static int __init dio_init()

in dio.c [166:261]

• 75 lines of code
• 17 McCabe index (conditional complexity)

static int __init dio_init(void)
{
	int scode;
	int i;
	struct dio_dev *dev;
	int error;

	if (!MACH_IS_HP300)
		return 0;

        printk(KERN_INFO "Scanning for DIO devices...\n");

	/* Initialize the DIO bus */ 
	INIT_LIST_HEAD(&dio_bus.devices);
	dev_set_name(&dio_bus.dev, "dio");
	error = device_register(&dio_bus.dev);
	if (error) {
		pr_err("DIO: Error registering dio_bus\n");
		return error;
	}

	/* Request all resources */
	dio_bus.num_resources = (hp300_model == HP_320 ? 1 : 2);
	for (i = 0; i < dio_bus.num_resources; i++)
		request_resource(&iomem_resource, &dio_bus.resources[i]);

	/* Register all devices */
        for (scode = 0; scode < DIO_SCMAX; ++scode)
        {
                u_char prid, secid = 0;        /* primary, secondary ID bytes */
                u_char *va;
		unsigned long pa;
                
                if (DIO_SCINHOLE(scode))
                        continue;

		pa = dio_scodetophysaddr(scode);

		if (!pa)
			continue;

		if (scode < DIOII_SCBASE)
			va = (void *)(pa + DIO_VIRADDRBASE);
		else
			va = ioremap(pa, PAGE_SIZE);

		if (copy_from_kernel_nofault(&i,
				(unsigned char *)va + DIO_IDOFF, 1)) {
			if (scode >= DIOII_SCBASE)
				iounmap(va);
                        continue;              /* no board present at that select code */
		}

                /* Found a board, allocate it an entry in the list */
		dev = kzalloc(sizeof(struct dio_dev), GFP_KERNEL);
		if (!dev)
			return -ENOMEM;

		dev->bus = &dio_bus;
		dev->dev.parent = &dio_bus.dev;
		dev->dev.bus = &dio_bus_type;
		dev->scode = scode;
		dev->resource.start = pa;
		dev->resource.end = pa + DIO_SIZE(scode, va);
		dev_set_name(&dev->dev, "%02x", scode);

                /* read the ID byte(s) and encode if necessary. */
		prid = DIO_ID(va);

                if (DIO_NEEDSSECID(prid)) {
                        secid = DIO_SECID(va);
                        dev->id = DIO_ENCODE_ID(prid, secid);
                } else
                        dev->id = prid;

                dev->ipl = DIO_IPL(va);
                strcpy(dev->name,dio_getname(dev->id));
                printk(KERN_INFO "select code %3d: ipl %d: ID %02X", dev->scode, dev->ipl, prid);
                if (DIO_NEEDSSECID(prid))
                        printk(":%02X", secid);
                printk(": %s\n", dev->name);

		if (scode >= DIOII_SCBASE)
			iounmap(va);
		error = device_register(&dev->dev);
		if (error) {
			pr_err("DIO: Error registering device %s\n",
			       dev->name);
			continue;
		}
		error = dio_create_sysfs_dev_files(dev);
		if (error)
			dev_err(&dev->dev, "Error creating sysfs files\n");
        }
	return 0;
}