drivers/usb/phy/phy-am335x.c

Source file repositories/reference/linux-study-clean/drivers/usb/phy/phy-am335x.c

File Facts

System
Linux kernel
Corpus path
drivers/usb/phy/phy-am335x.c
Extension
.c
Size
3831 bytes
Lines
147
Domain
Driver Families
Bucket
drivers/usb
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 am335x_phy {
	struct usb_phy_generic usb_phy_gen;
	struct phy_control *phy_ctrl;
	int id;
	enum usb_dr_mode dr_mode;
};

static int am335x_init(struct usb_phy *phy)
{
	struct am335x_phy *am_phy = dev_get_drvdata(phy->dev);

	phy_ctrl_power(am_phy->phy_ctrl, am_phy->id, am_phy->dr_mode, true);
	return 0;
}

static void am335x_shutdown(struct usb_phy *phy)
{
	struct am335x_phy *am_phy = dev_get_drvdata(phy->dev);

	phy_ctrl_power(am_phy->phy_ctrl, am_phy->id, am_phy->dr_mode, false);
}

static int am335x_phy_probe(struct platform_device *pdev)
{
	struct am335x_phy *am_phy;
	struct device *dev = &pdev->dev;
	int ret;

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

	am_phy->phy_ctrl = am335x_get_phy_control(dev);
	if (!am_phy->phy_ctrl)
		return -EPROBE_DEFER;

	am_phy->id = of_alias_get_id(pdev->dev.of_node, "phy");
	if (am_phy->id < 0) {
		dev_err(&pdev->dev, "Missing PHY id: %d\n", am_phy->id);
		return am_phy->id;
	}

	am_phy->dr_mode = of_usb_get_dr_mode_by_phy(pdev->dev.of_node, -1);

	ret = usb_phy_gen_create_phy(dev, &am_phy->usb_phy_gen);
	if (ret)
		return ret;

	am_phy->usb_phy_gen.phy.init = am335x_init;
	am_phy->usb_phy_gen.phy.shutdown = am335x_shutdown;

	platform_set_drvdata(pdev, am_phy);
	device_init_wakeup(dev, true);

	/*
	 * If we leave PHY wakeup enabled then AM33XX wakes up
	 * immediately from DS0. To avoid this we mark dev->power.can_wakeup
	 * to false. The same is checked in suspend routine to decide
	 * on whether to enable PHY wakeup or not.
	 * PHY wakeup works fine in standby mode, there by allowing us to
	 * handle remote wakeup, wakeup on disconnect and connect.
	 */

	device_set_wakeup_enable(dev, false);
	phy_ctrl_power(am_phy->phy_ctrl, am_phy->id, am_phy->dr_mode, false);

	return usb_add_phy_dev(&am_phy->usb_phy_gen.phy);
}

static void am335x_phy_remove(struct platform_device *pdev)
{
	struct am335x_phy *am_phy = platform_get_drvdata(pdev);

	usb_remove_phy(&am_phy->usb_phy_gen.phy);
}

#ifdef CONFIG_PM_SLEEP
static int am335x_phy_suspend(struct device *dev)
{
	struct am335x_phy *am_phy = dev_get_drvdata(dev);

	/*
	 * Enable phy wakeup only if dev->power.can_wakeup is true.
	 * Make sure to enable wakeup to support remote wakeup	in
	 * standby mode ( same is not supported in OFF(DS0) mode).
	 * Enable it by doing
	 * echo enabled > /sys/bus/platform/devices/<usb-phy-id>/power/wakeup
	 */

	if (device_may_wakeup(dev))

Annotation

Implementation Notes