[PATCH v4 10/13] phy: usb: PHY's MDIO registers not accessible without device installed
From: Al Cooper <alcooperx@gmail.com>
Date: 2020-01-03 18:19:46
Also in:
linux-devicetree, lkml
Subsystem:
broadcom brcmstb usb2 and usb3 phy driver, generic phy framework, the rest · Maintainers:
Justin Chen, Al Cooper, Vinod Koul, Linus Torvalds
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> --- drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c b/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
index ee49cbdb55bb..ce4226ac552e 100644
--- 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); }
--
2.17.1
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