drivers/i2c/chips/twl4030-pwrbutton.c

   1 /**
   2  * drivers/i2c/chips/twl4030-pwrbutton.c
   3  *
   4  * Driver for sending triton2 power button event to input-layer
   5  *
   6  * Copyright (C) 2008 Nokia Corporation
   7  *
   8  * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
   9  *
  10  * This file is subject to the terms and conditions of the GNU General
  11  * Public License. See the file "COPYING" in the main directory of this
  12  * archive for more details.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/kernel.h>
  27 #include <linux/errno.h>
  28 #include <linux/input.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/i2c/twl4030.h>
  31
  32 #define PWR_ISR1 0
  33 #define PWR_IMR1 1
  34 #define PWR_PWRON_IRQ (1<<0)
  35
  36 #define PWR_EDR1 5
  37 #define PWR_PWRON_RISING (1<<1)
  38 #define PWR_PWRON_FALLING  (1<<0)
  39 #define PWR_PWRON_BOTH (PWR_PWRON_RISING | PWR_PWRON_FALLING)
  40
  41 #define PWR_SIH_CTRL 7
  42
  43 #define STS_HW_CONDITIONS 0xf
  44
  45 static struct input_dev *powerbutton_dev;
  46
  47 static irqreturn_t powerbutton_irq(int irq, void *dev_id)
  48 {
  49         int err;
  50         u8 value;
  51
  52         err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &value,
  53                                   STS_HW_CONDITIONS);
  54         if (!err)  {
  55                 input_report_key(powerbutton_dev, KEY_POWER,
  56                                  value & PWR_PWRON_IRQ);
  57         } else {
  58                 pr_err("twl4030: i2c error %d while reading TWL4030"
  59                         " PM_MASTER STS_HW_CONDITIONS register\n", err);
  60         }
  61
  62         return IRQ_HANDLED;
  63 }
  64
  65 static int __init twl4030_pwrbutton_init(void)
  66 {
  67         int err = 0;
  68         u8 value;
  69
  70         if (request_irq(TWL4030_PWRIRQ_PWRBTN, powerbutton_irq, 0,
  71                         "PwrButton", NULL) < 0) {
  72                 printk(KERN_ERR "Unable to allocate IRQ for power button\n");
  73                 err = -EBUSY;
  74                 goto out;
  75         }
  76
  77         powerbutton_dev = input_allocate_device();
  78         if (!powerbutton_dev) {
  79                 printk(KERN_ERR
  80                         "Unable to allocate input device for power button\n");
  81                 err = -ENOMEM;
  82                 goto free_irq_and_out;
  83         }
  84
  85         powerbutton_dev->evbit[0] = BIT_MASK(EV_KEY);
  86         powerbutton_dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
  87         powerbutton_dev->name = "triton2-pwrbutton";
  88
  89         err = input_register_device(powerbutton_dev);
  90         if (err) {
  91                 input_free_device(powerbutton_dev);
  92                 goto free_irq_and_out;
  93         }
  94
  95         err = twl4030_i2c_read_u8(TWL4030_MODULE_INT, &value, PWR_IMR1);
  96         if (err) {
  97                 printk(KERN_WARNING "I2C error %d while reading TWL4030"
  98                                         " INT PWR_IMR1 register\n", err);
  99
 100                 goto free_input_dev;
 101         }
 102
 103         err = twl4030_i2c_write_u8(TWL4030_MODULE_INT,
 104                                    value & (~PWR_PWRON_IRQ), PWR_IMR1);
 105         if (err) {
 106                 printk(KERN_WARNING "I2C error %d while writing TWL4030"
 107                                     " INT PWR_IMR1 register\n", err);
 108                 goto free_input_dev;
 109         }
 110
 111         err = twl4030_i2c_read_u8(TWL4030_MODULE_INT, &value, PWR_EDR1);
 112         if (err) {
 113                 printk(KERN_WARNING "I2C error %d while reading TWL4030"
 114                                         " INT PWR_EDR1 register\n", err);
 115                 goto free_input_dev;
 116         }
 117
 118         err = twl4030_i2c_write_u8(TWL4030_MODULE_INT,
 119                                    value | PWR_PWRON_BOTH, PWR_EDR1);
 120
 121         if (err) {
 122                 printk(KERN_WARNING "I2C error %d while writing TWL4030"
 123                                         " INT PWR_EDR1 register\n", err);
 124                 goto free_input_dev;
 125         }
 126
 127         printk(KERN_INFO "triton2 power button driver initialized\n");
 128
 129         return 0;
 130
 131
 132 free_input_dev:
 133         input_unregister_device(powerbutton_dev);
 134 free_irq_and_out:
 135         free_irq(TWL4030_PWRIRQ_PWRBTN, NULL);
 136 out:
 137         return err;
 138 }
 139
 140 static void __exit twl4030_pwrbutton_exit(void)
 141 {
 142         free_irq(TWL4030_PWRIRQ_PWRBTN, NULL);
 143         input_unregister_device(powerbutton_dev);
 144         input_free_device(powerbutton_dev);
 145
 146 }
 147
 148 module_init(twl4030_pwrbutton_init);
 149 module_exit(twl4030_pwrbutton_exit);
 150
 151 MODULE_ALIAS("i2c:twl4030-pwrbutton");
 152 MODULE_DESCRIPTION("Triton2 Power Button");
 153 MODULE_LICENSE("GPL");
 154 MODULE_AUTHOR("Peter De Schrijver");
 155