drivers/input/misc/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/platform_device.h>
  31 #include <linux/i2c/twl4030.h>
  32
  33 #define PWR_PWRON_IRQ (1 << 0)
  34
  35 #define STS_HW_CONDITIONS 0xf
  36
  37 static struct input_dev *powerbutton_dev;
  38 static struct device *dbg_dev;
  39
  40 static irqreturn_t powerbutton_irq(int irq, void *dev_id)
  41 {
  42         int err;
  43         u8 value;
  44
  45 #ifdef CONFIG_LOCKDEP
  46         /* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
  47          * we don't want and can't tolerate.  Although it might be
  48          * friendlier not to borrow this thread context...
  49          */
  50         local_irq_enable();
  51 #endif
  52
  53         err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &value,
  54                                   STS_HW_CONDITIONS);
  55         if (!err)  {
  56                 input_report_key(powerbutton_dev, KEY_POWER,
  57                                  value & PWR_PWRON_IRQ);
  58         } else {
  59                 dev_err(dbg_dev, "twl4030: i2c error %d while reading TWL4030"
  60                         " PM_MASTER STS_HW_CONDITIONS register\n", err);
  61         }
  62
  63         return IRQ_HANDLED;
  64 }
  65
  66 static int __devinit twl4030_pwrbutton_probe(struct platform_device *pdev)
  67 {
  68         int err = 0;
  69         int irq = platform_get_irq(pdev, 0);
  70
  71         dbg_dev = &pdev->dev;
  72
  73         /* PWRBTN == PWRON */
  74         err = request_irq(irq, powerbutton_irq,
  75                         IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
  76                         "twl4030-pwrbutton", NULL);
  77         if (err < 0) {
  78                 dev_dbg(&pdev->dev, "Can't get IRQ for power button: %d\n", err);
  79                 goto out;
  80         }
  81
  82         powerbutton_dev = input_allocate_device();
  83         if (!powerbutton_dev) {
  84                 dev_dbg(&pdev->dev, "Can't allocate power button\n");
  85                 err = -ENOMEM;
  86                 goto free_irq_and_out;
  87         }
  88
  89         powerbutton_dev->evbit[0] = BIT_MASK(EV_KEY);
  90         powerbutton_dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
  91         powerbutton_dev->name = "triton2-pwrbutton";
  92
  93         err = input_register_device(powerbutton_dev);
  94         if (err) {
  95                 dev_dbg(&pdev->dev, "Can't register power button: %d\n", err);
  96                 goto free_input_dev;
  97         }
  98
  99         dev_info(&pdev->dev, "triton2 power button driver initialized\n");
 100
 101         return 0;
 102
 103
 104 free_input_dev:
 105         input_free_device(powerbutton_dev);
 106 free_irq_and_out:
 107         free_irq(TWL4030_PWRIRQ_PWRBTN, NULL);
 108 out:
 109         return err;
 110 }
 111
 112 static int __devexit twl4030_pwrbutton_remove(struct platform_device *pdev)
 113 {
 114         int irq = platform_get_irq(pdev, 0);
 115
 116         free_irq(irq, NULL);
 117         input_unregister_device(powerbutton_dev);
 118         input_free_device(powerbutton_dev);
 119
 120         return 0;
 121 }
 122
 123 struct platform_driver twl4030_pwrbutton_driver = {
 124         .probe          = twl4030_pwrbutton_probe,
 125         .remove         = twl4030_pwrbutton_remove,
 126         .driver         = {
 127                 .name   = "twl4030-pwrbutton",
 128                 .owner  = THIS_MODULE,
 129         },
 130 };
 131
 132 static int __init twl4030_pwrbutton_init(void)
 133 {
 134         return platform_driver_register(&twl4030_pwrbutton_driver);
 135 }
 136 module_init(twl4030_pwrbutton_init);
 137
 138 static void __exit twl4030_pwrbutton_exit(void)
 139 {
 140         platform_driver_unregister(&twl4030_pwrbutton_driver);
 141 }
 142 module_exit(twl4030_pwrbutton_exit);
 143
 144 MODULE_DESCRIPTION("Triton2 Power Button");
 145 MODULE_LICENSE("GPL");
 146 MODULE_AUTHOR("Peter De Schrijver");
 147