phy: usb: PHY's MDIO registers not accessible without device installed

When there is no device connected and FSM is enabled, the XHCI puts
the PHY into suspend mode.  When the PHY is put into suspend mode
the USB LDO powers down the PHY. This causes the MDIO to be
inaccessible and its registers reset to default. The fix is to
disable FSM.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

diff --git a/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c b/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
index ee49cbdb55bb448ae76d0431eb106131b73c5426..ce4226ac552e1498fc6e56a969ea7755babec2af 100644 (file)
--- a/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
+++ b/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
@@ -56,6 +56,7 @@
 #define USB_PHY_PLL_LDO_CTL            0x08
 #define   USB_PHY_PLL_LDO_CTL_AFE_CORERDY_MASK         0x00000004
 #define USB_PHY_UTMI_CTL_1             0x04
+#define   USB_PHY_UTMI_CTL_1_POWER_UP_FSM_EN_MASK      0x00000800
 #define   USB_PHY_UTMI_CTL_1_PHY_MODE_MASK             0x0000000c
 #define   USB_PHY_UTMI_CTL_1_PHY_MODE_SHIFT            2
 #define USB_PHY_STATUS                 0x20
@@ -229,6 +230,14 @@ static void usb_init_common_7211b0(struct brcm_usb_init_params *params)
 
        usb_init_common(params);
 
+       /*
+        * Disable FSM, otherwise the PHY will auto suspend when no
+        * device is connected and will be reset on resume.
+        */
+       reg = brcm_usb_readl(usb_phy + USB_PHY_UTMI_CTL_1);
+       reg &= ~USB_PHY_UTMI_CTL_1_POWER_UP_FSM_EN_MASK;
+       brcm_usb_writel(reg, usb_phy + USB_PHY_UTMI_CTL_1);
+
        usb2_eye_fix_7211b0(params);
 }