drivers/usb/phy/phy-omap-otg.c

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

File Facts

System
Linux kernel
Corpus path
drivers/usb/phy/phy-omap-otg.c
Extension
.c
Size
3796 bytes
Lines
151
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 otg_device {
	void __iomem			*base;
	bool				id;
	bool				vbus;
	struct extcon_dev		*extcon;
	struct notifier_block		vbus_nb;
	struct notifier_block		id_nb;
};

#define OMAP_OTG_CTRL		0x0c
#define OMAP_OTG_ASESSVLD	(1 << 20)
#define OMAP_OTG_BSESSEND	(1 << 19)
#define OMAP_OTG_BSESSVLD	(1 << 18)
#define OMAP_OTG_VBUSVLD	(1 << 17)
#define OMAP_OTG_ID		(1 << 16)
#define OMAP_OTG_XCEIV_OUTPUTS \
	(OMAP_OTG_ASESSVLD | OMAP_OTG_BSESSEND | OMAP_OTG_BSESSVLD | \
	 OMAP_OTG_VBUSVLD  | OMAP_OTG_ID)

static void omap_otg_ctrl(struct otg_device *otg_dev, u32 outputs)
{
	u32 l;

	l = readl(otg_dev->base + OMAP_OTG_CTRL);
	l &= ~OMAP_OTG_XCEIV_OUTPUTS;
	l |= outputs;
	writel(l, otg_dev->base + OMAP_OTG_CTRL);
}

static void omap_otg_set_mode(struct otg_device *otg_dev)
{
	if (!otg_dev->id && otg_dev->vbus)
		/* Set B-session valid. */
		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSVLD);
	else if (otg_dev->vbus)
		/* Set A-session valid. */
		omap_otg_ctrl(otg_dev, OMAP_OTG_ASESSVLD);
	else if (!otg_dev->id)
		/* Set B-session end to indicate no VBUS. */
		omap_otg_ctrl(otg_dev, OMAP_OTG_ID | OMAP_OTG_BSESSEND);
}

static int omap_otg_id_notifier(struct notifier_block *nb,
				unsigned long event, void *ptr)
{
	struct otg_device *otg_dev = container_of(nb, struct otg_device, id_nb);

	otg_dev->id = event;
	omap_otg_set_mode(otg_dev);

	return NOTIFY_DONE;
}

static int omap_otg_vbus_notifier(struct notifier_block *nb,
				  unsigned long event, void *ptr)
{
	struct otg_device *otg_dev = container_of(nb, struct otg_device,
						  vbus_nb);

	otg_dev->vbus = event;
	omap_otg_set_mode(otg_dev);

	return NOTIFY_DONE;
}

static int omap_otg_probe(struct platform_device *pdev)
{
	const struct omap_usb_config *config = pdev->dev.platform_data;
	struct otg_device *otg_dev;
	struct extcon_dev *extcon;
	int ret;
	u32 rev;

	if (!config || !config->extcon)
		return -ENODEV;

	extcon = extcon_get_extcon_dev(config->extcon);
	if (IS_ERR(extcon))
		return PTR_ERR(extcon);

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

	otg_dev->base = devm_ioremap_resource(&pdev->dev, &pdev->resource[0]);
	if (IS_ERR(otg_dev->base))
		return PTR_ERR(otg_dev->base);

	otg_dev->extcon = extcon;
	otg_dev->id_nb.notifier_call = omap_otg_id_notifier;

Annotation

Implementation Notes