[PATCH RFC 1/2] phy: qcom-snps-femto-v2: properly enable ref clock

[Adrien Thierry]

The driver is not enabling the ref clock, which thus gets disabled by
the clk_disable_unused initcall. This leads to the dwc3 controller
failing to initialize if probed after clk_disable_unused is called, for
instance when the driver is built as a module.

To fix this, add calls to clk_prepare_enable/clk_disable_unprepare at
the proper places.

Signed-off-by: Adrien Thierry <athierry at redhat.com>
---
 drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 20 +++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
index 6c237f3cc66d..8abf482e81a8 100644
--- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
+++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
@@ -166,6 +166,7 @@ static int qcom_snps_hsphy_suspend(struct qcom_snps_hsphy *hsphy)
 	}
 
 	clk_disable_unprepare(hsphy->cfg_ahb_clk);
+	clk_disable_unprepare(hsphy->ref_clk);
 	return 0;
 }
 
@@ -181,6 +182,12 @@ static int qcom_snps_hsphy_resume(struct qcom_snps_hsphy *hsphy)
 		return ret;
 	}
 
+	ret = clk_prepare_enable(hsphy->ref_clk);
+	if (ret) {
+		dev_err(&hsphy->phy->dev, "failed to enable ref clock\n");
+		return ret;
+	}
+
 	return 0;
 }
 
@@ -380,10 +387,16 @@ static int qcom_snps_hsphy_init(struct phy *phy)
 		goto poweroff_phy;
 	}
 
+	ret = clk_prepare_enable(hsphy->ref_clk);
+	if (ret) {
+		dev_err(&phy->dev, "failed to enable ref clock, %d\n", ret);
+		goto disable_ahb_clk;
+	}
+
 	ret = reset_control_assert(hsphy->phy_reset);
 	if (ret) {
 		dev_err(&phy->dev, "failed to assert phy_reset, %d\n", ret);
-		goto disable_ahb_clk;
+		goto disable_ref_clk;
 	}
 
 	usleep_range(100, 150);
@@ -391,7 +404,7 @@ static int qcom_snps_hsphy_init(struct phy *phy)
 	ret = reset_control_deassert(hsphy->phy_reset);
 	if (ret) {
 		dev_err(&phy->dev, "failed to de-assert phy_reset, %d\n", ret);
-		goto disable_ahb_clk;
+		goto disable_ref_clk;
 	}
 
 	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_CFG0,
@@ -448,6 +461,8 @@ static int qcom_snps_hsphy_init(struct phy *phy)
 
 	return 0;
 
+disable_ref_clk:
+	clk_disable_unprepare(hsphy->ref_clk);
 disable_ahb_clk:
 	clk_disable_unprepare(hsphy->cfg_ahb_clk);
 poweroff_phy:
@@ -462,6 +477,7 @@ static int qcom_snps_hsphy_exit(struct phy *phy)
 
 	reset_control_assert(hsphy->phy_reset);
 	clk_disable_unprepare(hsphy->cfg_ahb_clk);
+	clk_disable_unprepare(hsphy->ref_clk);
 	regulator_bulk_disable(ARRAY_SIZE(hsphy->vregs), hsphy->vregs);
 	hsphy->phy_initialized = false;
 
-- 
2.40.1