static int ssb_extpci_read_config()

in driver_pcicore.c [110:154]

• 41 lines of code
• 10 McCabe index (conditional complexity)

static int ssb_extpci_read_config(struct ssb_pcicore *pc,
				  unsigned int bus, unsigned int dev,
				  unsigned int func, unsigned int off,
				  void *buf, int len)
{
	int err = -EINVAL;
	u32 addr, val;
	void __iomem *mmio;

	WARN_ON(!pc->hostmode);
	if (unlikely(len != 1 && len != 2 && len != 4))
		goto out;
	addr = get_cfgspace_addr(pc, bus, dev, func, off);
	if (unlikely(!addr))
		goto out;
	err = -ENOMEM;
	mmio = ioremap(addr, len);
	if (!mmio)
		goto out;

	if (mips_busprobe32(val, mmio)) {
		val = 0xffffffff;
		goto unmap;
	}

	val = readl(mmio);
	val >>= (8 * (off & 3));

	switch (len) {
	case 1:
		*((u8 *)buf) = (u8)val;
		break;
	case 2:
		*((u16 *)buf) = (u16)val;
		break;
	case 4:
		*((u32 *)buf) = (u32)val;
		break;
	}
	err = 0;
unmap:
	iounmap(mmio);
out:
	return err;
}