[nrf fromtree] drivers: udc_dwc2: Fix large control write transfers

The DOEPTSIZ0 XferSize field is 7 bits long, meaning that maximum single
transfer can be 127 bytes long. Configure the control write (OUT)
transfers considering the XferSize field size to support transfers with
data stage larger than 127 bytes.

Signed-off-by: Tomasz Moń <[email protected]>
(cherry picked from commit 18be1d0)
(cherry picked from commit 817a6d2)

Author: tmon-nordic

drivers/usb/udc/udc_dwc2.c

@@ -250,6 +250,28 @@ static uint32_t dwc2_get_iept_xfersize(const struct device *dev, const uint32_t
 	}
 }
 
+static uint32_t dwc2_get_oept_pktctn(const struct device *dev, const uint32_t idx)
+{
+	struct udc_dwc2_data *const priv = udc_get_private(dev);
+
+	if (idx == 0) {
+		return usb_dwc2_get_doeptsiz0_pktcnt(UINT32_MAX);
+	} else {
+		return priv->max_pktcnt;
+	}
+}
+
+static uint32_t dwc2_get_oept_xfersize(const struct device *dev, const uint32_t idx)
+{
+	struct udc_dwc2_data *const priv = udc_get_private(dev);
+
+	if (idx == 0) {
+		return usb_dwc2_get_doeptsiz0_xfersize(UINT32_MAX);
+	} else {
+		return priv->max_xfersize;
+	}
+}
+
 static void dwc2_flush_rx_fifo(const struct device *dev)
 {
 	struct usb_dwc2_reg *const base = dwc2_get_base(dev);
@@ -582,18 +604,23 @@ static void dwc2_prep_rx(const struct device *dev, struct net_buf *buf,
 	uint8_t ep_idx = USB_EP_GET_IDX(cfg->addr);
 	mem_addr_t doeptsiz_reg = (mem_addr_t)&base->out_ep[ep_idx].doeptsiz;
 	mem_addr_t doepctl_reg = dwc2_get_dxepctl_reg(dev, ep_idx);
+	uint32_t max_xfersize, max_pktcnt;
+	const uint32_t addnl = USB_MPS_ADDITIONAL_TRANSACTIONS(cfg->mps);
 	uint32_t pktcnt;
 	uint32_t doeptsiz;
 	uint32_t doepctl;
 	uint32_t xfersize;
 
+	max_xfersize = dwc2_get_oept_xfersize(dev, ep_idx);
+	max_pktcnt = dwc2_get_oept_pktctn(dev, ep_idx);
+
 	/* Clear NAK and set endpoint enable */
 	doepctl = sys_read32(doepctl_reg);
 	doepctl |= USB_DWC2_DEPCTL_EPENA | USB_DWC2_DEPCTL_CNAK;
 
 	if (dwc2_ep_is_iso(cfg)) {
 		xfersize = USB_MPS_TO_TPL(cfg->mps);
-		pktcnt = 1 + USB_MPS_ADDITIONAL_TRANSACTIONS(cfg->mps);
+		pktcnt = 1 + addnl;
 
 		if (xfersize > net_buf_tailroom(buf)) {
 			LOG_ERR("ISO RX buffer too small");
@@ -610,14 +637,18 @@ static void dwc2_prep_rx(const struct device *dev, struct net_buf *buf,
 		xfersize = net_buf_tailroom(buf);
 
 		/* Do as many packets in a single transfer as possible */
-		if (xfersize > priv->max_xfersize) {
-			xfersize = ROUND_DOWN(priv->max_xfersize, USB_MPS_TO_TPL(cfg->mps));
+		if (xfersize > max_xfersize) {
+			xfersize = ROUND_DOWN(max_xfersize, USB_MPS_TO_TPL(cfg->mps));
 		}
 
 		pktcnt = DIV_ROUND_UP(xfersize, USB_MPS_EP_SIZE(cfg->mps));
 	}
 
-	pktcnt = DIV_ROUND_UP(xfersize, udc_mps_ep_size(cfg));
+	if (pktcnt > max_pktcnt) {
+		pktcnt = ROUND_DOWN(max_pktcnt, (1 + addnl));
+		xfersize = pktcnt * udc_mps_ep_size(cfg);
+	}
+
 	doeptsiz = usb_dwc2_set_doeptsizn_pktcnt(pktcnt) |
 		   usb_dwc2_set_doeptsizn_xfersize(xfersize);
 	if (cfg->addr == USB_CONTROL_EP_OUT) {