static int dspi_probe()

in spi-fsl-dspi.c [1218:1395]

• 147 lines of code
• 24 McCabe index (conditional complexity)

static int dspi_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	const struct regmap_config *regmap_config;
	struct fsl_dspi_platform_data *pdata;
	struct spi_controller *ctlr;
	int ret, cs_num, bus_num = -1;
	struct fsl_dspi *dspi;
	struct resource *res;
	void __iomem *base;
	bool big_endian;

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

	ctlr = spi_alloc_master(&pdev->dev, 0);
	if (!ctlr)
		return -ENOMEM;

	spi_controller_set_devdata(ctlr, dspi);
	platform_set_drvdata(pdev, dspi);

	dspi->pdev = pdev;
	dspi->ctlr = ctlr;

	ctlr->setup = dspi_setup;
	ctlr->transfer_one_message = dspi_transfer_one_message;
	ctlr->dev.of_node = pdev->dev.of_node;

	ctlr->cleanup = dspi_cleanup;
	ctlr->slave_abort = dspi_slave_abort;
	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;

	pdata = dev_get_platdata(&pdev->dev);
	if (pdata) {
		ctlr->num_chipselect = ctlr->max_native_cs = pdata->cs_num;
		ctlr->bus_num = pdata->bus_num;

		/* Only Coldfire uses platform data */
		dspi->devtype_data = &devtype_data[MCF5441X];
		big_endian = true;
	} else {

		ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
		if (ret < 0) {
			dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
			goto out_ctlr_put;
		}
		ctlr->num_chipselect = ctlr->max_native_cs = cs_num;

		of_property_read_u32(np, "bus-num", &bus_num);
		ctlr->bus_num = bus_num;

		if (of_property_read_bool(np, "spi-slave"))
			ctlr->slave = true;

		dspi->devtype_data = of_device_get_match_data(&pdev->dev);
		if (!dspi->devtype_data) {
			dev_err(&pdev->dev, "can't get devtype_data\n");
			ret = -EFAULT;
			goto out_ctlr_put;
		}

		big_endian = of_device_is_big_endian(np);
	}
	if (big_endian) {
		dspi->pushr_cmd = 0;
		dspi->pushr_tx = 2;
	} else {
		dspi->pushr_cmd = 2;
		dspi->pushr_tx = 0;
	}

	if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
		ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
	else
		ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(base)) {
		ret = PTR_ERR(base);
		goto out_ctlr_put;
	}

	if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
		regmap_config = &dspi_xspi_regmap_config[0];
	else
		regmap_config = &dspi_regmap_config;
	dspi->regmap = devm_regmap_init_mmio(&pdev->dev, base, regmap_config);
	if (IS_ERR(dspi->regmap)) {
		dev_err(&pdev->dev, "failed to init regmap: %ld\n",
				PTR_ERR(dspi->regmap));
		ret = PTR_ERR(dspi->regmap);
		goto out_ctlr_put;
	}

	if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE) {
		dspi->regmap_pushr = devm_regmap_init_mmio(
			&pdev->dev, base + SPI_PUSHR,
			&dspi_xspi_regmap_config[1]);
		if (IS_ERR(dspi->regmap_pushr)) {
			dev_err(&pdev->dev,
				"failed to init pushr regmap: %ld\n",
				PTR_ERR(dspi->regmap_pushr));
			ret = PTR_ERR(dspi->regmap_pushr);
			goto out_ctlr_put;
		}
	}

	dspi->clk = devm_clk_get(&pdev->dev, "dspi");
	if (IS_ERR(dspi->clk)) {
		ret = PTR_ERR(dspi->clk);
		dev_err(&pdev->dev, "unable to get clock\n");
		goto out_ctlr_put;
	}
	ret = clk_prepare_enable(dspi->clk);
	if (ret)
		goto out_ctlr_put;

	ret = dspi_init(dspi);
	if (ret)
		goto out_clk_put;

	dspi->irq = platform_get_irq(pdev, 0);
	if (dspi->irq <= 0) {
		dev_info(&pdev->dev,
			 "can't get platform irq, using poll mode\n");
		dspi->irq = 0;
		goto poll_mode;
	}

	init_completion(&dspi->xfer_done);

	ret = request_threaded_irq(dspi->irq, dspi_interrupt, NULL,
				   IRQF_SHARED, pdev->name, dspi);
	if (ret < 0) {
		dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
		goto out_clk_put;
	}

poll_mode:

	if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) {
		ret = dspi_request_dma(dspi, res->start);
		if (ret < 0) {
			dev_err(&pdev->dev, "can't get dma channels\n");
			goto out_free_irq;
		}
	}

	ctlr->max_speed_hz =
		clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor;

	if (dspi->devtype_data->trans_mode != DSPI_DMA_MODE)
		ctlr->ptp_sts_supported = true;

	ret = spi_register_controller(ctlr);
	if (ret != 0) {
		dev_err(&pdev->dev, "Problem registering DSPI ctlr\n");
		goto out_release_dma;
	}

	return ret;

out_release_dma:
	dspi_release_dma(dspi);
out_free_irq:
	if (dspi->irq)
		free_irq(dspi->irq, dspi);
out_clk_put:
	clk_disable_unprepare(dspi->clk);
out_ctlr_put:
	spi_controller_put(ctlr);

	return ret;
}