usb ep enable 和 disable做了什么事情

/* USB_DT_ENDPOINT: Endpoint descriptor */
struct usb_endpoint_descriptor {
	__u8  bLength;
	__u8  bDescriptorType;

	__u8  bEndpointAddress;
	__u8  bmAttributes;
	__le16 wMaxPacketSize;
	__u8  bInterval;

	/* NOTE:  these two are _only_ in audio endpoints. */
	/* use USB_DT_ENDPOINT*_SIZE in bLength, not sizeof. */
	__u8  bRefresh;
	__u8  bSynchAddress;
} __attribute__ ((packed));

#define USB_DT_ENDPOINT_SIZE		7

struct usb_ep {
	void			*driver_data;

	const char		*name;
	const struct usb_ep_ops	*ops;
	struct list_head	ep_list;
	struct usb_ep_caps	caps;
	bool			claimed;
	bool			enabled;
	unsigned		maxpacket:16;
	unsigned		maxpacket_limit:16;
	unsigned		max_streams:16;
	unsigned		mult:2;
	unsigned		maxburst:5;
	u8			address;
	const struct usb_endpoint_descriptor	*desc;
	const struct usb_ss_ep_comp_descriptor	*comp_desc;
};

struct s3c2410_ep {
	struct list_head		queue;
	unsigned long			last_io;	/* jiffies timestamp */
	struct usb_gadget		*gadget;
	struct s3c2410_udc		*dev;
	struct usb_ep			ep;
	u8				num;

	unsigned short			fifo_size;
	u8				bEndpointAddress;
	u8				bmAttributes;

	unsigned			halted : 1;
	unsigned			already_seen : 1;
	unsigned			setup_stage : 1;
};

static const struct usb_ep_ops s3c2410_ep_ops = {
	.enable		= s3c2410_udc_ep_enable,
	.disable	= s3c2410_udc_ep_disable,
     
};

*
 *	s3c2410_udc_ep_enable
 */
static int s3c2410_udc_ep_enable(struct usb_ep *_ep,
				 const struct usb_endpoint_descriptor *desc)
{
	struct s3c2410_udc	*dev;
	struct s3c2410_ep	*ep;
	u32			max, tmp;
	unsigned long		flags;
	u32			csr1, csr2;
	u32			int_en_reg;

	ep = to_s3c2410_ep(_ep);

	if (!_ep || !desc
			|| _ep->name == ep0name
			|| desc->bDescriptorType != USB_DT_ENDPOINT)
		return -EINVAL;

	dev = ep->dev;
	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;

	max = usb_endpoint_maxp(desc) & 0x1fff;   ////根据endpoint 描述符设置 udc reg 

	local_irq_save(flags);
	_ep->maxpacket = max & 0x7ff;
	ep->ep.desc = desc;
	ep->halted = 0;
	ep->bEndpointAddress = desc->bEndpointAddress;

	/* set max packet */
	udc_write(ep->num, S3C2410_UDC_INDEX_REG);
	udc_write(max >> 3, S3C2410_UDC_MAXP_REG);

	/* set type, direction, address; reset fifo counters */
	if (desc->bEndpointAddress & USB_DIR_IN) {
		csr1 = S3C2410_UDC_ICSR1_FFLUSH|S3C2410_UDC_ICSR1_CLRDT;
		csr2 = S3C2410_UDC_ICSR2_MODEIN|S3C2410_UDC_ICSR2_DMAIEN;

		udc_write(ep->num, S3C2410_UDC_INDEX_REG);
		udc_write(csr1, S3C2410_UDC_IN_CSR1_REG);
		udc_write(ep->num, S3C2410_UDC_INDEX_REG);
		udc_write(csr2, S3C2410_UDC_IN_CSR2_REG);
	} else {
		/* don't flush in fifo or it will cause endpoint interrupt */
		csr1 = S3C2410_UDC_ICSR1_CLRDT;
		csr2 = S3C2410_UDC_ICSR2_DMAIEN;

		udc_write(ep->num, S3C2410_UDC_INDEX_REG);
		udc_write(csr1, S3C2410_UDC_IN_CSR1_REG);
		udc_write(ep->num, S3C2410_UDC_INDEX_REG);
		udc_write(csr2, S3C2410_UDC_IN_CSR2_REG);

		csr1 = S3C2410_UDC_OCSR1_FFLUSH | S3C2410_UDC_OCSR1_CLRDT;
		csr2 = S3C2410_UDC_OCSR2_DMAIEN;

		udc_write(ep->num, S3C2410_UDC_INDEX_REG);
		udc_write(csr1, S3C2410_UDC_OUT_CSR1_REG);
		udc_write(ep->num, S3C2410_UDC_INDEX_REG);
		udc_write(csr2, S3C2410_UDC_OUT_CSR2_REG);
	}

	/* enable irqs */
	int_en_reg = udc_read(S3C2410_UDC_EP_INT_EN_REG);
	udc_write(int_en_reg | (1 << ep->num), S3C2410_UDC_EP_INT_EN_REG);

	/* print some debug message */
	tmp = desc->bEndpointAddress;
	dprintk(DEBUG_NORMAL, "enable %s(%d) ep%x%s-blk max %02x\n",
		 _ep->name, ep->num, tmp,
		 desc->bEndpointAddress & USB_DIR_IN ? "in" : "out", max);

	local_irq_restore(flags);
	s3c2410_udc_set_halt(_ep, 0);

	return 0;
}

/*
 * s3c2410_udc_ep_disable
 */
static int s3c2410_udc_ep_disable(struct usb_ep *_ep)
{
	struct s3c2410_ep *ep = to_s3c2410_ep(_ep);
	unsigned long flags;
	u32 int_en_reg;

	if (!_ep || !ep->ep.desc) {
		dprintk(DEBUG_NORMAL, "%s not enabled\n",
			_ep ? ep->ep.name : NULL);
		return -EINVAL;
	}

	local_irq_save(flags);

	dprintk(DEBUG_NORMAL, "ep_disable: %s\n", _ep->name);

	ep->ep.desc = NULL;
	ep->halted = 1;

	s3c2410_udc_nuke(ep->dev, ep, -ESHUTDOWN);

	/* disable irqs */
	int_en_reg = udc_read(S3C2410_UDC_EP_INT_EN_REG);
	udc_write(int_en_reg & ~(1<<ep->num), S3C2410_UDC_EP_INT_EN_REG);

	local_irq_restore(flags);

	dprintk(DEBUG_NORMAL, "%s disabled\n", _ep->name);

	return 0;
}