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/input-polldev.h>
  21 #include <linux/ioport.h>
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/slab.h>
  25
  26 #ifdef CONFIG_SGI_IP22
  27 #include <asm/sgi/ioc.h>
  28
  29 static inline u8 button_status(void)
  30 {
  31         u8 status;
  32
  33         status = readb(&sgioc->panel) ^ 0xa0;
  34         return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);
  35 }
  36 #endif
  37
  38 #ifdef CONFIG_SGI_IP32
  39 #include <asm/ip32/mace.h>
  40
  41 static inline u8 button_status(void)
  42 {
  43         u64 status;
  44
  45         status = readq(&mace->perif.audio.control);
  46         writeq(status & ~(3U << 23), &mace->perif.audio.control);
  47
  48         return (status >> 23) & 3;
  49 }
  50 #endif
  51
  52 #define BUTTONS_POLL_INTERVAL   30      /* msec */
  53 #define BUTTONS_COUNT_THRESHOLD 3
  54
  55 static const unsigned short sgi_map[] = {
  56         KEY_VOLUMEDOWN,
  57         KEY_VOLUMEUP
  58 };
  59
  60 struct buttons_dev {
  61         struct input_polled_dev *poll_dev;
  62         unsigned short keymap[ARRAY_SIZE(sgi_map)];
  63         int count[ARRAY_SIZE(sgi_map)];
  64 };
  65
  66 static void handle_buttons(struct input_polled_dev *dev)
  67 {
  68         struct buttons_dev *bdev = dev->private;
  69         struct input_dev *input = dev->input;
  70         u8 status;
  71         int i;
  72
  73         status = button_status();
  74
  75         for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
  76                 if (status & (1U << i)) {
  77                         if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
  78                                 input_event(input, EV_MSC, MSC_SCAN, i);
  79                                 input_report_key(input, bdev->keymap[i], 1);
  80                                 input_sync(input);
  81                         }
  82                 } else {
  83                         if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
  84                                 input_event(input, EV_MSC, MSC_SCAN, i);
  85                                 input_report_key(input, bdev->keymap[i], 0);
  86                                 input_sync(input);
  87                         }
  88                         bdev->count[i] = 0;
  89                 }
  90         }
  91 }
  92
  93 static int sgi_buttons_probe(struct platform_device *pdev)
  94 {
  95         struct buttons_dev *bdev;
  96         struct input_polled_dev *poll_dev;
  97         struct input_dev *input;
  98         int error, i;
  99
 100         bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
 101         poll_dev = input_allocate_polled_device();
 102         if (!bdev || !poll_dev) {
 103                 error = -ENOMEM;
 104                 goto err_free_mem;
 105         }
 106
 107         memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap));
 108
 109         poll_dev->private = bdev;
 110         poll_dev->poll = handle_buttons;
 111         poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
 112
 113         input = poll_dev->input;
 114         input->name = "SGI buttons";
 115         input->phys = "sgi/input0";
 116         input->id.bustype = BUS_HOST;
 117         input->dev.parent = &pdev->dev;
 118
 119         input->keycode = bdev->keymap;
 120         input->keycodemax = ARRAY_SIZE(bdev->keymap);
 121         input->keycodesize = sizeof(unsigned short);
 122
 123         input_set_capability(input, EV_MSC, MSC_SCAN);
 124         __set_bit(EV_KEY, input->evbit);
 125         for (i = 0; i < ARRAY_SIZE(sgi_map); i++)
 126                 __set_bit(bdev->keymap[i], input->keybit);
 127         __clear_bit(KEY_RESERVED, input->keybit);
 128
 129         bdev->poll_dev = poll_dev;
 130         platform_set_drvdata(pdev, bdev);
 131
 132         error = input_register_polled_device(poll_dev);
 133         if (error)
 134                 goto err_free_mem;
 135
 136         return 0;
 137
 138  err_free_mem:
 139         input_free_polled_device(poll_dev);
 140         kfree(bdev);
 141         return error;
 142 }
 143
 144 static int sgi_buttons_remove(struct platform_device *pdev)
 145 {
 146         struct buttons_dev *bdev = platform_get_drvdata(pdev);
 147
 148         input_unregister_polled_device(bdev->poll_dev);
 149         input_free_polled_device(bdev->poll_dev);
 150         kfree(bdev);
 151
 152         return 0;
 153 }
 154
 155 static struct platform_driver sgi_buttons_driver = {
 156         .probe  = sgi_buttons_probe,
 157         .remove = sgi_buttons_remove,
 158         .driver = {
 159                 .name   = "sgibtns",
 160         },
 161 };
 162 module_platform_driver(sgi_buttons_driver);
 163
 164 MODULE_LICENSE("GPL");