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