libpayload dwc2: Use a new FIFO allocation method

Total FIFO length is split into 512 byte blocks.
Allocate these blocks to GRXFSIZ and GNPTXFSZ evenly.
This method avoids hardcoding and makes the FIFO size value
work for dwc2 controllers that have a different FIFO ram size.

BUG=chrome-os-partner:32634
BRANCH=None
TEST=Boot kernel from USB

Change-Id: I78ce0fa4c4600fb56c991874a93bdd6674e648c2
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 5645a25e95f84359cd10fc9fcf56e1f73fd6ce87
Original-Change-Id: Ib50a08c193f7f65392810ca3528a97554f2c3999
Original-Signed-off-by: huang lin <hl@rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/233119
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: http://review.coreboot.org/9454
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

2 files changed, 33 insertions, 6 deletions

diff --git a/payloads/libpayload/drivers/usb/dwc2.c b/payloads/libpayload/drivers/usb/dwc2.c
index 1092cb4ee397..71c4967e7e39 100644
--- a/payloads/libpayload/drivers/usb/dwc2.c
+++ b/payloads/libpayload/drivers/usb/dwc2.c
@@ -35,11 +35,12 @@ static void dwc2_reinit(hci_t *controller)
 	gintsts_t gintsts = { .d32 = 0 };
 	gahbcfg_t gahbcfg = { .d32 = 0 };
 	grxfsiz_t grxfsiz = { .d32 = 0 };
+	ghwcfg3_t hwcfg3 = { .d32 = 0 };
 	hcintmsk_t hcintmsk = { .d32 = 0 };
 	gnptxfsiz_t gnptxfsiz = { .d32 = 0 };
 
 	const int timeout = 10000;
-	int i;
+	int i, fifo_blocks, tx_blocks;
 
 	/* Wait for AHB idle */
 	for (i = 0; i < timeout; i++) {
@@ -86,10 +87,24 @@ static void dwc2_reinit(hci_t *controller)
 	 * The non-periodic tx fifo and rx fifo share one continuous
 	 * piece of IP-internal SRAM.
 	 */
-	grxfsiz.rxfdep = DWC2_RXFIFO_DEPTH;
+
+	/*
+	 * Read total data FIFO depth from HWCFG3
+	 * this value is in terms of 32-bit words
+	 */
+	hwcfg3.d32 = readl(&reg->core.ghwcfg3);
+	/*
+	 * Reserve 2 spaces for the status entries of received packets
+	 * and 2 spaces for bulk and control OUT endpoints. Calculate how
+	 * many blocks can be alloted, assume largest packet size is 512.
+	 */
+	fifo_blocks = (hwcfg3.dfifodepth - 4) / (512 / 4);
+	tx_blocks = fifo_blocks / 2;
+
+	grxfsiz.rxfdep = (fifo_blocks - tx_blocks) * (512 / 4) + 4;
 	writel(grxfsiz.d32, &reg->core.grxfsiz);
-	gnptxfsiz.nptxfstaddr = DWC2_RXFIFO_DEPTH;
-	gnptxfsiz.nptxfdep = DWC2_NPTXFIFO_DEPTH;
+	gnptxfsiz.nptxfstaddr = grxfsiz.rxfdep;
+	gnptxfsiz.nptxfdep = tx_blocks * (512 / 4);
 	writel(gnptxfsiz.d32, &reg->core.gnptxfsiz);
 
 	/* Init host channels */
diff --git a/payloads/libpayload/drivers/usb/dwc2_private.h b/payloads/libpayload/drivers/usb/dwc2_private.h
index 9bd83763ea48..fc658bf5fa40 100644
--- a/payloads/libpayload/drivers/usb/dwc2_private.h
+++ b/payloads/libpayload/drivers/usb/dwc2_private.h
@@ -374,7 +374,6 @@ typedef union {
 	struct {
 		unsigned nptxfstaddr:16;
 		unsigned nptxfdep:16;
-#define DWC2_NPTXFIFO_DEPTH 0x80
 	};
 } gnptxfsiz_t;
 
@@ -390,7 +389,6 @@ typedef union {
 	 */
 	struct {
 		unsigned rxfdep:16;
-#define DWC2_RXFIFO_DEPTH 0x200
 		unsigned reserved:16;
 	};
 } grxfsiz_t;
@@ -438,6 +436,20 @@ typedef union {
 } gintsts_t;
 
 /**
+ * This union represents the bit fields of the User HW Config3 Register
+ * (GHWCFG3).
+ */
+typedef union {
+	/* raw register data */
+	uint32_t d32;
+	/* register bits */
+	struct {
+		unsigned reserved:16;
+		unsigned dfifodepth:16;
+	};
+} ghwcfg3_t;
+
+/**
  * This union represents the bit fields in the Host Configuration Register.
  */
 typedef union {