What is the effect of using ioremap on physical address already ioremapped by a driver?

I am trying to use the ARM watchdog thorough kernel space. I have a watchdog driver which is statically built and deployed in the kernel. The memory remapped by the driver is seen in /proc/iomem.

cat /proc/iomem | grep wdt
ff567000-ff567018 : /wdt@ff567000

The driver has remapped the address starting from 0xff567000 to a virtual address in the kernel.
Now I wrote a module to ioremap the same address and write to it.

static int __init wdt_init(void)
{
    int ret;

    wdev = kzalloc(sizeof(*wdev), GFP_KERNEL);
    if (!wdev)
        return -ENOMEM;
    mutex_init(&wdev->lock);

    printk(KERN_INFO "before mapping %p.\n", wdev->base);

    wdev->base = ioremap (0xff567000, 0x18);
    if (!wdev->base) 
    {
        ret = -ENOMEM;
        goto fail;
    }
    printk(KERN_INFO "wdt base address successfully mapped to %p.\n", wdev->base);
    wdt_start(wdev);
    wdt_get_timeout (wdev);

    wdt_set_timeout (wdev, 30);
    wdt_get_timeout (wdev);

    while (1)
    {
        wdt_ping(wdev);
    }

    return 0;

fail:
    printk(KERN_INFO "failed to map wdt base address\n");

    return ret;
}

The output seen after inserting the module is:

root@bdk:/opt# insmod test_ioremap.ko 
[ 1770.862628] before mapping   (null).
[ 1770.867477] VXR10 wdt base address successfully mapped to f0988000.

Further I am able to read and write to the watchdog registers successfully.

Please tell me, Will this mapping have any effect on the normal working of the driver ?

Thanks for all your help in advance.

Simply making another mapping on device "memory" should cause no issues on ARM. But multiple drivers accessing/manipulating the same device memory will probably cause device malfunction and/or unpredictable behavior. Well-behaved drivers (e.g. the original watchdog driver) call request_mem_region() before ioremap(), which would completely avoid this issue that you raise.

Russell King, the ARM Linux guru mentions "On ARM, we (probably) have a lot of cases where ioremap() is used multiple times for the same physical address space." Regardless, the preferred practice is only one mapping.