/*
 *  asus-laptop.c - Asus Laptop Support
 *
 *
 *  Copyright (C) 2002-2005 Julien Lerouge, 2003-2006 Karol Kozimor
 *  Copyright (C) 2006 Corentin Chary
 *
 *  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
 *
 *
 *  The development page for this driver is located at
 *  http://sourceforge.net/projects/acpi4asus/
 *
 *  Credits:
 *  Pontus Fuchs   - Helper functions, cleanup
 *  Johann Wiesner - Small compile fixes
 *  John Belmonte  - ACPI code for Toshiba laptop was a good starting point.
 *  Eric Burghard  - LED display support for W1N
 *  Josh Green     - Light Sens support
 *  Thomas Tuttle  - His first patch for led support was very helpfull
 *
 */

#include <linux/autoconf.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/err.h>
#include <linux/proc_fs.h>
#include <linux/platform_device.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>
#include <asm/uaccess.h>

#define ASUS_LAPTOP_VERSION "0.40"

#define ASUS_HOTK_NAME          "Asus Laptop Support"
#define ASUS_HOTK_CLASS         "hotkey"
#define ASUS_HOTK_DEVICE_NAME   "Hotkey"
#define ASUS_HOTK_HID           "ATK0100"
#define ASUS_HOTK_FILE          "asus-laptop"
#define ASUS_HOTK_PREFIX        "\\_SB.ATKD."

#define ASUS_LOG    ASUS_HOTK_FILE ": "
#define ASUS_ERR    KERN_ERR    ASUS_LOG
#define ASUS_WARNING    KERN_WARNING    ASUS_LOG
#define ASUS_NOTICE KERN_NOTICE ASUS_LOG
#define ASUS_INFO   KERN_INFO   ASUS_LOG
#define ASUS_DEBUG  KERN_DEBUG  ASUS_LOG

MODULE_AUTHOR("Julien Lerouge, Karol Kozimor, Corentin Chary");
MODULE_DESCRIPTION(ASUS_HOTK_NAME);
MODULE_LICENSE("GPL");

#define ASUS_HANDLE(object, paths...)					\
	static acpi_handle  object##_handle = NULL;			\
	static char *object##_paths[] = { paths }

/*
 * This is the main structure, we can use it to store anything interesting
 * about the hotk device
 */
struct asus_hotk {
	char *name; //laptop name
	struct acpi_device *device;	//the device we are in
	acpi_handle handle;	//the handle of the hotk device
	char status;		//status of the hotk, for LEDs, ...
	u16 event_count[128];	//count for each event TODO make this better
};

/*
 * This header is made available to allow proper configuration given model,
 * revision number , ... this info cannot go in struct asus_hotk because it is
 * available before the hotk
 */
static struct acpi_table_header *asus_info;

/* The actual device the driver binds to */
static struct asus_hotk *hotk;

/*
 * The hotkey driver declaration
 */
static int asus_hotk_add(struct acpi_device *device);
static int asus_hotk_remove(struct acpi_device *device, int type);
static struct acpi_driver asus_hotk_driver = {
	.name = ASUS_HOTK_NAME,
	.class = ASUS_HOTK_CLASS,
	.ids = ASUS_HOTK_HID,
	.ops = {
		.add = asus_hotk_add,
		.remove = asus_hotk_remove,
		},
};

/*
 * This function evaluates an ACPI method, given an int as parameter, the
 * method is searched within the scope of the handle, can be NULL. The output
 * of the method is written is output, which can also be NULL
 *
 * returns 1 if write is successful, 0 else.
 */
static int write_acpi_int(acpi_handle handle, const char *method, int val,
			  struct acpi_buffer *output)
{
	struct acpi_object_list params;	//list of input parameters (an int here)
	union acpi_object in_obj;	//the only param we use
	acpi_status status;

	params.count = 1;
	params.pointer = &in_obj;
	in_obj.type = ACPI_TYPE_INTEGER;
	in_obj.integer.value = val;

	status = acpi_evaluate_object(handle, (char *)method, &params, output);
	return (status == AE_OK);
}

static int read_acpi_int(acpi_handle handle, const char *method, int *val,
			 struct acpi_object_list *params)
{
	struct acpi_buffer output;
	union acpi_object out_obj;
	acpi_status status;

	output.length = sizeof(out_obj);
	output.pointer = &out_obj;

	status = acpi_evaluate_object(handle, (char *)method, params, &output);
	*val = out_obj.integer.value;
	return (status == AE_OK) && (out_obj.type == ACPI_TYPE_INTEGER);
}

/*
 * Platform device handlers
 */

/*
 * We write our info in page, we begin at offset off and cannot write more
 * than count bytes. We set eof to 1 if we handle those 2 values. We return the
 * number of bytes written in page
 */
static ssize_t show_infos(struct device *dev,
			 struct device_attribute *attr, char *page)
{
	int len = 0;
	int temp;
	char buf[16];		//enough for all info
	/*
	 * We use the easy way, we don't care of off and count, so we don't set eof
	 * to 1
	 */

	len += sprintf(page, ASUS_HOTK_NAME " " ASUS_LAPTOP_VERSION "\n");
	len += sprintf(page + len, "Model reference    : %s\n", hotk->name);
	/*
	 * The SFUN method probably allows the original driver to get the list
	 * of features supported by a given model. For now, 0x0100 or 0x0800
	 * bit signifies that the laptop is equipped with a Wi-Fi MiniPCI card.
	 * The significance of others is yet to be found.
	 */
	if (read_acpi_int(hotk->handle, "SFUN", &temp, NULL))
		len +=
		    sprintf(page + len, "SFUN value         : 0x%04x\n", temp);
	/*
	 * Another value for userspace: the ASYM method returns 0x02 for
	 * battery low and 0x04 for battery critical, its readings tend to be
	 * more accurate than those provided by _BST.
	 * Note: since not all the laptops provide this method, errors are
	 * silently ignored.
	 */
	if (read_acpi_int(hotk->handle, "ASYM", &temp, NULL))
		len +=
		    sprintf(page + len, "ASYM value         : 0x%04x\n", temp);
	if (asus_info) {
		snprintf(buf, 16, "%d", asus_info->length);
		len += sprintf(page + len, "DSDT length        : %s\n", buf);
		snprintf(buf, 16, "%d", asus_info->checksum);
		len += sprintf(page + len, "DSDT checksum      : %s\n", buf);
		snprintf(buf, 16, "%d", asus_info->revision);
		len += sprintf(page + len, "DSDT revision      : %s\n", buf);
		snprintf(buf, 7, "%s", asus_info->oem_id);
		len += sprintf(page + len, "OEM id             : %s\n", buf);
		snprintf(buf, 9, "%s", asus_info->oem_table_id);
		len += sprintf(page + len, "OEM table id       : %s\n", buf);
		snprintf(buf, 16, "%x", asus_info->oem_revision);
		len += sprintf(page + len, "OEM revision       : 0x%s\n", buf);
		snprintf(buf, 5, "%s", asus_info->asl_compiler_id);
		len += sprintf(page + len, "ASL comp vendor id : %s\n", buf);
		snprintf(buf, 16, "%x", asus_info->asl_compiler_revision);
		len += sprintf(page + len, "ASL comp revision  : 0x%s\n", buf);
	}

	return len;
}

static int parse_arg(const char *buf, unsigned long count, int *val)
{
	if (!count)
		return 0;
	if (count > 31)
		return -EINVAL;
	if (sscanf(buf, "%i", val) != 1)
		return -EINVAL;
	return count;
}

static void asus_hotk_notify(acpi_handle handle, u32 event, void *data)
{
	/* TODO Find a better way to handle events count. */
	if (!hotk)
		return;

	acpi_bus_generate_event(hotk->device, event,
				hotk->event_count[event % 128]++);

	return;
}

#define ASUS_CREATE_DEVICE_ATTR(_name)					\
	struct device_attribute dev_attr_##_name = {			\
		.attr = {						\
			.name = __stringify(_name),			\
			.mode = 0,					\
			.owner = THIS_MODULE },				\
		.show   = NULL,						\
		.store  = NULL,						\
	}

#define ASUS_SET_DEVICE_ATTR(_name, _mode, _show, _store)		\
	do {								\
		dev_attr_##_name.attr.mode = _mode;			\
		dev_attr_##_name.show = _show;				\
		dev_attr_##_name.store = _store;			\
	} while(0)

static ASUS_CREATE_DEVICE_ATTR(infos);

static struct attribute *asuspf_attributes[] = {
        &dev_attr_infos.attr,
        NULL
};

static struct attribute_group asuspf_attribute_group = {
        .attrs = asuspf_attributes
};

static struct platform_driver asuspf_driver = {
        .driver = {
                .name = ASUS_HOTK_FILE,
                .owner = THIS_MODULE,
        }
};

static struct platform_device *asuspf_device;


static void asus_hotk_add_fs(void)
{
	ASUS_SET_DEVICE_ATTR(infos, 0444, show_infos, NULL);
}

static int asus_handle_init(char *name, acpi_handle *handle,
			    char **paths, int num_paths)
{
	int i;
	acpi_status status;

	for (i = 0; i < num_paths; i++) {
		status = acpi_get_handle(NULL, paths[i], handle);
		if (ACPI_SUCCESS(status))
			return 0;
	}

	*handle = NULL;
	return -ENODEV;
}

#define ASUS_HANDLE_INIT(object)					\
	asus_handle_init(#object, &object##_handle, object##_paths,	\
			 ARRAY_SIZE(object##_paths))


/*
 * This function is used to initialize the hotk with right values. In this
 * method, we can make all the detection we want, and modify the hotk struct
 */
static int asus_hotk_get_info(void)
{
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	struct acpi_buffer dsdt = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *model = NULL;
	int bsts_result;
	char *string = NULL;
	acpi_status status;

	/*
	 * Get DSDT headers early enough to allow for differentiating between
	 * models, but late enough to allow acpi_bus_register_driver() to fail
	 * before doing anything ACPI-specific. Should we encounter a machine,
	 * which needs special handling (i.e. its hotkey device has a different
	 * HID), this bit will be moved. A global variable asus_info contains
	 * the DSDT header.
	 */
	status = acpi_get_table(ACPI_TABLE_ID_DSDT, 1, &dsdt);
	if (ACPI_FAILURE(status))
		printk(ASUS_WARNING "Couldn't get the DSDT table header\n");
	else
		asus_info = dsdt.pointer;

	/* We have to write 0 on init this far for all ASUS models */
	if (!write_acpi_int(hotk->handle, "INIT", 0, &buffer)) {
		printk(ASUS_ERR "Hotkey initialization failed\n");
		return -ENODEV;
	}

	/* This needs to be called for some laptops to init properly */
	if (!read_acpi_int(hotk->handle, "BSTS", &bsts_result, NULL))
		printk(ASUS_WARNING "Error calling BSTS\n");
	else if (bsts_result)
		printk(ASUS_NOTICE "BSTS called, 0x%02x returned\n",
		       bsts_result);

	/*
	 * Try to match the object returned by INIT to the specific model.
	 * Handle every possible object (or the lack of thereof) the DSDT
	 * writers might throw at us. When in trouble, we pass NULL to
	 * asus_model_match() and try something completely different.
	 */
	if (buffer.pointer) {
		model = buffer.pointer;
		switch (model->type) {
		case ACPI_TYPE_STRING:
			string = model->string.pointer;
			break;
		case ACPI_TYPE_BUFFER:
			string = model->buffer.pointer;
			break;
		default:
			string = "";
			break;
		}
	}
	hotk->name = kstrdup(string, GFP_KERNEL);
	if (!hotk->name)
		return -ENOMEM;

	if(*string)
		printk(ASUS_NOTICE "  %s model detected\n", string);

	kfree(model);

	return AE_OK;
}

static int asus_hotk_check(void)
{
	int result = 0;

	result = acpi_bus_get_status(hotk->device);
	if (result)
		return result;

	if (hotk->device->status.present) {
		result = asus_hotk_get_info();
	} else {
		printk(ASUS_ERR "Hotkey device not present, aborting\n");
		return -EINVAL;
	}

	return result;
}

static int asus_hotk_found;

static int asus_hotk_add(struct acpi_device *device)
{
	acpi_status status = AE_OK;
	int result;

	if (!device)
		return -EINVAL;

	printk(ASUS_NOTICE "Asus Laptop Support version %s\n",
	       ASUS_LAPTOP_VERSION);

	hotk = kmalloc(sizeof(struct asus_hotk), GFP_KERNEL);
	if (!hotk)
		return -ENOMEM;
	memset(hotk, 0, sizeof(struct asus_hotk));

	hotk->handle = device->handle;
	strcpy(acpi_device_name(device), ASUS_HOTK_DEVICE_NAME);
	strcpy(acpi_device_class(device), ASUS_HOTK_CLASS);
	acpi_driver_data(device) = hotk;
	hotk->device = device;

	result = asus_hotk_check();
	if (result)
		goto end;

	asus_hotk_add_fs();

	/*
	 * We install the handler, it will receive the hotk in parameter, so, we
	 * could add other data to the hotk struct
	 */
	status = acpi_install_notify_handler(hotk->handle, ACPI_SYSTEM_NOTIFY,
					     asus_hotk_notify, hotk);
	if (ACPI_FAILURE(status))
		printk(ASUS_ERR "Error installing notify handler\n");

	asus_hotk_found = 1;

      end:
	if (result) {
		kfree(hotk->name);
		kfree(hotk);
	}

	return result;
}

static int asus_hotk_remove(struct acpi_device *device, int type)
{
	acpi_status status = 0;

	if (!device || !acpi_driver_data(device))
		return -EINVAL;

	status = acpi_remove_notify_handler(hotk->handle, ACPI_SYSTEM_NOTIFY,
					    asus_hotk_notify);
	if (ACPI_FAILURE(status))
		printk(ASUS_ERR "Error removing notify handler\n");

	kfree(hotk->name);
	kfree(hotk);

	return 0;
}

static void __exit asus_laptop_exit(void)
{
	acpi_bus_unregister_driver(&asus_hotk_driver);
        sysfs_remove_group(&asuspf_device->dev.kobj, &asuspf_attribute_group);
        platform_device_unregister(asuspf_device);
        platform_driver_unregister(&asuspf_driver);

	kfree(asus_info);
}

static int __init asus_laptop_init(void)
{
	int result;

	if (acpi_disabled)
		return -ENODEV;

	if (!acpi_specific_hotkey_enabled) {
		printk(ASUS_ERR "Using generic hotkey driver\n");
		return -ENODEV;
	}

	result = acpi_bus_register_driver(&asus_hotk_driver);
	if (result < 0)
		return result;

	/*
	 * This is a bit of a kludge.  We only want this module loaded
	 * for ASUS systems, but there's currently no way to probe the
	 * ACPI namespace for ASUS HIDs.  So we just return failure if
	 * we didn't find one, which will cause the module to be
	 * unloaded.
	 */
	if (!asus_hotk_found) {
		acpi_bus_unregister_driver(&asus_hotk_driver);
		return -ENODEV;
	}

        /* Register platform stuff */
	result = platform_driver_register(&asuspf_driver);
        if (result)
                goto fail_platform_driver;

        asuspf_device = platform_device_alloc(ASUS_HOTK_FILE, -1);
        if (!asuspf_device) {
                result = -ENOMEM;
                goto fail_platform_device1;
        }

        result = platform_device_add(asuspf_device);
        if (result)
                goto fail_platform_device2;

        result = sysfs_create_group(&asuspf_device->dev.kobj,
				    &asuspf_attribute_group);
        if (result)
                goto fail_sysfs;

        return 0;

fail_sysfs:
        platform_device_del(asuspf_device);

fail_platform_device2:
	platform_device_put(asuspf_device);

fail_platform_device1:
        platform_driver_unregister(&asuspf_driver);

fail_platform_driver:

	return result;
}

module_init(asus_laptop_init);
module_exit(asus_laptop_exit);