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
 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	int irq, i, error;
 43
 44	irq = platform_get_irq(pdev, 0);
 45	if (irq < 0)
 46		return -EINVAL;
 47
 48	opencores_kbd = devm_kzalloc(&pdev->dev, sizeof(*opencores_kbd),
 49				     GFP_KERNEL);
 50	if (!opencores_kbd)
 51		return -ENOMEM;
 52
 53	input = devm_input_allocate_device(&pdev->dev);
 54	if (!input) {
 55		dev_err(&pdev->dev, "failed to allocate input device\n");
 56		return -ENOMEM;
 57	}
 58
 59	opencores_kbd->input = input;
 60
 61	opencores_kbd->addr = devm_platform_ioremap_resource(pdev, 0);
 62	if (IS_ERR(opencores_kbd->addr))
 63		return PTR_ERR(opencores_kbd->addr);
 64
 65	input->name = pdev->name;
 66	input->phys = "opencores-kbd/input0";
 67
 68	input->id.bustype = BUS_HOST;
 69	input->id.vendor = 0x0001;
 70	input->id.product = 0x0001;
 71	input->id.version = 0x0100;
 72
 73	input->keycode = opencores_kbd->keycodes;
 74	input->keycodesize = sizeof(opencores_kbd->keycodes[0]);
 75	input->keycodemax = ARRAY_SIZE(opencores_kbd->keycodes);
 76
 77	__set_bit(EV_KEY, input->evbit);
 78
 79	for (i = 0; i < ARRAY_SIZE(opencores_kbd->keycodes); i++) {
 80		/*
 81		 * OpenCores controller happens to have scancodes match
 82		 * our KEY_* definitions.
 83		 */
 84		opencores_kbd->keycodes[i] = i;
 85		__set_bit(opencores_kbd->keycodes[i], input->keybit);
 86	}
 87	__clear_bit(KEY_RESERVED, input->keybit);
 88
 89	error = devm_request_irq(&pdev->dev, irq, &opencores_kbd_isr,
 90				 IRQF_TRIGGER_RISING,
 91				 pdev->name, opencores_kbd);
 92	if (error) {
 93		dev_err(&pdev->dev, "unable to claim irq %d\n", irq);
 94		return error;
 95	}
 96
 97	error = input_register_device(input);
 98	if (error) {
 99		dev_err(&pdev->dev, "unable to register input device\n");
100		return error;
101	}
102
103	return 0;
104}
105
106static struct platform_driver opencores_kbd_device_driver = {
107	.probe    = opencores_kbd_probe,
108	.driver   = {
109		.name = "opencores-kbd",
110	},
111};
112module_platform_driver(opencores_kbd_device_driver);
113
114MODULE_LICENSE("GPL");
115MODULE_AUTHOR("Javier Herrero <jherrero@hvsistemas.es>");
116MODULE_DESCRIPTION("Keyboard driver for OpenCores Keyboard Controller");