static int ocores_i2c_probe()

in busses/i2c-ocores.c [602:741]

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

static int ocores_i2c_probe(struct platform_device *pdev)
{
	struct ocores_i2c *i2c;
	struct ocores_i2c_platform_data *pdata;
	struct resource *res;
	int irq;
	int ret;
	int i;

	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
	if (!i2c)
		return -ENOMEM;

	spin_lock_init(&i2c->process_lock);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res) {
		i2c->base = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(i2c->base))
			return PTR_ERR(i2c->base);
	} else {
		res = platform_get_resource(pdev, IORESOURCE_IO, 0);
		if (!res)
			return -EINVAL;
		i2c->iobase = res->start;
		if (!devm_request_region(&pdev->dev, res->start,
					 resource_size(res),
					 pdev->name)) {
			dev_err(&pdev->dev, "Can't get I/O resource.\n");
			return -EBUSY;
		}
		i2c->setreg = oc_setreg_io_8;
		i2c->getreg = oc_getreg_io_8;
	}

	pdata = dev_get_platdata(&pdev->dev);
	if (pdata) {
		i2c->reg_shift = pdata->reg_shift;
		i2c->reg_io_width = pdata->reg_io_width;
		i2c->ip_clock_khz = pdata->clock_khz;
		if (pdata->bus_khz)
			i2c->bus_clock_khz = pdata->bus_khz;
		else
			i2c->bus_clock_khz = 100;
	} else {
		ret = ocores_i2c_of_probe(pdev, i2c);
		if (ret)
			return ret;
	}

	if (i2c->reg_io_width == 0)
		i2c->reg_io_width = 1; /* Set to default value */

	if (!i2c->setreg || !i2c->getreg) {
		bool be = pdata ? pdata->big_endian :
			of_device_is_big_endian(pdev->dev.of_node);

		switch (i2c->reg_io_width) {
		case 1:
			i2c->setreg = oc_setreg_8;
			i2c->getreg = oc_getreg_8;
			break;

		case 2:
			i2c->setreg = be ? oc_setreg_16be : oc_setreg_16;
			i2c->getreg = be ? oc_getreg_16be : oc_getreg_16;
			break;

		case 4:
			i2c->setreg = be ? oc_setreg_32be : oc_setreg_32;
			i2c->getreg = be ? oc_getreg_32be : oc_getreg_32;
			break;

		default:
			dev_err(&pdev->dev, "Unsupported I/O width (%d)\n",
				i2c->reg_io_width);
			ret = -EINVAL;
			goto err_clk;
		}
	}

	init_waitqueue_head(&i2c->wait);

	irq = platform_get_irq_optional(pdev, 0);
	/*
	 * Since the SoC does have an interrupt, its DT has an interrupt
	 * property - But this should be bypassed as the IRQ logic in this
	 * SoC is broken.
	 */
	if (of_device_is_compatible(pdev->dev.of_node,
				    "sifive,fu540-c000-i2c")) {
		i2c->flags |= OCORES_FLAG_BROKEN_IRQ;
		irq = -ENXIO;
	}

	if (irq == -ENXIO) {
		ocores_algorithm.master_xfer = ocores_xfer_polling;
	} else {
		if (irq < 0)
			return irq;
	}

	if (ocores_algorithm.master_xfer != ocores_xfer_polling) {
		ret = devm_request_any_context_irq(&pdev->dev, irq,
						   ocores_isr, 0,
						   pdev->name, i2c);
		if (ret) {
			dev_err(&pdev->dev, "Cannot claim IRQ\n");
			goto err_clk;
		}
	}

	ret = ocores_init(&pdev->dev, i2c);
	if (ret)
		goto err_clk;

	/* hook up driver to tree */
	platform_set_drvdata(pdev, i2c);
	i2c->adap = ocores_adapter;
	i2c_set_adapdata(&i2c->adap, i2c);
	i2c->adap.dev.parent = &pdev->dev;
	i2c->adap.dev.of_node = pdev->dev.of_node;

	/* add i2c adapter to i2c tree */
	ret = i2c_add_adapter(&i2c->adap);
	if (ret)
		goto err_clk;

	/* add in known devices to the bus */
	if (pdata) {
		for (i = 0; i < pdata->num_devices; i++)
			i2c_new_client_device(&i2c->adap, pdata->devices + i);
	}

	return 0;

err_clk:
	clk_disable_unprepare(i2c->clk);
	return ret;
}