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

• Lines: 860
• Date: 2003-08-25 04:44:41.000000000 -0700
• Orig file: linux-2.4.21/drivers/acpi/ec.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/drivers/acpi/ec.c linux-2.4.22/drivers/acpi/ec.c
@@ -0,0 +1,859 @@
+/*
+ *  acpi_ec.c - ACPI Embedded Controller Driver ($Revision: 36 $)
+ *
+ *  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/compatmac.h>
+#include <linux/proc_fs.h>
+#include <asm/io.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+
+#define _COMPONENT		ACPI_EC_COMPONENT
+ACPI_MODULE_NAME		("acpi_ec")
+
+#define PREFIX			"ACPI: "
+
+
+#define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
+#define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
+#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_UDELAY		100	/* Poll @ 100us increments */
+#define ACPI_EC_UDELAY_COUNT	1000	/* Wait 10ms max. during EC ops */
+#define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
+
+#define ACPI_EC_COMMAND_READ	0x80
+#define ACPI_EC_COMMAND_WRITE	0x81
+#define ACPI_EC_COMMAND_QUERY	0x84
+
+static int acpi_ec_add (struct acpi_device *device);
+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 struct acpi_driver acpi_ec_driver = {
+	.name =		ACPI_EC_DRIVER_NAME,
+	.class =	ACPI_EC_CLASS,
+	.ids =		ACPI_EC_HID,
+	.ops =		{
+				.add =		acpi_ec_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;
+	spinlock_t			lock;
+};
+
+/* If we find an EC via the ECDT, we need to keep a ptr to its context */
+static struct acpi_ec	*ec_ecdt;
+
+/* External interfaces use first EC only, so remember */
+static struct acpi_device *first_ec;
+
+/* --------------------------------------------------------------------------
+                             Transaction Management
+   -------------------------------------------------------------------------- */
+
+static int
+acpi_ec_wait (
+	struct 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->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->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_read (
+	struct 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->global_lock) {
+		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
+		if (ACPI_FAILURE(status))
+			return_VALUE(-ENODEV);
+	}
+	
+	spin_lock_irqsave(&ec->lock, flags);
+
+	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->command_addr);
+	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+	if (result)
+		goto end;
+
+	acpi_hw_low_level_write(8, address, &ec->data_addr);
+	result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
+	if (result)
+		goto end;
+
+
+	acpi_hw_low_level_read(8, data, &ec->data_addr);
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
+		*data, address));
+
+end:
+	spin_unlock_irqrestore(&ec->lock, flags);
+
+	if (ec->global_lock)
+		acpi_release_global_lock(glk);
+
+	return_VALUE(result);
+}
+
+
+static int
+acpi_ec_write (
+	struct 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->global_lock) {
+		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
+		if (ACPI_FAILURE(status))
+			return_VALUE(-ENODEV);
+	}
+
+	spin_lock_irqsave(&ec->lock, flags);
+
+	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->command_addr);
+	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+	if (result)
+		goto end;
+
+	acpi_hw_low_level_write(8, address, &ec->data_addr);
+	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+	if (result)
+		goto end;
+
+	acpi_hw_low_level_write(8, data, &ec->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->lock, flags);
+
+	if (ec->global_lock)
+		acpi_release_global_lock(glk);
+
+	return_VALUE(result);
+}
+
+/*
+ * Externally callable EC access functions. For now, assume 1 EC only
+ */
+int
+ec_read(u8 addr, u8 *val)
+{
+	struct 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;
+}
+
+int
+ec_write(u8 addr, u8 val)
+{
+	struct 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;
+}
+
+
+static int
+acpi_ec_query (
+	struct 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->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->lock, flags);
+
+	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY, &ec->command_addr);
+	result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
+	if (result)
+		goto end;
+	
+	acpi_hw_low_level_read(8, data, &ec->data_addr);
+	if (!*data)
+		result = -ENODATA;
+
+end:
+	spin_unlock_irqrestore(&ec->lock, flags);
+
+	if (ec->global_lock)
+		acpi_release_global_lock(glk);
+
+	return_VALUE(result);
+}
+
+
+/* --------------------------------------------------------------------------
+                                Event Management
+   -------------------------------------------------------------------------- */
+
+struct acpi_ec_query_data {
+	acpi_handle		handle;
+	u8			data;
+};
+
+static void
+acpi_ec_gpe_query (
+	void			*ec_cxt)
+{
+	struct acpi_ec		*ec = (struct 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->lock, flags);
+	acpi_hw_low_level_read(8, &value, &ec->command_addr);
+	spin_unlock_irqrestore(&ec->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->handle, object_name, NULL, NULL);
+
+end:
+	acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
+}
+
+static void
+acpi_ec_gpe_handler (
+	void			*data)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_ec		*ec = (struct acpi_ec *) data;
+
+	if (!ec)
+		return;
+
+	acpi_disable_gpe(NULL, ec->gpe_bit, ACPI_ISR);
+
+	status = acpi_os_queue_for_execution(OSD_PRIORITY_GPE,
+		acpi_ec_gpe_query, ec);
+}
+
+/* --------------------------------------------------------------------------
+                             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 = handler_context;
+
+	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;
+	struct acpi_ec		*ec = NULL;
+	u32			temp = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_space_handler");
+
+	if ((address > 0xFF) || (bit_width != 8) || !value || !handler_context)
+		return_VALUE(AE_BAD_PARAMETER);
+
+	ec = (struct acpi_ec *) handler_context;
+
+	switch (function) {
+	case ACPI_READ:
+		result = acpi_ec_read(ec, (u8) address, &temp);
+		*value = (acpi_integer) temp;
+		break;
+	case ACPI_WRITE:
+		result = acpi_ec_write(ec, (u8) address, (u8) *value);
+		break;
+	default:
+		result = -EINVAL;
+		break;
+	}
+
+	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)
+   -------------------------------------------------------------------------- */
+
+struct proc_dir_entry		*acpi_ec_dir = NULL;
+
+
+static int
+acpi_ec_read_info (
+	char			*page,
+	char			**start,
+	off_t			off,
+	int 			count,
+	int 			*eof,
+	void			*data)
+{
+	struct acpi_ec		*ec = (struct acpi_ec *) data;
+	char			*p = page;
+	int			len = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_read_info");
+
+	if (!ec || (off != 0))
+		goto end;
+
+	p += sprintf(p, "gpe bit:                 0x%02x\n",
+		(u32) ec->gpe_bit);
+	p += sprintf(p, "ports:                   0x%02x, 0x%02x\n",
+		(u32) ec->status_addr.address, (u32) ec->data_addr.address);
+	p += sprintf(p, "use global lock:         %s\n",
+		ec->global_lock?"yes":"no");
+
+end:
+	len = (p - page);
+	if (len <= off+count) *eof = 1;
+	*start = page + off;
+	len -= off;
+	if (len>count) len = count;
+	if (len<0) len = 0;
+
+	return_VALUE(len);
+}
+
+
+static int
+acpi_ec_add_fs (
+	struct acpi_device	*device)
+{
+	struct proc_dir_entry	*entry = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_add_fs");
+
+	if (!acpi_device_dir(device)) {
+		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
+			acpi_ec_dir);
+		if (!acpi_device_dir(device))
+			return_VALUE(-ENODEV);
+	}
+
+	entry = create_proc_read_entry(ACPI_EC_FILE_INFO, S_IRUGO,
+		acpi_device_dir(device), acpi_ec_read_info,
+		acpi_driver_data(device));
+	if (!entry)
+		ACPI_DEBUG_PRINT((ACPI_DB_WARN,
+			"Unable to create '%s' fs entry\n",
+			ACPI_EC_FILE_INFO));
+
+	return_VALUE(0);
+}
+
+
+static int
+acpi_ec_remove_fs (
+	struct acpi_device	*device)
+{
+	ACPI_FUNCTION_TRACE("acpi_ec_remove_fs");
+
+	return_VALUE(0);
+}
+
+
+/* --------------------------------------------------------------------------
+                               Driver Interface
+   -------------------------------------------------------------------------- */
+
+static int
+acpi_ec_add (
+	struct acpi_device	*device)
+{
+	int			result = 0;
+	acpi_status		status = AE_OK;
+	struct acpi_ec		*ec = NULL;
+	unsigned long		uid;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_add");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
+	if (!ec)
+		return_VALUE(-ENOMEM);
+	memset(ec, 0, sizeof(struct acpi_ec));
+
+	ec->handle = device->handle;
+	ec->uid = -1;
+	ec->lock = SPIN_LOCK_UNLOCKED;
+	sprintf(acpi_device_name(device), "%s", ACPI_EC_DEVICE_NAME);
+	sprintf(acpi_device_class(device), "%s", 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);
+
+	/* 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_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);
+
+		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);
+	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->gpe_bit);
+
+	if (!first_ec)
+		first_ec = device;
+
+end:
+	if (result)
+		kfree(ec);
+
+	return_VALUE(result);
+}
+
+
+static int
+acpi_ec_remove (
+	struct acpi_device	*device,
+	int			type)
+{
+	struct acpi_ec		*ec = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_remove");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	ec = acpi_driver_data(device);
+
+	acpi_ec_remove_fs(device);
+
+	kfree(ec);
+
+	return_VALUE(0);
+}
+
+
+static acpi_status
+acpi_ec_io_ports (
+	struct acpi_resource	*resource,
+	void			*context)
+{
+	struct acpi_ec		*ec = (struct acpi_ec *) context;
+	struct acpi_generic_address *addr;
+
+	if (resource->id != ACPI_RSTYPE_IO) {
+		return AE_OK;
+	}
+
+	/*
+	 * The first address region returned is the data port, and
+	 * 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;
+	} else {
+		return AE_CTRL_TERMINATE;
+	}
+
+	addr->address_space_id = ACPI_ADR_SPACE_SYSTEM_IO;
+	addr->register_bit_width = 8;
+	addr->register_bit_offset = 0;
+	addr->address = resource->data.io.min_base_address;
+
+	return AE_OK;
+}
+
+
+static int
+acpi_ec_start (
+	struct acpi_device	*device)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_ec		*ec = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_start");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	ec = acpi_driver_data(device);
+
+	if (!ec)
+		return_VALUE(-EINVAL);
+
+	/*
+	 * Get I/O port addresses. Convert to GAS format.
+	 */
+	status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
+		acpi_ec_io_ports, ec);
+	if (ACPI_FAILURE(status) || ec->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;
+
+	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));
+
+	/*
+	 * Install GPE handler
+	 */
+	status = acpi_install_gpe_handler(NULL, ec->gpe_bit,
+		ACPI_EVENT_EDGE_TRIGGERED, &acpi_ec_gpe_handler, ec);
+	if (ACPI_FAILURE(status)) {
+		return_VALUE(-ENODEV);
+	}
+
+	status = acpi_install_address_space_handler (ec->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);
+		return_VALUE(-ENODEV);
+	}
+
+	return_VALUE(AE_OK);
+}
+
+
+static int
+acpi_ec_stop (
+	struct acpi_device	*device,
+	int			type)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_ec		*ec = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_stop");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	ec = acpi_driver_data(device);
+
+	status = acpi_remove_address_space_handler(ec->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);
+	if (ACPI_FAILURE(status))
+		return_VALUE(-ENODEV);
+
+	return_VALUE(0);
+}
+
+
+int __init
+acpi_ec_ecdt_probe (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 0;
+
+	printk(KERN_INFO PREFIX "Found ECDT\n");
+
+	 /*
+	 * Generate a temporary ec context to use until the namespace is scanned
+	 */
+	ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
+	if (!ec_ecdt)
+		return -ENOMEM;
+	memset(ec_ecdt, 0, sizeof(struct acpi_ec));
+
+	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;
+	ec_ecdt->lock = SPIN_LOCK_UNLOCKED;
+	/* use the GL just to be safe */
+	ec_ecdt->global_lock = TRUE;
+	ec_ecdt->uid = ecdt_ptr->uid;
+
+	status = acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->handle);
+	if (ACPI_FAILURE(status)) {
+		goto error;
+	}
+
+	/*
+	 * Install GPE handler
+	 */
+	status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe_bit,
+		ACPI_EVENT_EDGE_TRIGGERED, &acpi_ec_gpe_handler,
+		ec_ecdt);
+	if (ACPI_FAILURE(status)) {
+		goto error;
+	}
+
+	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_ec_gpe_handler);
+		goto error;
+	}
+
+	return 0;
+
+error:
+	printk(KERN_ERR PREFIX "Could not use ECDT\n");
+	kfree(ec_ecdt);
+	ec_ecdt = NULL;
+
+	return -ENODEV;
+}
+
+
+int __init
+acpi_ec_init (void)
+{
+	int			result = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_ec_init");
+
+	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
+	if (!acpi_ec_dir)
+		return_VALUE(-ENODEV);
+
+	result = acpi_bus_register_driver(&acpi_ec_driver);
+	if (result < 0) {
+		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
+		return_VALUE(-ENODEV);
+	}
+
+	return_VALUE(0);
+}
+
+/* EC can't be unloaded atm, so don't compile these */
+#if 0
+void __exit
+acpi_ec_exit (void)
+{
+	ACPI_FUNCTION_TRACE("acpi_ec_exit");
+
+	acpi_bus_unregister_driver(&acpi_ec_driver);
+
+	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
+
+	return_VOID;
+}
+#endif /* 0 */
+