[PATCH v2 2/5] usb: dwc2: gadget: fix TX FIFO size and address initialization

[Robert Baldyga]

According to DWC2 documentation, DPTxFSize field of DPTXFSIZn register
is read only, which means that software cannot change FIFO size.

Register description says:
"The value of this register is the Largest Device Mode Periodic Tx Data
FIFO Depth (parameter OTG_TX_DPERIO_DFIFO_DEPTH_n), as specified during
coreConsultant configuration."

That means, that we have to setup only FIFO start addresses (DPTxFStAddr),
taking into account reset values of DPTxFSize.

Initialize FIFO start addresses properly and remove unneeded core related
to incorrect FIFO size initialization.

Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
---
 drivers/usb/dwc2/core.h   |  7 -------
 drivers/usb/dwc2/gadget.c | 47 ++++++++---------------------------------------
 2 files changed, 8 insertions(+), 46 deletions(-)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 7fb6434..441da5c 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -208,13 +208,6 @@ 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,
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 0d0f6fe..5de9236 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -170,6 +170,7 @@ 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 */
@@ -198,13 +199,13 @@ static void dwc2_hsotg_init_fifo(struct dwc2_hsotg *hsotg)
 	 * given endpoint.
 	 */
 	for (ep = 1; ep < MAX_EPS_CHANNELS; ep++) {
-		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];
+		dptxfsizn = dwc2_readl(hsotg->regs + DPTXFSIZN(ep));
+
+		val = (dptxfsizn & FIFOSIZE_DEPTH_MASK) | addr;
+		addr += dptxfsizn >> FIFOSIZE_DEPTH_SHIFT;
+
+		if (addr > hsotg->fifo_mem)
+			break;
 
 		dwc2_writel(val, hsotg->regs + DPTXFSIZN(ep));
 	}
@@ -3453,36 +3454,10 @@ 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);
 
@@ -3504,13 +3479,10 @@ 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);
 
@@ -3528,9 +3500,6 @@ 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;
-- 
1.9.1