linux/drivers/input/keyboard/opencores-kbd.c
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   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
  18struct opencores_kbd {
  19        struct input_dev *input;
  20        void __iomem *addr;
  21        int irq;
  22        unsigned short keycodes[128];
  23};
  24
  25static 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
  38static 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
 113static struct platform_driver opencores_kbd_device_driver = {
 114        .probe    = opencores_kbd_probe,
 115        .driver   = {
 116                .name = "opencores-kbd",
 117        },
 118};
 119module_platform_driver(opencores_kbd_device_driver);
 120
 121MODULE_LICENSE("GPL");
 122MODULE_AUTHOR("Javier Herrero <jherrero@hvsistemas.es>");
 123MODULE_DESCRIPTION("Keyboard driver for OpenCores Keyboard Controller");
 124