drivers/input/misc/sgi_btns.c

   1 /*
   2  *  SGI 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 #include <linux/slab.h>
  26
  27 #ifdef CONFIG_SGI_IP22
  28 #include <asm/sgi/ioc.h>
  29
  30 static inline u8 button_status(void)
  31 {
  32         u8 status;
  33
  34         status = readb(&sgioc->panel) ^ 0xa0;
  35         return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);
  36 }
  37 #endif
  38
  39 #ifdef CONFIG_SGI_IP32
  40 #include <asm/ip32/mace.h>
  41
  42 static inline u8 button_status(void)
  43 {
  44         u64 status;
  45
  46         status = readq(&mace->perif.audio.control);
  47         writeq(status & ~(3U << 23), &mace->perif.audio.control);
  48
  49         return (status >> 23) & 3;
  50 }
  51 #endif
  52
  53 #define BUTTONS_POLL_INTERVAL   30      /* msec */
  54 #define BUTTONS_COUNT_THRESHOLD 3
  55
  56 static const unsigned short sgi_map[] = {
  57         KEY_VOLUMEDOWN,
  58         KEY_VOLUMEUP
  59 };
  60
  61 struct buttons_dev {
  62         struct input_polled_dev *poll_dev;
  63         unsigned short keymap[ARRAY_SIZE(sgi_map)];
  64         int count[ARRAY_SIZE(sgi_map)];
  65 };
  66
  67 static void handle_buttons(struct input_polled_dev *dev)
  68 {
  69         struct buttons_dev *bdev = dev->private;
  70         struct input_dev *input = dev->input;
  71         u8 status;
  72         int i;
  73
  74         status = button_status();
  75
  76         for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
  77                 if (status & (1U << i)) {
  78                         if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
  79                                 input_event(input, EV_MSC, MSC_SCAN, i);
  80                                 input_report_key(input, bdev->keymap[i], 1);
  81                                 input_sync(input);
  82                         }
  83                 } else {
  84                         if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
  85                                 input_event(input, EV_MSC, MSC_SCAN, i);
  86                                 input_report_key(input, bdev->keymap[i], 0);
  87                                 input_sync(input);
  88                         }
  89                         bdev->count[i] = 0;
  90                 }
  91         }
  92 }
  93
  94 static int sgi_buttons_probe(struct platform_device *pdev)
  95 {
  96         struct buttons_dev *bdev;
  97         struct input_polled_dev *poll_dev;
  98         struct input_dev *input;
  99         int error, i;
 100
 101         bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
 102         poll_dev = input_allocate_polled_device();
 103         if (!bdev || !poll_dev) {
 104                 error = -ENOMEM;
 105                 goto err_free_mem;
 106         }
 107
 108         memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap));
 109
 110         poll_dev->private = bdev;
 111         poll_dev->poll = handle_buttons;
 112         poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
 113
 114         input = poll_dev->input;
 115         input->name = "SGI buttons";
 116         input->phys = "sgi/input0";
 117         input->id.bustype = BUS_HOST;
 118         input->dev.parent = &pdev->dev;
 119
 120         input->keycode = bdev->keymap;
 121         input->keycodemax = ARRAY_SIZE(bdev->keymap);
 122         input->keycodesize = sizeof(unsigned short);
 123
 124         input_set_capability(input, EV_MSC, MSC_SCAN);
 125         __set_bit(EV_KEY, input->evbit);
 126         for (i = 0; i < ARRAY_SIZE(sgi_map); i++)
 127                 __set_bit(bdev->keymap[i], input->keybit);
 128         __clear_bit(KEY_RESERVED, input->keybit);
 129
 130         bdev->poll_dev = poll_dev;
 131         platform_set_drvdata(pdev, bdev);
 132
 133         error = input_register_polled_device(poll_dev);
 134         if (error)
 135                 goto err_free_mem;
 136
 137         return 0;
 138
 139  err_free_mem:
 140         input_free_polled_device(poll_dev);
 141         kfree(bdev);
 142         return error;
 143 }
 144
 145 static int sgi_buttons_remove(struct platform_device *pdev)
 146 {
 147         struct buttons_dev *bdev = platform_get_drvdata(pdev);
 148
 149         input_unregister_polled_device(bdev->poll_dev);
 150         input_free_polled_device(bdev->poll_dev);
 151         kfree(bdev);
 152
 153         return 0;
 154 }
 155
 156 static struct platform_driver sgi_buttons_driver = {
 157         .probe  = sgi_buttons_probe,
 158         .remove = sgi_buttons_remove,
 159         .driver = {
 160                 .name   = "sgibtns",
 161                 .owner  = THIS_MODULE,
 162         },
 163 };
 164 module_platform_driver(sgi_buttons_driver);
 165
 166 MODULE_LICENSE("GPL");