drivers/phy/marvell/phy-armada375-usb2.c

Source file repositories/reference/linux-study-clean/drivers/phy/marvell/phy-armada375-usb2.c

File Facts

System
Linux kernel
Corpus path
drivers/phy/marvell/phy-armada375-usb2.c
Extension
.c
Size
3989 bytes
Lines
148
Domain
Driver Families
Bucket
drivers/phy
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct armada375_cluster_phy {
	struct phy *phy;
	void __iomem *reg;
	bool use_usb3;
	int phy_provided;
};

static int armada375_usb_phy_init(struct phy *phy)
{
	struct armada375_cluster_phy *cluster_phy;
	u32 reg;

	cluster_phy = phy_get_drvdata(phy);
	if (!cluster_phy)
		return -ENODEV;

	reg = readl(cluster_phy->reg);
	if (cluster_phy->use_usb3)
		reg |= USB2_PHY_CONFIG_DISABLE;
	else
		reg &= ~USB2_PHY_CONFIG_DISABLE;
	writel(reg, cluster_phy->reg);

	return 0;
}

static const struct phy_ops armada375_usb_phy_ops = {
	.init = armada375_usb_phy_init,
	.owner = THIS_MODULE,
};

/*
 * Only one controller can use this PHY. We shouldn't have the case
 * when two controllers want to use this PHY. But if this case occurs
 * then we provide a phy to the first one and return an error for the
 * next one. This error has also to be an error returned by
 * devm_phy_optional_get() so different from ENODEV for USB2. In the
 * USB3 case it still optional and we use ENODEV.
 */
static struct phy *armada375_usb_phy_xlate(struct device *dev,
					const struct of_phandle_args *args)
{
	struct armada375_cluster_phy *cluster_phy = dev_get_drvdata(dev);

	if (!cluster_phy)
		return  ERR_PTR(-ENODEV);

	/*
	 * Either the phy had never been requested and then the first
	 * usb claiming it can get it, or it had already been
	 * requested in this case, we only allow to use it with the
	 * same configuration.
	 */
	if (WARN_ON((cluster_phy->phy_provided != PHY_NONE) &&
			(cluster_phy->phy_provided != args->args[0]))) {
		dev_err(dev, "This PHY has already been provided!\n");
		dev_err(dev, "Check your device tree, only one controller can use it\n.");
		if (args->args[0] == PHY_TYPE_USB2)
			return ERR_PTR(-EBUSY);
		else
			return ERR_PTR(-ENODEV);
	}

	if (args->args[0] == PHY_TYPE_USB2)
		cluster_phy->use_usb3 = false;
	else if (args->args[0] == PHY_TYPE_USB3)
		cluster_phy->use_usb3 = true;
	else {
		dev_err(dev, "Invalid PHY mode\n");
		return ERR_PTR(-ENODEV);
	}

	/* Store which phy mode is used for next test */
	cluster_phy->phy_provided = args->args[0];

	return cluster_phy->phy;
}

static int armada375_usb_phy_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct phy *phy;
	struct phy_provider *phy_provider;
	void __iomem *usb_cluster_base;
	struct armada375_cluster_phy *cluster_phy;

	cluster_phy = devm_kzalloc(dev, sizeof(*cluster_phy), GFP_KERNEL);
	if (!cluster_phy)
		return  -ENOMEM;

Annotation

Implementation Notes