[PATCH v3 3/9] usb: xhci: add quirks flag to support MediaTek xHCI 0.96

[Chunfeng Yun]

There some vendor quirks for MTK xHCI 0.96 host controller:
1. It defines some extra SW scheduling parameters for HW
   to minimize the scheduling effort for synchronous and
   interrupt endpoints. The parameters are put into reserved
   DWs of slot context and endpoint context.
2. Its TDS in  Normal TRB defines a number of packets that
   remains to be transferred for a TD after processing all
   Max packets in all previous TRBs.

Signed-off-by: Chunfeng Yun <chunfeng.yun at mediatek.com>
Tested-by: Frank Wunderlich <frank-w at public-files.de>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---
v3: fix typo, and add reviewed-by Bin

v2: add Tested-by Frank
---
 drivers/usb/host/xhci-mtk.c  | 1 +
 drivers/usb/host/xhci-ring.c | 9 +++++++--
 drivers/usb/host/xhci.c      | 2 +-
 include/usb/xhci.h           | 2 ++
 4 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 8ff7185..f3f181d 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -258,6 +258,7 @@ static int xhci_mtk_probe(struct udevice *dev)
 	if (ret)
 		goto ssusb_init_err;
 
+	mtk->ctrl.quirks = XHCI_MTK_HOST;
 	hcor = (struct xhci_hcor *)((uintptr_t)mtk->hcd +
 			HC_LENGTH(xhci_readl(&mtk->hcd->cr_capbase)));
 
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 0f86b01..cf8b9d2 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -332,7 +332,8 @@ static u32 xhci_td_remainder(struct xhci_ctrl *ctrl, int transferred,
 {
 	u32 total_packet_count;
 
-	if (ctrl->hci_version < 0x100)
+	/* MTK xHCI 0.96 contains some features from 1.0 */
+	if (ctrl->hci_version < 0x100 && !(ctrl->quirks & XHCI_MTK_HOST))
 		return ((td_total_len - transferred) >> 10);
 
 	/* One TRB with a zero-length data packet. */
@@ -340,6 +341,10 @@ static u32 xhci_td_remainder(struct xhci_ctrl *ctrl, int transferred,
 	    trb_buff_len == td_total_len)
 		return 0;
 
+	/* for MTK xHCI 0.96, TD size include this TRB, but not in 1.x */
+	if ((ctrl->quirks & XHCI_MTK_HOST) && (ctrl->hci_version < 0x100))
+		trb_buff_len = 0;
+
 	total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
 
 	/* Queueing functions don't count the current TRB into transferred */
@@ -823,7 +828,7 @@ int xhci_ctrl_tx(struct usb_device *udev, unsigned long pipe,
 		field |= 0x1;
 
 	/* xHCI 1.0 6.4.1.2.1: Transfer Type field */
-	if (ctrl->hci_version >= 0x100) {
+	if (ctrl->hci_version >= 0x100 || ctrl->quirks & XHCI_MTK_HOST) {
 		if (length > 0) {
 			if (req->requesttype & USB_DIR_IN)
 				field |= (TRB_DATA_IN << TRB_TX_TYPE_SHIFT);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 4be1411..51edeb2 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -650,7 +650,7 @@ static int xhci_set_configuration(struct usb_device *udev)
 		 * are put into reserved DWs in Slot and Endpoint Contexts
 		 * for synchronous endpoints.
 		 */
-		if (IS_ENABLED(CONFIG_USB_XHCI_MTK)) {
+		if (ctrl->quirks & XHCI_MTK_HOST) {
 			ep_ctx[ep_index]->reserved[0] =
 				cpu_to_le32(EP_BPKTS(1) | EP_BBM(1));
 		}
diff --git a/include/usb/xhci.h b/include/usb/xhci.h
index 15926eb..3de46cd 100644
--- a/include/usb/xhci.h
+++ b/include/usb/xhci.h
@@ -1230,6 +1230,8 @@ struct xhci_ctrl {
 	struct xhci_virt_device *devs[MAX_HC_SLOTS];
 	int rootdev;
 	u16 hci_version;
+	u32 quirks;
+#define XHCI_MTK_HOST		BIT(0)
 };
 
 unsigned long trb_addr(struct xhci_segment *seg, union xhci_trb *trb);
-- 
1.9.1