opencores-kbd.c

Go to the documentation of this file.

/*
 * OpenCores Keyboard Controller Driver
 * http://www.opencores.org/project,keyboardcontroller
 *
 * Copyright 2007-2009 HV Sistemas S.L.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

struct opencores_kbd {
    struct input_dev *input;
    struct resource *addr_res;
    void __iomem *addr;
    int irq;
    unsigned short keycodes[128];
};

static irqreturn_t opencores_kbd_isr(int irq, void *dev_id)
{
    struct opencores_kbd *opencores_kbd = dev_id;
    struct input_dev *input = opencores_kbd->input;
    unsigned char c;

    c = readb(opencores_kbd->addr);
    input_report_key(input, c & 0x7f, c & 0x80 ? 0 : 1);
    input_sync(input);

    return IRQ_HANDLED;
}

static int __devinit opencores_kbd_probe(struct platform_device *pdev)
{
    struct input_dev *input;
    struct opencores_kbd *opencores_kbd;
    struct resource *res;
    int irq, i, error;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        dev_err(&pdev->dev, "missing board memory resource\n");
        return -EINVAL;
    }

    irq = platform_get_irq(pdev, 0);
    if (irq < 0) {
        dev_err(&pdev->dev, "missing board IRQ resource\n");
        return -EINVAL;
    }

    opencores_kbd = kzalloc(sizeof(*opencores_kbd), GFP_KERNEL);
    input = input_allocate_device();
    if (!opencores_kbd || !input) {
        dev_err(&pdev->dev, "failed to allocate device structures\n");
        error = -ENOMEM;
        goto err_free_mem;
    }

    opencores_kbd->addr_res = res;
    res = request_mem_region(res->start, resource_size(res), pdev->name);
    if (!res) {
        dev_err(&pdev->dev, "failed to request I/O memory\n");
        error = -EBUSY;
        goto err_free_mem;
    }

    opencores_kbd->addr = ioremap(res->start, resource_size(res));
    if (!opencores_kbd->addr) {
        dev_err(&pdev->dev, "failed to remap I/O memory\n");
        error = -ENXIO;
        goto err_rel_mem;
    }

    opencores_kbd->input = input;
    opencores_kbd->irq = irq;

    input->name = pdev->name;
    input->phys = "opencores-kbd/input0";
    input->dev.parent = &pdev->dev;

    input_set_drvdata(input, opencores_kbd);

    input->id.bustype = BUS_HOST;
    input->id.vendor = 0x0001;
    input->id.product = 0x0001;
    input->id.version = 0x0100;

    input->keycode = opencores_kbd->keycodes;
    input->keycodesize = sizeof(opencores_kbd->keycodes[0]);
    input->keycodemax = ARRAY_SIZE(opencores_kbd->keycodes);

    __set_bit(EV_KEY, input->evbit);

    for (i = 0; i < ARRAY_SIZE(opencores_kbd->keycodes); i++) {
        /*
         * OpenCores controller happens to have scancodes match
         * our KEY_* definitions.
         */
        opencores_kbd->keycodes[i] = i;
        __set_bit(opencores_kbd->keycodes[i], input->keybit);
    }
    __clear_bit(KEY_RESERVED, input->keybit);

    error = request_irq(irq, &opencores_kbd_isr,
                IRQF_TRIGGER_RISING, pdev->name, opencores_kbd);
    if (error) {
        dev_err(&pdev->dev, "unable to claim irq %d\n", irq);
        goto err_unmap_mem;
    }

    error = input_register_device(input);
    if (error) {
        dev_err(&pdev->dev, "unable to register input device\n");
        goto err_free_irq;
    }

    platform_set_drvdata(pdev, opencores_kbd);

    return 0;

 err_free_irq:
    free_irq(irq, opencores_kbd);
 err_unmap_mem:
    iounmap(opencores_kbd->addr);
 err_rel_mem:
    release_mem_region(res->start, resource_size(res));
 err_free_mem:
    input_free_device(input);
    kfree(opencores_kbd);

    return error;
}

static int __devexit opencores_kbd_remove(struct platform_device *pdev)
{
    struct opencores_kbd *opencores_kbd = platform_get_drvdata(pdev);

    free_irq(opencores_kbd->irq, opencores_kbd);

    iounmap(opencores_kbd->addr);
    release_mem_region(opencores_kbd->addr_res->start,
        resource_size(opencores_kbd->addr_res));
    input_unregister_device(opencores_kbd->input);
    kfree(opencores_kbd);

    platform_set_drvdata(pdev, NULL);

    return 0;
}

static struct platform_driver opencores_kbd_device_driver = {
    .probe    = opencores_kbd_probe,
    .remove   = __devexit_p(opencores_kbd_remove),
    .driver   = {
        .name = "opencores-kbd",
    },
};
module_platform_driver(opencores_kbd_device_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Javier Herrero <[email protected]>");
MODULE_DESCRIPTION("Keyboard driver for OpenCores Keyboard Controller");