1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * bios-less APM driver for hp680
4  *
5  * Copyright 2005 (c) Andriy Skulysh <askulysh@gmail.com>
6  * Copyright 2008 (c) Kristoffer Ericson <kristoffer.ericson@gmail.com>
7  */
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/interrupt.h>
12 #include <linux/apm-emulation.h>
13 #include <linux/io.h>
14 #include <asm/adc.h>
15 #include <mach/hp6xx.h>
16 
17 /* percentage values */
18 #define APM_CRITICAL			10
19 #define APM_LOW				30
20 
21 /* resonably sane values */
22 #define HP680_BATTERY_MAX		898
23 #define HP680_BATTERY_MIN		486
24 #define HP680_BATTERY_AC_ON		1023
25 
26 #define MODNAME "hp6x0_apm"
27 
28 #define PGDR	0xa400012c
29 
hp6x0_apm_get_power_status(struct apm_power_info * info)30 static void hp6x0_apm_get_power_status(struct apm_power_info *info)
31 {
32 	int battery, backup, charging, percentage;
33 	u8 pgdr;
34 
35 	battery		= adc_single(ADC_CHANNEL_BATTERY);
36 	backup		= adc_single(ADC_CHANNEL_BACKUP);
37 	charging	= adc_single(ADC_CHANNEL_CHARGE);
38 
39 	percentage = 100 * (battery - HP680_BATTERY_MIN) /
40 			   (HP680_BATTERY_MAX - HP680_BATTERY_MIN);
41 
42 	/* % of full battery */
43 	info->battery_life = percentage;
44 
45 	/* We want our estimates in minutes */
46 	info->units = 0;
47 
48 	/* Extremely(!!) rough estimate, we will replace this with a datalist later on */
49 	info->time = (2 * battery);
50 
51 	info->ac_line_status = (battery > HP680_BATTERY_AC_ON) ?
52 			 APM_AC_ONLINE : APM_AC_OFFLINE;
53 
54 	pgdr = __raw_readb(PGDR);
55 	if (pgdr & PGDR_MAIN_BATTERY_OUT) {
56 		info->battery_status	= APM_BATTERY_STATUS_NOT_PRESENT;
57 		info->battery_flag	= 0x80;
58 	} else if (charging < 8) {
59 		info->battery_status	= APM_BATTERY_STATUS_CHARGING;
60 		info->battery_flag	= 0x08;
61 		info->ac_line_status	= 0x01;
62 	} else if (percentage <= APM_CRITICAL) {
63 		info->battery_status	= APM_BATTERY_STATUS_CRITICAL;
64 		info->battery_flag	= 0x04;
65 	} else if (percentage <= APM_LOW) {
66 		info->battery_status	= APM_BATTERY_STATUS_LOW;
67 		info->battery_flag	= 0x02;
68 	} else {
69 		info->battery_status	= APM_BATTERY_STATUS_HIGH;
70 		info->battery_flag	= 0x01;
71 	}
72 }
73 
hp6x0_apm_interrupt(int irq,void * dev)74 static irqreturn_t hp6x0_apm_interrupt(int irq, void *dev)
75 {
76 	if (!APM_DISABLED)
77 		apm_queue_event(APM_USER_SUSPEND);
78 
79 	return IRQ_HANDLED;
80 }
81 
hp6x0_apm_init(void)82 static int __init hp6x0_apm_init(void)
83 {
84 	int ret;
85 
86 	ret = request_irq(HP680_BTN_IRQ, hp6x0_apm_interrupt,
87 			  0, MODNAME, NULL);
88 	if (unlikely(ret < 0)) {
89 		printk(KERN_ERR MODNAME ": IRQ %d request failed\n",
90 		       HP680_BTN_IRQ);
91 		return ret;
92 	}
93 
94 	apm_get_power_status = hp6x0_apm_get_power_status;
95 
96 	return ret;
97 }
98 
hp6x0_apm_exit(void)99 static void __exit hp6x0_apm_exit(void)
100 {
101 	free_irq(HP680_BTN_IRQ, 0);
102 }
103 
104 module_init(hp6x0_apm_init);
105 module_exit(hp6x0_apm_exit);
106 
107 MODULE_AUTHOR("Adriy Skulysh");
108 MODULE_DESCRIPTION("hp6xx Advanced Power Management");
109 MODULE_LICENSE("GPL");
110