phy: fsl-imx8mq-usb: enable RX Termination override

This is to resolve the problem of wakeup system by USB3 device insertion
if HSIOMIX on, in that case, the USB3 device detects RX term on so the
USB3 device doesn't downgrade to high-speed, we can't expect CONN wakeup
(for USB3) happen because the 24MHz OSC is required ON to trigger it.
Because the device works at Super-speed so DP/DM wakeup can't happen
either. Then the entire systen can't be waken up by such device attach
event.

With this override bit we can force the RX term off when enters system
suspend, and disable the override after system resume. Therefore, the
USB3 device will always downgrade to High-speed, then DP/DM wakeup can
always happen. It will correctly switch to Super-speed later when the
host reset it after the system resume back.

Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://patch.msgid.link/20260116101835.1810675-1-xu.yang_2@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
index 6c5f8271c52df8b3490b001e31df388e6876de5c..2a8fbc3ad163e3e5d3de4d6c20e8efba64803cb1 100644 (file)
--- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
+++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
@@ -51,6 +51,7 @@
 #define PHY_CTRL5_PCS_TX_SWING_FULL_MASK       GENMASK(6, 0)
 
 #define PHY_CTRL6                      0x18
+#define PHY_CTRL6_RXTERM_OVERRIDE_SEL  BIT(29)
 #define PHY_CTRL6_ALT_CLK_EN           BIT(1)
 #define PHY_CTRL6_ALT_CLK_SEL          BIT(0)
 
@@ -630,6 +631,7 @@ static int imx8mp_usb_phy_init(struct phy *phy)
 static int imx8mq_phy_power_on(struct phy *phy)
 {
        struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
+       u32 value;
        int ret;
 
        ret = regulator_enable(imx_phy->vbus);
@@ -646,12 +648,23 @@ static int imx8mq_phy_power_on(struct phy *phy)
                return ret;
        }
 
-       return ret;
+       /* Disable rx term override */
+       value = readl(imx_phy->base + PHY_CTRL6);
+       value &= ~PHY_CTRL6_RXTERM_OVERRIDE_SEL;
+       writel(value, imx_phy->base + PHY_CTRL6);
+
+       return 0;
 }
 
 static int imx8mq_phy_power_off(struct phy *phy)
 {
        struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
+       u32 value;
+
+       /* Override rx term to be 0 */
+       value = readl(imx_phy->base + PHY_CTRL6);
+       value |= PHY_CTRL6_RXTERM_OVERRIDE_SEL;
+       writel(value, imx_phy->base + PHY_CTRL6);
 
        clk_disable_unprepare(imx_phy->alt_clk);
        clk_disable_unprepare(imx_phy->clk);