static int tb10x_gpio_probe()

in gpio-tb10x.c [108:212]

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

static int tb10x_gpio_probe(struct platform_device *pdev)
{
	struct tb10x_gpio *tb10x_gpio;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	int ret = -EBUSY;
	u32 ngpio;

	if (!np)
		return -EINVAL;

	if (of_property_read_u32(np, "abilis,ngpio", &ngpio))
		return -EINVAL;

	tb10x_gpio = devm_kzalloc(dev, sizeof(*tb10x_gpio), GFP_KERNEL);
	if (tb10x_gpio == NULL)
		return -ENOMEM;

	tb10x_gpio->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(tb10x_gpio->base))
		return PTR_ERR(tb10x_gpio->base);

	tb10x_gpio->gc.label =
		devm_kasprintf(dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
	if (!tb10x_gpio->gc.label)
		return -ENOMEM;

	/*
	 * Initialize generic GPIO with one single register for reading and setting
	 * the lines, no special set or clear registers and a data direction register
	 * wher 1 means "output".
	 */
	ret = bgpio_init(&tb10x_gpio->gc, dev, 4,
			 tb10x_gpio->base + OFFSET_TO_REG_DATA,
			 NULL,
			 NULL,
			 tb10x_gpio->base + OFFSET_TO_REG_DDR,
			 NULL,
			 0);
	if (ret) {
		dev_err(dev, "unable to init generic GPIO\n");
		return ret;
	}
	tb10x_gpio->gc.base = -1;
	tb10x_gpio->gc.parent = dev;
	tb10x_gpio->gc.owner = THIS_MODULE;
	/*
	 * ngpio is set by bgpio_init() but we override it, this .request()
	 * callback also overrides the one set up by generic GPIO.
	 */
	tb10x_gpio->gc.ngpio = ngpio;
	tb10x_gpio->gc.request = gpiochip_generic_request;
	tb10x_gpio->gc.free = gpiochip_generic_free;

	ret = devm_gpiochip_add_data(dev, &tb10x_gpio->gc, tb10x_gpio);
	if (ret < 0) {
		dev_err(dev, "Could not add gpiochip.\n");
		return ret;
	}

	platform_set_drvdata(pdev, tb10x_gpio);

	if (of_find_property(np, "interrupt-controller", NULL)) {
		struct irq_chip_generic *gc;

		ret = platform_get_irq(pdev, 0);
		if (ret < 0)
			return ret;

		tb10x_gpio->gc.to_irq	= tb10x_gpio_to_irq;
		tb10x_gpio->irq		= ret;

		ret = devm_request_irq(dev, ret, tb10x_gpio_irq_cascade,
				IRQF_TRIGGER_NONE | IRQF_SHARED,
				dev_name(dev), tb10x_gpio);
		if (ret != 0)
			return ret;

		tb10x_gpio->domain = irq_domain_add_linear(np,
						tb10x_gpio->gc.ngpio,
						&irq_generic_chip_ops, NULL);
		if (!tb10x_gpio->domain) {
			return -ENOMEM;
		}

		ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
				tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
				handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
				IRQ_GC_INIT_MASK_CACHE);
		if (ret)
			return ret;

		gc = tb10x_gpio->domain->gc->gc[0];
		gc->reg_base                         = tb10x_gpio->base;
		gc->chip_types[0].type               = IRQ_TYPE_EDGE_BOTH;
		gc->chip_types[0].chip.irq_ack       = irq_gc_ack_set_bit;
		gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
		gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
		gc->chip_types[0].chip.irq_set_type  = tb10x_gpio_irq_set_type;
		gc->chip_types[0].regs.ack           = OFFSET_TO_REG_CHANGE;
		gc->chip_types[0].regs.mask          = OFFSET_TO_REG_INT_EN;
	}

	return 0;
}