4 files changed, 104 insertions, 2 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 7c9df630dbe4..d119a1fbf946 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -48,6 +48,7 @@
 #include <linux/list.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
+#include <linux/of.h>
 
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
@@ -404,6 +405,7 @@ static void dwc3_core_exit(struct dwc3 *dwc)
 
 static int __devinit dwc3_probe(struct platform_device *pdev)
 {
+	struct device_node	*node = pdev->dev.of_node;
 	struct resource		*res;
 	struct dwc3		*dwc;
 
@@ -469,6 +471,9 @@ static int __devinit dwc3_probe(struct platform_device *pdev)
 	else
 		dwc->maximum_speed = DWC3_DCFG_SUPERSPEED;
 
+	if (of_get_property(node, "tx-fifo-resize", NULL))
+		dwc->needs_fifo_resize = true;
+
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_get_sync(&pdev->dev);
 	pm_runtime_forbid(&pdev->dev);
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index f4878c4dec0f..123c3aa47128 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -172,6 +172,10 @@
 #define DWC3_GUSB3PIPECTL_PHYSOFTRST (1 << 31)
 #define DWC3_GUSB3PIPECTL_SUSPHY (1 << 17)
 
+/* Global TX Fifo Size Register */
+#define DWC3_GTXFIFOSIZ_TXFDEF(n) ((n) & 0xffff)
+#define DWC3_GTXFIFOSIZ_TXFSTADDR(n) ((n) & 0xffff0000)
+
 /* Global HWPARAMS1 Register */
 #define DWC3_GHWPARAMS1_EN_PWROPT(n)	((n & (3 << 24)) >> 24)
 #define DWC3_GHWPARAMS1_EN_PWROPT_NO	0
@@ -546,8 +550,13 @@ struct dwc3_hwparams {
 #define DWC3_MODE_DRD		2
 #define DWC3_MODE_HUB		3
 
+#define DWC3_MDWIDTH(n)		(((n) & 0xff00) >> 8)
+
 /* HWPARAMS1 */
-#define DWC3_NUM_INT(n)	(((n) & (0x3f << 15)) >> 15)
+#define DWC3_NUM_INT(n)		(((n) & (0x3f << 15)) >> 15)
+
+/* HWPARAMS7 */
+#define DWC3_RAM1_DEPTH(n)	((n) & 0xffff)
 
 struct dwc3_request {
 	struct usb_request	request;
@@ -594,6 +603,8 @@ struct dwc3_request {
  * @ep0_expect_in: true when we expect a DATA IN transfer
  * @start_config_issued: true when StartConfig command has been issued
  * @setup_packet_pending: true when there's a Setup Packet in FIFO. Workaround
+ * @needs_fifo_resize: not all users might want fifo resizing, flag it
+ * @resize_fifos: tells us it's ok to reconfigure our TxFIFO sizes.
  * @ep0_next_event: hold the next expected event
  * @ep0state: state of endpoint zero
  * @link_state: link state
@@ -651,6 +662,8 @@ struct dwc3 {
 	unsigned		start_config_issued:1;
 	unsigned		setup_packet_pending:1;
 	unsigned		delayed_status:1;
+	unsigned		needs_fifo_resize:1;
+	unsigned		resize_fifos:1;
 
 	enum dwc3_ep0_next	ep0_next_event;
 	enum dwc3_ep0_state	ep0state;
@@ -812,6 +825,7 @@ union dwc3_event {
 
 /* prototypes */
 void dwc3_set_mode(struct dwc3 *dwc, u32 mode);
+int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc);
 
 int dwc3_host_init(struct dwc3 *dwc);
 void dwc3_host_exit(struct dwc3 *dwc);
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index e90ebb9dd3e8..5104dbf46680 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -457,8 +457,11 @@ static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 	case DWC3_ADDRESS_STATE:
 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
 		/* if the cfg matches and the cfg is non zero */
-		if (cfg && (!ret || (ret == USB_GADGET_DELAYED_STATUS)))
+		if (cfg && (!ret || (ret == USB_GADGET_DELAYED_STATUS))) {
 			dwc->dev_state = DWC3_CONFIGURED_STATE;
+			dwc->resize_fifos = true;
+			dev_dbg(dwc->dev, "resize fifos flag SET\n");
+		}
 		break;
 
 	case DWC3_CONFIGURED_STATE:
@@ -707,6 +710,12 @@ static void dwc3_ep0_do_control_status(struct dwc3 *dwc, u32 epnum)
 {
 	struct dwc3_ep		*dep = dwc->eps[epnum];
 
+	if (dwc->resize_fifos) {
+		dev_dbg(dwc->dev, "starting to resize fifos\n");
+		dwc3_gadget_resize_tx_fifos(dwc);
+		dwc->resize_fifos = 0;
+	}
+
 	WARN_ON(dwc3_ep0_start_control_status(dep));
 }
 
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index d406a75456a0..7913d1b50e38 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -125,6 +125,80 @@ int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
 	return -ETIMEDOUT;
 }
 
+/**
+ * dwc3_gadget_resize_tx_fifos - reallocate fifo spaces for current use-case
+ * @dwc: pointer to our context structure
+ *
+ * This function will a best effort FIFO allocation in order
+ * to improve FIFO usage and throughput, while still allowing
+ * us to enable as many endpoints as possible.
+ *
+ * Keep in mind that this operation will be highly dependent
+ * on the configured size for RAM1 - which contains TxFifo -,
+ * the amount of endpoints enabled on coreConsultant tool, and
+ * the width of the Master Bus.
+ *
+ * In the ideal world, we would always be able to satisfy the
+ * following equation:
+ *
+ * ((512 + 2 * MDWIDTH-Bytes) + (Number of IN Endpoints - 1) * \
+ * (3 * (1024 + MDWIDTH-Bytes) + MDWIDTH-Bytes)) / MDWIDTH-Bytes
+ *
+ * Unfortunately, due to many variables that's not always the case.
+ */
+int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc)
+{
+	int		last_fifo_depth = 0;
+	int		ram1_depth;
+	int		fifo_size;
+	int		mdwidth;
+	int		num;
+
+	if (!dwc->needs_fifo_resize)
+		return 0;
+
+	ram1_depth = DWC3_RAM1_DEPTH(dwc->hwparams.hwparams7);
+	mdwidth = DWC3_MDWIDTH(dwc->hwparams.hwparams0);
+
+	/* MDWIDTH is represented in bits, we need it in bytes */
+	mdwidth >>= 3;
+
+	/*
+	 * FIXME For now we will only allocate 1 wMaxPacketSize space
+	 * for each enabled endpoint, later patches will come to
+	 * improve this algorithm so that we better use the internal
+	 * FIFO space
+	 */
+	for (num = 0; num < DWC3_ENDPOINTS_NUM; num++) {
+		struct dwc3_ep	*dep = dwc->eps[num];
+		int		fifo_number = dep->number >> 1;
+		int		tmp;
+
+		if (!(dep->number & 1))
+			continue;
+
+		if (!(dep->flags & DWC3_EP_ENABLED))
+			continue;
+
+		tmp = dep->endpoint.maxpacket;
+		tmp += mdwidth;
+		tmp += mdwidth;
+
+		fifo_size = DIV_ROUND_UP(tmp, mdwidth);
+		fifo_size |= (last_fifo_depth << 16);
+
+		dev_vdbg(dwc->dev, "%s: Fifo Addr %04x Size %d\n",
+				dep->name, last_fifo_depth, fifo_size & 0xffff);
+
+		dwc3_writel(dwc->regs, DWC3_GTXFIFOSIZ(fifo_number),
+				fifo_size);
+
+		last_fifo_depth += (fifo_size & 0xffff);
+	}
+
+	return 0;
+}
+
 void dwc3_map_buffer_to_dma(struct dwc3_request *req)
 {
 	struct dwc3			*dwc = req->dep->dwc;