arch/sh/boards/mach-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 <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");