// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * APM emulation for PMU-based machines

   *

   * Copyright 2001 Benjamin Herrenschmidt (benh@kernel.crashing.org)

   */

  #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.
  ");

  
  	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.
  ");

  }
  
  module_init(apm_emu_init);
  module_exit(apm_emu_exit);
  
  MODULE_AUTHOR("Benjamin Herrenschmidt");

  MODULE_DESCRIPTION("APM emulation for PowerMac");

  MODULE_LICENSE("GPL");