drivers/input/misc/twl4030-pwrbutton.c

   1 /**
   2  * twl4030-pwrbutton.c - TWL4030 Power Button Input Driver
   3  *
   4  * Copyright (C) 2008-2009 Nokia Corporation
   5  *
   6  * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
   7  * Several fixes by Felipe Balbi <felipe.balbi@nokia.com>
   8  *
   9  * This file is subject to the terms and conditions of the GNU General
  10  * Public License. See the file "COPYING" in the main directory of this
  11  * archive for more details.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/kernel.h>
  26 #include <linux/errno.h>
  27 #include <linux/input.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/i2c/twl4030.h>
  31
  32 #define PWR_PWRON_IRQ (1 << 0)
  33
  34 #define STS_HW_CONDITIONS 0xf
  35
  36 static irqreturn_t powerbutton_irq(int irq, void *_pwr)
  37 {
  38         struct input_dev *pwr = _pwr;
  39         int err;
  40         u8 value;
  41
  42 #ifdef CONFIG_LOCKDEP
  43         /* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
  44          * we don't want and can't tolerate since this is a threaded
  45          * IRQ and can sleep due to the i2c reads it has to issue.
  46          * Although it might be friendlier not to borrow this thread
  47          * context...
  48          */
  49         local_irq_enable();
  50 #endif
  51
  52         err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &value,
  53                                   STS_HW_CONDITIONS);
  54         if (!err)  {
  55                 input_report_key(pwr, KEY_POWER, value & PWR_PWRON_IRQ);
  56                 input_sync(pwr);
  57         } else {
  58                 dev_err(pwr->dev.parent, "twl4030: i2c error %d while reading"
  59                         " TWL4030 PM_MASTER STS_HW_CONDITIONS register\n", err);
  60         }
  61
  62         return IRQ_HANDLED;
  63 }
  64
  65 static int __devinit twl4030_pwrbutton_probe(struct platform_device *pdev)
  66 {
  67         struct input_dev *pwr;
  68         int irq = platform_get_irq(pdev, 0);
  69         int err;
  70
  71         pwr = input_allocate_device();
  72         if (!pwr) {
  73                 dev_dbg(&pdev->dev, "Can't allocate power button\n");
  74                 return -ENOMEM;
  75         }
  76
  77         pwr->evbit[0] = BIT_MASK(EV_KEY);
  78         pwr->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
  79         pwr->name = "twl4030_pwrbutton";
  80         pwr->phys = "twl4030_pwrbutton/input0";
  81         pwr->dev.parent = &pdev->dev;
  82
  83         err = request_irq(irq, powerbutton_irq,
  84                         IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
  85                         "twl4030_pwrbutton", pwr);
  86         if (err < 0) {
  87                 dev_dbg(&pdev->dev, "Can't get IRQ for pwrbutton: %d\n", err);
  88                 goto free_input_dev;
  89         }
  90
  91         err = input_register_device(pwr);
  92         if (err) {
  93                 dev_dbg(&pdev->dev, "Can't register power button: %d\n", err);
  94                 goto free_irq;
  95         }
  96
  97         platform_set_drvdata(pdev, pwr);
  98
  99         return 0;
 100
 101 free_irq:
 102         free_irq(irq, NULL);
 103 free_input_dev:
 104         input_free_device(pwr);
 105         return err;
 106 }
 107
 108 static int __devexit twl4030_pwrbutton_remove(struct platform_device *pdev)
 109 {
 110         struct input_dev *pwr = platform_get_drvdata(pdev);
 111         int irq = platform_get_irq(pdev, 0);
 112
 113         free_irq(irq, pwr);
 114         input_unregister_device(pwr);
 115
 116         return 0;
 117 }
 118
 119 struct platform_driver twl4030_pwrbutton_driver = {
 120         .probe          = twl4030_pwrbutton_probe,
 121         .remove         = __devexit_p(twl4030_pwrbutton_remove),
 122         .driver         = {
 123                 .name   = "twl4030_pwrbutton",
 124                 .owner  = THIS_MODULE,
 125         },
 126 };
 127
 128 static int __init twl4030_pwrbutton_init(void)
 129 {
 130         return platform_driver_register(&twl4030_pwrbutton_driver);
 131 }
 132 module_init(twl4030_pwrbutton_init);
 133
 134 static void __exit twl4030_pwrbutton_exit(void)
 135 {
 136         platform_driver_unregister(&twl4030_pwrbutton_driver);
 137 }
 138 module_exit(twl4030_pwrbutton_exit);
 139
 140 MODULE_ALIAS("platform:twl4030_pwrbutton");
 141 MODULE_DESCRIPTION("Triton2 Power Button");
 142 MODULE_LICENSE("GPL");
 143 MODULE_AUTHOR("Peter De Schrijver <peter.de-schrijver@nokia.com>");
 144 MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
 145