drivers/input/misc/cobalt_btns.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Cobalt button interface driver.
   4  *
   5  *  Copyright (C) 2007-2008  Yoichi Yuasa <yuasa@linux-mips.org>
   6  */
   7 #include <linux/input.h>
   8 #include <linux/io.h>
   9 #include <linux/ioport.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/slab.h>
  13
  14 #define BUTTONS_POLL_INTERVAL   30      /* msec */
  15 #define BUTTONS_COUNT_THRESHOLD 3
  16 #define BUTTONS_STATUS_MASK     0xfe000000
  17
  18 static const unsigned short cobalt_map[] = {
  19         KEY_RESERVED,
  20         KEY_RESTART,
  21         KEY_LEFT,
  22         KEY_UP,
  23         KEY_DOWN,
  24         KEY_RIGHT,
  25         KEY_ENTER,
  26         KEY_SELECT
  27 };
  28
  29 struct buttons_dev {
  30         unsigned short keymap[ARRAY_SIZE(cobalt_map)];
  31         int count[ARRAY_SIZE(cobalt_map)];
  32         void __iomem *reg;
  33 };
  34
  35 static void handle_buttons(struct input_dev *input)
  36 {
  37         struct buttons_dev *bdev = input_get_drvdata(input);
  38         uint32_t status;
  39         int i;
  40
  41         status = ~readl(bdev->reg) >> 24;
  42
  43         for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
  44                 if (status & (1U << i)) {
  45                         if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
  46                                 input_event(input, EV_MSC, MSC_SCAN, i);
  47                                 input_report_key(input, bdev->keymap[i], 1);
  48                                 input_sync(input);
  49                         }
  50                 } else {
  51                         if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
  52                                 input_event(input, EV_MSC, MSC_SCAN, i);
  53                                 input_report_key(input, bdev->keymap[i], 0);
  54                                 input_sync(input);
  55                         }
  56                         bdev->count[i] = 0;
  57                 }
  58         }
  59 }
  60
  61 static int cobalt_buttons_probe(struct platform_device *pdev)
  62 {
  63         struct buttons_dev *bdev;
  64         struct input_dev *input;
  65         struct resource *res;
  66         int error, i;
  67
  68         bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
  69         if (!bdev)
  70                 return -ENOMEM;
  71
  72         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  73         if (!res)
  74                 return -EBUSY;
  75
  76         bdev->reg = devm_ioremap(&pdev->dev, res->start, resource_size(res));
  77         if (!bdev->reg)
  78                 return -ENOMEM;
  79
  80         memcpy(bdev->keymap, cobalt_map, sizeof(bdev->keymap));
  81
  82         input = devm_input_allocate_device(&pdev->dev);
  83         if (!input)
  84                 return -ENOMEM;
  85
  86         input_set_drvdata(input, bdev);
  87
  88         input->name = "Cobalt buttons";
  89         input->phys = "cobalt/input0";
  90         input->id.bustype = BUS_HOST;
  91
  92         input->keycode = bdev->keymap;
  93         input->keycodemax = ARRAY_SIZE(bdev->keymap);
  94         input->keycodesize = sizeof(unsigned short);
  95
  96         input_set_capability(input, EV_MSC, MSC_SCAN);
  97         __set_bit(EV_KEY, input->evbit);
  98         for (i = 0; i < ARRAY_SIZE(cobalt_map); i++)
  99                 __set_bit(bdev->keymap[i], input->keybit);
 100         __clear_bit(KEY_RESERVED, input->keybit);
 101
 102
 103         error = input_setup_polling(input, handle_buttons);
 104         if (error)
 105                 return error;
 106
 107         input_set_poll_interval(input, BUTTONS_POLL_INTERVAL);
 108
 109         error = input_register_device(input);
 110         if (error)
 111                 return error;
 112
 113         return 0;
 114 }
 115
 116 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
 117 MODULE_DESCRIPTION("Cobalt button interface driver");
 118 MODULE_LICENSE("GPL");
 119 /* work with hotplug and coldplug */
 120 MODULE_ALIAS("platform:Cobalt buttons");
 121
 122 static struct platform_driver cobalt_buttons_driver = {
 123         .probe  = cobalt_buttons_probe,
 124         .driver = {
 125                 .name   = "Cobalt buttons",
 126         },
 127 };
 128 module_platform_driver(cobalt_buttons_driver);