drivers/macintosh/apm_emu.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * APM emulation for PMU-based machines
   4  *
   5  * Copyright 2001 Benjamin Herrenschmidt (benh@kernel.crashing.org)
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/apm-emulation.h>
  11 #include <linux/adb.h>
  12 #include <linux/pmu.h>
  13
  14 #define APM_CRITICAL            10
  15 #define APM_LOW                 30
  16
  17 static void pmu_apm_get_power_status(struct apm_power_info *info)
  18 {
  19         int percentage = -1;
  20         int batteries = 0;
  21         int time_units = -1;
  22         int real_count = 0;
  23         int i;
  24         char charging = 0;
  25         long charge = -1;
  26         long amperage = 0;
  27         unsigned long btype = 0;
  28
  29         info->battery_status = APM_BATTERY_STATUS_UNKNOWN;
  30         info->battery_flag = APM_BATTERY_FLAG_UNKNOWN;
  31         info->units = APM_UNITS_MINS;
  32
  33         if (pmu_power_flags & PMU_PWR_AC_PRESENT)
  34                 info->ac_line_status = APM_AC_ONLINE;
  35         else
  36                 info->ac_line_status = APM_AC_OFFLINE;
  37
  38         for (i=0; i<pmu_battery_count; i++) {
  39                 if (pmu_batteries[i].flags & PMU_BATT_PRESENT) {
  40                         batteries++;
  41                         if (percentage < 0)
  42                                 percentage = 0;
  43                         if (charge < 0)
  44                                 charge = 0;
  45                         percentage += (pmu_batteries[i].charge * 100) /
  46                                 pmu_batteries[i].max_charge;
  47                         charge += pmu_batteries[i].charge;
  48                         amperage += pmu_batteries[i].amperage;
  49                         if (btype == 0)
  50                                 btype = (pmu_batteries[i].flags & PMU_BATT_TYPE_MASK);
  51                         real_count++;
  52                         if ((pmu_batteries[i].flags & PMU_BATT_CHARGING))
  53                                 charging++;
  54                 }
  55         }
  56         if (batteries == 0)
  57                 info->ac_line_status = APM_AC_ONLINE;
  58
  59         if (real_count) {
  60                 if (amperage < 0) {
  61                         if (btype == PMU_BATT_TYPE_SMART)
  62                                 time_units = (charge * 59) / (amperage * -1);
  63                         else
  64                                 time_units = (charge * 16440) / (amperage * -60);
  65                 }
  66                 percentage /= real_count;
  67                 if (charging > 0) {
  68                         info->battery_status = APM_BATTERY_STATUS_CHARGING;
  69                         info->battery_flag = APM_BATTERY_FLAG_CHARGING;
  70                 } else if (percentage <= APM_CRITICAL) {
  71                         info->battery_status = APM_BATTERY_STATUS_CRITICAL;
  72                         info->battery_flag = APM_BATTERY_FLAG_CRITICAL;
  73                 } else if (percentage <= APM_LOW) {
  74                         info->battery_status = APM_BATTERY_STATUS_LOW;
  75                         info->battery_flag = APM_BATTERY_FLAG_LOW;
  76                 } else {
  77                         info->battery_status = APM_BATTERY_STATUS_HIGH;
  78                         info->battery_flag = APM_BATTERY_FLAG_HIGH;
  79                 }
  80         }
  81
  82         info->battery_life = percentage;
  83         info->time = time_units;
  84 }
  85
  86 static int __init apm_emu_init(void)
  87 {
  88         apm_get_power_status = pmu_apm_get_power_status;
  89
  90         printk(KERN_INFO "apm_emu: PMU APM Emulation initialized.\n");
  91
  92         return 0;
  93 }
  94
  95 static void __exit apm_emu_exit(void)
  96 {
  97         if (apm_get_power_status == pmu_apm_get_power_status)
  98                 apm_get_power_status = NULL;
  99
 100         printk(KERN_INFO "apm_emu: PMU APM Emulation removed.\n");
 101 }
 102
 103 module_init(apm_emu_init);
 104 module_exit(apm_emu_exit);
 105
 106 MODULE_AUTHOR("Benjamin Herrenschmidt");
 107 MODULE_DESCRIPTION("APM emulation for PowerMac");
 108 MODULE_LICENSE("GPL");