static int rockchip_spi_probe()

in spi-rockchip.c [650:840]

• 157 lines of code
• 26 McCabe index (conditional complexity)

static int rockchip_spi_probe(struct platform_device *pdev)
{
	int ret;
	struct rockchip_spi *rs;
	struct spi_controller *ctlr;
	struct resource *mem;
	struct device_node *np = pdev->dev.of_node;
	u32 rsd_nsecs;
	bool slave_mode;

	slave_mode = of_property_read_bool(np, "spi-slave");

	if (slave_mode)
		ctlr = spi_alloc_slave(&pdev->dev,
				sizeof(struct rockchip_spi));
	else
		ctlr = spi_alloc_master(&pdev->dev,
				sizeof(struct rockchip_spi));

	if (!ctlr)
		return -ENOMEM;

	platform_set_drvdata(pdev, ctlr);

	rs = spi_controller_get_devdata(ctlr);
	ctlr->slave = slave_mode;

	/* Get basic io resource and map it */
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
	if (IS_ERR(rs->regs)) {
		ret =  PTR_ERR(rs->regs);
		goto err_put_ctlr;
	}

	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
	if (IS_ERR(rs->apb_pclk)) {
		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
		ret = PTR_ERR(rs->apb_pclk);
		goto err_put_ctlr;
	}

	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
	if (IS_ERR(rs->spiclk)) {
		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
		ret = PTR_ERR(rs->spiclk);
		goto err_put_ctlr;
	}

	ret = clk_prepare_enable(rs->apb_pclk);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
		goto err_put_ctlr;
	}

	ret = clk_prepare_enable(rs->spiclk);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
		goto err_disable_apbclk;
	}

	spi_enable_chip(rs, false);

	ret = platform_get_irq(pdev, 0);
	if (ret < 0)
		goto err_disable_spiclk;

	ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
			IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
	if (ret)
		goto err_disable_spiclk;

	rs->dev = &pdev->dev;
	rs->freq = clk_get_rate(rs->spiclk);

	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
				  &rsd_nsecs)) {
		/* rx sample delay is expressed in parent clock cycles (max 3) */
		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
				1000000000 >> 8);
		if (!rsd) {
			dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
					rs->freq, rsd_nsecs);
		} else if (rsd > CR0_RSD_MAX) {
			rsd = CR0_RSD_MAX;
			dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
					rs->freq, rsd_nsecs,
					CR0_RSD_MAX * 1000000000U / rs->freq);
		}
		rs->rsd = rsd;
	}

	rs->fifo_len = get_fifo_len(rs);
	if (!rs->fifo_len) {
		dev_err(&pdev->dev, "Failed to get fifo length\n");
		ret = -EINVAL;
		goto err_disable_spiclk;
	}

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

	ctlr->auto_runtime_pm = true;
	ctlr->bus_num = pdev->id;
	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
	if (slave_mode) {
		ctlr->mode_bits |= SPI_NO_CS;
		ctlr->slave_abort = rockchip_spi_slave_abort;
	} else {
		ctlr->flags = SPI_MASTER_GPIO_SS;
		ctlr->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
		/*
		 * rk spi0 has two native cs, spi1..5 one cs only
		 * if num-cs is missing in the dts, default to 1
		 */
		if (of_property_read_u16(np, "num-cs", &ctlr->num_chipselect))
			ctlr->num_chipselect = 1;
		ctlr->use_gpio_descriptors = true;
	}
	ctlr->dev.of_node = pdev->dev.of_node;
	ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
	ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
	ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);

	ctlr->set_cs = rockchip_spi_set_cs;
	ctlr->transfer_one = rockchip_spi_transfer_one;
	ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
	ctlr->handle_err = rockchip_spi_handle_err;

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

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

	if (ctlr->dma_tx && ctlr->dma_rx) {
		rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
		rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
		ctlr->can_dma = rockchip_spi_can_dma;
	}

	switch (readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION)) {
	case ROCKCHIP_SPI_VER2_TYPE2:
		ctlr->mode_bits |= SPI_CS_HIGH;
		break;
	default:
		break;
	}

	ret = devm_spi_register_controller(&pdev->dev, ctlr);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to register controller\n");
		goto err_free_dma_rx;
	}

	return 0;

err_free_dma_rx:
	if (ctlr->dma_rx)
		dma_release_channel(ctlr->dma_rx);
err_free_dma_tx:
	if (ctlr->dma_tx)
		dma_release_channel(ctlr->dma_tx);
err_disable_pm_runtime:
	pm_runtime_disable(&pdev->dev);
err_disable_spiclk:
	clk_disable_unprepare(rs->spiclk);
err_disable_apbclk:
	clk_disable_unprepare(rs->apb_pclk);
err_put_ctlr:
	spi_controller_put(ctlr);

	return ret;
}