1 /*
2  * bios-less APM driver for hp680
3  *
4  * Copyright 2005 (c) Andriy Skulysh <askulysh@gmail.com>
5  * Copyright 2008 (c) Kristoffer Ericson <kristoffer.ericson@gmail.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License.
9  */
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/apm-emulation.h>
15 #include <linux/io.h>
16 #include <asm/adc.h>
17 #include <mach/hp6xx.h>
18 
19 /* percentage values */
20 #define APM_CRITICAL			10
21 #define APM_LOW				30
22 
23 /* resonably sane values */
24 #define HP680_BATTERY_MAX		898
25 #define HP680_BATTERY_MIN		486
26 #define HP680_BATTERY_AC_ON		1023
27 
28 #define MODNAME "hp6x0_apm"
29 
30 #define PGDR	0xa400012c
31 
32 static void hp6x0_apm_get_power_status(struct apm_power_info *info)
33 {
34 	int battery, backup, charging, percentage;
35 	u8 pgdr;
36 
37 	battery		= adc_single(ADC_CHANNEL_BATTERY);
38 	backup		= adc_single(ADC_CHANNEL_BACKUP);
39 	charging	= adc_single(ADC_CHANNEL_CHARGE);
40 
41 	percentage = 100 * (battery - HP680_BATTERY_MIN) /
42 			   (HP680_BATTERY_MAX - HP680_BATTERY_MIN);
43 
44 	/* % of full battery */
45 	info->battery_life = percentage;
46 
47 	/* We want our estimates in minutes */
48 	info->units = 0;
49 
50 	/* Extremely(!!) rough estimate, we will replace this with a datalist later on */
51 	info->time = (2 * battery);
52 
53 	info->ac_line_status = (battery > HP680_BATTERY_AC_ON) ?
54 			 APM_AC_ONLINE : APM_AC_OFFLINE;
55 
56 	pgdr = __raw_readb(PGDR);
57 	if (pgdr & PGDR_MAIN_BATTERY_OUT) {
58 		info->battery_status	= APM_BATTERY_STATUS_NOT_PRESENT;
59 		info->battery_flag	= 0x80;
60 	} else if (charging < 8) {
61 		info->battery_status	= APM_BATTERY_STATUS_CHARGING;
62 		info->battery_flag	= 0x08;
63 		info->ac_line_status	= 0x01;
64 	} else if (percentage <= APM_CRITICAL) {
65 		info->battery_status	= APM_BATTERY_STATUS_CRITICAL;
66 		info->battery_flag	= 0x04;
67 	} else if (percentage <= APM_LOW) {
68 		info->battery_status	= APM_BATTERY_STATUS_LOW;
69 		info->battery_flag	= 0x02;
70 	} else {
71 		info->battery_status	= APM_BATTERY_STATUS_HIGH;
72 		info->battery_flag	= 0x01;
73 	}
74 }
75 
76 static irqreturn_t hp6x0_apm_interrupt(int irq, void *dev)
77 {
78 	if (!APM_DISABLED)
79 		apm_queue_event(APM_USER_SUSPEND);
80 
81 	return IRQ_HANDLED;
82 }
83 
84 static int __init hp6x0_apm_init(void)
85 {
86 	int ret;
87 
88 	ret = request_irq(HP680_BTN_IRQ, hp6x0_apm_interrupt,
89 			  0, MODNAME, NULL);
90 	if (unlikely(ret < 0)) {
91 		printk(KERN_ERR MODNAME ": IRQ %d request failed\n",
92 		       HP680_BTN_IRQ);
93 		return ret;
94 	}
95 
96 	apm_get_power_status = hp6x0_apm_get_power_status;
97 
98 	return ret;
99 }
100 
101 static void __exit hp6x0_apm_exit(void)
102 {
103 	free_irq(HP680_BTN_IRQ, 0);
104 }
105 
106 module_init(hp6x0_apm_init);
107 module_exit(hp6x0_apm_exit);
108 
109 MODULE_AUTHOR("Adriy Skulysh");
110 MODULE_DESCRIPTION("hp6xx Advanced Power Management");
111 MODULE_LICENSE("GPL");
112