[PATCH v4 5/5] phy: fsl-imx8mq-usb: keep PHY power domain runtime always-on for i.MX8MP

[Xu Yang]

From: Xu Yang <xu.yang_2 at nxp.com>

On i.MX8MP, the USB PHY has a dedicated power domain that was previously
never powered off at runtime. With the introduction of runtime PM support,
the power domain will be powered off if the device is runtime suspended,
which breaks USB wakeup functionality.

To preserve wakeup functionality, mark the PHY power domain as runtime
always-on for i.MX8MP platform. To limit the behavior to i.MX8MP, add a
new imx95_usb_phy_ops for i.MX95 and introduce usb_phy_is_imx8mp() helper
to identify i.MX8MP PHY instance.

Signed-off-by: Xu Yang <xu.yang_2 at nxp.com>

---
Changes in v4:
 - no changes
Changes in v3:
 - new patch
---
 drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
index e24f46d7924b..c8b93ae2035f 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_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
 #include <linux/regmap.h>
@@ -660,13 +661,20 @@ static const struct phy_ops imx8mp_usb_phy_ops = {
 	.owner		= THIS_MODULE,
 };
 
+static const struct phy_ops imx95_usb_phy_ops = {
+	.init		= imx8mp_usb_phy_init,
+	.power_on	= imx8mq_phy_power_on,
+	.power_off	= imx8mq_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
 static const struct of_device_id imx8mq_usb_phy_of_match[] = {
 	{.compatible = "fsl,imx8mq-usb-phy",
 	 .data = &imx8mq_usb_phy_ops,},
 	{.compatible = "fsl,imx8mp-usb-phy",
 	 .data = &imx8mp_usb_phy_ops,},
 	{.compatible = "fsl,imx95-usb-phy",
-	 .data = &imx8mp_usb_phy_ops,},
+	 .data = &imx95_usb_phy_ops,},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, imx8mq_usb_phy_of_match);
@@ -679,6 +687,11 @@ static const struct regmap_config imx_cr_regmap_config = {
 	.max_register = 0x7,
 };
 
+static bool usb_phy_is_imx8mp(const void *data)
+{
+	return data == &imx8mp_usb_phy_ops;
+}
+
 static int imx8mq_usb_phy_probe(struct platform_device *pdev)
 {
 	struct phy_provider *phy_provider;
@@ -723,6 +736,9 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev)
 	if (!phy_ops)
 		return -EINVAL;
 
+	if (usb_phy_is_imx8mp(phy_ops))
+		dev_pm_genpd_rpm_always_on(dev, true);
+
 	imx_phy->phy = devm_phy_create(dev, NULL, phy_ops);
 	if (IS_ERR(imx_phy->phy))
 		return PTR_ERR(imx_phy->phy);

-- 
2.34.1