static int xgpio_probe()

in gpio-xilinx.c [553:709]

• 113 lines of code
• 15 McCabe index (conditional complexity)

static int xgpio_probe(struct platform_device *pdev)
{
	struct xgpio_instance *chip;
	int status = 0;
	struct device_node *np = pdev->dev.of_node;
	u32 is_dual = 0;
	u32 cells = 2;
	u32 width[2];
	u32 state[2];
	u32 dir[2];
	struct gpio_irq_chip *girq;
	u32 temp;

	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	platform_set_drvdata(pdev, chip);

	/* First, check if the device is dual-channel */
	of_property_read_u32(np, "xlnx,is-dual", &is_dual);

	/* Setup defaults */
	memset32(width, 0, ARRAY_SIZE(width));
	memset32(state, 0, ARRAY_SIZE(state));
	memset32(dir, 0xFFFFFFFF, ARRAY_SIZE(dir));

	/* Update GPIO state shadow register with default value */
	of_property_read_u32(np, "xlnx,dout-default", &state[0]);
	of_property_read_u32(np, "xlnx,dout-default-2", &state[1]);

	bitmap_from_arr32(chip->state, state, 64);

	/* Update GPIO direction shadow register with default value */
	of_property_read_u32(np, "xlnx,tri-default", &dir[0]);
	of_property_read_u32(np, "xlnx,tri-default-2", &dir[1]);

	bitmap_from_arr32(chip->dir, dir, 64);

	/* Update cells with gpio-cells value */
	if (of_property_read_u32(np, "#gpio-cells", &cells))
		dev_dbg(&pdev->dev, "Missing gpio-cells property\n");

	if (cells != 2) {
		dev_err(&pdev->dev, "#gpio-cells mismatch\n");
		return -EINVAL;
	}

	/*
	 * Check device node and parent device node for device width
	 * and assume default width of 32
	 */
	if (of_property_read_u32(np, "xlnx,gpio-width", &width[0]))
		width[0] = 32;

	if (width[0] > 32)
		return -EINVAL;

	if (is_dual && of_property_read_u32(np, "xlnx,gpio2-width", &width[1]))
		width[1] = 32;

	if (width[1] > 32)
		return -EINVAL;

	/* Setup software pin mapping */
	bitmap_set(chip->sw_map, 0, width[0] + width[1]);

	/* Setup hardware pin mapping */
	bitmap_set(chip->hw_map,  0, width[0]);
	bitmap_set(chip->hw_map, 32, width[1]);

	spin_lock_init(&chip->gpio_lock);

	chip->gc.base = -1;
	chip->gc.ngpio = bitmap_weight(chip->hw_map, 64);
	chip->gc.parent = &pdev->dev;
	chip->gc.direction_input = xgpio_dir_in;
	chip->gc.direction_output = xgpio_dir_out;
	chip->gc.of_gpio_n_cells = cells;
	chip->gc.get = xgpio_get;
	chip->gc.set = xgpio_set;
	chip->gc.request = xgpio_request;
	chip->gc.free = xgpio_free;
	chip->gc.set_multiple = xgpio_set_multiple;

	chip->gc.label = dev_name(&pdev->dev);

	chip->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(chip->regs)) {
		dev_err(&pdev->dev, "failed to ioremap memory resource\n");
		return PTR_ERR(chip->regs);
	}

	chip->clk = devm_clk_get_optional(&pdev->dev, NULL);
	if (IS_ERR(chip->clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(chip->clk), "input clock not found.\n");

	status = clk_prepare_enable(chip->clk);
	if (status < 0) {
		dev_err(&pdev->dev, "Failed to prepare clk\n");
		return status;
	}
	pm_runtime_get_noresume(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);

	xgpio_save_regs(chip);

	chip->irq = platform_get_irq_optional(pdev, 0);
	if (chip->irq <= 0)
		goto skip_irq;

	chip->irqchip.name = "gpio-xilinx";
	chip->irqchip.irq_ack = xgpio_irq_ack;
	chip->irqchip.irq_mask = xgpio_irq_mask;
	chip->irqchip.irq_unmask = xgpio_irq_unmask;
	chip->irqchip.irq_set_type = xgpio_set_irq_type;

	/* Disable per-channel interrupts */
	xgpio_writereg(chip->regs + XGPIO_IPIER_OFFSET, 0);
	/* Clear any existing per-channel interrupts */
	temp = xgpio_readreg(chip->regs + XGPIO_IPISR_OFFSET);
	xgpio_writereg(chip->regs + XGPIO_IPISR_OFFSET, temp);
	/* Enable global interrupts */
	xgpio_writereg(chip->regs + XGPIO_GIER_OFFSET, XGPIO_GIER_IE);

	girq = &chip->gc.irq;
	girq->chip = &chip->irqchip;
	girq->parent_handler = xgpio_irqhandler;
	girq->num_parents = 1;
	girq->parents = devm_kcalloc(&pdev->dev, 1,
				     sizeof(*girq->parents),
				     GFP_KERNEL);
	if (!girq->parents) {
		status = -ENOMEM;
		goto err_pm_put;
	}
	girq->parents[0] = chip->irq;
	girq->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_bad_irq;

skip_irq:
	status = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip);
	if (status) {
		dev_err(&pdev->dev, "failed to add GPIO chip\n");
		goto err_pm_put;
	}

	pm_runtime_put(&pdev->dev);
	return 0;

err_pm_put:
	pm_runtime_disable(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);
	clk_disable_unprepare(chip->clk);
	return status;
}