static int sun6i_spi_probe()

in spi-sun6i.c [549:684]

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

static int sun6i_spi_probe(struct platform_device *pdev)
{
	struct spi_master *master;
	struct sun6i_spi *sspi;
	struct resource *mem;
	int ret = 0, irq;

	master = spi_alloc_master(&pdev->dev, sizeof(struct sun6i_spi));
	if (!master) {
		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
		return -ENOMEM;
	}

	platform_set_drvdata(pdev, master);
	sspi = spi_master_get_devdata(master);

	sspi->base_addr = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
	if (IS_ERR(sspi->base_addr)) {
		ret = PTR_ERR(sspi->base_addr);
		goto err_free_master;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		ret = -ENXIO;
		goto err_free_master;
	}

	ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
			       0, "sun6i-spi", sspi);
	if (ret) {
		dev_err(&pdev->dev, "Cannot request IRQ\n");
		goto err_free_master;
	}

	sspi->master = master;
	sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);

	master->max_speed_hz = 100 * 1000 * 1000;
	master->min_speed_hz = 3 * 1000;
	master->use_gpio_descriptors = true;
	master->set_cs = sun6i_spi_set_cs;
	master->transfer_one = sun6i_spi_transfer_one;
	master->num_chipselect = 4;
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
	master->bits_per_word_mask = SPI_BPW_MASK(8);
	master->dev.of_node = pdev->dev.of_node;
	master->auto_runtime_pm = true;
	master->max_transfer_size = sun6i_spi_max_transfer_size;

	sspi->hclk = devm_clk_get(&pdev->dev, "ahb");
	if (IS_ERR(sspi->hclk)) {
		dev_err(&pdev->dev, "Unable to acquire AHB clock\n");
		ret = PTR_ERR(sspi->hclk);
		goto err_free_master;
	}

	sspi->mclk = devm_clk_get(&pdev->dev, "mod");
	if (IS_ERR(sspi->mclk)) {
		dev_err(&pdev->dev, "Unable to acquire module clock\n");
		ret = PTR_ERR(sspi->mclk);
		goto err_free_master;
	}

	init_completion(&sspi->done);

	sspi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
	if (IS_ERR(sspi->rstc)) {
		dev_err(&pdev->dev, "Couldn't get reset controller\n");
		ret = PTR_ERR(sspi->rstc);
		goto err_free_master;
	}

	master->dma_tx = dma_request_chan(&pdev->dev, "tx");
	if (IS_ERR(master->dma_tx)) {
		/* Check tx to see if we need defer probing driver */
		if (PTR_ERR(master->dma_tx) == -EPROBE_DEFER) {
			ret = -EPROBE_DEFER;
			goto err_free_master;
		}
		dev_warn(&pdev->dev, "Failed to request TX DMA channel\n");
		master->dma_tx = NULL;
	}

	master->dma_rx = dma_request_chan(&pdev->dev, "rx");
	if (IS_ERR(master->dma_rx)) {
		if (PTR_ERR(master->dma_rx) == -EPROBE_DEFER) {
			ret = -EPROBE_DEFER;
			goto err_free_dma_tx;
		}
		dev_warn(&pdev->dev, "Failed to request RX DMA channel\n");
		master->dma_rx = NULL;
	}

	if (master->dma_tx && master->dma_rx) {
		sspi->dma_addr_tx = mem->start + SUN6I_TXDATA_REG;
		sspi->dma_addr_rx = mem->start + SUN6I_RXDATA_REG;
		master->can_dma = sun6i_spi_can_dma;
	}

	/*
	 * This wake-up/shutdown pattern is to be able to have the
	 * device woken up, even if runtime_pm is disabled
	 */
	ret = sun6i_spi_runtime_resume(&pdev->dev);
	if (ret) {
		dev_err(&pdev->dev, "Couldn't resume the device\n");
		goto err_free_dma_rx;
	}

	pm_runtime_set_autosuspend_delay(&pdev->dev, SUN6I_AUTOSUSPEND_TIMEOUT);
	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);

	ret = devm_spi_register_master(&pdev->dev, master);
	if (ret) {
		dev_err(&pdev->dev, "cannot register SPI master\n");
		goto err_pm_disable;
	}

	return 0;

err_pm_disable:
	pm_runtime_disable(&pdev->dev);
	sun6i_spi_runtime_suspend(&pdev->dev);
err_free_dma_rx:
	if (master->dma_rx)
		dma_release_channel(master->dma_rx);
err_free_dma_tx:
	if (master->dma_tx)
		dma_release_channel(master->dma_tx);
err_free_master:
	spi_master_put(master);
	return ret;
}