static int orion_spi_probe()

in spi-orion.c [645:805]

• 115 lines of code
• 18 McCabe index (conditional complexity)

static int orion_spi_probe(struct platform_device *pdev)
{
	const struct orion_spi_dev *devdata;
	struct spi_master *master;
	struct orion_spi *spi;
	struct resource *r;
	unsigned long tclk_hz;
	int status = 0;
	struct device_node *np;

	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
	if (master == NULL) {
		dev_dbg(&pdev->dev, "master allocation failed\n");
		return -ENOMEM;
	}

	if (pdev->id != -1)
		master->bus_num = pdev->id;
	if (pdev->dev.of_node) {
		u32 cell_index;

		if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
					  &cell_index))
			master->bus_num = cell_index;
	}

	/* we support all 4 SPI modes and LSB first option */
	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST | SPI_CS_WORD;
	master->set_cs = orion_spi_set_cs;
	master->transfer_one = orion_spi_transfer_one;
	master->num_chipselect = ORION_NUM_CHIPSELECTS;
	master->setup = orion_spi_setup;
	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
	master->auto_runtime_pm = true;
	master->use_gpio_descriptors = true;
	master->flags = SPI_MASTER_GPIO_SS;

	platform_set_drvdata(pdev, master);

	spi = spi_master_get_devdata(master);
	spi->master = master;
	spi->dev = &pdev->dev;

	devdata = device_get_match_data(&pdev->dev);
	devdata = devdata ? devdata : &orion_spi_dev_data;
	spi->devdata = devdata;

	spi->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(spi->clk)) {
		status = PTR_ERR(spi->clk);
		goto out;
	}

	status = clk_prepare_enable(spi->clk);
	if (status)
		goto out;

	/* The following clock is only used by some SoCs */
	spi->axi_clk = devm_clk_get(&pdev->dev, "axi");
	if (PTR_ERR(spi->axi_clk) == -EPROBE_DEFER) {
		status = -EPROBE_DEFER;
		goto out_rel_clk;
	}
	if (!IS_ERR(spi->axi_clk))
		clk_prepare_enable(spi->axi_clk);

	tclk_hz = clk_get_rate(spi->clk);

	/*
	 * With old device tree, armada-370-spi could be used with
	 * Armada XP, however for this SoC the maximum frequency is
	 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
	 * higher than 200MHz. So, in order to be able to handle both
	 * SoCs, we can take the minimum of 50MHz and tclk/4.
	 */
	if (of_device_is_compatible(pdev->dev.of_node,
					"marvell,armada-370-spi"))
		master->max_speed_hz = min(devdata->max_hz,
				DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
	else if (devdata->min_divisor)
		master->max_speed_hz =
			DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
	else
		master->max_speed_hz = devdata->max_hz;
	master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	spi->base = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(spi->base)) {
		status = PTR_ERR(spi->base);
		goto out_rel_axi_clk;
	}

	for_each_available_child_of_node(pdev->dev.of_node, np) {
		struct orion_direct_acc *dir_acc;
		u32 cs;

		/* Get chip-select number from the "reg" property */
		status = of_property_read_u32(np, "reg", &cs);
		if (status) {
			dev_err(&pdev->dev,
				"%pOF has no valid 'reg' property (%d)\n",
				np, status);
			continue;
		}

		/*
		 * Check if an address is configured for this SPI device. If
		 * not, the MBus mapping via the 'ranges' property in the 'soc'
		 * node is not configured and this device should not use the
		 * direct mode. In this case, just continue with the next
		 * device.
		 */
		status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
		if (status)
			continue;

		/*
		 * Only map one page for direct access. This is enough for the
		 * simple TX transfer which only writes to the first word.
		 * This needs to get extended for the direct SPI NOR / SPI NAND
		 * support, once this gets implemented.
		 */
		dir_acc = &spi->child[cs].direct_access;
		dir_acc->vaddr = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
		if (!dir_acc->vaddr) {
			status = -ENOMEM;
			of_node_put(np);
			goto out_rel_axi_clk;
		}
		dir_acc->size = PAGE_SIZE;

		dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
	}

	pm_runtime_set_active(&pdev->dev);
	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
	pm_runtime_enable(&pdev->dev);

	status = orion_spi_reset(spi);
	if (status < 0)
		goto out_rel_pm;

	master->dev.of_node = pdev->dev.of_node;
	status = spi_register_master(master);
	if (status < 0)
		goto out_rel_pm;

	return status;

out_rel_pm:
	pm_runtime_disable(&pdev->dev);
out_rel_axi_clk:
	clk_disable_unprepare(spi->axi_clk);
out_rel_clk:
	clk_disable_unprepare(spi->clk);
out:
	spi_master_put(master);
	return status;
}