usb: xhci-mtk: modify the SOF/ITP interval for mt8195

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@mediatek.com>
Link: https://lore.kernel.org/r/1629189389-18779-9-git-send-email-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-mtk.c

@@ -56,6 +56,27 @@
 /* u2_phy_pll register */
 #define CTRL_U2_FORCE_PLL_STB	BIT(28)
 
+/* 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		(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_CFG		0x990
+#define SSG2EOF_OFFSET		0x3c
+
+#define XSEOF_OFFSET_MASK	GENMASK(11, 0)
+
 /* usb remote wakeup registers in syscon */
 
 /* mt8173 etc */
@@ -86,6 +107,46 @@ enum ssusb_uwk_vers {
 	SSUSB_UWK_V1_2,		/* specific revision 1.2 */
 };
 
+/*
+ * 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, add workaround for it.
+ */
+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,mt8195-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_CFG);
+	value &= ~XSEOF_OFFSET_MASK;
+	value |= LSEOF_OFFSET;
+	writel(value, hcd->regs + LS_EOF_CFG);
+
+	value = readl(hcd->regs + FS_EOF_CFG);
+	value &= ~XSEOF_OFFSET_MASK;
+	value |= FSEOF_OFFSET;
+	writel(value, hcd->regs + FS_EOF_CFG);
+
+	value = readl(hcd->regs + SS_GEN1_EOF_CFG);
+	value &= ~XSEOF_OFFSET_MASK;
+	value |= SSG1EOF_OFFSET;
+	writel(value, hcd->regs + SS_GEN1_EOF_CFG);
+
+	value = readl(hcd->regs + SS_GEN2_EOF_CFG);
+	value &= ~XSEOF_OFFSET_MASK;
+	value |= SSG2EOF_OFFSET;
+	writel(value, hcd->regs + SS_GEN2_EOF_CFG);
+}
+
 static int xhci_mtk_host_enable(struct xhci_hcd_mtk *mtk)
 {
 	struct mu3c_ippc_regs __iomem *ippc = mtk->ippc_regs;
@@ -367,6 +428,9 @@ static int xhci_mtk_setup(struct usb_hcd *hcd)
 		ret = xhci_mtk_ssusb_config(mtk);
 		if (ret)
 			return ret;
+
+		/* workaround only for mt8195 */
+		xhci_mtk_set_frame_interval(mtk);
 	}
 
 	ret = xhci_gen_setup(hcd, xhci_mtk_quirks);
@@ -712,6 +776,7 @@ static const struct dev_pm_ops xhci_mtk_pm_ops = {
 
 static const struct of_device_id mtk_xhci_of_match[] = {
 	{ .compatible = "mediatek,mt8173-xhci"},
+	{ .compatible = "mediatek,mt8195-xhci"},
 	{ .compatible = "mediatek,mtk-xhci"},
 	{ },
 };