.command_addr.address,
+		(u32) ec_ecdt->common.data_addr.address);
 
 	return AE_CTRL_TERMINATE;
 }
@@ -1005,12 +1495,12 @@ acpi_ec_fake_ecdt(void)
 
 	printk(KERN_INFO PREFIX "Try to make an fake ECDT\n");
 
-	ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
+	ec_ecdt = kmalloc(sizeof(union acpi_ec), GFP_KERNEL);
 	if (!ec_ecdt) {
 		ret = -ENOMEM;
 		goto error;
 	}
-	memset(ec_ecdt, 0, sizeof(struct acpi_ec));
+	memset(ec_ecdt, 0, sizeof(union acpi_ec));
 
 	status = acpi_get_devices (ACPI_EC_HID,
 				acpi_fake_ecdt_callback,
@@ -1031,6 +1521,60 @@ error:
 static int __init
 acpi_ec_get_real_ecdt(void)
 {
+	if (acpi_ec_polling_mode)
+		return acpi_ec_polling_get_real_ecdt();
+	else
+		return acpi_ec_burst_get_real_ecdt();
+}
+
+static int __init
+acpi_ec_polling_get_real_ecdt(void)
+{
+	acpi_status		status;
+	struct acpi_table_ecdt 	*ecdt_ptr;
+
+	status = acpi_get_firmware_table("ECDT", 1, ACPI_LOGICAL_ADDRESSING, 
+		(struct acpi_table_header **) &ecdt_ptr);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	printk(KERN_INFO PREFIX "Found ECDT\n");
+
+	/*
+	 * Generate a temporary ec context to use until the namespace is scanned
+	 */
+	ec_ecdt = kmalloc(sizeof(union acpi_ec), GFP_KERNEL);
+	if (!ec_ecdt)
+		return -ENOMEM;
+	memset(ec_ecdt, 0, sizeof(union acpi_ec));
+
+	ec_ecdt->common.command_addr = ecdt_ptr->ec_control;
+	ec_ecdt->common.status_addr = ecdt_ptr->ec_control;
+	ec_ecdt->common.data_addr = ecdt_ptr->ec_data;
+	ec_ecdt->common.gpe_bit = ecdt_ptr->gpe_bit;
+	spin_lock_init(&ec_ecdt->polling.lock);
+	/* use the GL just to be safe */
+	ec_ecdt->common.global_lock = TRUE;
+	ec_ecdt->common.uid = ecdt_ptr->uid;
+
+	status = acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->common.handle);
+	if (ACPI_FAILURE(status)) {
+		goto error;
+	}
+
+	return 0;
+error:
+	printk(KERN_ERR PREFIX "Could not use ECDT\n");
+	kfree(ec_ecdt);
+	ec_ecdt = NULL;
+
+	return -ENODEV;
+}
+
+
+static int __init
+acpi_ec_burst_get_real_ecdt(void)
+{
 	acpi_status		status;
 	struct acpi_table_ecdt 	*ecdt_ptr;
 
@@ -1044,22 +1588,22 @@ acpi_ec_get_real_ecdt(void)
 	/*
 	 * Generate a temporary ec context to use until the namespace is scanned
 	 */
-	ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
+	ec_ecdt = kmalloc(sizeof(union acpi_ec), GFP_KERNEL);
 	if (!ec_ecdt)
 		return -ENOMEM;
-	memset(ec_ecdt, 0, sizeof(struct acpi_ec));
-
- 	init_MUTEX(&ec_ecdt->sem);
- 	init_waitqueue_head(&ec_ecdt->wait);
-	ec_ecdt->command_addr = ecdt_ptr->ec_control;
-	ec_ecdt->status_addr = ecdt_ptr->ec_control;
-	ec_ecdt->data_addr = ecdt_ptr->ec_data;
-	ec_ecdt->gpe_bit = ecdt_ptr->gpe_bit;
+	memset(ec_ecdt, 0, sizeof(union acpi_ec));
+
+ 	init_MUTEX(&ec_ecdt->burst.sem);
+ 	init_waitqueue_head(&ec_ecdt->burst.wait);
+	ec_ecdt->common.command_addr = ecdt_ptr->ec_control;
+	ec_ecdt->common.status_addr = ecdt_ptr->ec_control;
+	ec_ecdt->common.data_addr = ecdt_ptr->ec_data;
+	ec_ecdt->common.gpe_bit = ecdt_ptr->gpe_bit;
 	/* use the GL just to be safe */
-	ec_ecdt->global_lock = TRUE;
-	ec_ecdt->uid = ecdt_ptr->uid;
+	ec_ecdt->common.global_lock = TRUE;
+	ec_ecdt->common.uid = ecdt_ptr->uid;
 
-	status = acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->handle);
+	status = acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->common.handle);
 	if (ACPI_FAILURE(status)) {
 		goto error;
 	}
@@ -1092,20 +1636,20 @@ acpi_ec_ecdt_probe (void)
 	/*
 	 * Install GPE handler
 	 */
-	status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe_bit,
+	status = acpi_install_gpe_handler(NULL, ec_ecdt->common.gpe_bit,
 		ACPI_GPE_EDGE_TRIGGERED, &acpi_ec_gpe_handler,
 		ec_ecdt);
 	if (ACPI_FAILURE(status)) {
 		goto error;
 	}
-	acpi_set_gpe_type (NULL, ec_ecdt->gpe_bit, ACPI_GPE_TYPE_RUNTIME);
-	acpi_enable_gpe (NULL, ec_ecdt->gpe_bit, ACPI_NOT_ISR);
+	acpi_set_gpe_type (NULL, ec_ecdt->common.gpe_bit, ACPI_GPE_TYPE_RUNTIME);
+	acpi_enable_gpe (NULL, ec_ecdt->common.gpe_bit, ACPI_NOT_ISR);
 
 	status = acpi_install_address_space_handler (ACPI_ROOT_OBJECT,
 			ACPI_ADR_SPACE_EC, &acpi_ec_space_handler,
 			&acpi_ec_space_setup, ec_ecdt);
 	if (ACPI_FAILURE(status)) {
-		acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit,
+		acpi_remove_gpe_handler(NULL, ec_ecdt->common.gpe_bit,
 			&acpi_ec_gpe_handler);
 		goto error;
 	}
@@ -1123,7 +1667,7 @@ error:
 
 static int __init acpi_ec_init (void)
 {
-	int			result;
+	int			result = 0;
 
 	ACPI_FUNCTION_TRACE("acpi_ec_init");
 
@@ -1167,3 +1711,10 @@ static int __init acpi_fake_ecdt_setup(char *str)
 	return 0;
 }
 __setup("acpi_fake_ecdt", acpi_fake_ecdt_setup);
+static int __init acpi_ec_set_polling_mode(char *str)
+{
+	acpi_ec_polling_mode = EC_POLLING;
+	acpi_ec_driver.ops.add = acpi_ec_polling_add;
+	return 0;
+}
+__setup("ec_polling", acpi_ec_set_polling_mode);