At very rare cases, the SoF will not send out after resume with low speed connection. The workaround is do not power down PWD.RXPWD1PT1 bit during the suspend. Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> --- drivers/usb/phy/phy-mxs-usb.c | 47 ++++++++++++++++++++++++++++++++++++++++- 1 files changed, 46 insertions(+), 1 deletions(-) diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c index 542b6ec..5ae4a57 100644 --- a/drivers/usb/phy/phy-mxs-usb.c +++ b/drivers/usb/phy/phy-mxs-usb.c @@ -69,6 +69,9 @@ #define ANADIG_USB2_LOOPBACK_SET 0x244 #define ANADIG_USB2_LOOPBACK_CLR 0x248 +#define ANADIG_USB1_MISC 0x1f0 +#define ANADIG_USB2_MISC 0x250 + #define BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG BIT(12) #define BM_ANADIG_ANA_MISC0_STOP_MODE_CONFIG_SL BIT(11) @@ -80,6 +83,11 @@ #define BM_ANADIG_USB2_LOOPBACK_UTMI_DIG_TST1 BIT(2) #define BM_ANADIG_USB2_LOOPBACK_TSTI_TX_EN BIT(5) +#define BM_ANADIG_USB1_MISC_RX_VPIN_FS BIT(29) +#define BM_ANADIG_USB1_MISC_RX_VMIN_FS BIT(28) +#define BM_ANADIG_USB2_MISC_RX_VPIN_FS BIT(29) +#define BM_ANADIG_USB2_MISC_RX_VMIN_FS BIT(28) + #define to_mxs_phy(p) container_of((p), struct mxs_phy, phy) /* Do disconnection between PHY and controller without vbus */ @@ -296,12 +304,49 @@ static void mxs_phy_shutdown(struct usb_phy *phy) clk_disable_unprepare(mxs_phy->clk); } +static bool mxs_phy_is_low_speed_connection(struct mxs_phy *mxs_phy) +{ + unsigned int line_state; + /* bit definition is the same for all controllers */ + unsigned int dp_bit = BM_ANADIG_USB1_MISC_RX_VPIN_FS, + dm_bit = BM_ANADIG_USB1_MISC_RX_VMIN_FS; + unsigned int reg = ANADIG_USB1_MISC; + + /* If the SoCs don't have anatop, quit */ + if (!mxs_phy->regmap_anatop) + return false; + + if (mxs_phy->port_id == 0) + reg = ANADIG_USB1_MISC; + else if (mxs_phy->port_id == 1) + reg = ANADIG_USB2_MISC; + + regmap_read(mxs_phy->regmap_anatop, reg, &line_state); + + if ((line_state & (dp_bit | dm_bit)) == dm_bit) + return true; + else + return false; +} + static int mxs_phy_suspend(struct usb_phy *x, int suspend) { struct mxs_phy *mxs_phy = to_mxs_phy(x); + bool low_speed_connection, vbus_is_on; + + low_speed_connection = mxs_phy_is_low_speed_connection(mxs_phy); + vbus_is_on = mxs_phy_get_vbus_status(mxs_phy); if (suspend) { - writel(0xffffffff, x->io_priv + HW_USBPHY_PWD); + /* + * FIXME: Do not power down RXPWD1PT1 bit for low speed + * connect. The low speed connection will have problem at + * very rare cases during usb suspend and resume process. + */ + if (low_speed_connection & vbus_is_on) + writel(0xfffbffff, x->io_priv + HW_USBPHY_PWD); + else + writel(0xffffffff, x->io_priv + HW_USBPHY_PWD); writel(BM_USBPHY_CTRL_CLKGATE, x->io_priv + HW_USBPHY_CTRL_SET); clk_disable_unprepare(mxs_phy->clk); -- 1.7.8 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html