static int i801_probe()

in busses/i2c-i801.c [1650:1785]

• 103 lines of code
• 20 McCabe index (conditional complexity)

static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
	int err, i;
	struct i801_priv *priv;

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

	i2c_set_adapdata(&priv->adapter, priv);
	priv->adapter.owner = THIS_MODULE;
	priv->adapter.class = i801_get_adapter_class(priv);
	priv->adapter.algo = &smbus_algorithm;
	priv->adapter.dev.parent = &dev->dev;
	ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&dev->dev));
	priv->adapter.retries = 3;
	mutex_init(&priv->acpi_lock);

	priv->pci_dev = dev;
	priv->features = id->driver_data;

	/* Disable features on user request */
	for (i = 0; i < ARRAY_SIZE(i801_feature_names); i++) {
		if (priv->features & disable_features & (1 << i))
			dev_notice(&dev->dev, "%s disabled by user\n",
				   i801_feature_names[i]);
	}
	priv->features &= ~disable_features;

	err = pcim_enable_device(dev);
	if (err) {
		dev_err(&dev->dev, "Failed to enable SMBus PCI device (%d)\n",
			err);
		return err;
	}
	pcim_pin_device(dev);

	/* Determine the address of the SMBus area */
	priv->smba = pci_resource_start(dev, SMBBAR);
	if (!priv->smba) {
		dev_err(&dev->dev,
			"SMBus base address uninitialized, upgrade BIOS\n");
		return -ENODEV;
	}

	if (i801_acpi_probe(priv))
		return -ENODEV;

	err = pcim_iomap_regions(dev, 1 << SMBBAR, DRV_NAME);
	if (err) {
		dev_err(&dev->dev,
			"Failed to request SMBus region 0x%lx-0x%Lx\n",
			priv->smba,
			(unsigned long long)pci_resource_end(dev, SMBBAR));
		i801_acpi_remove(priv);
		return err;
	}

	pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &priv->original_hstcfg);
	i801_setup_hstcfg(priv);
	if (!(priv->original_hstcfg & SMBHSTCFG_HST_EN))
		dev_info(&dev->dev, "Enabling SMBus device\n");

	if (priv->original_hstcfg & SMBHSTCFG_SMB_SMI_EN) {
		dev_dbg(&dev->dev, "SMBus using interrupt SMI#\n");
		/* Disable SMBus interrupt feature if SMBus using SMI# */
		priv->features &= ~FEATURE_IRQ;
	}
	if (priv->original_hstcfg & SMBHSTCFG_SPD_WD)
		dev_info(&dev->dev, "SPD Write Disable is set\n");

	/* Clear special mode bits */
	if (priv->features & (FEATURE_SMBUS_PEC | FEATURE_BLOCK_BUFFER))
		outb_p(inb_p(SMBAUXCTL(priv)) &
		       ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv));

	/* Remember original Interrupt and Host Notify settings */
	priv->original_hstcnt = inb_p(SMBHSTCNT(priv)) & ~SMBHSTCNT_KILL;
	if (priv->features & FEATURE_HOST_NOTIFY)
		priv->original_slvcmd = inb_p(SMBSLVCMD(priv));

	/* Default timeout in interrupt mode: 200 ms */
	priv->adapter.timeout = HZ / 5;

	if (dev->irq == IRQ_NOTCONNECTED)
		priv->features &= ~FEATURE_IRQ;

	if (priv->features & FEATURE_IRQ) {
		u16 pcists;

		/* Complain if an interrupt is already pending */
		pci_read_config_word(priv->pci_dev, PCI_STATUS, &pcists);
		if (pcists & PCI_STATUS_INTERRUPT)
			dev_warn(&dev->dev, "An interrupt is pending!\n");
	}

	if (priv->features & FEATURE_IRQ) {
		init_completion(&priv->done);

		err = devm_request_irq(&dev->dev, dev->irq, i801_isr,
				       IRQF_SHARED, DRV_NAME, priv);
		if (err) {
			dev_err(&dev->dev, "Failed to allocate irq %d: %d\n",
				dev->irq, err);
			priv->features &= ~FEATURE_IRQ;
		}
	}
	dev_info(&dev->dev, "SMBus using %s\n",
		 priv->features & FEATURE_IRQ ? "PCI interrupt" : "polling");

	i801_add_tco(priv);

	snprintf(priv->adapter.name, sizeof(priv->adapter.name),
		"SMBus I801 adapter at %04lx", priv->smba);
	err = i2c_add_adapter(&priv->adapter);
	if (err) {
		i801_acpi_remove(priv);
		return err;
	}

	i801_enable_host_notify(&priv->adapter);

	i801_probe_optional_slaves(priv);
	/* We ignore errors - multiplexing is optional */
	i801_add_mux(priv);

	pci_set_drvdata(dev, priv);

	dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NO_DIRECT_COMPLETE);
	pm_runtime_set_autosuspend_delay(&dev->dev, 1000);
	pm_runtime_use_autosuspend(&dev->dev);
	pm_runtime_put_autosuspend(&dev->dev);
	pm_runtime_allow(&dev->dev);

	return 0;
}