[PATCH v7 3/6] phy: fsl-imx8mq-usb: add runtime PM support
Xu Yang
xu.yang_2 at oss.nxp.com
Tue Jul 28 23:38:32 PDT 2026
From: Xu Yang <xu.yang_2 at nxp.com>
Add runtime PM support to ensure the PHY clocks are properly gated
when the PHY is not in use, reducing power consumption.
Clock management is moved from power_on()/power_off() callbacks into
the runtime_resume()/runtime_suspend() callbacks respectively. The PHY
subsystem core already holds a runtime PM reference around init() and
power_on/off() calls, so no explicit clock handling is needed there.
Use devm_clk_get_enabled() and devm_clk_get_optional_enabled() in
probe() to keep clocks enabled initially. This ensures the PHY remains
functional when CONFIG_PM is disabled, where runtime suspend/resume
callbacks are never invoked.
In tca_blk_typec_switch_set(), replace the manual clk_prepare_enable()
/ clk_disable_unprepare() pair with PM_RUNTIME_ACQUIRE_IF_ENABLED() to
guard register access against a concurrently suspended PHY.
Move devm_regulator_get() before pm_runtime_enable() to avoid having
to clean up runtime PM state on regulator acquisition failure.
In remove(), call pm_runtime_get_sync() before pm_runtime_disable() to
ensure the PHY is resumed and clocks are enabled before the devres
teardown disables them.
Signed-off-by: Xu Yang <xu.yang_2 at nxp.com>
---
Changes in v7:
- replase PM_RUNTIME_ACQUIRE() with PM_RUNTIME_ACQUIRE_IF_ENABLED()
- use non-devm PM runtime callback because it's hard to avoid double clock
disable issue when probe fails or remove the driver
- improve commit message
Changes in v6:
- use devm_pm_runtime_enable() to disable runtime PM when probe fails
- simply pm_runtime_get_sync/disable/put_noidle() to pm_runtime_resume()
Changes in v5:
- use non-devm PM runtime callback to correctly enable/disable clocks
when unbind the device
Changes in v4:
- replace guard() with PM_RUNTIME_ACQUIRE()
Changes in v3:
- new patch
---
drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 103 +++++++++++++++++++++--------
1 file changed, 74 insertions(+), 29 deletions(-)
diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
index 3a5788c609e1..74e665525ec4 100644
--- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
+++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
@@ -9,6 +9,7 @@
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/usb/typec_mux.h>
@@ -136,17 +137,15 @@ static int tca_blk_typec_switch_set(struct typec_switch_dev *sw,
{
struct imx8mq_usb_phy *imx_phy = typec_switch_get_drvdata(sw);
struct tca_blk *tca = imx_phy->tca;
- int ret;
if (tca->orientation == orientation)
return 0;
- ret = clk_prepare_enable(imx_phy->clk);
- if (ret)
- return ret;
+ PM_RUNTIME_ACQUIRE_IF_ENABLED(&imx_phy->phy->dev, pm);
+ if (PM_RUNTIME_ACQUIRE_ERR(&pm))
+ return -ENXIO;
tca_blk_orientation_set(tca, orientation);
- clk_disable_unprepare(imx_phy->clk);
return 0;
}
@@ -620,16 +619,6 @@ static int imx8mq_phy_power_on(struct phy *phy)
if (ret)
return ret;
- ret = clk_prepare_enable(imx_phy->clk);
- if (ret)
- return ret;
-
- ret = clk_prepare_enable(imx_phy->alt_clk);
- if (ret) {
- clk_disable_unprepare(imx_phy->clk);
- return ret;
- }
-
/* Disable rx term override */
value = readl(imx_phy->base + PHY_CTRL6);
value &= ~PHY_CTRL6_RXTERM_OVERRIDE_SEL;
@@ -648,8 +637,6 @@ static int imx8mq_phy_power_off(struct phy *phy)
value |= PHY_CTRL6_RXTERM_OVERRIDE_SEL;
writel(value, imx_phy->base + PHY_CTRL6);
- clk_disable_unprepare(imx_phy->alt_clk);
- clk_disable_unprepare(imx_phy->clk);
regulator_disable(imx_phy->vbus);
return 0;
@@ -686,6 +673,7 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct imx8mq_usb_phy *imx_phy;
const struct phy_ops *phy_ops;
+ int ret;
imx_phy = devm_kzalloc(dev, sizeof(*imx_phy), GFP_KERNEL);
if (!imx_phy)
@@ -693,13 +681,13 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, imx_phy);
- imx_phy->clk = devm_clk_get(dev, "phy");
+ imx_phy->clk = devm_clk_get_enabled(dev, "phy");
if (IS_ERR(imx_phy->clk)) {
dev_err(dev, "failed to get imx8mq usb phy clock\n");
return PTR_ERR(imx_phy->clk);
}
- imx_phy->alt_clk = devm_clk_get_optional(dev, "alt");
+ imx_phy->alt_clk = devm_clk_get_optional_enabled(dev, "alt");
if (IS_ERR(imx_phy->alt_clk))
return dev_err_probe(dev, PTR_ERR(imx_phy->alt_clk),
"Failed to get alt clk\n");
@@ -708,44 +696,101 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev)
if (IS_ERR(imx_phy->base))
return PTR_ERR(imx_phy->base);
+ imx_phy->vbus = devm_regulator_get(dev, "vbus");
+ if (IS_ERR(imx_phy->vbus))
+ return dev_err_probe(dev, PTR_ERR(imx_phy->vbus), "failed to get vbus\n");
+
phy_ops = of_device_get_match_data(dev);
if (!phy_ops)
return -EINVAL;
- imx_phy->phy = devm_phy_create(dev, NULL, phy_ops);
- if (IS_ERR(imx_phy->phy))
- return PTR_ERR(imx_phy->phy);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
- imx_phy->vbus = devm_regulator_get(dev, "vbus");
- if (IS_ERR(imx_phy->vbus))
- return dev_err_probe(dev, PTR_ERR(imx_phy->vbus), "failed to get vbus\n");
+ imx_phy->phy = devm_phy_create(dev, NULL, phy_ops);
+ if (IS_ERR(imx_phy->phy)) {
+ ret = dev_err_probe(dev, PTR_ERR(imx_phy->phy),
+ "failed to create PHY\n");
+ goto disable_rpm;
+ }
phy_set_drvdata(imx_phy->phy, imx_phy);
imx_phy->tca = imx95_usb_phy_get_tca(pdev, imx_phy);
- if (IS_ERR(imx_phy->tca))
- return dev_err_probe(dev, PTR_ERR(imx_phy->tca),
- "failed to get tca\n");
+ if (IS_ERR(imx_phy->tca)) {
+ ret = dev_err_probe(dev, PTR_ERR(imx_phy->tca),
+ "failed to get tca\n");
+ goto disable_rpm;
+ }
imx8m_get_phy_tuning_data(imx_phy);
device_set_wakeup_capable(dev, true);
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+ if (IS_ERR(phy_provider)) {
+ ret = dev_err_probe(dev, PTR_ERR(phy_provider),
+ "failed to register phy provider\n");
+ goto disable_rpm;
+ }
- return PTR_ERR_OR_ZERO(phy_provider);
+ return 0;
+
+disable_rpm:
+ pm_runtime_disable(dev);
+ return ret;
}
static void imx8mq_usb_phy_remove(struct platform_device *pdev)
{
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ ret = pm_runtime_get_sync(dev);
+ if (ret)
+ dev_warn(dev, "failed to resume on remove: %d\n", ret);
+
+ pm_runtime_disable(dev);
+ pm_runtime_put_noidle(dev);
+}
+
+static int imx8mq_usb_phy_runtime_suspend(struct device *dev)
+{
+ struct imx8mq_usb_phy *imx_phy = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(imx_phy->alt_clk);
+ clk_disable_unprepare(imx_phy->clk);
+
+ return 0;
+}
+
+static int imx8mq_usb_phy_runtime_resume(struct device *dev)
+{
+ struct imx8mq_usb_phy *imx_phy = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(imx_phy->clk);
+ if (ret)
+ return ret;
+ ret = clk_prepare_enable(imx_phy->alt_clk);
+ if (ret) {
+ clk_disable_unprepare(imx_phy->clk);
+ return ret;
+ }
+
+ return 0;
}
+static DEFINE_RUNTIME_DEV_PM_OPS(imx8mq_usb_phy_pm_ops, imx8mq_usb_phy_runtime_suspend,
+ imx8mq_usb_phy_runtime_resume, NULL);
+
static struct platform_driver imx8mq_usb_phy_driver = {
.probe = imx8mq_usb_phy_probe,
.remove = imx8mq_usb_phy_remove,
.driver = {
.name = "imx8mq-usb-phy",
.of_match_table = imx8mq_usb_phy_of_match,
+ .pm = pm_ptr(&imx8mq_usb_phy_pm_ops),
.suppress_bind_attrs = true,
}
};
--
2.34.1
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