drivers/input/misc/sgi_btns.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  SGI Volume Button interface driver
   4  *
   5  *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de>
   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 #ifdef CONFIG_SGI_IP22
  14 #include <asm/sgi/ioc.h>
  15
  16 static inline u8 button_status(void)
  17 {
  18         u8 status;
  19
  20         status = readb(&sgioc->panel) ^ 0xa0;
  21         return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);
  22 }
  23 #endif
  24
  25 #ifdef CONFIG_SGI_IP32
  26 #include <asm/ip32/mace.h>
  27
  28 static inline u8 button_status(void)
  29 {
  30         u64 status;
  31
  32         status = readq(&mace->perif.audio.control);
  33         writeq(status & ~(3U << 23), &mace->perif.audio.control);
  34
  35         return (status >> 23) & 3;
  36 }
  37 #endif
  38
  39 #define BUTTONS_POLL_INTERVAL   30      /* msec */
  40 #define BUTTONS_COUNT_THRESHOLD 3
  41
  42 static const unsigned short sgi_map[] = {
  43         KEY_VOLUMEDOWN,
  44         KEY_VOLUMEUP
  45 };
  46
  47 struct buttons_dev {
  48         struct input_polled_dev *poll_dev;
  49         unsigned short keymap[ARRAY_SIZE(sgi_map)];
  50         int count[ARRAY_SIZE(sgi_map)];
  51 };
  52
  53 static void handle_buttons(struct input_polled_dev *dev)
  54 {
  55         struct buttons_dev *bdev = dev->private;
  56         struct input_dev *input = dev->input;
  57         u8 status;
  58         int i;
  59
  60         status = button_status();
  61
  62         for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
  63                 if (status & (1U << i)) {
  64                         if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
  65                                 input_event(input, EV_MSC, MSC_SCAN, i);
  66                                 input_report_key(input, bdev->keymap[i], 1);
  67                                 input_sync(input);
  68                         }
  69                 } else {
  70                         if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
  71                                 input_event(input, EV_MSC, MSC_SCAN, i);
  72                                 input_report_key(input, bdev->keymap[i], 0);
  73                                 input_sync(input);
  74                         }
  75                         bdev->count[i] = 0;
  76                 }
  77         }
  78 }
  79
  80 static int sgi_buttons_probe(struct platform_device *pdev)
  81 {
  82         struct buttons_dev *bdev;
  83         struct input_polled_dev *poll_dev;
  84         struct input_dev *input;
  85         int error, i;
  86
  87         bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
  88         poll_dev = input_allocate_polled_device();
  89         if (!bdev || !poll_dev) {
  90                 error = -ENOMEM;
  91                 goto err_free_mem;
  92         }
  93
  94         memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap));
  95
  96         poll_dev->private = bdev;
  97         poll_dev->poll = handle_buttons;
  98         poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
  99
 100         input = poll_dev->input;
 101         input->name = "SGI buttons";
 102         input->phys = "sgi/input0";
 103         input->id.bustype = BUS_HOST;
 104         input->dev.parent = &pdev->dev;
 105
 106         input->keycode = bdev->keymap;
 107         input->keycodemax = ARRAY_SIZE(bdev->keymap);
 108         input->keycodesize = sizeof(unsigned short);
 109
 110         input_set_capability(input, EV_MSC, MSC_SCAN);
 111         __set_bit(EV_KEY, input->evbit);
 112         for (i = 0; i < ARRAY_SIZE(sgi_map); i++)
 113                 __set_bit(bdev->keymap[i], input->keybit);
 114         __clear_bit(KEY_RESERVED, input->keybit);
 115
 116         bdev->poll_dev = poll_dev;
 117         platform_set_drvdata(pdev, bdev);
 118
 119         error = input_register_polled_device(poll_dev);
 120         if (error)
 121                 goto err_free_mem;
 122
 123         return 0;
 124
 125  err_free_mem:
 126         input_free_polled_device(poll_dev);
 127         kfree(bdev);
 128         return error;
 129 }
 130
 131 static int sgi_buttons_remove(struct platform_device *pdev)
 132 {
 133         struct buttons_dev *bdev = platform_get_drvdata(pdev);
 134
 135         input_unregister_polled_device(bdev->poll_dev);
 136         input_free_polled_device(bdev->poll_dev);
 137         kfree(bdev);
 138
 139         return 0;
 140 }
 141
 142 static struct platform_driver sgi_buttons_driver = {
 143         .probe  = sgi_buttons_probe,
 144         .remove = sgi_buttons_remove,
 145         .driver = {
 146                 .name   = "sgibtns",
 147         },
 148 };
 149 module_platform_driver(sgi_buttons_driver);
 150
 151 MODULE_LICENSE("GPL");