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-polldev.h>
   8 #include <linux/ioport.h>
   9 #include <linux/module.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12
  13 #define BUTTONS_POLL_INTERVAL   30      /* msec */
  14 #define BUTTONS_COUNT_THRESHOLD 3
  15 #define BUTTONS_STATUS_MASK     0xfe000000
  16
  17 static const unsigned short cobalt_map[] = {
  18         KEY_RESERVED,
  19         KEY_RESTART,
  20         KEY_LEFT,
  21         KEY_UP,
  22         KEY_DOWN,
  23         KEY_RIGHT,
  24         KEY_ENTER,
  25         KEY_SELECT
  26 };
  27
  28 struct buttons_dev {
  29         struct input_polled_dev *poll_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_polled_dev *dev)
  36 {
  37         struct buttons_dev *bdev = dev->private;
  38         struct input_dev *input = dev->input;
  39         uint32_t status;
  40         int i;
  41
  42         status = ~readl(bdev->reg) >> 24;
  43
  44         for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
  45                 if (status & (1U << i)) {
  46                         if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
  47                                 input_event(input, EV_MSC, MSC_SCAN, i);
  48                                 input_report_key(input, bdev->keymap[i], 1);
  49                                 input_sync(input);
  50                         }
  51                 } else {
  52                         if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
  53                                 input_event(input, EV_MSC, MSC_SCAN, i);
  54                                 input_report_key(input, bdev->keymap[i], 0);
  55                                 input_sync(input);
  56                         }
  57                         bdev->count[i] = 0;
  58                 }
  59         }
  60 }
  61
  62 static int cobalt_buttons_probe(struct platform_device *pdev)
  63 {
  64         struct buttons_dev *bdev;
  65         struct input_polled_dev *poll_dev;
  66         struct input_dev *input;
  67         struct resource *res;
  68         int error, i;
  69
  70         bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
  71         poll_dev = input_allocate_polled_device();
  72         if (!bdev || !poll_dev) {
  73                 error = -ENOMEM;
  74                 goto err_free_mem;
  75         }
  76
  77         memcpy(bdev->keymap, cobalt_map, sizeof(bdev->keymap));
  78
  79         poll_dev->private = bdev;
  80         poll_dev->poll = handle_buttons;
  81         poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
  82
  83         input = poll_dev->input;
  84         input->name = "Cobalt buttons";
  85         input->phys = "cobalt/input0";
  86         input->id.bustype = BUS_HOST;
  87         input->dev.parent = &pdev->dev;
  88
  89         input->keycode = bdev->keymap;
  90         input->keycodemax = ARRAY_SIZE(bdev->keymap);
  91         input->keycodesize = sizeof(unsigned short);
  92
  93         input_set_capability(input, EV_MSC, MSC_SCAN);
  94         __set_bit(EV_KEY, input->evbit);
  95         for (i = 0; i < ARRAY_SIZE(cobalt_map); i++)
  96                 __set_bit(bdev->keymap[i], input->keybit);
  97         __clear_bit(KEY_RESERVED, input->keybit);
  98
  99         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 100         if (!res) {
 101                 error = -EBUSY;
 102                 goto err_free_mem;
 103         }
 104
 105         bdev->poll_dev = poll_dev;
 106         bdev->reg = ioremap(res->start, resource_size(res));
 107         dev_set_drvdata(&pdev->dev, bdev);
 108
 109         error = input_register_polled_device(poll_dev);
 110         if (error)
 111                 goto err_iounmap;
 112
 113         return 0;
 114
 115  err_iounmap:
 116         iounmap(bdev->reg);
 117  err_free_mem:
 118         input_free_polled_device(poll_dev);
 119         kfree(bdev);
 120         return error;
 121 }
 122
 123 static int cobalt_buttons_remove(struct platform_device *pdev)
 124 {
 125         struct device *dev = &pdev->dev;
 126         struct buttons_dev *bdev = dev_get_drvdata(dev);
 127
 128         input_unregister_polled_device(bdev->poll_dev);
 129         input_free_polled_device(bdev->poll_dev);
 130         iounmap(bdev->reg);
 131         kfree(bdev);
 132
 133         return 0;
 134 }
 135
 136 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
 137 MODULE_DESCRIPTION("Cobalt button interface driver");
 138 MODULE_LICENSE("GPL");
 139 /* work with hotplug and coldplug */
 140 MODULE_ALIAS("platform:Cobalt buttons");
 141
 142 static struct platform_driver cobalt_buttons_driver = {
 143         .probe  = cobalt_buttons_probe,
 144         .remove = cobalt_buttons_remove,
 145         .driver = {
 146                 .name   = "Cobalt buttons",
 147         },
 148 };
 149 module_platform_driver(cobalt_buttons_driver);