drivers/platform/x86/intel_mid_powerbtn.c

   1 /*
   2  * Power button driver for Medfield.
   3  *
   4  * Copyright (C) 2010 Intel Corp
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/slab.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/input.h>
  26
  27 #include <asm/intel_scu_ipc.h>
  28
  29 #define DRIVER_NAME "msic_power_btn"
  30
  31 #define MSIC_PB_STATUS  0x3f
  32 #define MSIC_PB_LEVEL   (1 << 3) /* 1 - release, 0 - press */
  33
  34 static irqreturn_t mfld_pb_isr(int irq, void *dev_id)
  35 {
  36         struct input_dev *input = dev_id;
  37         int ret;
  38         u8 pbstat;
  39
  40         ret = intel_scu_ipc_ioread8(MSIC_PB_STATUS, &pbstat);
  41         if (ret < 0) {
  42                 dev_err(input->dev.parent, "Read error %d while reading"
  43                                " MSIC_PB_STATUS\n", ret);
  44         } else {
  45                 input_event(input, EV_KEY, KEY_POWER,
  46                                !(pbstat & MSIC_PB_LEVEL));
  47                 input_sync(input);
  48         }
  49
  50         return IRQ_HANDLED;
  51 }
  52
  53 static int __devinit mfld_pb_probe(struct platform_device *pdev)
  54 {
  55         struct input_dev *input;
  56         int irq = platform_get_irq(pdev, 0);
  57         int error;
  58
  59         if (irq < 0)
  60                 return -EINVAL;
  61
  62         input = input_allocate_device();
  63         if (!input) {
  64                 dev_err(&pdev->dev, "Input device allocation error\n");
  65                 return -ENOMEM;
  66         }
  67
  68         input->name = pdev->name;
  69         input->phys = "power-button/input0";
  70         input->id.bustype = BUS_HOST;
  71         input->dev.parent = &pdev->dev;
  72
  73         input_set_capability(input, EV_KEY, KEY_POWER);
  74
  75         error = request_threaded_irq(irq, NULL, mfld_pb_isr, 0,
  76                         DRIVER_NAME, input);
  77         if (error) {
  78                 dev_err(&pdev->dev, "Unable to request irq %d for mfld power"
  79                                 "button\n", irq);
  80                 goto err_free_input;
  81         }
  82
  83         error = input_register_device(input);
  84         if (error) {
  85                 dev_err(&pdev->dev, "Unable to register input dev, error "
  86                                 "%d\n", error);
  87                 goto err_free_irq;
  88         }
  89
  90         platform_set_drvdata(pdev, input);
  91         return 0;
  92
  93 err_free_irq:
  94         free_irq(irq, input);
  95 err_free_input:
  96         input_free_device(input);
  97         return error;
  98 }
  99
 100 static int __devexit mfld_pb_remove(struct platform_device *pdev)
 101 {
 102         struct input_dev *input = platform_get_drvdata(pdev);
 103         int irq = platform_get_irq(pdev, 0);
 104
 105         free_irq(irq, input);
 106         input_unregister_device(input);
 107         platform_set_drvdata(pdev, NULL);
 108
 109         return 0;
 110 }
 111
 112 static struct platform_driver mfld_pb_driver = {
 113         .driver = {
 114                 .name = DRIVER_NAME,
 115                 .owner = THIS_MODULE,
 116         },
 117         .probe  = mfld_pb_probe,
 118         .remove = __devexit_p(mfld_pb_remove),
 119 };
 120
 121 static int __init mfld_pb_init(void)
 122 {
 123         return platform_driver_register(&mfld_pb_driver);
 124 }
 125 module_init(mfld_pb_init);
 126
 127 static void __exit mfld_pb_exit(void)
 128 {
 129         platform_driver_unregister(&mfld_pb_driver);
 130 }
 131 module_exit(mfld_pb_exit);
 132
 133 MODULE_AUTHOR("Hong Liu <hong.liu@intel.com>");
 134 MODULE_DESCRIPTION("Intel Medfield Power Button Driver");
 135 MODULE_LICENSE("GPL v2");
 136 MODULE_ALIAS("platform:" DRIVER_NAME);