drivers/cbus/retu-pwrbutton.c

   1 /**
   2  * drivers/cbus/retu-pwrbutton.c
   3  *
   4  * Driver for sending retu power button event to input-layer
   5  *
   6  * Copyright (C) 2004 Nokia Corporation
   7  *
   8  * Written by Ari Saastamoinen <ari.saastamoinen@elektrobit.com>
   9  *
  10  * Contact Juha Yrjölä <juha.yrjola@nokia.com>
  11  *
  12  * This file is subject to the terms and conditions of the GNU General
  13  * Public License. See the file "COPYING" in the main directory of this
  14  * archive for more details.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/init.h>
  28 #include <linux/kernel.h>
  29 #include <linux/errno.h>
  30 #include <linux/input.h>
  31 #include <linux/timer.h>
  32 #include <linux/jiffies.h>
  33 #include <linux/bitops.h>
  34
  35 #include "retu.h"
  36
  37 #define RETU_STATUS_PWRONX      (1 << 5)
  38
  39 #define PWRBTN_DELAY            20
  40 #define PWRBTN_UP               0
  41 #define PWRBTN_PRESSED          1
  42
  43 static int pwrbtn_state;
  44 static struct input_dev *pwrbtn_dev;
  45 static struct timer_list pwrbtn_timer;
  46
  47 static void retubutton_timer_func(unsigned long arg)
  48 {
  49         int state;
  50
  51         if (retu_read_reg(RETU_REG_STATUS) & RETU_STATUS_PWRONX)
  52                 state = PWRBTN_UP;
  53         else
  54                 state = PWRBTN_PRESSED;
  55
  56         if (pwrbtn_state != state) {
  57                 input_report_key(pwrbtn_dev, KEY_POWER, state);
  58                 pwrbtn_state = state;
  59         }
  60 }
  61
  62 /**
  63  * Interrupt function is called whenever power button key is pressed
  64  * or released.
  65  */
  66 static void retubutton_irq(unsigned long arg)
  67 {
  68         retu_ack_irq(RETU_INT_PWR);
  69         mod_timer(&pwrbtn_timer, jiffies + msecs_to_jiffies(PWRBTN_DELAY));
  70 }
  71
  72 /**
  73  * Init function.
  74  * Allocates interrupt for power button and registers itself to input layer.
  75  */
  76 static int __init retubutton_init(void)
  77 {
  78         int irq;
  79
  80         printk(KERN_INFO "Retu power button driver initialized\n");
  81         irq = RETU_INT_PWR;
  82
  83         init_timer(&pwrbtn_timer);
  84         pwrbtn_timer.function = retubutton_timer_func;
  85
  86         if (retu_request_irq(irq, &retubutton_irq, 0, "PwrOnX") < 0) {
  87                 printk(KERN_ERR "%s@%s: Cannot allocate irq\n",
  88                        __FUNCTION__, __FILE__);
  89                 return -EBUSY;
  90         }
  91
  92         pwrbtn_dev = input_allocate_device();
  93         if (!pwrbtn_dev)
  94                 return -ENOMEM;
  95
  96         pwrbtn_dev->evbit[0] = BIT_MASK(EV_KEY);
  97         pwrbtn_dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
  98         pwrbtn_dev->name = "retu-pwrbutton";
  99
 100         return input_register_device(pwrbtn_dev);
 101 }
 102
 103 /**
 104  * Cleanup function which is called when driver is unloaded
 105  */
 106 static void __exit retubutton_exit(void)
 107 {
 108         retu_free_irq(RETU_INT_PWR);
 109         del_timer_sync(&pwrbtn_timer);
 110         input_unregister_device(pwrbtn_dev);
 111 }
 112
 113 module_init(retubutton_init);
 114 module_exit(retubutton_exit);
 115
 116 MODULE_DESCRIPTION("Retu Power Button");
 117 MODULE_LICENSE("GPL");
 118 MODULE_AUTHOR("Ari Saastamoinen");