// SPDX-License-Identifier: GPL-2.0
/*
 * arch/sh/boards/landisk/gio.c - driver for landisk
 *
 * This driver will also support the I-O DATA Device, Inc. LANDISK Board.
 * LANDISK and USL-5P Button, LED and GIO driver drive function.
 *
 *   Copylight (C) 2006 kogiidena
 *   Copylight (C) 2002 Atom Create Engineering Co., Ltd. *
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kdev_t.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <asm/io.h>
#include <linux/uaccess.h>
#include <mach-landisk/mach/gio.h>
#include <mach-landisk/mach/iodata_landisk.h>

#define DEVCOUNT                4
#define GIO_MINOR               2       /* GIO minor no. */

static dev_t dev;
static struct cdev *cdev_p;
static int openCnt;

static int gio_open(struct inode *inode, struct file *filp)
{
        int minor = iminor(inode);
        int ret = -ENOENT;

        preempt_disable();
        if (minor < DEVCOUNT) {
                if (openCnt > 0) {
                        ret = -EALREADY;
                } else {
                        openCnt++;
                        ret = 0;
                }
        }
        preempt_enable();
        return ret;
}

static int gio_close(struct inode *inode, struct file *filp)
{
        int minor = iminor(inode);

        if (minor < DEVCOUNT) {
                openCnt--;
        }
        return 0;
}

static long gio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
        unsigned int data;
        static unsigned int addr = 0;

        if (cmd & 0x01) {       /* write */
                if (copy_from_user(&data, (int *)arg, sizeof(int))) {
                        return -EFAULT;
                }
        }

        switch (cmd) {
        case GIODRV_IOCSGIOSETADDR:     /* address set */
                addr = data;
                break;

        case GIODRV_IOCSGIODATA1:       /* write byte */
                __raw_writeb((unsigned char)(0x0ff & data), addr);
                break;

        case GIODRV_IOCSGIODATA2:       /* write word */
                if (addr & 0x01) {
                        return -EFAULT;
                }
                __raw_writew((unsigned short int)(0x0ffff & data), addr);
                break;

        case GIODRV_IOCSGIODATA4:       /* write long */
                if (addr & 0x03) {
                        return -EFAULT;
                }
                __raw_writel(data, addr);
                break;

        case GIODRV_IOCGGIODATA1:       /* read byte */
                data = __raw_readb(addr);
                break;

        case GIODRV_IOCGGIODATA2:       /* read word */
                if (addr & 0x01) {
                        return -EFAULT;
                }
                data = __raw_readw(addr);
                break;

        case GIODRV_IOCGGIODATA4:       /* read long */
                if (addr & 0x03) {
                        return -EFAULT;
                }
                data = __raw_readl(addr);
                break;
        default:
                return -EFAULT;
                break;
        }

        if ((cmd & 0x01) == 0) {        /* read */
                if (copy_to_user((int *)arg, &data, sizeof(int))) {
                        return -EFAULT;
                }
        }
        return 0;
}

static const struct file_operations gio_fops = {
        .owner = THIS_MODULE,
        .open = gio_open,       /* open */
        .release = gio_close,   /* release */
        .unlocked_ioctl = gio_ioctl,
        .llseek = noop_llseek,
};

static int __init gio_init(void)
{
        int error;

        printk(KERN_INFO "gio: driver initialized\n");

        openCnt = 0;

        if ((error = alloc_chrdev_region(&dev, 0, DEVCOUNT, "gio")) < 0) {
                printk(KERN_ERR
                       "gio: Couldn't alloc_chrdev_region, error=%d\n",
                       error);
                return 1;
        }

        cdev_p = cdev_alloc();
        cdev_p->ops = &gio_fops;
        error = cdev_add(cdev_p, dev, DEVCOUNT);
        if (error) {
                printk(KERN_ERR
                       "gio: Couldn't cdev_add, error=%d\n", error);
                return 1;
        }

        return 0;
}

static void __exit gio_exit(void)
{
        cdev_del(cdev_p);
        unregister_chrdev_region(dev, DEVCOUNT);
}

module_init(gio_init);
module_exit(gio_exit);

MODULE_LICENSE("GPL");