[PATCH] phy: qualcomm: qmp-combo: Differentiate clocks related to the USB block

[PATCH] phy: qualcomm: qmp-combo: Differentiate clocks related to the USB block

[Wesley Cheng]

The Qualcomm QMP combo PHY has a USB and Displayport block that is
sourced with different clocks.  In situations where the USB path is not
utilized, and only Displayport is active, unnecessary clocks are enabled
and not used.  Split the current clock list into USB specific clocks,
which will be enabled whenever the USB initialization routine is
executed.

In addition, move autonomous mode control specifically when USB is
active, as its primary purpose is to detect RX detection and LFPS
signals, which occurs only when USB is active.

Signed-off-by: Wesley Cheng <wesley.cheng@oss.qualcomm.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 56 ++++++++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index a4f130fc33e3..f14fb8ef9028 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -2607,6 +2607,8 @@ struct qmp_combo {
 	struct clk_bulk_data *clks;
 	struct clk *p2rr2p_pipe_clk;
 	int num_clks;
+	struct clk_bulk_data *usb_clks;
+	int num_usb_clks;
 	struct reset_control_bulk_data *resets;
 	struct regulator_bulk_data *vregs;
 
@@ -2678,7 +2680,11 @@ static inline void qphy_clrbits(void __iomem *base, u32 offset, u32 val)
 
 /* list of clocks required by phy */
 static const char * const qmp_combo_phy_clk_l[] = {
-	"aux", "cfg_ahb", "ref", "com_aux",
+	"cfg_ahb", "ref",
+};
+
+static const char * const qmp_combo_usb_phy_clk_l[] = {
+	"aux", "com_aux",
 };
 
 /* list of resets */
@@ -4403,13 +4409,20 @@ static int qmp_combo_usb_init(struct phy *phy)
 		return 0;
 	}
 
-	ret = qmp_combo_com_init(qmp, false);
+	ret = clk_bulk_prepare_enable(qmp->num_usb_clks, qmp->usb_clks);
 	if (ret)
 		return ret;
 
+	ret = qmp_combo_com_init(qmp, false);
+	if (ret) {
+		clk_bulk_disable_unprepare(qmp->num_usb_clks, qmp->usb_clks);
+		return ret;
+	}
+
 	ret = qmp_combo_usb_power_on(phy);
 	if (ret) {
 		qmp_combo_com_exit(qmp, false);
+		clk_bulk_disable_unprepare(qmp->num_usb_clks, qmp->usb_clks);
 		return ret;
 	}
 
@@ -4440,6 +4453,8 @@ static int qmp_combo_usb_exit(struct phy *phy)
 	if (ret)
 		return ret;
 
+	clk_bulk_disable_unprepare(qmp->num_usb_clks, qmp->usb_clks);
+
 	qmp->usb_init_count--;
 
 	return 0;
@@ -4670,7 +4685,10 @@ static int __maybe_unused qmp_combo_runtime_suspend(struct device *dev)
 		return 0;
 	}
 
-	qmp_combo_enable_autonomous_mode(qmp);
+	if (qmp->usb_init_count) {
+		qmp_combo_enable_autonomous_mode(qmp);
+		clk_bulk_disable_unprepare(qmp->num_usb_clks, qmp->usb_clks);
+	}
 
 	clk_disable_unprepare(qmp->pipe_clk);
 	clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);
@@ -4701,7 +4719,12 @@ static int __maybe_unused qmp_combo_runtime_resume(struct device *dev)
 		return ret;
 	}
 
-	qmp_combo_disable_autonomous_mode(qmp);
+	if (qmp->usb_init_count) {
+		ret = clk_bulk_prepare_enable(qmp->num_usb_clks, qmp->usb_clks);
+		if (ret)
+			return ret;
+		qmp_combo_disable_autonomous_mode(qmp);
+	}
 
 	return 0;
 }
@@ -4736,19 +4759,34 @@ static int qmp_combo_reset_init(struct qmp_combo *qmp)
 static int qmp_combo_clk_init(struct qmp_combo *qmp)
 {
 	struct device *dev = qmp->dev;
-	int num = ARRAY_SIZE(qmp_combo_phy_clk_l);
+	int num_clks = ARRAY_SIZE(qmp_combo_phy_clk_l);
+	int num_usb_clks = ARRAY_SIZE(qmp_combo_usb_phy_clk_l);
 	int i;
+	int ret;
 
-	qmp->clks = devm_kcalloc(dev, num, sizeof(*qmp->clks), GFP_KERNEL);
+	qmp->clks = devm_kcalloc(dev, num_clks, sizeof(*qmp->clks), GFP_KERNEL);
 	if (!qmp->clks)
 		return -ENOMEM;
 
-	for (i = 0; i < num; i++)
+	for (i = 0; i < num_clks; i++)
 		qmp->clks[i].id = qmp_combo_phy_clk_l[i];
 
-	qmp->num_clks = num;
+	qmp->num_clks = num_clks;
+
+	qmp->usb_clks = devm_kcalloc(dev, num_usb_clks, sizeof(*qmp->usb_clks), GFP_KERNEL);
+	if (!qmp->usb_clks)
+		return -ENOMEM;
+
+	for (i = 0; i < num_usb_clks; i++)
+		qmp->usb_clks[i].id = qmp_combo_usb_phy_clk_l[i];
+
+	qmp->num_usb_clks = num_usb_clks;
+
+	ret = devm_clk_bulk_get_optional(dev, num_clks, qmp->clks);
+	if (ret)
+		return ret;
 
-	return devm_clk_bulk_get_optional(dev, num, qmp->clks);
+	return devm_clk_bulk_get_optional(dev, num_usb_clks, qmp->usb_clks);
 }
 
 static void phy_clk_release_provider(void *res)

---
base-commit: c7f2322431cb6d108b18fb4154606b49e2bc50f7
change-id: 20260930-qmp_phy_usb_clks_v1-25b9374086b2

Best regards,
--  
Wesley Cheng <wesley.cheng@oss.qualcomm.com>

Re: [PATCH] phy: qualcomm: qmp-combo: Differentiate clocks related to the USB block

[Konrad Dybcio]

On 10/1/26 3:16 AM, Wesley Cheng wrote:
> The Qualcomm QMP combo PHY has a USB and Displayport block that is
> sourced with different clocks.  In situations where the USB path is not
> utilized, and only Displayport is active, unnecessary clocks are enabled
> and not used.  Split the current clock list into USB specific clocks,
> which will be enabled whenever the USB initialization routine is
> executed.
> 
> In addition, move autonomous mode control specifically when USB is
> active, as its primary purpose is to detect RX detection and LFPS
> signals, which occurs only when USB is active.
> 
> Signed-off-by: Wesley Cheng <wesley.cheng@oss.qualcomm.com>
> ---

GPT has the following concerns:

[P1] Don't disable USB clocks that USB init didn't acquire
drivers/phy/qualcomm/phy-qcom-qmp-combo.c: USB init/runtime suspend

When USB4 is active, `qmp_combo_usb_init()` takes its early return and
increments `usb_init_count` before the new clock-enable call. Runtime
suspend then uses that count to disable `usb_clks`, although that path
didn't acquire them. This can unbalance clock references; the count
needs to reflect actual clock ownership, or the USB4 case needs
separate handling.

=> the USB4 state machinery is a bit fragile.. but perhaps an if or
   two will solve things

[P2] Unwind clocks if USB-clock resume fails
drivers/phy/qualcomm/phy-qcom-qmp-combo.c: runtime resume

The patch enables the common clocks and `pipe_clk` before enabling
`usb_clks`. If the latter enable fails, it returns without disabling
the earlier clocks, leaving them enabled after a failed resume.

Konrad

Re: [PATCH] phy: qualcomm: qmp-combo: Differentiate clocks related to the USB block

[Manivannan Sadhasivam]

On 2026-09-30 18:16 -0700, Wesley Cheng wrote:
> The Qualcomm QMP combo PHY has a USB and Displayport block that is
> sourced with different clocks.  In situations where the USB path is not
> utilized, and only Displayport is active, unnecessary clocks are enabled
> and not used.  Split the current clock list into USB specific clocks,
> which will be enabled whenever the USB initialization routine is
> executed.
> 
> In addition, move autonomous mode control specifically when USB is
> active, as its primary purpose is to detect RX detection and LFPS
> signals, which occurs only when USB is active.
> 
> Signed-off-by: Wesley Cheng <wesley.cheng@oss.qualcomm.com>

Please take a look at the issues pointed out by Sashiko.

- Mani