drivers/usb/mtu3/mtu3_gadget.c

Source file repositories/reference/linux-study-clean/drivers/usb/mtu3/mtu3_gadget.c

File Facts

System
Linux kernel
Corpus path
drivers/usb/mtu3/mtu3_gadget.c
Extension
.c
Size
18228 bytes
Lines
773
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

usb_endpoint_xfer_isoc(desc)) {
			interval = desc->bInterval;
			interval = clamp_val(interval, 1, 16);
			if (usb_endpoint_xfer_isoc(desc) && comp_desc)
				mult = comp_desc->bmAttributes;
		}
		if (comp_desc)
			burst = comp_desc->bMaxBurst;

		break;
	case USB_SPEED_HIGH:
		if (usb_endpoint_xfer_isoc(desc) ||
				usb_endpoint_xfer_int(desc)) {
			interval = desc->bInterval;
			interval = clamp_val(interval, 1, 16);
			mult = usb_endpoint_maxp_mult(desc) - 1;
		}
		break;
	case USB_SPEED_FULL:
		if (usb_endpoint_xfer_isoc(desc))
			interval = clamp_val(desc->bInterval, 1, 16);
		else if (usb_endpoint_xfer_int(desc))
			interval = clamp_val(desc->bInterval, 1, 255);

		break;
	default:
		break; /*others are ignored */
	}

	dev_dbg(mtu->dev, "%s maxp:%d, interval:%d, burst:%d, mult:%d\n",
		__func__, mep->maxp, interval, burst, mult);

	mep->ep.maxpacket = mep->maxp;
	mep->ep.desc = desc;
	mep->ep.comp_desc = comp_desc;

	/* slot mainly affects bulk/isoc transfer, so ignore int */
	mep->slot = usb_endpoint_xfer_int(desc) ? 0 : mtu->slot;

	ret = mtu3_config_ep(mtu, mep, interval, burst, mult);
	if (ret < 0)
		return ret;

	ret = mtu3_gpd_ring_alloc(mep);
	if (ret < 0) {
		mtu3_deconfig_ep(mtu, mep);
		return ret;
	}

	mtu3_qmu_start(mep);

	return 0;
}

static int mtu3_ep_disable(struct mtu3_ep *mep)
{
	struct mtu3 *mtu = mep->mtu;

	/* abort all pending requests */
	nuke(mep, -ESHUTDOWN);
	mtu3_qmu_stop(mep);
	mtu3_deconfig_ep(mtu, mep);
	mtu3_gpd_ring_free(mep);

	mep->desc = NULL;
	mep->ep.desc = NULL;
	mep->comp_desc = NULL;
	mep->type = 0;
	mep->flags = 0;

	return 0;
}

static int mtu3_gadget_ep_enable(struct usb_ep *ep,
		const struct usb_endpoint_descriptor *desc)
{
	struct mtu3_ep *mep;
	struct mtu3 *mtu;
	unsigned long flags;
	int ret = -EINVAL;

	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
		pr_debug("%s invalid parameters\n", __func__);
		return -EINVAL;
	}

	if (!desc->wMaxPacketSize) {
		pr_debug("%s missing wMaxPacketSize\n", __func__);
		return -EINVAL;
	}

Annotation

Implementation Notes