/*****************************************************************************
 *
 * Module Name: bm_osl.c
 *   $Revision: 17 $
 *
 *****************************************************************************/

/*
 *  Copyright (C) 2000, 2001 Andrew Grover
 *
 *  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/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/poll.h>
#include <asm/uaccess.h>
#include <acpi.h>
#include "bm.h"


MODULE_AUTHOR("Andrew Grover");
MODULE_DESCRIPTION("ACPI Component Architecture (CA) - ACPI Bus Manager");
MODULE_LICENSE("GPL");


/*****************************************************************************
 *                               Types & Defines
 *****************************************************************************/

typedef struct
{
	BM_HANDLE		device_handle;
	char			*device_type;
	char			*device_instance;
	u32			event_type;
	u32			event_data;
	struct list_head	list;
} BM_OSL_EVENT;


#define BM_PROC_ROOT		"acpi"
#define BM_PROC_EVENT		"event"
#define BM_PROC_DEVICES		"devices"

#define BM_MAX_STRING_LENGTH	80


/****************************************************************************
 *                                  Globals
 ****************************************************************************/

struct proc_dir_entry		*bm_proc_root = NULL;
static struct proc_dir_entry	*bm_proc_event = NULL;

#ifdef ACPI_DEBUG
static u32			save_dbg_layer;
static u32			save_dbg_level;
#endif /*ACPI_DEBUG*/

extern BM_NODE_LIST		node_list;

static spinlock_t		bm_osl_event_lock = SPIN_LOCK_UNLOCKED;

static LIST_HEAD(bm_event_list);

static DECLARE_WAIT_QUEUE_HEAD(bm_event_wait_queue);

static int event_is_open = 0;


/****************************************************************************
 *                                 Functions
 ****************************************************************************/

/****************************************************************************
 *
 * FUNCTION:	bm_osl_generate_event
 *
 * DESCRIPTION: Generates an event for user-space consumption by writing
 *              the event data to the 'event' file.
 *
 ****************************************************************************/

acpi_status
bm_osl_generate_event (
	BM_HANDLE		device_handle,
	char			*device_type,
	char			*device_instance,
	u32			event_type,
	u32			event_data)
{
	BM_OSL_EVENT		*event = NULL;
	u32			flags = 0;

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

	/*
	 * Allocate a new event structure.
	 */
	event = acpi_os_callocate(sizeof(BM_OSL_EVENT));
	if (!event)
		goto alloc_error;

	event->device_type = acpi_os_callocate(strlen(device_type)
		+ sizeof(char));
	if (!event->device_type)
		goto alloc_error;

	event->device_instance = acpi_os_callocate(strlen(device_instance)
		+ sizeof(char));
	if (!event->device_instance)
		goto alloc_error;

	/*
	 * Set event data.
	 */
	event->device_handle = device_handle;
	strcpy(event->device_type, device_type);
	strcpy(event->device_instance, device_instance);
	event->event_type = event_type;
	event->event_data = event_data;

	/*
	 * Add to the end of our event list.
	 */
	spin_lock_irqsave(&bm_osl_event_lock, flags);
	list_add_tail(&event->list, &bm_event_list);
	spin_unlock_irqrestore(&bm_osl_event_lock, flags);

	/*
	 * Signal waiting threads (if any).
	 */
	wake_up_interruptible(&bm_event_wait_queue);

	return(AE_OK);

alloc_error:
	if (event->device_instance)
		acpi_os_free(event->device_instance);

	if (event->device_type)
		acpi_os_free(event->device_type);

	if (event)
		acpi_os_free(event);		

	return (AE_NO_MEMORY);
}

static int bm_osl_open_event(struct inode *inode, struct file *file)
{
	spin_lock_irq (&bm_osl_event_lock);

	if(event_is_open)
		goto out_busy;

	event_is_open = 1;

	spin_unlock_irq (&bm_osl_event_lock);
	return 0;

out_busy:
	spin_unlock_irq (&bm_osl_event_lock);
	return -EBUSY;
}


static int bm_osl_close_event(struct inode *inode, struct file *file)
{
	event_is_open = 0;
	return 0;
}

/****************************************************************************
 *
 * FUNCTION:	bm_osl_read_event
 *
 * DESCRIPTION: Handles reads to the 'event' file by blocking user-mode
 *              threads until data (an event) is generated.
 *
 ****************************************************************************/
static ssize_t
bm_osl_read_event(
	struct file		*file,
	char			*buf,
	size_t			count,
	loff_t			*ppos)
{
	BM_OSL_EVENT		*event = NULL;
	unsigned long		flags = 0;
	static char		str[BM_MAX_STRING_LENGTH];
	static int		chars_remaining = 0;
	static char 		*ptr;

	if (!chars_remaining) {
		DECLARE_WAITQUEUE(wait, current);

		if (list_empty(&bm_event_list)) {

			if (file->f_flags & O_NONBLOCK)
				return -EAGAIN;

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

			if (list_empty(&bm_event_list)) {
				schedule();
			}

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

			if (signal_pending(current)) {
				return -ERESTARTSYS;
			}
		}

		spin_lock_irqsave(&bm_osl_event_lock, flags);
		event = list_entry(bm_event_list.next, BM_OSL_EVENT, list);
		list_del(&event->list);
		spin_unlock_irqrestore(&bm_osl_event_lock, flags);

		chars_remaining = sprintf(str, "%s %s %08x %08x\n",
			event->device_type, event->device_instance,
			event->event_type, event->event_data);
		ptr = str;

		acpi_os_free(event->device_type);
		acpi_os_free(event->device_instance);
		acpi_os_free(event);
	}

	if (chars_remaining < count)
		count = chars_remaining;
	
	if (copy_to_user(buf, ptr, count))
		return -EFAULT;

	*ppos += count;
	chars_remaining -= count;
	ptr += count;

	return count;
}

/****************************************************************************
 *
 * FUNCTION:	bm_osl_poll_event
 *
 * DESCRIPTION: Handles poll() of the 'event' file by blocking user-mode 
 *              threads until data (an event) is generated.
 *
 ****************************************************************************/
static unsigned int
bm_osl_poll_event(
	struct file		*file, 
	poll_table		*wait)
{
	poll_wait(file, &bm_event_wait_queue, wait);
	if (!list_empty(&bm_event_list))
		return POLLIN | POLLRDNORM;
	return 0;
}

struct file_operations proc_event_operations = {
	open:		bm_osl_open_event,
	read:		bm_osl_read_event,
	release:	bm_osl_close_event,
	poll:		bm_osl_poll_event,	
};

/****************************************************************************
 *
 * FUNCTION:    bm_osl_init
 *
 ****************************************************************************/

int
bm_osl_init(void)
{
	acpi_status		status = AE_OK;

	status = acpi_subsystem_status();
	if (ACPI_FAILURE(status))
		return -ENODEV;

	bm_proc_root = proc_mkdir(BM_PROC_ROOT, NULL);
	if (!bm_proc_root) {
		return(AE_ERROR);
	}

	bm_proc_event = create_proc_entry(BM_PROC_EVENT, S_IRUSR, bm_proc_root);
	if (bm_proc_event) {
		bm_proc_event->proc_fops = &proc_event_operations;
	}

	status = bm_initialize();

	return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
}


/****************************************************************************
 *
 * FUNCTION:    bm_osl_cleanup
 *
 ****************************************************************************/

void
bm_osl_cleanup(void)
{
	bm_terminate();

	if (bm_proc_event) {
		remove_proc_entry(BM_PROC_EVENT, bm_proc_root);
		bm_proc_event = NULL;
	}

	if (bm_proc_root) {
		remove_proc_entry(BM_PROC_ROOT, NULL);
		bm_proc_root = NULL;
	}

	return;
}


module_init(bm_osl_init);
module_exit(bm_osl_cleanup);


/****************************************************************************
 *                                  Symbols
 ****************************************************************************/

/* bm.c */

EXPORT_SYMBOL(bm_get_node);

/* bmdriver.c */

EXPORT_SYMBOL(bm_get_device_power_state);
EXPORT_SYMBOL(bm_set_device_power_state);
EXPORT_SYMBOL(bm_get_device_info);
EXPORT_SYMBOL(bm_get_device_status);
EXPORT_SYMBOL(bm_get_device_context);
EXPORT_SYMBOL(bm_register_driver);
EXPORT_SYMBOL(bm_unregister_driver);

/* bmsearch.c */

EXPORT_SYMBOL(bm_search);

/* bmrequest.c */

EXPORT_SYMBOL(bm_request);

/* bmutils.c */

EXPORT_SYMBOL(bm_extract_package_data);
EXPORT_SYMBOL(bm_evaluate_object);
EXPORT_SYMBOL(bm_evaluate_simple_integer);
EXPORT_SYMBOL(bm_evaluate_reference_list);
EXPORT_SYMBOL(bm_copy_to_buffer);
EXPORT_SYMBOL(bm_cast_buffer);

/* bm_proc.c */

EXPORT_SYMBOL(bm_osl_generate_event);
EXPORT_SYMBOL(bm_proc_root);