battery.c

Linux Kernel 2.6.9 for OMAP1710

/*
 *  acpi_battery.c - ACPI Battery Driver ($Revision: 37 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <[e-mail]>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[e-mail]>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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 <asm/uaccess.h>

#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>


#define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF

#define ACPI_BATTERY_FORMAT_BIF	"NNNNNNNNNSSSS"
#define ACPI_BATTERY_FORMAT_BST	"NNNN"

#define ACPI_BATTERY_COMPONENT		0x00040000
#define ACPI_BATTERY_CLASS		"battery"
#define ACPI_BATTERY_HID		"PNP0C0A"
#define ACPI_BATTERY_DRIVER_NAME	"ACPI Battery Driver"
#define ACPI_BATTERY_DEVICE_NAME	"Battery"
#define ACPI_BATTERY_FILE_INFO		"info"
#define ACPI_BATTERY_FILE_STATUS	"state"
#define ACPI_BATTERY_FILE_ALARM		"alarm"
#define ACPI_BATTERY_NOTIFY_STATUS	0x80
#define ACPI_BATTERY_NOTIFY_INFO	0x81
#define ACPI_BATTERY_UNITS_WATTS	"mW"
#define ACPI_BATTERY_UNITS_AMPS		"mA"


#define _COMPONENT		ACPI_BATTERY_COMPONENT
ACPI_MODULE_NAME		("acpi_battery")

MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION(ACPI_BATTERY_DRIVER_NAME);
MODULE_LICENSE("GPL");

static int acpi_battery_add (struct acpi_device *device);
static int acpi_battery_remove (struct acpi_device *device, int type);

static struct acpi_driver acpi_battery_driver = {
	.name =		ACPI_BATTERY_DRIVER_NAME,
	.class =	ACPI_BATTERY_CLASS,
	.ids =		ACPI_BATTERY_HID,
	.ops =		{
				.add =		acpi_battery_add,
				.remove =	acpi_battery_remove,
			},
};

struct acpi_battery_status {
	acpi_integer		state;
	acpi_integer		present_rate;
	acpi_integer		remaining_capacity;
	acpi_integer		present_voltage;
};

struct acpi_battery_info {
	acpi_integer		power_unit;
	acpi_integer		design_capacity;
	acpi_integer		last_full_capacity;
	acpi_integer		battery_technology;
	acpi_integer		design_voltage;
	acpi_integer		design_capacity_warning;
	acpi_integer		design_capacity_low;
	acpi_integer		battery_capacity_granularity_1;
	acpi_integer		battery_capacity_granularity_2;
	acpi_string		model_number;
	acpi_string		serial_number;
	acpi_string		battery_type;
	acpi_string		oem_info;
};

struct acpi_battery_flags {
	u8			present:1;	/* Bay occupied? */
	u8			power_unit:1;	/* 0=watts, 1=apms */
	u8			alarm:1;	/* _BTP present? */
	u8			reserved:5;
};

struct acpi_battery_trips {
	unsigned long		warning;
	unsigned long		low;
};

struct acpi_battery {
	acpi_handle		handle;
	struct acpi_battery_flags flags;
	struct acpi_battery_trips trips;
	unsigned long		alarm;
	struct acpi_battery_info *info;
};


/* --------------------------------------------------------------------------
                               Battery Management
   -------------------------------------------------------------------------- */

static int
acpi_battery_get_info (
	struct acpi_battery	*battery,
	struct acpi_battery_info **bif)
{
	int			result = 0;
	acpi_status 		status = 0;
	struct acpi_buffer	buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	struct acpi_buffer	format = {sizeof(ACPI_BATTERY_FORMAT_BIF),
						ACPI_BATTERY_FORMAT_BIF};
	struct acpi_buffer	data = {0, NULL};
	union acpi_object	*package = NULL;

	ACPI_FUNCTION_TRACE("acpi_battery_get_info");

	if (!battery || !bif)
		return_VALUE(-EINVAL);

	/* Evalute _BIF */

	status = acpi_evaluate_object(battery->handle, "_BIF", NULL, &buffer);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _BIF\n"));
		return_VALUE(-ENODEV);
	}

	package = (union acpi_object *) buffer.pointer;

	/* Extract Package Data */

	status = acpi_extract_package(package, &format, &data);
	if (status != AE_BUFFER_OVERFLOW) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error extracting _BIF\n"));
		result = -ENODEV;
		goto end;
	}

	data.pointer = kmalloc(data.length, GFP_KERNEL);
	if (!data.pointer) {
		result = -ENOMEM;
		goto end;
	}
	memset(data.pointer, 0, data.length);

	status = acpi_extract_package(package, &format, &data);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error extracting _BIF\n"));
		kfree(data.pointer);
		result = -ENODEV;
		goto end;
	}

end:
	acpi_os_free(buffer.pointer);

	if (!result)
		(*bif) = (struct acpi_battery_info *) data.pointer;

	return_VALUE(result);
}

static int
acpi_battery_get_status (
	struct acpi_battery	*battery,
	struct acpi_battery_status **bst)
{
	int			result = 0;
	acpi_status 		status = 0;
	struct acpi_buffer	buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	struct acpi_buffer	format = {sizeof(ACPI_BATTERY_FORMAT_BST),
						ACPI_BATTERY_FORMAT_BST};
	struct acpi_buffer	data = {0, NULL};
	union acpi_object	*package = NULL;

	ACPI_FUNCTION_TRACE("acpi_battery_get_status");

	if (!battery || !bst)
		return_VALUE(-EINVAL);

	/* Evalute _BST */

	status = acpi_evaluate_object(battery->handle, "_BST", NULL, &buffer);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _BST\n"));
		return_VALUE(-ENODEV);
	}

	package = (union acpi_object *) buffer.pointer;

	/* Extract Package Data */

	status = acpi_extract_package(package, &format, &data);
	if (status != AE_BUFFER_OVERFLOW) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error extracting _BST\n"));
		result = -ENODEV;
		goto end;
	}

	data.pointer = kmalloc(data.length, GFP_KERNEL);
	if (!data.pointer) {
		result = -ENOMEM;
		goto end;
	}
	memset(data.pointer, 0, data.length);

	status = acpi_extract_package(package, &format, &data);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error extracting _BST\n"));
		kfree(data.pointer);
		result = -ENODEV;
		goto end;
	}

end:
	acpi_os_free(buffer.pointer);

	if (!result)
		(*bst) = (struct acpi_battery_status *) data.pointer;

	return_VALUE(result);
}


static int
acpi_battery_set_alarm (
	struct acpi_battery	*battery,
	unsigned long		alarm)
{
	acpi_status		status = 0;
	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
	struct acpi_object_list	arg_list = {1, &arg0};

	ACPI_FUNCTION_TRACE("acpi_battery_set_alarm");

	if (!battery)
		return_VALUE(-EINVAL);

	if (!battery->flags.alarm)
		return_VALUE(-ENODEV);

	arg0.integer.value = alarm;

	status = acpi_evaluate_object(battery->handle, "_BTP", &arg_list, NULL);
	if (ACPI_FAILURE(status))
		return_VALUE(-ENODEV);

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", (u32) alarm));

	battery->alarm = alarm;

	return_VALUE(0);
}


static int
acpi_battery_check (
	struct acpi_battery	*battery)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	acpi_handle		handle = NULL;
	struct acpi_device	*device = NULL;
	struct acpi_battery_info *bif = NULL;

	ACPI_FUNCTION_TRACE("acpi_battery_check");
	
	if (!battery)
		return_VALUE(-EINVAL);

	result = acpi_bus_get_device(battery->handle, &device);
	if (result)
		return_VALUE(result);

	result = acpi_bus_get_status(device);
	if (result)
		return_VALUE(result);

	/* Insertion? */

	if (!battery->flags.present && device->status.battery_present) {

		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Battery inserted\n"));

		/* Evalute _BIF to get certain static information */

		result = acpi_battery_get_info(battery, &bif);
		if (result)
			return_VALUE(result);

		battery->flags.power_unit = bif->power_unit;
		battery->trips.warning = bif->design_capacity_warning;
		battery->trips.low = bif->design_capacity_low;
		kfree(bif);

		/* See if alarms are supported, and if so, set default */

		status = acpi_get_handle(battery->handle, "_BTP", &handle);
		if (ACPI_SUCCESS(status)) {
			battery->flags.alarm = 1;
			acpi_battery_set_alarm(battery, battery->trips.warning);
		}
	}

	/* Removal? */

	else if (battery->flags.present && !device->status.battery_present) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Battery removed\n"));
	}

	battery->flags.present = device->status.battery_present;

	return_VALUE(result);
}


/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

struct proc_dir_entry		*acpi_battery_dir;

static int
acpi_battery_read_info (
	char			*page,
	char			**start,
	off_t			off,
	int 			count,
	int 			*eof,
	void			*data)
{
	int			result = 0;
	struct acpi_battery	*battery = (struct acpi_battery *) data;
	struct acpi_battery_info *bif = NULL;
	char			*units = "?";
	char			*p = page;
	int			len = 0;

	ACPI_FUNCTION_TRACE("acpi_battery_read_info");

	if (!battery || (off != 0))
		goto end;

	if (battery->flags.present)
		p += sprintf(p, "present:                 yes\n");
	else {
		p += sprintf(p, "present:                 no\n");
		goto end;
	}

	/* Battery Info (_BIF) */

	result = acpi_battery_get_info(battery, &bif);
	if (result || !bif) {
		p += sprintf(p, "ERROR: Unable to read battery information\n");
		goto end;
	}

	units = bif->power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
					
	if (bif->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
		p += sprintf(p, "design capacity:         unknown\n");
	else
		p += sprintf(p, "design capacity:         %d %sh\n",
			(u32) bif->design_capacity, units);

	if (bif->last_full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
		p += sprintf(p, "last full capacity:      unknown\n");
	else
		p += sprintf(p, "last full capacity:      %d %sh\n",
			(u32) bif->last_full_capacity, units);

	switch ((u32) bif->battery_technology) {
	case 0:
		p += sprintf(p, "battery technology:      non-rechargeable\n");
		break;
	case 1:
		p += sprintf(p, "battery technology:      rechargeable\n");
		break;
	default:
		p += sprintf(p, "battery technology:      unknown\n");
		break;
	}

	if (bif->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
		p += sprintf(p, "design voltage:          unknown\n");
	else
		p += sprintf(p, "design voltage:          %d mV\n",
			(u32) bif->design_voltage);
	
	p += sprintf(p, "design capacity warning: %d %sh\n",
		(u32) bif->design_capacity_warning, units);
	p += sprintf(p, "design capacity low:     %d %sh\n",
		(u32) bif->design_capacity_low, units);
	p += sprintf(p, "capacity granularity 1:  %d %sh\n",
		(u32) bif->battery_capacity_granularity_1, units);
	p += sprintf(p, "capacity granularity 2:  %d %sh\n",
		(u32) bif->battery_capacity_granularity_2, units);
	p += sprintf(p, "model number:            %s\n",
		bif->model_number);
	p += sprintf(p, "serial number:           %s\n",
		bif->serial_number);
	p += sprintf(p, "battery type:            %s\n",
		bif->battery_type);
	p += sprintf(p, "OEM info:                %s\n",