static int __init arch_timer_mem_of_init()

in arm_arch_timer.c [1523:1596]

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

static int __init arch_timer_mem_of_init(struct device_node *np)
{
	struct arch_timer_mem *timer_mem;
	struct arch_timer_mem_frame *frame;
	struct device_node *frame_node;
	struct resource res;
	int ret = -EINVAL;
	u32 rate;

	timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL);
	if (!timer_mem)
		return -ENOMEM;

	if (of_address_to_resource(np, 0, &res))
		goto out;
	timer_mem->cntctlbase = res.start;
	timer_mem->size = resource_size(&res);

	for_each_available_child_of_node(np, frame_node) {
		u32 n;
		struct arch_timer_mem_frame *frame;

		if (of_property_read_u32(frame_node, "frame-number", &n)) {
			pr_err(FW_BUG "Missing frame-number.\n");
			of_node_put(frame_node);
			goto out;
		}
		if (n >= ARCH_TIMER_MEM_MAX_FRAMES) {
			pr_err(FW_BUG "Wrong frame-number, only 0-%u are permitted.\n",
			       ARCH_TIMER_MEM_MAX_FRAMES - 1);
			of_node_put(frame_node);
			goto out;
		}
		frame = &timer_mem->frame[n];

		if (frame->valid) {
			pr_err(FW_BUG "Duplicated frame-number.\n");
			of_node_put(frame_node);
			goto out;
		}

		if (of_address_to_resource(frame_node, 0, &res)) {
			of_node_put(frame_node);
			goto out;
		}
		frame->cntbase = res.start;
		frame->size = resource_size(&res);

		frame->virt_irq = irq_of_parse_and_map(frame_node,
						       ARCH_TIMER_VIRT_SPI);
		frame->phys_irq = irq_of_parse_and_map(frame_node,
						       ARCH_TIMER_PHYS_SPI);

		frame->valid = true;
	}

	frame = arch_timer_mem_find_best_frame(timer_mem);
	if (!frame) {
		pr_err("Unable to find a suitable frame in timer @ %pa\n",
			&timer_mem->cntctlbase);
		ret = -EINVAL;
		goto out;
	}

	rate = arch_timer_mem_frame_get_cntfrq(frame);
	arch_timer_of_configure_rate(rate, np);

	ret = arch_timer_mem_frame_register(frame);
	if (!ret && !arch_timer_needs_of_probing())
		ret = arch_timer_common_init();
out:
	kfree(timer_mem);
	return ret;
}