text: /*
   * bios-less APM driver for hp680
   *
   * Copyright 2005 (c) Andriy Skulysh <askulysh@gmail.com>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License.
   */
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/apm-emulation.h>
  #include <linux/io.h>
  #include <asm/adc.h>
  #include <asm/hp6xx.h>
  
  #define SH7709_PGDR			0xa400012c
  
  #define APM_CRITICAL			10
  #define APM_LOW				30
  
  #define HP680_BATTERY_MAX		875
  #define HP680_BATTERY_MIN		600
  #define HP680_BATTERY_AC_ON		900
  
  #define MODNAME "hp6x0_apm"
  
  static void hp6x0_apm_get_power_status(struct apm_power_info *info)
  {
  	int battery, backup, charging, percentage;
  	u8 pgdr;
  
  	battery		= adc_single(ADC_CHANNEL_BATTERY);
  	backup		= adc_single(ADC_CHANNEL_BACKUP);
  	charging	= adc_single(ADC_CHANNEL_CHARGE);
  
  	percentage = 100 * (battery - HP680_BATTERY_MIN) /
  			   (HP680_BATTERY_MAX - HP680_BATTERY_MIN);
  
  	info->ac_line_status = (battery > HP680_BATTERY_AC_ON) ?
  			 APM_AC_ONLINE : APM_AC_OFFLINE;
  
  	pgdr = ctrl_inb(SH7709_PGDR);
  	if (pgdr & PGDR_MAIN_BATTERY_OUT) {
  		info->battery_status	= APM_BATTERY_STATUS_NOT_PRESENT;
  		info->battery_flag	= 0x80;
  	} else if (charging < 8) {
  		info->battery_status	= APM_BATTERY_STATUS_CHARGING;
  		info->battery_flag	= 0x08;
  		info->ac_line_status = 0xff;
  	} else if (percentage <= APM_CRITICAL) {
  		info->battery_status	= APM_BATTERY_STATUS_CRITICAL;
  		info->battery_flag	= 0x04;
  	} else if (percentage <= APM_LOW) {
  		info->battery_status	= APM_BATTERY_STATUS_LOW;
  		info->battery_flag	= 0x02;
  	} else {
  		info->battery_status	= APM_BATTERY_STATUS_HIGH;
  		info->battery_flag	= 0x01;
  	}
  
  	info->units = 0;
  }
  
  static irqreturn_t hp6x0_apm_interrupt(int irq, void *dev)
  {
  	if (!apm_suspended)
  		apm_queue_event(APM_USER_SUSPEND);
  
  	return IRQ_HANDLED;
  }
  
  static int __init hp6x0_apm_init(void)
  {
  	int ret;
  
  	ret = request_irq(HP680_BTN_IRQ, hp6x0_apm_interrupt,
  			  IRQF_DISABLED, MODNAME, NULL);
  	if (unlikely(ret < 0)) {
  		printk(KERN_ERR MODNAME ": IRQ %d request failed\n",
  		       HP680_BTN_IRQ);
  		return ret;
  	}
  
  	apm_get_power_status = hp6x0_apm_get_power_status;
  
  	return ret;
  }
  
  static void __exit hp6x0_apm_exit(void)
  {
  	free_irq(HP680_BTN_IRQ, 0);
  	apm_get_info = NULL;
  }
  
  module_init(hp6x0_apm_init);
  module_exit(hp6x0_apm_exit);
  
  MODULE_AUTHOR("Adriy Skulysh");
  MODULE_DESCRIPTION("hp6xx Advanced Power Management");
  MODULE_LICENSE("GPL");
  