static int xgene_slimpro_i2c_probe()

in busses/i2c-xgene-slimpro.c [441:558]

• 97 lines of code
• 14 McCabe index (conditional complexity)

static int xgene_slimpro_i2c_probe(struct platform_device *pdev)
{
	struct slimpro_i2c_dev *ctx;
	struct i2c_adapter *adapter;
	struct mbox_client *cl;
	int rc;

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

	ctx->dev = &pdev->dev;
	platform_set_drvdata(pdev, ctx);
	cl = &ctx->mbox_client;

	/* Request mailbox channel */
	cl->dev = &pdev->dev;
	init_completion(&ctx->rd_complete);
	cl->tx_tout = MAILBOX_OP_TIMEOUT;
	cl->knows_txdone = false;
	if (acpi_disabled) {
		cl->tx_block = true;
		cl->rx_callback = slimpro_i2c_rx_cb;
		ctx->mbox_chan = mbox_request_channel(cl, MAILBOX_I2C_INDEX);
		if (IS_ERR(ctx->mbox_chan)) {
			dev_err(&pdev->dev, "i2c mailbox channel request failed\n");
			return PTR_ERR(ctx->mbox_chan);
		}
	} else {
		struct pcc_mbox_chan *pcc_chan;
		const struct acpi_device_id *acpi_id;
		int version = XGENE_SLIMPRO_I2C_V1;

		acpi_id = acpi_match_device(pdev->dev.driver->acpi_match_table,
					    &pdev->dev);
		if (!acpi_id)
			return -EINVAL;

		version = (int)acpi_id->driver_data;

		if (device_property_read_u32(&pdev->dev, "pcc-channel",
					     &ctx->mbox_idx))
			ctx->mbox_idx = MAILBOX_I2C_INDEX;

		cl->tx_block = false;
		cl->rx_callback = slimpro_i2c_pcc_rx_cb;
		pcc_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx);
		if (IS_ERR(pcc_chan)) {
			dev_err(&pdev->dev, "PCC mailbox channel request failed\n");
			return PTR_ERR(pcc_chan);
		}

		ctx->pcc_chan = pcc_chan;
		ctx->mbox_chan = pcc_chan->mchan;

		if (!ctx->mbox_chan->mbox->txdone_irq) {
			dev_err(&pdev->dev, "PCC IRQ not supported\n");
			rc = -ENOENT;
			goto mbox_err;
		}

		/*
		 * This is the shared communication region
		 * for the OS and Platform to communicate over.
		 */
		ctx->comm_base_addr = pcc_chan->shmem_base_addr;
		if (ctx->comm_base_addr) {
			if (version == XGENE_SLIMPRO_I2C_V2)
				ctx->pcc_comm_addr = memremap(
							ctx->comm_base_addr,
							pcc_chan->shmem_size,
							MEMREMAP_WT);
			else
				ctx->pcc_comm_addr = memremap(
							ctx->comm_base_addr,
							pcc_chan->shmem_size,
							MEMREMAP_WB);
		} else {
			dev_err(&pdev->dev, "Failed to get PCC comm region\n");
			rc = -ENOENT;
			goto mbox_err;
		}

		if (!ctx->pcc_comm_addr) {
			dev_err(&pdev->dev,
				"Failed to ioremap PCC comm region\n");
			rc = -ENOMEM;
			goto mbox_err;
		}
	}
	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
	if (rc)
		dev_warn(&pdev->dev, "Unable to set dma mask\n");

	/* Setup I2C adapter */
	adapter = &ctx->adapter;
	snprintf(adapter->name, sizeof(adapter->name), "MAILBOX I2C");
	adapter->algo = &xgene_slimpro_i2c_algorithm;
	adapter->class = I2C_CLASS_HWMON;
	adapter->dev.parent = &pdev->dev;
	adapter->dev.of_node = pdev->dev.of_node;
	ACPI_COMPANION_SET(&adapter->dev, ACPI_COMPANION(&pdev->dev));
	i2c_set_adapdata(adapter, ctx);
	rc = i2c_add_adapter(adapter);
	if (rc)
		goto mbox_err;

	dev_info(&pdev->dev, "Mailbox I2C Adapter registered\n");
	return 0;

mbox_err:
	if (acpi_disabled)
		mbox_free_channel(ctx->mbox_chan);
	else
		pcc_mbox_free_channel(ctx->pcc_chan);

	return rc;
}