static int ipack_device_read_id()

in ipack.c [345:423]

• 65 lines of code
• 21 McCabe index (conditional complexity)

static int ipack_device_read_id(struct ipack_device *dev)
{
	u8 __iomem *idmem;
	int i;
	int ret = 0;

	idmem = ioremap(dev->region[IPACK_ID_SPACE].start,
			dev->region[IPACK_ID_SPACE].size);
	if (!idmem) {
		dev_err(&dev->dev, "error mapping memory\n");
		return -ENOMEM;
	}

	/* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
	 * we are dealing with a IndustryPack  format 1 device.  If we detect
	 * "VITA4 " (16 bit big endian formatted) we are dealing with a
	 * IndustryPack format 2 device */
	if ((ioread8(idmem + 1) == 'I') &&
			(ioread8(idmem + 3) == 'P') &&
			(ioread8(idmem + 5) == 'A') &&
			((ioread8(idmem + 7) == 'C') ||
			 (ioread8(idmem + 7) == 'H'))) {
		dev->id_format = IPACK_ID_VERSION_1;
		dev->id_avail = ioread8(idmem + 0x15);
		if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
			dev_warn(&dev->dev, "invalid id size");
			dev->id_avail = 0x0c;
		}
	} else if ((ioread8(idmem + 0) == 'I') &&
			(ioread8(idmem + 1) == 'V') &&
			(ioread8(idmem + 2) == 'A') &&
			(ioread8(idmem + 3) == 'T') &&
			(ioread8(idmem + 4) == ' ') &&
			(ioread8(idmem + 5) == '4')) {
		dev->id_format = IPACK_ID_VERSION_2;
		dev->id_avail = ioread16be(idmem + 0x16);
		if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
			dev_warn(&dev->dev, "invalid id size");
			dev->id_avail = 0x1a;
		}
	} else {
		dev->id_format = IPACK_ID_VERSION_INVALID;
		dev->id_avail = 0;
	}

	if (!dev->id_avail) {
		ret = -ENODEV;
		goto out;
	}

	/* Obtain the amount of memory required to store a copy of the complete
	 * ID ROM contents */
	dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
	if (!dev->id) {
		ret = -ENOMEM;
		goto out;
	}
	for (i = 0; i < dev->id_avail; i++) {
		if (dev->id_format == IPACK_ID_VERSION_1)
			dev->id[i] = ioread8(idmem + (i << 1) + 1);
		else
			dev->id[i] = ioread8(idmem + i);
	}

	/* now we can finally work with the copy */
	switch (dev->id_format) {
	case IPACK_ID_VERSION_1:
		ipack_parse_id1(dev);
		break;
	case IPACK_ID_VERSION_2:
		ipack_parse_id2(dev);
		break;
	}

out:
	iounmap(idmem);

	return ret;
}