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_POLL			0xFF
#define EC_INTR			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_intr_add(struct acpi_device *device);
static int acpi_ec_poll_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_intr_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;
	} intr;

	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;
		struct semaphore sem;
	} poll;
};

static int acpi_ec_poll_wait(union acpi_ec *ec, u8 event);
static int acpi_ec_intr_wait(union acpi_ec *ec, unsigned int event);
static int acpi_ec_poll_transaction(union acpi_ec *ec, u8 command,
                                    const u8 *wdata, unsigned wdata_len,
                                    u8 *rdata, unsigned rdata_len);
static int acpi_ec_intr_transaction(union acpi_ec *ec, u8 command,
                                    const u8 *wdata, unsigned wdata_len,
                                    u8 *rdata, unsigned rdata_len);
static void acpi_ec_gpe_poll_query(void *ec_cxt);
static void acpi_ec_gpe_intr_query(void *ec_cxt);
static u32 acpi_ec_gpe_poll_handler(void *data);
static u32 acpi_ec_gpe_intr_handler(void *data);
static acpi_status __init
acpi_fake_ecdt_poll_callback(acpi_handle handle,
				u32 Level, void *context, void **retval);

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

static int __init acpi_ec_poll_get_real_ecdt(void);
static int __init acpi_ec_intr_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_poll_mode = EC_INTR;

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

static 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_poll_mode)
		return acpi_ec_poll_wait(ec, event);
	else
		return acpi_ec_intr_wait(ec, event);
}

static int acpi_ec_poll_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: