drivers/input/misc/sgio2_btns.c

   1 /*
   2  *  SGI O2 Volume Button interface driver
   3  *
   4  *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de>
   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; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20 #include <linux/init.h>
  21 #include <linux/input-polldev.h>
  22 #include <linux/ioport.h>
  23 #include <linux/module.h>
  24 #include <linux/platform_device.h>
  25
  26 #include <asm/ip32/mace.h>
  27
  28 #define BUTTONS_POLL_INTERVAL   30      /* msec */
  29 #define BUTTONS_COUNT_THRESHOLD 3
  30
  31 static const unsigned short sgio2_map[] = {
  32         KEY_VOLUMEUP,
  33         KEY_VOLUMEDOWN
  34 };
  35
  36 struct buttons_dev {
  37         struct input_polled_dev *poll_dev;
  38         unsigned short keymap[ARRAY_SIZE(sgio2_map)];
  39         int count[ARRAY_SIZE(sgio2_map)];
  40         void __iomem *reg;
  41 };
  42
  43 static void handle_buttons(struct input_polled_dev *dev)
  44 {
  45         struct buttons_dev *bdev = dev->private;
  46         struct input_dev *input = dev->input;
  47         u64 status;
  48         int i;
  49
  50         status = (readq(&mace->perif.audio.control) >> 23) & 3;
  51
  52         for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
  53                 if (status & (1U << i)) {
  54                         writeq(status & ~(1U << i), &mace->perif.audio.control);
  55                         if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
  56                                 input_event(input, EV_MSC, MSC_SCAN, i);
  57                                 input_report_key(input, bdev->keymap[i], 1);
  58                                 input_sync(input);
  59                         }
  60                 } else {
  61                         if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
  62                                 input_event(input, EV_MSC, MSC_SCAN, i);
  63                                 input_report_key(input, bdev->keymap[i], 0);
  64                                 input_sync(input);
  65                         }
  66                         bdev->count[i] = 0;
  67                 }
  68         }
  69 }
  70
  71 static int __devinit sgio2_buttons_probe(struct platform_device *pdev)
  72 {
  73         struct buttons_dev *bdev;
  74         struct input_polled_dev *poll_dev;
  75         struct input_dev *input;
  76         int error, i;
  77
  78         bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
  79         poll_dev = input_allocate_polled_device();
  80         if (!bdev || !poll_dev) {
  81                 error = -ENOMEM;
  82                 goto err_free_mem;
  83         }
  84
  85         memcpy(bdev->keymap, sgio2_map, sizeof(bdev->keymap));
  86
  87         poll_dev->private = bdev;
  88         poll_dev->poll = handle_buttons;
  89         poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
  90
  91         input = poll_dev->input;
  92         input->name = "SGI O2 buttons";
  93         input->phys = "sgio2/input0";
  94         input->id.bustype = BUS_HOST;
  95         input->dev.parent = &pdev->dev;
  96
  97         input->keycode = bdev->keymap;
  98         input->keycodemax = ARRAY_SIZE(bdev->keymap);
  99         input->keycodesize = sizeof(unsigned short);
 100
 101         input_set_capability(input, EV_MSC, MSC_SCAN);
 102         __set_bit(EV_KEY, input->evbit);
 103         for (i = 0; i < ARRAY_SIZE(sgio2_map); i++)
 104                 __set_bit(bdev->keymap[i], input->keybit);
 105         __clear_bit(KEY_RESERVED, input->keybit);
 106
 107         bdev->poll_dev = poll_dev;
 108         dev_set_drvdata(&pdev->dev, bdev);
 109
 110         error = input_register_polled_device(poll_dev);
 111         if (error)
 112                 goto err_free_mem;
 113
 114         return 0;
 115
 116  err_free_mem:
 117         input_free_polled_device(poll_dev);
 118         kfree(bdev);
 119         dev_set_drvdata(&pdev->dev, NULL);
 120         return error;
 121 }
 122
 123 static int __devexit sgio2_buttons_remove(struct platform_device *pdev)
 124 {
 125         struct device *dev = &pdev->dev;
 126         struct buttons_dev *bdev = dev_get_drvdata(dev);
 127
 128         input_unregister_polled_device(bdev->poll_dev);
 129         input_free_polled_device(bdev->poll_dev);
 130         kfree(bdev);
 131         dev_set_drvdata(dev, NULL);
 132
 133         return 0;
 134 }
 135
 136 static struct platform_driver sgio2_buttons_driver = {
 137         .probe  = sgio2_buttons_probe,
 138         .remove = __devexit_p(sgio2_buttons_remove),
 139         .driver = {
 140                 .name   = "sgio2btns",
 141                 .owner  = THIS_MODULE,
 142         },
 143 };
 144
 145 static int __init sgio2_buttons_init(void)
 146 {
 147         return platform_driver_register(&sgio2_buttons_driver);
 148 }
 149
 150 static void __exit sgio2_buttons_exit(void)
 151 {
 152         platform_driver_unregister(&sgio2_buttons_driver);
 153 }
 154
 155 module_init(sgio2_buttons_init);
 156 module_exit(sgio2_buttons_exit);