arch/sh/boards/hp6xx/hp6xx_apm.c

   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 <asm/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 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 = ctrl_inb(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
  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
  82 static int __init hp6x0_apm_init(void)
  83 {
  84         int ret;
  85
  86         ret = request_irq(HP680_BTN_IRQ, hp6x0_apm_interrupt,
  87                           IRQF_DISABLED, 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
  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");