uio_aec.c

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/*
 * uio_aec.c -- simple driver for Adrienne Electronics Corp time code PCI device
 *
 * Copyright (C) 2008 Brandon Philips <[email protected]>
 *
 *   This program is free software; you can redistribute it and/or modify it
 *   under the terms of the GNU General Public License version 2 as published
 *   by the Free Software Foundation.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License along
 *   with this program; if not, write to the Free Software Foundation, Inc., 59
 *   Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/uio_driver.h>
#include <linux/slab.h>

#define PCI_VENDOR_ID_AEC 0xaecb
#define PCI_DEVICE_ID_AEC_VITCLTC 0x6250

#define INT_ENABLE_ADDR     0xFC
#define INT_ENABLE      0x10
#define INT_DISABLE     0x0

#define INT_MASK_ADDR       0x2E
#define INT_MASK_ALL        0x3F

#define INTA_DRVR_ADDR      0xFE
#define INTA_ENABLED_FLAG   0x08
#define INTA_FLAG       0x01

#define MAILBOX         0x0F

static struct pci_device_id ids[] = {
    { PCI_DEVICE(PCI_VENDOR_ID_AEC, PCI_DEVICE_ID_AEC_VITCLTC), },
    { 0, }
};
MODULE_DEVICE_TABLE(pci, ids);

static irqreturn_t aectc_irq(int irq, struct uio_info *dev_info)
{
    void __iomem *int_flag = dev_info->priv + INTA_DRVR_ADDR;
    unsigned char status = ioread8(int_flag);


    if ((status & INTA_ENABLED_FLAG) && (status & INTA_FLAG)) {
        /* application writes 0x00 to 0x2F to get next interrupt */
        status = ioread8(dev_info->priv + MAILBOX);
        return IRQ_HANDLED;
    }

    return IRQ_NONE;
}

static void print_board_data(struct pci_dev *pdev, struct uio_info *i)
{
    dev_info(&pdev->dev, "PCI-TC board vendor: %x%x number: %x%x"
        " revision: %c%c\n",
        ioread8(i->priv + 0x01),
        ioread8(i->priv + 0x00),
        ioread8(i->priv + 0x03),
        ioread8(i->priv + 0x02),
        ioread8(i->priv + 0x06),
        ioread8(i->priv + 0x07));
}

static int __devinit probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
    struct uio_info *info;
    int ret;

    info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
    if (!info)
        return -ENOMEM;

    if (pci_enable_device(pdev))
        goto out_free;

    if (pci_request_regions(pdev, "aectc"))
        goto out_disable;

    info->name = "aectc";
    info->port[0].start = pci_resource_start(pdev, 0);
    if (!info->port[0].start)
        goto out_release;
    info->priv = pci_iomap(pdev, 0, 0);
    if (!info->priv)
        goto out_release;
    info->port[0].size = pci_resource_len(pdev, 0);
    info->port[0].porttype = UIO_PORT_GPIO;

    info->version = "0.0.1";
    info->irq = pdev->irq;
    info->irq_flags = IRQF_SHARED;
    info->handler = aectc_irq;

    print_board_data(pdev, info);
    ret = uio_register_device(&pdev->dev, info);
    if (ret)
        goto out_unmap;

    iowrite32(INT_ENABLE, info->priv + INT_ENABLE_ADDR);
    iowrite8(INT_MASK_ALL, info->priv + INT_MASK_ADDR);
    if (!(ioread8(info->priv + INTA_DRVR_ADDR)
            & INTA_ENABLED_FLAG))
        dev_err(&pdev->dev, "aectc: interrupts not enabled\n");

    pci_set_drvdata(pdev, info);

    return 0;

out_unmap:
    pci_iounmap(pdev, info->priv);
out_release:
    pci_release_regions(pdev);
out_disable:
    pci_disable_device(pdev);
out_free:
    kfree(info);
    return -ENODEV;
}

static void remove(struct pci_dev *pdev)
{
    struct uio_info *info = pci_get_drvdata(pdev);

    /* disable interrupts */
    iowrite8(INT_DISABLE, info->priv + INT_MASK_ADDR);
    iowrite32(INT_DISABLE, info->priv + INT_ENABLE_ADDR);
    /* read mailbox to ensure board drops irq */
    ioread8(info->priv + MAILBOX);

    uio_unregister_device(info);
    pci_release_regions(pdev);
    pci_disable_device(pdev);
    pci_set_drvdata(pdev, NULL);
    iounmap(info->priv);

    kfree(info);
}

static struct pci_driver pci_driver = {
    .name = "aectc",
    .id_table = ids,
    .probe = probe,
    .remove = remove,
};

static int __init aectc_init(void)
{
    return pci_register_driver(&pci_driver);
}

static void __exit aectc_exit(void)
{
    pci_unregister_driver(&pci_driver);
}

MODULE_LICENSE("GPL");

module_init(aectc_init);
module_exit(aectc_exit);