static int au1550_spi_probe()

in spi-au1550.c [723:924]

• 158 lines of code
• 22 McCabe index (conditional complexity)

static int au1550_spi_probe(struct platform_device *pdev)
{
	struct au1550_spi *hw;
	struct spi_master *master;
	struct resource *r;
	int err = 0;

	master = spi_alloc_master(&pdev->dev, sizeof(struct au1550_spi));
	if (master == NULL) {
		dev_err(&pdev->dev, "No memory for spi_master\n");
		err = -ENOMEM;
		goto err_nomem;
	}

	/* the spi->mode bits understood by this driver: */
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 24);

	hw = spi_master_get_devdata(master);

	hw->master = master;
	hw->pdata = dev_get_platdata(&pdev->dev);
	hw->dev = &pdev->dev;

	if (hw->pdata == NULL) {
		dev_err(&pdev->dev, "No platform data supplied\n");
		err = -ENOENT;
		goto err_no_pdata;
	}

	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!r) {
		dev_err(&pdev->dev, "no IRQ\n");
		err = -ENODEV;
		goto err_no_iores;
	}
	hw->irq = r->start;

	hw->usedma = 0;
	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
	if (r) {
		hw->dma_tx_id = r->start;
		r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
		if (r) {
			hw->dma_rx_id = r->start;
			if (usedma && ddma_memid) {
				if (pdev->dev.dma_mask == NULL)
					dev_warn(&pdev->dev, "no dma mask\n");
				else
					hw->usedma = 1;
			}
		}
	}

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r) {
		dev_err(&pdev->dev, "no mmio resource\n");
		err = -ENODEV;
		goto err_no_iores;
	}

	hw->ioarea = request_mem_region(r->start, sizeof(psc_spi_t),
					pdev->name);
	if (!hw->ioarea) {
		dev_err(&pdev->dev, "Cannot reserve iomem region\n");
		err = -ENXIO;
		goto err_no_iores;
	}

	hw->regs = (psc_spi_t __iomem *)ioremap(r->start, sizeof(psc_spi_t));
	if (!hw->regs) {
		dev_err(&pdev->dev, "cannot ioremap\n");
		err = -ENXIO;
		goto err_ioremap;
	}

	platform_set_drvdata(pdev, hw);

	init_completion(&hw->master_done);

	hw->bitbang.master = hw->master;
	hw->bitbang.setup_transfer = au1550_spi_setupxfer;
	hw->bitbang.chipselect = au1550_spi_chipsel;
	hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs;

	if (hw->usedma) {
		hw->dma_tx_ch = au1xxx_dbdma_chan_alloc(ddma_memid,
			hw->dma_tx_id, NULL, (void *)hw);
		if (hw->dma_tx_ch == 0) {
			dev_err(&pdev->dev,
				"Cannot allocate tx dma channel\n");
			err = -ENXIO;
			goto err_no_txdma;
		}
		au1xxx_dbdma_set_devwidth(hw->dma_tx_ch, 8);
		if (au1xxx_dbdma_ring_alloc(hw->dma_tx_ch,
			AU1550_SPI_DBDMA_DESCRIPTORS) == 0) {
			dev_err(&pdev->dev,
				"Cannot allocate tx dma descriptors\n");
			err = -ENXIO;
			goto err_no_txdma_descr;
		}


		hw->dma_rx_ch = au1xxx_dbdma_chan_alloc(hw->dma_rx_id,
			ddma_memid, NULL, (void *)hw);
		if (hw->dma_rx_ch == 0) {
			dev_err(&pdev->dev,
				"Cannot allocate rx dma channel\n");
			err = -ENXIO;
			goto err_no_rxdma;
		}
		au1xxx_dbdma_set_devwidth(hw->dma_rx_ch, 8);
		if (au1xxx_dbdma_ring_alloc(hw->dma_rx_ch,
			AU1550_SPI_DBDMA_DESCRIPTORS) == 0) {
			dev_err(&pdev->dev,
				"Cannot allocate rx dma descriptors\n");
			err = -ENXIO;
			goto err_no_rxdma_descr;
		}

		err = au1550_spi_dma_rxtmp_alloc(hw,
			AU1550_SPI_DMA_RXTMP_MINSIZE);
		if (err < 0) {
			dev_err(&pdev->dev,
				"Cannot allocate initial rx dma tmp buffer\n");
			goto err_dma_rxtmp_alloc;
		}
	}

	au1550_spi_bits_handlers_set(hw, 8);

	err = request_irq(hw->irq, au1550_spi_irq, 0, pdev->name, hw);
	if (err) {
		dev_err(&pdev->dev, "Cannot claim IRQ\n");
		goto err_no_irq;
	}

	master->bus_num = pdev->id;
	master->num_chipselect = hw->pdata->num_chipselect;

	/*
	 *  precompute valid range for spi freq - from au1550 datasheet:
	 *    psc_tempclk = psc_mainclk / (2 << DIV)
	 *    spiclk = psc_tempclk / (2 * (BRG + 1))
	 *    BRG valid range is 4..63
	 *    DIV valid range is 0..3
	 *  round the min and max frequencies to values that would still
	 *  produce valid brg and div
	 */
	{
		int min_div = (2 << 0) * (2 * (4 + 1));
		int max_div = (2 << 3) * (2 * (63 + 1));

		master->max_speed_hz = hw->pdata->mainclk_hz / min_div;
		master->min_speed_hz =
				hw->pdata->mainclk_hz / (max_div + 1) + 1;
	}

	au1550_spi_setup_psc_as_spi(hw);

	err = spi_bitbang_start(&hw->bitbang);
	if (err) {
		dev_err(&pdev->dev, "Failed to register SPI master\n");
		goto err_register;
	}

	dev_info(&pdev->dev,
		"spi master registered: bus_num=%d num_chipselect=%d\n",
		master->bus_num, master->num_chipselect);

	return 0;

err_register:
	free_irq(hw->irq, hw);

err_no_irq:
	au1550_spi_dma_rxtmp_free(hw);

err_dma_rxtmp_alloc:
err_no_rxdma_descr:
	if (hw->usedma)
		au1xxx_dbdma_chan_free(hw->dma_rx_ch);

err_no_rxdma:
err_no_txdma_descr:
	if (hw->usedma)
		au1xxx_dbdma_chan_free(hw->dma_tx_ch);

err_no_txdma:
	iounmap((void __iomem *)hw->regs);

err_ioremap:
	release_mem_region(r->start, sizeof(psc_spi_t));

err_no_iores:
err_no_pdata:
	spi_master_put(hw->master);

err_nomem:
	return err;
}