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authorPeter Chen <peter.chen@freescale.com>2014-02-24 03:21:04 +0100
committerFelipe Balbi <balbi@ti.com>2014-03-05 21:40:09 +0100
commit47d1845ffac0af9e4b439277fee50b62aed650a7 (patch)
treeca52c877fb4cbe99ec406ab06313335ef2768b56 /drivers
parentusb: phy: mxs: Add system suspend/resume API (diff)
downloadlinux-47d1845ffac0af9e4b439277fee50b62aed650a7.tar.xz
linux-47d1845ffac0af9e4b439277fee50b62aed650a7.zip
usb: phy: mxs: Add sync time after controller clear phcd
After clear portsc.phcd, PHY needs 200us stable time for switch 32K clock to AHB clock. Signed-off-by: Peter Chen <peter.chen@freescale.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/phy/phy-mxs-usb.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
index 31ef59f88901..c42bdf0c4a1f 100644
--- a/drivers/usb/phy/phy-mxs-usb.c
+++ b/drivers/usb/phy/phy-mxs-usb.c
@@ -151,6 +151,15 @@ static inline bool is_imx6sl_phy(struct mxs_phy *mxs_phy)
return mxs_phy->data == &imx6sl_phy_data;
}
+/*
+ * PHY needs some 32K cycles to switch from 32K clock to
+ * bus (such as AHB/AXI, etc) clock.
+ */
+static void mxs_phy_clock_switch_delay(void)
+{
+ usleep_range(300, 400);
+}
+
static int mxs_phy_hw_init(struct mxs_phy *mxs_phy)
{
int ret;
@@ -261,6 +270,7 @@ static int mxs_phy_init(struct usb_phy *phy)
int ret;
struct mxs_phy *mxs_phy = to_mxs_phy(phy);
+ mxs_phy_clock_switch_delay();
ret = clk_prepare_enable(mxs_phy->clk);
if (ret)
return ret;
@@ -289,6 +299,7 @@ static int mxs_phy_suspend(struct usb_phy *x, int suspend)
x->io_priv + HW_USBPHY_CTRL_SET);
clk_disable_unprepare(mxs_phy->clk);
} else {
+ mxs_phy_clock_switch_delay();
ret = clk_prepare_enable(mxs_phy->clk);
if (ret)
return ret;