Revert "usb: dwc2: gadget: fix TX FIFO size and address initialization"

This reverts commit aa381a7259c3 ("usb: dwc2: gadget: fix TX FIFO size
and address initialization").

The original commit removed the FIFO size programming per endpoint. The
DPTXFSIZn register is also used for DIEPTXFn and the SIZE field is r/w
in dedicated fifo mode. So it isn't appropriate to simply remove this
initialization as it might break existing behavior.

Also, some cores might not have enough fifo space to handle the
programming method used in the reverted patch, resulting in fifo
initialization failure.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Cc: Robert Baldyga <r.baldyga@samsung.com>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/core.h

@@ -259,6 +259,13 @@ enum dwc2_lx_state {
 	DWC2_L3,	/* Off state */
 };
 
+/*
+ * Gadget periodic tx fifo sizes as used by legacy driver
+ * EP0 is not included
+ */
+#define DWC2_G_P_LEGACY_TX_FIFO_SIZE {256, 256, 256, 256, 768, 768, 768, \
+					   768, 0, 0, 0, 0, 0, 0, 0}
+
 /* Gadget ep0 states */
 enum dwc2_ep0_state {
 	DWC2_EP0_SETUP,

drivers/usb/dwc2/gadget.c

@@ -189,7 +189,6 @@ static void dwc2_hsotg_init_fifo(struct dwc2_hsotg *hsotg)
 	unsigned int ep;
 	unsigned int addr;
 	int timeout;
-	u32 dptxfsizn;
 	u32 val;
 
 	/* Reset fifo map if not correctly cleared during previous session */
@@ -218,13 +217,13 @@ static void dwc2_hsotg_init_fifo(struct dwc2_hsotg *hsotg)
 	 * given endpoint.
 	 */
 	for (ep = 1; ep < MAX_EPS_CHANNELS; ep++) {
-		dptxfsizn = dwc2_readl(hsotg->regs + DPTXFSIZN(ep));
-
-		val = (dptxfsizn & FIFOSIZE_DEPTH_MASK) | addr;
-		addr += dptxfsizn >> FIFOSIZE_DEPTH_SHIFT;
-
-		if (addr > hsotg->fifo_mem)
-			break;
+		if (!hsotg->g_tx_fifo_sz[ep])
+			continue;
+		val = addr;
+		val |= hsotg->g_tx_fifo_sz[ep] << FIFOSIZE_DEPTH_SHIFT;
+		WARN_ONCE(addr + hsotg->g_tx_fifo_sz[ep] > hsotg->fifo_mem,
+			  "insufficient fifo memory");
+		addr += hsotg->g_tx_fifo_sz[ep];
 
 		dwc2_writel(val, hsotg->regs + DPTXFSIZN(ep));
 	}
@@ -3807,10 +3806,36 @@ static void dwc2_hsotg_dump(struct dwc2_hsotg *hsotg)
 static void dwc2_hsotg_of_probe(struct dwc2_hsotg *hsotg)
 {
 	struct device_node *np = hsotg->dev->of_node;
+	u32 len = 0;
+	u32 i = 0;
 
 	/* Enable dma if requested in device tree */
 	hsotg->g_using_dma = of_property_read_bool(np, "g-use-dma");
 
+	/*
+	* Register TX periodic fifo size per endpoint.
+	* EP0 is excluded since it has no fifo configuration.
+	*/
+	if (!of_find_property(np, "g-tx-fifo-size", &len))
+		goto rx_fifo;
+
+	len /= sizeof(u32);
+
+	/* Read tx fifo sizes other than ep0 */
+	if (of_property_read_u32_array(np, "g-tx-fifo-size",
+						&hsotg->g_tx_fifo_sz[1], len))
+		goto rx_fifo;
+
+	/* Add ep0 */
+	len++;
+
+	/* Make remaining TX fifos unavailable */
+	if (len < MAX_EPS_CHANNELS) {
+		for (i = len; i < MAX_EPS_CHANNELS; i++)
+			hsotg->g_tx_fifo_sz[i] = 0;
+	}
+
+rx_fifo:
 	/* Register RX fifo size */
 	of_property_read_u32(np, "g-rx-fifo-size", &hsotg->g_rx_fifo_sz);
 
@@ -3832,10 +3857,13 @@ int dwc2_gadget_init(struct dwc2_hsotg *hsotg, int irq)
 	struct device *dev = hsotg->dev;
 	int epnum;
 	int ret;
+	int i;
+	u32 p_tx_fifo[] = DWC2_G_P_LEGACY_TX_FIFO_SIZE;
 
 	/* Initialize to legacy fifo configuration values */
 	hsotg->g_rx_fifo_sz = 2048;
 	hsotg->g_np_g_tx_fifo_sz = 1024;
+	memcpy(&hsotg->g_tx_fifo_sz[1], p_tx_fifo, sizeof(p_tx_fifo));
 	/* Device tree specific probe */
 	dwc2_hsotg_of_probe(hsotg);
 
@@ -3853,6 +3881,9 @@ int dwc2_gadget_init(struct dwc2_hsotg *hsotg, int irq)
 	dev_dbg(dev, "NonPeriodic TXFIFO size: %d\n",
 						hsotg->g_np_g_tx_fifo_sz);
 	dev_dbg(dev, "RXFIFO size: %d\n", hsotg->g_rx_fifo_sz);
+	for (i = 0; i < MAX_EPS_CHANNELS; i++)
+		dev_dbg(dev, "Periodic TXFIFO%2d size: %d\n", i,
+						hsotg->g_tx_fifo_sz[i]);
 
 	hsotg->gadget.max_speed = USB_SPEED_HIGH;
 	hsotg->gadget.ops = &dwc2_hsotg_gadget_ops;