drivers/input/keyboard/opencores-kbd.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * OpenCores Keyboard Controller Driver
   4  * http://www.opencores.org/project,keyboardcontroller
   5  *
   6  * Copyright 2007-2009 HV Sistemas S.L.
   7  */
   8
   9 #include <linux/input.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/io.h>
  12 #include <linux/ioport.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/slab.h>
  17
  18 struct opencores_kbd {
  19         struct input_dev *input;
  20         void __iomem *addr;
  21         int irq;
  22         unsigned short keycodes[128];
  23 };
  24
  25 static irqreturn_t opencores_kbd_isr(int irq, void *dev_id)
  26 {
  27         struct opencores_kbd *opencores_kbd = dev_id;
  28         struct input_dev *input = opencores_kbd->input;
  29         unsigned char c;
  30
  31         c = readb(opencores_kbd->addr);
  32         input_report_key(input, c & 0x7f, c & 0x80 ? 0 : 1);
  33         input_sync(input);
  34
  35         return IRQ_HANDLED;
  36 }
  37
  38 static int opencores_kbd_probe(struct platform_device *pdev)
  39 {
  40         struct input_dev *input;
  41         struct opencores_kbd *opencores_kbd;
  42         struct resource *res;
  43         int irq, i, error;
  44
  45         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  46         if (!res) {
  47                 dev_err(&pdev->dev, "missing board memory resource\n");
  48                 return -EINVAL;
  49         }
  50
  51         irq = platform_get_irq(pdev, 0);
  52         if (irq < 0)
  53                 return -EINVAL;
  54
  55         opencores_kbd = devm_kzalloc(&pdev->dev, sizeof(*opencores_kbd),
  56                                      GFP_KERNEL);
  57         if (!opencores_kbd)
  58                 return -ENOMEM;
  59
  60         input = devm_input_allocate_device(&pdev->dev);
  61         if (!input) {
  62                 dev_err(&pdev->dev, "failed to allocate input device\n");
  63                 return -ENOMEM;
  64         }
  65
  66         opencores_kbd->input = input;
  67
  68         opencores_kbd->addr = devm_ioremap_resource(&pdev->dev, res);
  69         if (IS_ERR(opencores_kbd->addr))
  70                 return PTR_ERR(opencores_kbd->addr);
  71
  72         input->name = pdev->name;
  73         input->phys = "opencores-kbd/input0";
  74
  75         input->id.bustype = BUS_HOST;
  76         input->id.vendor = 0x0001;
  77         input->id.product = 0x0001;
  78         input->id.version = 0x0100;
  79
  80         input->keycode = opencores_kbd->keycodes;
  81         input->keycodesize = sizeof(opencores_kbd->keycodes[0]);
  82         input->keycodemax = ARRAY_SIZE(opencores_kbd->keycodes);
  83
  84         __set_bit(EV_KEY, input->evbit);
  85
  86         for (i = 0; i < ARRAY_SIZE(opencores_kbd->keycodes); i++) {
  87                 /*
  88                  * OpenCores controller happens to have scancodes match
  89                  * our KEY_* definitions.
  90                  */
  91                 opencores_kbd->keycodes[i] = i;
  92                 __set_bit(opencores_kbd->keycodes[i], input->keybit);
  93         }
  94         __clear_bit(KEY_RESERVED, input->keybit);
  95
  96         error = devm_request_irq(&pdev->dev, irq, &opencores_kbd_isr,
  97                                  IRQF_TRIGGER_RISING,
  98                                  pdev->name, opencores_kbd);
  99         if (error) {
 100                 dev_err(&pdev->dev, "unable to claim irq %d\n", irq);
 101                 return error;
 102         }
 103
 104         error = input_register_device(input);
 105         if (error) {
 106                 dev_err(&pdev->dev, "unable to register input device\n");
 107                 return error;
 108         }
 109
 110         return 0;
 111 }
 112
 113 static struct platform_driver opencores_kbd_device_driver = {
 114         .probe    = opencores_kbd_probe,
 115         .driver   = {
 116                 .name = "opencores-kbd",
 117         },
 118 };
 119 module_platform_driver(opencores_kbd_device_driver);
 120
 121 MODULE_LICENSE("GPL");
 122 MODULE_AUTHOR("Javier Herrero <jherrero@hvsistemas.es>");
 123 MODULE_DESCRIPTION("Keyboard driver for OpenCores Keyboard Controller");