[RFC PATCH v2 09/15] usb:cdns3: EpX operations part of the API

[Pawel Laszczak <pawell@cadence.com>]

Patch implements callback functions for non-default endpoints
defined in usb_ep_ops object.

Signed-off-by: Pawel Laszczak <pawell@cadence.com>
---
 drivers/usb/cdns3/ep0.c    |  18 ++
 drivers/usb/cdns3/gadget.c | 442 ++++++++++++++++++++++++++++++++++++-
 drivers/usb/cdns3/gadget.h |   3 +
 3 files changed, 461 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/cdns3/ep0.c b/drivers/usb/cdns3/ep0.c
index c08d02665f9d..ca1795467155 100644
--- a/drivers/usb/cdns3/ep0.c
+++ b/drivers/usb/cdns3/ep0.c
@@ -23,6 +23,24 @@ static void cdns3_prepare_setup_packet(struct cdns3_device *priv_dev)
 	//TODO: Implements this function
 }
 
+/**
+ * cdns3_gadget_ep_set_wedge Set wedge on selected endpoint
+ * @ep: endpoint object
+ *
+ * Returns 0
+ */
+int cdns3_gadget_ep_set_wedge(struct usb_ep *ep)
+{
+	struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
+	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+
+	dev_dbg(&priv_dev->dev, "Wedge for %s\n", ep->name);
+	cdns3_gadget_ep_set_halt(ep, 1);
+	priv_ep->flags |= EP_WEDGE;
+
+	return 0;
+}
+
 /**
  * cdns3_ep0_config - Configures default endpoint
  * @priv_dev: extended gadget object
diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 702a05faa664..1f2a434486dc 100644
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -58,6 +58,19 @@ void cdns3_set_register_bit(void __iomem *ptr, u32 mask)
 	writel(mask, ptr);
 }
 
+/**
+ * cdns3_next_request - returns next request from list
+ * @list: list containing requests
+ *
+ * Returns request or NULL if no requests in list
+ */
+struct usb_request *cdns3_next_request(struct list_head *list)
+{
+	if (list_empty(list))
+		return NULL;
+	return list_first_entry(list, struct usb_request, list);
+}
+
 /**
  * select_ep - selects endpoint
  * @priv_dev:  extended gadget object
@@ -73,6 +86,53 @@ void cdns3_select_ep(struct cdns3_device *priv_dev, u32 ep)
 	writel(ep, &priv_dev->regs->ep_sel);
 }
 
+/**
+ * cdns3_allocate_trb_pool - Allocates TRB's pool for selected endpoint
+ * @priv_ep:  endpoint object
+ *
+ * Function will return 0 on success or -ENOMEM on allocation error
+ */
+static int cdns3_allocate_trb_pool(struct cdns3_endpoint *priv_ep)
+{
+	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+	struct cdns3_trb *link_trb;
+
+	if (!priv_ep->trb_pool) {
+		priv_ep->trb_pool = dma_zalloc_coherent(priv_dev->sysdev,
+							TRB_RIGN_SIZE,
+							&priv_ep->trb_pool_dma,
+							GFP_DMA);
+		if (!priv_ep->trb_pool)
+			return -ENOMEM;
+	} else {
+		memset(priv_ep->trb_pool, 0, TRB_RIGN_SIZE);
+	}
+
+	if (!priv_ep->aligned_buff) {
+		priv_ep->aligned_buff = dma_alloc_coherent(priv_dev->sysdev,
+							   CDNS3_UNALIGNED_BUF_SIZE,
+							   &priv_ep->aligned_dma_addr,
+							   GFP_DMA);
+		if (!priv_ep->aligned_buff) {
+			dma_free_coherent(priv_dev->sysdev,
+					  TRB_RIGN_SIZE,
+					  priv_ep->trb_pool,
+					  priv_ep->trb_pool_dma);
+			priv_ep->trb_pool = NULL;
+
+			return -ENOMEM;
+		}
+	}
+
+	/* Initialize the last TRB as Link TRB */
+	link_trb = (priv_ep->trb_pool + TRBS_PER_SEGMENT - 1);
+	link_trb->buffer = TRB_BUFFER(priv_ep->trb_pool_dma);
+	link_trb->control = TRB_CYCLE | TRB_TYPE(TRB_LINK) |
+			    TRB_CHAIN | TRB_TOGGLE;
+
+	return 0;
+}
+
 static void cdns3_free_trb_pool(struct cdns3_endpoint *priv_ep)
 {
 	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
@@ -92,6 +152,73 @@ static void cdns3_free_trb_pool(struct cdns3_endpoint *priv_ep)
 	}
 }
 
+/**
+ * cdns3_data_flush - flush data at onchip buffer
+ * @priv_ep: endpoint object
+ *
+ * Endpoint must be selected before call to this function
+ *
+ * Returns zero on success or negative value on failure
+ */
+static int cdns3_data_flush(struct cdns3_endpoint *priv_ep)
+{
+	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+
+	writel(EP_CMD_DFLUSH, &priv_dev->regs->ep_cmd);
+
+	/* wait for DFLUSH cleared */
+	return cdns3_handshake(&priv_dev->regs->ep_cmd, EP_CMD_DFLUSH, 0, 100);
+}
+
+/**
+ * cdns3_ep_stall_flush - Stalls and flushes selected endpoint
+ * @priv_ep: endpoint object
+ *
+ * Endpoint must be selected before call to this function
+ */
+static void cdns3_ep_stall_flush(struct cdns3_endpoint *priv_ep)
+{
+	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+
+	writel(EP_CMD_DFLUSH | EP_CMD_ERDY | EP_CMD_SSTALL,
+	       &priv_dev->regs->ep_cmd);
+
+	/* wait for DFLUSH cleared */
+	cdns3_handshake(&priv_dev->regs->ep_cmd, EP_CMD_DFLUSH, 0, 100);
+	priv_ep->flags |= EP_STALL;
+}
+
+/**
+ * cdns3_gadget_giveback - call struct usb_request's ->complete callback
+ * @priv_ep: The endpoint to whom the request belongs to
+ * @priv_req: The request we're giving back
+ * @status: completion code for the request
+ *
+ * Must be called with controller's lock held and interrupts disabled. This
+ * function will unmap @req and call its ->complete() callback to notify upper
+ * layers that it has completed.
+ */
+void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep,
+			   struct cdns3_request *priv_req,
+			   int status)
+{
+	//TODO: Implements this function.
+}
+
+/**
+ * cdns3_ep_run_transfer - start transfer on no-default endpoint hardware
+ * @priv_ep: endpoint object
+ *
+ * Returns zero on success or negative value on failure
+ */
+int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep,
+			  struct usb_request *request)
+{
+	//TODO: Implements this function.
+
+	return 0;
+}
+
 /**
  * cdns3_irq_handler - irq line interrupt handler
  * @cdns: cdns3 instance
@@ -170,6 +297,318 @@ static struct usb_ep *cdns3_gadget_match_ep(struct usb_gadget *gadget,
 	return &priv_ep->endpoint;
 }
 
+/**
+ * cdns3_gadget_ep_enable Enable endpoint
+ * @ep: endpoint object
+ * @desc: endpoint descriptor
+ *
+ * Returns 0 on success, error code elsewhere
+ */
+static int cdns3_gadget_ep_enable(struct usb_ep *ep,
+				  const struct usb_endpoint_descriptor *desc)
+{
+	struct cdns3_endpoint *priv_ep;
+	struct cdns3_device *priv_dev;
+	unsigned long flags;
+	int ret;
+	u32 reg;
+
+	priv_ep = ep_to_cdns3_ep(ep);
+	priv_dev = priv_ep->cdns3_dev;
+
+	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
+		dev_err(&priv_dev->dev, "usbss: invalid parameters\n");
+		return -EINVAL;
+	}
+
+	if (!desc->wMaxPacketSize) {
+		dev_err(&priv_dev->dev, "usbss: missing wMaxPacketSize\n");
+		return -EINVAL;
+	}
+
+	if (dev_WARN_ONCE(&priv_dev->dev, priv_ep->flags & EP_ENABLED,
+			  "%s is already enabled\n", priv_ep->name))
+		return 0;
+
+	ret = cdns3_allocate_trb_pool(priv_ep);
+	if (ret)
+		return ret;
+
+	dev_dbg(&priv_dev->dev, "Enabling endpoint: %s\n", ep->name);
+	spin_lock_irqsave(&priv_dev->lock, flags);
+	cdns3_select_ep(priv_dev, desc->bEndpointAddress);
+	writel(EP_CMD_EPRST, &priv_dev->regs->ep_cmd);
+
+	ret = cdns3_handshake(&priv_dev->regs->ep_cmd,
+			      EP_CMD_CSTALL | EP_CMD_EPRST, 0, 100);
+
+	cdns3_set_register_bit(&priv_dev->regs->ep_cfg, EP_CFG_ENABLE);
+
+	ep->desc = desc;
+	priv_ep->flags &= ~(EP_PENDING_REQUEST | EP_STALL);
+	priv_ep->flags |= EP_ENABLED | EP_UPDATE_EP_TRBADDR;
+	priv_ep->enqueue = 0;
+	priv_ep->dequeue = 0;
+	reg = readl(&priv_dev->regs->ep_sts);
+	priv_ep->pcs = !!EP_STS_CCS(reg);
+	priv_ep->ccs = !!EP_STS_CCS(reg);
+	/* one TRB is reserved for link TRB used in DMULT mode*/
+	priv_ep->free_trbs = TRBS_PER_SEGMENT - 1;
+
+	spin_unlock_irqrestore(&priv_dev->lock, flags);
+	return 0;
+}
+
+/**
+ * cdns3_gadget_ep_disable Disable endpoint
+ * @ep: endpoint object
+ *
+ * Returns 0 on success, error code elsewhere
+ */
+static int cdns3_gadget_ep_disable(struct usb_ep *ep)
+{
+	struct cdns3_endpoint *priv_ep;
+	struct cdns3_device *priv_dev;
+	unsigned long flags;
+	int ret = 0;
+	struct usb_request *request;
+	u32 ep_cfg;
+
+	if (!ep) {
+		pr_debug("usbss: invalid parameters\n");
+		return -EINVAL;
+	}
+
+	priv_ep = ep_to_cdns3_ep(ep);
+	priv_dev = priv_ep->cdns3_dev;
+
+	if (dev_WARN_ONCE(&priv_dev->dev, !(priv_ep->flags & EP_ENABLED),
+			  "%s is already disabled\n", priv_ep->name))
+		return 0;
+
+	spin_lock_irqsave(&priv_dev->lock, flags);
+	if (!priv_dev->start_gadget) {
+		dev_dbg(&priv_dev->dev,
+			"Disabling endpoint at disconnection: %s\n", ep->name);
+		spin_unlock_irqrestore(&priv_dev->lock, flags);
+		return 0;
+	}
+
+	dev_dbg(&priv_dev->dev, "Disabling endpoint: %s\n", ep->name);
+
+	cdns3_select_ep(priv_dev, ep->desc->bEndpointAddress);
+	ret = cdns3_data_flush(priv_ep);
+	while (!list_empty(&priv_ep->request_list)) {
+		request = cdns3_next_request(&priv_ep->request_list);
+
+		cdns3_gadget_giveback(priv_ep, to_cdns3_request(request),
+				      -ESHUTDOWN);
+	}
+
+	ep_cfg = readl(&priv_dev->regs->ep_cfg);
+	ep_cfg &= ~EP_CFG_ENABLE;
+	writel(ep_cfg, &priv_dev->regs->ep_cfg);
+	ep->desc = NULL;
+	priv_ep->flags &= ~EP_ENABLED;
+
+	spin_unlock_irqrestore(&priv_dev->lock, flags);
+
+	return ret;
+}
+
+/**
+ * cdns3_gadget_ep_alloc_request Allocates request
+ * @ep: endpoint object associated with request
+ * @gfp_flags: gfp flags
+ *
+ * Returns allocated request address, NULL on allocation error
+ */
+struct usb_request *cdns3_gadget_ep_alloc_request(struct usb_ep *ep,
+						  gfp_t gfp_flags)
+{
+	struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
+	struct cdns3_request *priv_req;
+
+	priv_req = kzalloc(sizeof(*priv_req), gfp_flags);
+	if (!priv_req)
+		return NULL;
+
+	priv_req->priv_ep = priv_ep;
+
+	return &priv_req->request;
+}
+
+/**
+ * cdns3_gadget_ep_free_request Free memory occupied by request
+ * @ep: endpoint object associated with request
+ * @request: request to free memory
+ */
+void cdns3_gadget_ep_free_request(struct usb_ep *ep,
+				  struct usb_request *request)
+{
+	struct cdns3_request *priv_req = to_cdns3_request(request);
+
+	kfree(priv_req);
+}
+
+/**
+ * cdns3_gadget_ep_queue Transfer data on endpoint
+ * @ep: endpoint object
+ * @request: request object
+ * @gfp_flags: gfp flags
+ *
+ * Returns 0 on success, error code elsewhere
+ */
+static int __cdns3_gadget_ep_queue(struct usb_ep *ep,
+				   struct usb_request *request,
+				   gfp_t gfp_flags)
+{
+	struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
+	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+	int ret = 0;
+
+	request->actual = 0;
+	request->status = -EINPROGRESS;
+
+	dev_dbg(&priv_dev->dev, "Queuing to endpoint: %s\n", priv_ep->name);
+
+	ret = usb_gadget_map_request_by_dev(priv_dev->sysdev, request,
+					    usb_endpoint_dir_in(ep->desc));
+
+	if (ret)
+		return ret;
+
+	if (!cdns3_ep_run_transfer(priv_ep, request))
+		list_add_tail(&request->list, &priv_ep->request_list);
+
+	return ret;
+}
+
+static int cdns3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
+				 gfp_t gfp_flags)
+{
+	struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
+	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+	struct usb_request *zlp_request;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&priv_dev->lock, flags);
+	ret = __cdns3_gadget_ep_queue(ep, request, gfp_flags);
+
+	if (ret == 0 && request->zero && request->length &&
+	    (request->length % ep->maxpacket == 0)) {
+		zlp_request = cdns3_gadget_ep_alloc_request(ep, GFP_ATOMIC);
+		zlp_request->buf = priv_dev->zlp_buf;
+		zlp_request->length = 0;
+
+		dev_dbg(&priv_dev->dev, "Queuing ZLP for endpoint: %s\n",
+			priv_ep->name);
+		ret = __cdns3_gadget_ep_queue(ep, zlp_request, gfp_flags);
+	}
+
+	spin_unlock_irqrestore(&priv_dev->lock, flags);
+	return ret;
+}
+
+/**
+ * cdns3_gadget_ep_dequeue Remove request from transfer queue
+ * @ep: endpoint object associated with request
+ * @request: request object
+ *
+ * Returns 0 on success, error code elsewhere
+ */
+int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
+			    struct usb_request *request)
+{
+	struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
+	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+	struct usb_request *req, *req_temp;
+	unsigned long flags;
+	int ret = 0;
+
+	if (!ep || !request || !ep->desc)
+		return -EINVAL;
+
+	spin_lock_irqsave(&priv_dev->lock, flags);
+	dev_dbg(&priv_dev->dev, "Dequeue from %s\n", ep->name);
+
+	cdns3_select_ep(priv_dev, ep->desc->bEndpointAddress);
+	if (priv_dev->start_gadget)
+		ret = cdns3_data_flush(priv_ep);
+
+	list_for_each_entry_safe(req, req_temp, &priv_ep->request_list, list) {
+		if (request == req) {
+			cdns3_gadget_giveback(priv_ep,
+					      to_cdns3_request(request),
+					      -ECONNRESET);
+			break;
+		}
+	}
+
+	spin_unlock_irqrestore(&priv_dev->lock, flags);
+	return ret;
+}
+
+/**
+ * cdns3_gadget_ep_set_halt Sets/clears stall on selected endpoint
+ * @ep: endpoint object to set/clear stall on
+ * @value: 1 for set stall, 0 for clear stall
+ *
+ * Returns 0 on success, error code elsewhere
+ */
+int cdns3_gadget_ep_set_halt(struct usb_ep *ep, int value)
+{
+	struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
+	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+	unsigned long flags;
+	int ret = 0;
+
+	if (!(priv_ep->flags & EP_ENABLED))
+		return -EPERM;
+
+	/* if actual transfer is pending defer setting stall on this endpoint */
+	if ((priv_ep->flags & EP_PENDING_REQUEST) && value) {
+		priv_ep->flags |= EP_STALL;
+		return 0;
+	}
+
+	dev_dbg(&priv_dev->dev, "Halt endpoint %s\n", priv_ep->name);
+
+	spin_lock_irqsave(&priv_dev->lock, flags);
+
+	cdns3_select_ep(priv_dev, ep->desc->bEndpointAddress);
+	if (value) {
+		cdns3_ep_stall_flush(priv_ep);
+	} else {
+		priv_ep->flags &= ~EP_WEDGE;
+		writel(EP_CMD_CSTALL | EP_CMD_EPRST, &priv_dev->regs->ep_cmd);
+
+		/* wait for EPRST cleared */
+		ret = cdns3_handshake(&priv_dev->regs->ep_cmd,
+				      EP_CMD_EPRST, 0, 100);
+		priv_ep->flags &= ~EP_STALL;
+	}
+
+	priv_ep->flags &= ~EP_PENDING_REQUEST;
+	spin_unlock_irqrestore(&priv_dev->lock, flags);
+
+	return ret;
+}
+
+extern const struct usb_ep_ops cdns3_gadget_ep0_ops;
+
+static const struct usb_ep_ops cdns3_gadget_ep_ops = {
+	.enable = cdns3_gadget_ep_enable,
+	.disable = cdns3_gadget_ep_disable,
+	.alloc_request = cdns3_gadget_ep_alloc_request,
+	.free_request = cdns3_gadget_ep_free_request,
+	.queue = cdns3_gadget_ep_queue,
+	.dequeue = cdns3_gadget_ep_dequeue,
+	.set_halt = cdns3_gadget_ep_set_halt,
+	.set_wedge = cdns3_gadget_ep_set_wedge,
+};
+
 /**
  * cdns3_gadget_get_frame Returns number of actual ITP frame
  * @gadget: gadget object
@@ -365,8 +804,7 @@ static int cdns3_init_ep(struct cdns3_device *priv_dev)
 		usb_ep_set_maxpacket_limit(&priv_ep->endpoint,
 					   ENDPOINT_MAX_PACKET_LIMIT);
 		priv_ep->endpoint.max_streams = ENDPOINT_MAX_STREAMS;
-		//TODO: Add implementation of cdns3_gadget_ep_ops
-		//priv_ep->endpoint.ops = &cdns3_gadget_ep_ops;
+		priv_ep->endpoint.ops = &cdns3_gadget_ep_ops;
 		if (ep_dir)
 			priv_ep->endpoint.caps.dir_in = 1;
 		else
diff --git a/drivers/usb/cdns3/gadget.h b/drivers/usb/cdns3/gadget.h
index 3b0d4d2e4831..a4be288b34cb 100644
--- a/drivers/usb/cdns3/gadget.h
+++ b/drivers/usb/cdns3/gadget.h
@@ -1072,4 +1072,7 @@ void cdns3_set_register_bit(void __iomem *ptr, u32 mask);
 int cdns3_init_ep0(struct cdns3_device *priv_dev);
 void cdns3_ep0_config(struct cdns3_device *priv_dev);
 void cdns3_select_ep(struct cdns3_device *priv_dev, u32 ep);
+int cdns3_gadget_ep_set_wedge(struct usb_ep *ep);
+int cdns3_gadget_ep_set_halt(struct usb_ep *ep, int value);
+
 #endif /* __LINUX_CDNS3_GADGET */
-- 
2.17.1