drivers/input/misc/cobalt_btns.c

   1 /*
   2  *  Cobalt button interface driver.
   3  *
   4  *  Copyright (C) 2007-2008  Yoichi Yuasa <yuasa@linux-mips.org>
   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 #define BUTTONS_POLL_INTERVAL   30      /* msec */
  28 #define BUTTONS_COUNT_THRESHOLD 3
  29 #define BUTTONS_STATUS_MASK     0xfe000000
  30
  31 static const unsigned short cobalt_map[] = {
  32         KEY_RESERVED,
  33         KEY_RESTART,
  34         KEY_LEFT,
  35         KEY_UP,
  36         KEY_DOWN,
  37         KEY_RIGHT,
  38         KEY_ENTER,
  39         KEY_SELECT
  40 };
  41
  42 struct buttons_dev {
  43         struct input_polled_dev *poll_dev;
  44         unsigned short keymap[ARRAY_SIZE(cobalt_map)];
  45         int count[ARRAY_SIZE(cobalt_map)];
  46         void __iomem *reg;
  47 };
  48
  49 static void handle_buttons(struct input_polled_dev *dev)
  50 {
  51         struct buttons_dev *bdev = dev->private;
  52         struct input_dev *input = dev->input;
  53         uint32_t status;
  54         int i;
  55
  56         status = ~readl(bdev->reg) >> 24;
  57
  58         for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
  59                 if (status & (1U << i)) {
  60                         if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
  61                                 input_event(input, EV_MSC, MSC_SCAN, i);
  62                                 input_report_key(input, bdev->keymap[i], 1);
  63                                 input_sync(input);
  64                         }
  65                 } else {
  66                         if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
  67                                 input_event(input, EV_MSC, MSC_SCAN, i);
  68                                 input_report_key(input, bdev->keymap[i], 0);
  69                                 input_sync(input);
  70                         }
  71                         bdev->count[i] = 0;
  72                 }
  73         }
  74 }
  75
  76 static int cobalt_buttons_probe(struct platform_device *pdev)
  77 {
  78         struct buttons_dev *bdev;
  79         struct input_polled_dev *poll_dev;
  80         struct input_dev *input;
  81         struct resource *res;
  82         int error, i;
  83
  84         bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
  85         poll_dev = input_allocate_polled_device();
  86         if (!bdev || !poll_dev) {
  87                 error = -ENOMEM;
  88                 goto err_free_mem;
  89         }
  90
  91         memcpy(bdev->keymap, cobalt_map, sizeof(bdev->keymap));
  92
  93         poll_dev->private = bdev;
  94         poll_dev->poll = handle_buttons;
  95         poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
  96
  97         input = poll_dev->input;
  98         input->name = "Cobalt buttons";
  99         input->phys = "cobalt/input0";
 100         input->id.bustype = BUS_HOST;
 101         input->dev.parent = &pdev->dev;
 102
 103         input->keycode = bdev->keymap;
 104         input->keycodemax = ARRAY_SIZE(bdev->keymap);
 105         input->keycodesize = sizeof(unsigned short);
 106
 107         input_set_capability(input, EV_MSC, MSC_SCAN);
 108         __set_bit(EV_KEY, input->evbit);
 109         for (i = 0; i < ARRAY_SIZE(cobalt_map); i++)
 110                 __set_bit(bdev->keymap[i], input->keybit);
 111         __clear_bit(KEY_RESERVED, input->keybit);
 112
 113         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 114         if (!res) {
 115                 error = -EBUSY;
 116                 goto err_free_mem;
 117         }
 118
 119         bdev->poll_dev = poll_dev;
 120         bdev->reg = ioremap(res->start, resource_size(res));
 121         dev_set_drvdata(&pdev->dev, bdev);
 122
 123         error = input_register_polled_device(poll_dev);
 124         if (error)
 125                 goto err_iounmap;
 126
 127         return 0;
 128
 129  err_iounmap:
 130         iounmap(bdev->reg);
 131  err_free_mem:
 132         input_free_polled_device(poll_dev);
 133         kfree(bdev);
 134         dev_set_drvdata(&pdev->dev, NULL);
 135         return error;
 136 }
 137
 138 static int cobalt_buttons_remove(struct platform_device *pdev)
 139 {
 140         struct device *dev = &pdev->dev;
 141         struct buttons_dev *bdev = dev_get_drvdata(dev);
 142
 143         input_unregister_polled_device(bdev->poll_dev);
 144         input_free_polled_device(bdev->poll_dev);
 145         iounmap(bdev->reg);
 146         kfree(bdev);
 147         dev_set_drvdata(dev, NULL);
 148
 149         return 0;
 150 }
 151
 152 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
 153 MODULE_DESCRIPTION("Cobalt button interface driver");
 154 MODULE_LICENSE("GPL");
 155 /* work with hotplug and coldplug */
 156 MODULE_ALIAS("platform:Cobalt buttons");
 157
 158 static struct platform_driver cobalt_buttons_driver = {
 159         .probe  = cobalt_buttons_probe,
 160         .remove = cobalt_buttons_remove,
 161         .driver = {
 162                 .name   = "Cobalt buttons",
 163                 .owner  = THIS_MODULE,
 164         },
 165 };
 166 module_platform_driver(cobalt_buttons_driver);