[PATCH v2 3/5] usb: xhci-mtk: modify the SOF/ITP interval for mt8195

[Chunfeng Yun]

There are 4 USB controllers on MT8195, the controllers (IP1~IP3,
exclude IP0) have a wrong default SOF/ITP interval which is
calculated from the frame counter clock 24Mhz by default, but
in fact, the frame counter clock is 48Mhz, so we shall set the
accurate interval according to 48Mhz for those controllers.

Note:
The first controller no need set it, but if set it, shall change
tphy's pll at the same time.

Signed-off-by: Chunfeng Yun <chunfeng.yun at mediatek.com>
---
v2: use FIELD_PREP() suggested by Marek
---
 drivers/usb/host/xhci-mtk.c | 49 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 3838a990ec..63dfb793c6 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -14,8 +14,9 @@
 #include <power/regulator.h>
 #include <usb.h>
 #include <usb/xhci.h>
-#include <linux/errno.h>
+#include <linux/bitfield.h>
 #include <linux/compat.h>
+#include <linux/errno.h>
 #include <linux/iopoll.h>
 
 /* IPPC (IP Port Control) registers */
@@ -50,6 +51,25 @@
 #define IPPC_U3_CTRL(p)	(IPPC_U3_CTRL_0P + ((p) * 0x08))
 #define IPPC_U2_CTRL(p)	(IPPC_U2_CTRL_0P + ((p) * 0x08))
 
+/* xHCI CSR */
+#define LS_EOF_CFG		0x930
+#define LSEOF_OFFSET		0x89
+
+#define FS_EOF_CFG		0x934
+#define FSEOF_OFFSET		0x2e
+
+#define SS_GEN1_EOF_CFG		0x93c
+#define SSG1EOF_OFFSET		0x78
+
+#define HFCNTR_CFG		0x944
+#define ITP_DELTA_CLK_MASK	GENMASK(5, 1)
+#define FRMCNT_LEV1_RANG_MASK	GENMASK(19, 8)
+
+#define SS_GEN2_EOF_CFG		0x990
+#define SSG2EOF_OFFSET		0x3c
+
+#define XSEOF_OFFSET_MASK	GENMASK(11, 0)
+
 struct mtk_xhci {
 	struct xhci_ctrl ctrl;	/* Needs to come first in this struct! */
 	struct xhci_hccr *hcd;
@@ -65,6 +85,30 @@ struct mtk_xhci {
 	u32 u2p_dis_msk;
 };
 
+/*
+ * workaround for mt8195:
+ * MT8195 has 4 controllers, the controller1~3's default SOF/ITP interval
+ * is calculated from the frame counter clock 24M, but in fact, the clock
+ * is 48M.
+ */
+static void xhci_mtk_set_frame_interval(struct mtk_xhci *mtk)
+{
+	void __iomem *mac = (void __iomem *)mtk->hcd;
+
+	if (!ofnode_device_is_compatible(dev_ofnode(mtk->dev), "mediatek,mt8195-xhci"))
+		return;
+
+	clrsetbits_le32(mac + HFCNTR_CFG,
+			ITP_DELTA_CLK_MASK | FRMCNT_LEV1_RANG_MASK,
+			FIELD_PREP(ITP_DELTA_CLK_MASK, 0xa) |
+			FIELD_PREP(FRMCNT_LEV1_RANG_MASK, 0x12b));
+
+	clrsetbits_le32(mac + LS_EOF_CFG, XSEOF_OFFSET_MASK, LSEOF_OFFSET);
+	clrsetbits_le32(mac + FS_EOF_CFG, XSEOF_OFFSET_MASK, FSEOF_OFFSET);
+	clrsetbits_le32(mac + SS_GEN1_EOF_CFG, XSEOF_OFFSET_MASK, SSG1EOF_OFFSET);
+	clrsetbits_le32(mac + SS_GEN2_EOF_CFG, XSEOF_OFFSET_MASK, SSG2EOF_OFFSET);
+}
+
 static int xhci_mtk_host_enable(struct mtk_xhci *mtk)
 {
 	int u3_ports_disabed = 0;
@@ -278,6 +322,8 @@ static int xhci_mtk_probe(struct udevice *dev)
 	if (ret)
 		goto ssusb_init_err;
 
+	xhci_mtk_set_frame_interval(mtk);
+
 	mtk->ctrl.quirks = XHCI_MTK_HOST;
 	hcor = (struct xhci_hcor *)((uintptr_t)mtk->hcd +
 			HC_LENGTH(xhci_readl(&mtk->hcd->cr_capbase)));
@@ -308,6 +354,7 @@ static int xhci_mtk_remove(struct udevice *dev)
 
 static const struct udevice_id xhci_mtk_ids[] = {
 	{ .compatible = "mediatek,mtk-xhci" },
+	{ .compatible = "mediatek,mt8195-xhci" },
 	{ }
 };
 
-- 
2.18.0