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
17static 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
86static 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
95static 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
103module_init(apm_emu_init);
104module_exit(apm_emu_exit);
105
106MODULE_AUTHOR("Benjamin Herrenschmidt");
107MODULE_DESCRIPTION("APM emulation for PowerMac");
108MODULE_LICENSE("GPL");
109