phy: stm32: restore utmi switch on resume

UTMI switch value can be lost during suspend/resume, depending on the power
state reached.
This patch adds resume function to usbphyc, to reconfigure utmi switch
after suspend.
Signed-off-by: NAmelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20211015161427.220784-2-amelie.delaunay@foss.st.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

drivers/phy/st/phy-stm32-usbphyc.c

@@ -598,6 +598,18 @@ static int stm32_usbphyc_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static int __maybe_unused stm32_usbphyc_resume(struct device *dev)
+{
+	struct stm32_usbphyc *usbphyc = dev_get_drvdata(dev);
+
+	if (usbphyc->switch_setup >= 0)
+		stm32_usbphyc_switch_setup(usbphyc, usbphyc->switch_setup);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(stm32_usbphyc_pm_ops, NULL, stm32_usbphyc_resume);
+
 static const struct of_device_id stm32_usbphyc_of_match[] = {
 	{ .compatible = "st,stm32mp1-usbphyc", },
 	{ },
@@ -610,6 +622,7 @@ static struct platform_driver stm32_usbphyc_driver = {
 	.driver = {
 		.of_match_table = stm32_usbphyc_of_match,
 		.name = "stm32-usbphyc",
+		.pm = &stm32_usbphyc_pm_ops,
 	}
 };
 module_platform_driver(stm32_usbphyc_driver);