[PATCH v3] phy: qcom: qmp-combo: Move pipe_clk on/off to common

[Val Packett <val@packett.cool>]

Keep the USB pipe clock working when the phy is in DP-only mode, because
the dwc controller still needs it for USB 2.0 over the same Type-C port.

Tested with the BenQ RD280UA monitor which has a downstream-facing port
for data passthrough that's manually switchable between USB 2 and 3,
corresponding to 4-lane and 2-lane DP respectively.

Note: the suspend/resume callbacks were already gating the enable/disable
of this clock only on init_count and not usb_init_count!

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Val Packett <val@packett.cool>
---
v3: Pull suggestion/fix and R-b
v2: https://lore.kernel.org/all/20260228220634.22778-2-val@packett.cool/
---
 drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index 93f1aa10d400..cdcfad2e86b1 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -3691,6 +3691,13 @@ static int qmp_combo_com_init(struct qmp_combo *qmp, bool force)
 	if (ret)
 		goto err_assert_reset;
 
+	/* In DP-only mode, the pipe clk is still required for USB2 */
+	ret = clk_prepare_enable(qmp->pipe_clk);
+	if (ret) {
+		dev_err(qmp->dev, "pipe_clk enable failed err=%d\n", ret);
+		goto err_disable_clocks;
+	}
+
 	qphy_setbits(com, QPHY_V3_DP_COM_POWER_DOWN_CTRL, SW_PWRDN);
 
 	/* override hardware control for reset of qmp phy */
@@ -3749,6 +3756,8 @@ static int qmp_combo_com_init(struct qmp_combo *qmp, bool force)
 
 	return 0;
 
+err_disable_clocks:
+	clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);
 err_assert_reset:
 	reset_control_bulk_assert(cfg->num_resets, qmp->resets);
 err_disable_regulators:
@@ -3768,6 +3777,7 @@ static int qmp_combo_com_exit(struct qmp_combo *qmp, bool force)
 
 	reset_control_bulk_assert(cfg->num_resets, qmp->resets);
 
+	clk_disable_unprepare(qmp->pipe_clk);
 	clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);
 
 	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
@@ -3871,12 +3881,6 @@ static int qmp_combo_usb_power_on(struct phy *phy)
 
 	qmp_configure(qmp->dev, serdes, cfg->serdes_tbl, cfg->serdes_tbl_num);
 
-	ret = clk_prepare_enable(qmp->pipe_clk);
-	if (ret) {
-		dev_err(qmp->dev, "pipe_clk enable failed err=%d\n", ret);
-		return ret;
-	}
-
 	/* Tx, Rx, and PCS configurations */
 	qmp_configure_lane(qmp->dev, tx, cfg->tx_tbl, cfg->tx_tbl_num, 1);
 	qmp_configure_lane(qmp->dev, tx2, cfg->tx_tbl, cfg->tx_tbl_num, 2);
@@ -3922,8 +3926,6 @@ static int qmp_combo_usb_power_off(struct phy *phy)
 	struct qmp_combo *qmp = phy_get_drvdata(phy);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
 
-	clk_disable_unprepare(qmp->pipe_clk);
-
 	/* PHY reset */
 	qphy_setbits(qmp->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);
 
-- 
2.52.0