int __init smu_init()

in smu.c [471:578]

• 78 lines of code
• 13 McCabe index (conditional complexity)

int __init smu_init (void)
{
	struct device_node *np;
	const u32 *data;
	int ret = 0;

        np = of_find_node_by_type(NULL, "smu");
        if (np == NULL)
		return -ENODEV;

	printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);

	/*
	 * SMU based G5s need some memory below 2Gb. Thankfully this is
	 * called at a time where memblock is still available.
	 */
	smu_cmdbuf_abs = memblock_phys_alloc_range(4096, 4096, 0, 0x80000000UL);
	if (smu_cmdbuf_abs == 0) {
		printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
		ret = -EINVAL;
		goto fail_np;
	}

	smu = memblock_alloc(sizeof(struct smu_device), SMP_CACHE_BYTES);
	if (!smu)
		panic("%s: Failed to allocate %zu bytes\n", __func__,
		      sizeof(struct smu_device));

	spin_lock_init(&smu->lock);
	INIT_LIST_HEAD(&smu->cmd_list);
	INIT_LIST_HEAD(&smu->cmd_i2c_list);
	smu->of_node = np;
	smu->db_irq = 0;
	smu->msg_irq = 0;

	/* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
	 * 32 bits value safely
	 */
	smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
	smu->cmd_buf = __va(smu_cmdbuf_abs);

	smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
	if (smu->db_node == NULL) {
		printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
		ret = -ENXIO;
		goto fail_bootmem;
	}
	data = of_get_property(smu->db_node, "reg", NULL);
	if (data == NULL) {
		printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
		ret = -ENXIO;
		goto fail_db_node;
	}

	/* Current setup has one doorbell GPIO that does both doorbell
	 * and ack. GPIOs are at 0x50, best would be to find that out
	 * in the device-tree though.
	 */
	smu->doorbell = *data;
	if (smu->doorbell < 0x50)
		smu->doorbell += 0x50;

	/* Now look for the smu-interrupt GPIO */
	do {
		smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
		if (smu->msg_node == NULL)
			break;
		data = of_get_property(smu->msg_node, "reg", NULL);
		if (data == NULL) {
			of_node_put(smu->msg_node);
			smu->msg_node = NULL;
			break;
		}
		smu->msg = *data;
		if (smu->msg < 0x50)
			smu->msg += 0x50;
	} while(0);

	/* Doorbell buffer is currently hard-coded, I didn't find a proper
	 * device-tree entry giving the address. Best would probably to use
	 * an offset for K2 base though, but let's do it that way for now.
	 */
	smu->db_buf = ioremap(0x8000860c, 0x1000);
	if (smu->db_buf == NULL) {
		printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
		ret = -ENXIO;
		goto fail_msg_node;
	}

	/* U3 has an issue with NAP mode when issuing SMU commands */
	smu->broken_nap = pmac_get_uninorth_variant() < 4;
	if (smu->broken_nap)
		printk(KERN_INFO "SMU: using NAP mode workaround\n");

	sys_ctrler = SYS_CTRLER_SMU;
	return 0;

fail_msg_node:
	of_node_put(smu->msg_node);
fail_db_node:
	of_node_put(smu->db_node);
fail_bootmem:
	memblock_free(smu, sizeof(struct smu_device));
	smu = NULL;
fail_np:
	of_node_put(np);
	return ret;
}