phy: starfive: jh7110-usb: Fix USB 2.0 host occasional detection failure

JH7110 USB 2.0 host fails to detect USB 2.0 devices occasionally. With a
long time of debugging and testing, we found that setting Rx clock gating
control signal to normal power consumption mode can solve this problem.

Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
Link: https://lore.kernel.org/r/20250422101244.51686-1-hal.feng@starfivetech.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/starfive/phy-jh7110-usb.c b/drivers/phy/starfive/phy-jh7110-usb.c
index cb5454fbe2c8fa2de425d50a481fd6c8500a7a91..b505d89860b439c4528d25dfba450329dc05b6c6 100644 (file)
--- a/drivers/phy/starfive/phy-jh7110-usb.c
+++ b/drivers/phy/starfive/phy-jh7110-usb.c
@@ -18,6 +18,8 @@
 #include <linux/usb/of.h>
 
 #define USB_125M_CLK_RATE              125000000
+#define USB_CLK_MODE_OFF               0x0
+#define USB_CLK_MODE_RX_NORMAL_PWR     BIT(1)
 #define USB_LS_KEEPALIVE_OFF           0x4
 #define USB_LS_KEEPALIVE_ENABLE                BIT(4)
 
@@ -78,6 +80,7 @@ static int jh7110_usb2_phy_init(struct phy *_phy)
 {
        struct jh7110_usb2_phy *phy = phy_get_drvdata(_phy);
        int ret;
+       unsigned int val;
 
        ret = clk_set_rate(phy->usb_125m_clk, USB_125M_CLK_RATE);
        if (ret)
@@ -87,6 +90,10 @@ static int jh7110_usb2_phy_init(struct phy *_phy)
        if (ret)
                return ret;
 
+       val = readl(phy->regs + USB_CLK_MODE_OFF);
+       val |= USB_CLK_MODE_RX_NORMAL_PWR;
+       writel(val, phy->regs + USB_CLK_MODE_OFF);
+
        return 0;
 }