[RFC PATCH 2/3] 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 should set
the accurate interval according to 48Mhz for those controllers.
Note: the first controller no need set it.

Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
 drivers/usb/host/xhci-mtk.c | 63 +++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 8f321f39ab96..45651b2ba2b3 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -68,11 +68,71 @@
 #define SSC_IP_SLEEP_EN	BIT(4)
 #define SSC_SPM_INT_EN		BIT(1)
 
+/* xHCI csr */
+#define LS_EOF			0x930
+#define LS_EOF_OFFSET		0x89
+
+#define FS_EOF			0x934
+#define FS_EOF_OFFSET		0x2e
+
+#define SS_GEN1_EOF		0x93c
+#define SS_GEN1_EOF_OFFSET	0x78
+
+#define HFCNTR_CFG		0x944
+#define ITP_DELTA_CLK		(0xa << 1)
+#define ITP_DELTA_CLK_MASK	GENMASK(5, 1)
+#define FRMCNT_LEV1_RANG	(0x12b << 8)
+#define FRMCNT_LEV1_RANG_MASK	GENMASK(19, 8)
+
+#define SS_GEN2_EOF		0x990
+#define SS_GEN2_EOF_OFFSET	0x3c
+#define EOF_OFFSET_MASK		GENMASK(11, 0)
+
 enum ssusb_uwk_vers {
 	SSUSB_UWK_V1 = 1,
 	SSUSB_UWK_V2,
 };
 
+/*
+ * 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, so need change the interval.
+ */
+static void xhci_mtk_set_frame_interval(struct xhci_hcd_mtk *mtk)
+{
+	struct device *dev = mtk->dev;
+	struct usb_hcd *hcd = mtk->hcd;
+	u32 value;
+
+	if (!of_device_is_compatible(dev->of_node, "mediatek,mt819-xhci"))
+		return;
+
+	value = readl(hcd->regs + HFCNTR_CFG);
+	value &= ~(ITP_DELTA_CLK_MASK | FRMCNT_LEV1_RANG_MASK);
+	value |= (ITP_DELTA_CLK | FRMCNT_LEV1_RANG);
+	writel(value, hcd->regs + HFCNTR_CFG);
+
+	value = readl(hcd->regs + LS_EOF);
+	value &= ~EOF_OFFSET_MASK;
+	value |= LS_EOF_OFFSET;
+	writel(value, hcd->regs + LS_EOF);
+
+	value = readl(hcd->regs + FS_EOF);
+	value &= ~EOF_OFFSET_MASK;
+	value |= FS_EOF_OFFSET;
+	writel(value, hcd->regs + FS_EOF);
+
+	value = readl(hcd->regs + SS_GEN1_EOF);
+	value &= ~EOF_OFFSET_MASK;
+	value |= SS_GEN1_EOF_OFFSET;
+	writel(value, hcd->regs + SS_GEN1_EOF);
+
+	value = readl(hcd->regs + SS_GEN2_EOF);
+	value &= ~EOF_OFFSET_MASK;
+	value |= SS_GEN2_EOF_OFFSET;
+	writel(value, hcd->regs + SS_GEN2_EOF);
+}
+
 static int xhci_mtk_host_enable(struct xhci_hcd_mtk *mtk)
 {
 	struct mu3c_ippc_regs __iomem *ippc = mtk->ippc_regs;
@@ -407,6 +467,8 @@ static int xhci_mtk_setup(struct usb_hcd *hcd)
 		ret = xhci_mtk_ssusb_config(mtk);
 		if (ret)
 			return ret;
+
+		xhci_mtk_set_frame_interval(mtk);
 	}
 
 	ret = xhci_gen_setup(hcd, xhci_mtk_quirks);
@@ -655,6 +717,7 @@ static const struct dev_pm_ops xhci_mtk_pm_ops = {
 #ifdef CONFIG_OF
 static const struct of_device_id mtk_xhci_of_match[] = {
 	{ .compatible = "mediatek,mt8173-xhci"},
+	{ .compatible = "mediatek,mt8195-xhci"},
 	{ .compatible = "mediatek,mtk-xhci"},
 	{ },
 };
-- 
2.18.0