drivers/input/misc/cobalt_btns.c

   1 /*
   2  *  Cobalt button interface driver.
   3  *
   4  *  Copyright (C) 2007  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
   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 #define BUTTONS_POLL_INTERVAL   30      /* msec */
  27 #define BUTTONS_COUNT_THRESHOLD 3
  28 #define BUTTONS_STATUS_MASK     0xfe000000
  29
  30 struct buttons_dev {
  31         struct input_polled_dev *poll_dev;
  32         void __iomem *reg;
  33 };
  34
  35 struct buttons_map {
  36         uint32_t mask;
  37         int keycode;
  38         int count;
  39 };
  40
  41 static struct buttons_map buttons_map[] = {
  42         { 0x02000000, KEY_RESTART, },
  43         { 0x04000000, KEY_LEFT, },
  44         { 0x08000000, KEY_UP, },
  45         { 0x10000000, KEY_DOWN, },
  46         { 0x20000000, KEY_RIGHT, },
  47         { 0x40000000, KEY_ENTER, },
  48         { 0x80000000, KEY_SELECT, },
  49 };
  50
  51 static void handle_buttons(struct input_polled_dev *dev)
  52 {
  53         struct buttons_map *button = buttons_map;
  54         struct buttons_dev *bdev = dev->private;
  55         struct input_dev *input = dev->input;
  56         uint32_t status;
  57         int i;
  58
  59         status = readl(bdev->reg);
  60         status = ~status & BUTTONS_STATUS_MASK;
  61
  62         for (i = 0; i < ARRAY_SIZE(buttons_map); i++) {
  63                 if (status & button->mask) {
  64                         button->count++;
  65                 } else {
  66                         if (button->count >= BUTTONS_COUNT_THRESHOLD) {
  67                                 input_report_key(input, button->keycode, 0);
  68                                 input_sync(input);
  69                         }
  70                         button->count = 0;
  71                 }
  72
  73                 if (button->count == BUTTONS_COUNT_THRESHOLD) {
  74                         input_report_key(input, button->keycode, 1);
  75                         input_sync(input);
  76                 }
  77
  78                 button++;
  79         }
  80 }
  81
  82 static int __devinit cobalt_buttons_probe(struct platform_device *pdev)
  83 {
  84         struct buttons_dev *bdev;
  85         struct input_polled_dev *poll_dev;
  86         struct input_dev *input;
  87         struct resource *res;
  88         int error, i;
  89
  90         bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
  91         poll_dev = input_allocate_polled_device();
  92         if (!bdev || !poll_dev) {
  93                 error = -ENOMEM;
  94                 goto err_free_mem;
  95         }
  96
  97         poll_dev->private = bdev;
  98         poll_dev->poll = handle_buttons;
  99         poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
 100
 101         input = poll_dev->input;
 102         input->name = "Cobalt buttons";
 103         input->phys = "cobalt/input0";
 104         input->id.bustype = BUS_HOST;
 105         input->cdev.dev = &pdev->dev;
 106
 107         input->evbit[0] = BIT(EV_KEY);
 108         for (i = 0; i < ARRAY_SIZE(buttons_map); i++) {
 109                 set_bit(buttons_map[i].keycode, input->keybit);
 110                 buttons_map[i].count = 0;
 111         }
 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, res->end - res->start + 1);
 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 __devexit 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 static struct platform_driver cobalt_buttons_driver = {
 153         .probe  = cobalt_buttons_probe,
 154         .remove = __devexit_p(cobalt_buttons_remove),
 155         .driver = {
 156                 .name   = "Cobalt buttons",
 157                 .owner  = THIS_MODULE,
 158         },
 159 };
 160
 161 static int __init cobalt_buttons_init(void)
 162 {
 163         return platform_driver_register(&cobalt_buttons_driver);
 164 }
 165
 166 static void __exit cobalt_buttons_exit(void)
 167 {
 168         platform_driver_unregister(&cobalt_buttons_driver);
 169 }
 170
 171 module_init(cobalt_buttons_init);
 172 module_exit(cobalt_buttons_exit);