apm_emu.c

Go to the documentation of this file.

/*
 * APM emulation for PMU-based machines
 *
 * Copyright 2001 Benjamin Herrenschmidt ([email protected])
 *
 * 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, 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.
 *
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/apm-emulation.h>
#include <linux/adb.h>
#include <linux/pmu.h>

#define APM_CRITICAL        10
#define APM_LOW         30

static void pmu_apm_get_power_status(struct apm_power_info *info)
{
    int percentage = -1;
    int batteries = 0;
    int time_units = -1;
    int real_count = 0;
    int i;
    char charging = 0;
    long charge = -1;
    long amperage = 0;
    unsigned long btype = 0;

    info->battery_status = APM_BATTERY_STATUS_UNKNOWN;
    info->battery_flag = APM_BATTERY_FLAG_UNKNOWN;
    info->units = APM_UNITS_MINS;

    if (pmu_power_flags & PMU_PWR_AC_PRESENT)
        info->ac_line_status = APM_AC_ONLINE;
    else
        info->ac_line_status = APM_AC_OFFLINE;

    for (i=0; i<pmu_battery_count; i++) {
        if (pmu_batteries[i].flags & PMU_BATT_PRESENT) {
            batteries++;
            if (percentage < 0)
                percentage = 0;
            if (charge < 0)
                charge = 0;
            percentage += (pmu_batteries[i].charge * 100) /
                pmu_batteries[i].max_charge;
            charge += pmu_batteries[i].charge;
            amperage += pmu_batteries[i].amperage;
            if (btype == 0)
                btype = (pmu_batteries[i].flags & PMU_BATT_TYPE_MASK);
            real_count++;
            if ((pmu_batteries[i].flags & PMU_BATT_CHARGING))
                charging++;
        }
    }
    if (batteries == 0)
        info->ac_line_status = APM_AC_ONLINE;

    if (real_count) {
        if (amperage < 0) {
            if (btype == PMU_BATT_TYPE_SMART)
                time_units = (charge * 59) / (amperage * -1);
            else
                time_units = (charge * 16440) / (amperage * -60);
        }
        percentage /= real_count;
        if (charging > 0) {
            info->battery_status = APM_BATTERY_STATUS_CHARGING;
            info->battery_flag = APM_BATTERY_FLAG_CHARGING;
        } else if (percentage <= APM_CRITICAL) {
            info->battery_status = APM_BATTERY_STATUS_CRITICAL;
            info->battery_flag = APM_BATTERY_FLAG_CRITICAL;
        } else if (percentage <= APM_LOW) {
            info->battery_status = APM_BATTERY_STATUS_LOW;
            info->battery_flag = APM_BATTERY_FLAG_LOW;
        } else {
            info->battery_status = APM_BATTERY_STATUS_HIGH;
            info->battery_flag = APM_BATTERY_FLAG_HIGH;
        }
    }

    info->battery_life = percentage;
    info->time = time_units;
}

static int __init apm_emu_init(void)
{
    apm_get_power_status = pmu_apm_get_power_status;

    printk(KERN_INFO "apm_emu: PMU APM Emulation initialized.\n");

    return 0;
}

static void __exit apm_emu_exit(void)
{
    if (apm_get_power_status == pmu_apm_get_power_status)
        apm_get_power_status = NULL;

    printk(KERN_INFO "apm_emu: PMU APM Emulation removed.\n");
}

module_init(apm_emu_init);
module_exit(apm_emu_exit);

MODULE_AUTHOR("Benjamin Herrenschmidt");
MODULE_DESCRIPTION("APM emulation for PowerMac");
MODULE_LICENSE("GPL");