ci_udc: Update the ci_udc driver to support bulk transfers

Update the ci_udc driver to support bulk transfer
and also added capability of having multiple dtds
if requested data is more than 16K.
These changes are tested for both the DFU and lthor.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>

drivers/usb/gadget/ci_udc.c

@@ -50,6 +50,8 @@
 /* For each endpoint, we need 2 QTDs, one for each of IN and OUT */
 #define ILIST_SZ		(NUM_ENDPOINTS * 2 * ILIST_ENT_SZ)
 
+#define EP_MAX_LENGTH_TRANSFER	0x4000
+
 #ifndef DEBUG
 #define DBG(x...) do {} while (0)
 #else
@@ -102,13 +104,28 @@ static struct usb_ep_ops ci_ep_ops = {
 };
 
 /* Init values for USB endpoints. */
-static const struct usb_ep ci_ep_init[2] = {
+static const struct usb_ep ci_ep_init[5] = {
 	[0] = {	/* EP 0 */
 		.maxpacket	= 64,
 		.name		= "ep0",
 		.ops		= &ci_ep_ops,
 	},
-	[1] = {	/* EP 1..n */
+	[1] = {
+		.maxpacket	= 512,
+		.name		= "ep1in-bulk",
+		.ops		= &ci_ep_ops,
+	},
+	[2] = {
+		.maxpacket	= 512,
+		.name		= "ep2out-bulk",
+		.ops		= &ci_ep_ops,
+	},
+	[3] = {
+		.maxpacket	= 512,
+		.name		= "ep3in-int",
+		.ops		= &ci_ep_ops,
+	},
+	[4] = {
 		.maxpacket	= 512,
 		.name		= "ep-",
 		.ops		= &ci_ep_ops,
@@ -197,6 +214,19 @@ static void ci_flush_qtd(int ep_num)
 }
 
 /**
+ * ci_flush_td - flush cache over queue item
+ * @td:	td pointer
+ *
+ * This function flushes cache for particular transfer descriptor.
+ */
+static void ci_flush_td(struct ept_queue_item *td)
+{
+	const uint32_t  start = (uint32_t)td;
+	const uint32_t end = (uint32_t) td + ILIST_ENT_SZ;
+	flush_dcache_range(start, end);
+}
+
+/**
  * ci_invalidate_qtd - invalidate cache over queue item
  * @ep_num:	Endpoint number
  *
@@ -211,6 +241,19 @@ static void ci_invalidate_qtd(int ep_num)
 	invalidate_dcache_range(start, end);
 }
 
+/**
+ * ci_invalidate_td - invalidate cache over queue item
+ * @td:	td pointer
+ *
+ * This function invalidates cache for particular transfer descriptor.
+ */
+static void ci_invalidate_td(struct ept_queue_item *td)
+{
+	const uint32_t start = (uint32_t)td;
+	const uint32_t end = start + ILIST_ENT_SZ;
+	invalidate_dcache_range(start, end);
+}
+
 static struct usb_request *
 ci_ep_alloc_request(struct usb_ep *ep, unsigned int gfp_flags)
 {
@@ -376,6 +419,9 @@ static void ci_ep_submit_next_request(struct ci_ep *ci_ep)
 	struct ept_queue_head *head;
 	int bit, num, len, in;
 	struct ci_req *ci_req;
+	u8 *buf;
+	uint32_t length, actlen;
+	struct ept_queue_item *dtd, *qtd;
 
 	ci_ep->req_primed = true;
 
@@ -387,16 +433,41 @@ static void ci_ep_submit_next_request(struct ci_ep *ci_ep)
 	ci_req = list_first_entry(&ci_ep->queue, struct ci_req, queue);
 	len = ci_req->req.length;
 
-	item->info = INFO_BYTES(len) | INFO_ACTIVE;
-	item->page0 = (unsigned long)ci_req->hw_buf;
-	item->page1 = ((unsigned long)ci_req->hw_buf & 0xfffff000) + 0x1000;
-	item->page2 = ((unsigned long)ci_req->hw_buf & 0xfffff000) + 0x2000;
-	item->page3 = ((unsigned long)ci_req->hw_buf & 0xfffff000) + 0x3000;
-	item->page4 = ((unsigned long)ci_req->hw_buf & 0xfffff000) + 0x4000;
-
 	head->next = (unsigned long)item;
 	head->info = 0;
 
+	ci_req->dtd_count = 0;
+	buf = ci_req->hw_buf;
+	actlen = 0;
+	dtd = item;
+
+	do {
+		length = min(ci_req->req.length - actlen,
+			     (unsigned)EP_MAX_LENGTH_TRANSFER);
+
+		dtd->info = INFO_BYTES(length) | INFO_ACTIVE;
+		dtd->page0 = (unsigned long)buf;
+		dtd->page1 = ((unsigned long)buf & 0xfffff000) + 0x1000;
+		dtd->page2 = ((unsigned long)buf & 0xfffff000) + 0x2000;
+		dtd->page3 = ((unsigned long)buf & 0xfffff000) + 0x3000;
+		dtd->page4 = ((unsigned long)buf & 0xfffff000) + 0x4000;
+
+		len -= length;
+		actlen += length;
+		buf += length;
+
+		if (len) {
+			qtd = (struct ept_queue_item *)
+			       memalign(ILIST_ALIGN, ILIST_ENT_SZ);
+			dtd->next = (uint32_t)qtd;
+			dtd = qtd;
+			memset(dtd, 0, ILIST_ENT_SZ);
+		}
+
+		ci_req->dtd_count++;
+	} while (len);
+
+	item = dtd;
 	/*
 	 * When sending the data for an IN transaction, the attached host
 	 * knows that all data for the IN is sent when one of the following
@@ -432,6 +503,12 @@ static void ci_ep_submit_next_request(struct ci_ep *ci_ep)
 
 	ci_flush_qtd(num);
 
+	item = (struct ept_queue_item *)head->next;
+	while (item->next != TERMINATE) {
+		ci_flush_td((struct ept_queue_item *)item->next);
+		item = (struct ept_queue_item *)item->next;
+	}
+
 	DBG("ept%d %s queue len %x, req %p, buffer %p\n",
 	    num, in ? "in" : "out", len, ci_req, ci_req->hw_buf);
 	ci_flush_qh(num);
@@ -497,21 +574,31 @@ static void flip_ep0_direction(void)
 
 static void handle_ep_complete(struct ci_ep *ci_ep)
 {
-	struct ept_queue_item *item;
+	struct ept_queue_item *item, *next_td;
-	int num, in, len;
+	int num, in, len, j;
 	struct ci_req *ci_req;
 
 	num = ci_ep->desc->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
 	in = (ci_ep->desc->bEndpointAddress & USB_DIR_IN) != 0;
 	item = ci_get_qtd(num, in);
 	ci_invalidate_qtd(num);
+	ci_req = list_first_entry(&ci_ep->queue, struct ci_req, queue);
 
-	len = (item->info >> 16) & 0x7fff;
+	next_td = item;
+	len = 0;
+	for (j = 0; j < ci_req->dtd_count; j++) {
+		ci_invalidate_td(next_td);
+		item = next_td;
+		len += (item->info >> 16) & 0x7fff;
 		if (item->info & 0xff)
 			printf("EP%d/%s FAIL info=%x pg0=%x\n",
 			       num, in ? "in" : "out", item->info, item->page0);
+		if (j != ci_req->dtd_count - 1)
+			next_td = (struct ept_queue_item *)item->next;
+		if (j != 0)
+			free(item);
+	}
 
-	ci_req = list_first_entry(&ci_ep->queue, struct ci_req, queue);
 	list_del_init(&ci_req->queue);
 	ci_ep->req_primed = false;
 
@@ -852,9 +939,19 @@ static int ci_udc_probe(void)
 	controller.gadget.ep0 = &controller.ep[0].ep;
 	INIT_LIST_HEAD(&controller.gadget.ep0->ep_list);
 
-	/* Init EP 1..n */
+	/* Init EP 1..3 */
-	for (i = 1; i < NUM_ENDPOINTS; i++) {
+	for (i = 1; i < 4; i++) {
-		memcpy(&controller.ep[i].ep, &ci_ep_init[1],
+		memcpy(&controller.ep[i].ep, &ci_ep_init[i],
+		       sizeof(*ci_ep_init));
+		INIT_LIST_HEAD(&controller.ep[i].queue);
+		controller.ep[i].req_primed = false;
+		list_add_tail(&controller.ep[i].ep.ep_list,
+			      &controller.gadget.ep_list);
+	}
+
+	/* Init EP 4..n */
+	for (i = 4; i < NUM_ENDPOINTS; i++) {
+		memcpy(&controller.ep[i].ep, &ci_ep_init[4],
 		       sizeof(*ci_ep_init));
 		INIT_LIST_HEAD(&controller.ep[i].queue);
 		controller.ep[i].req_primed = false;

drivers/usb/gadget/ci_udc.h

@@ -86,6 +86,7 @@ struct ci_req {
 	/* Buffer for the current transfer. Either req.buf/len or b_buf/len */
 	uint8_t *hw_buf;
 	uint32_t hw_len;
+	uint32_t dtd_count;
 };
 
 struct ci_ep {