[PATCH 22/25] phy: metanoia: add USB2 PHY driver

[Benoît Monin]

Add a minimal reset-only PHY provider for the Metanoia MT2824 USB2 PHY.
It deasserts the PHY reset required by the DWC2 USB controller on init
and asserts it again on exit.

Originally-by: Jun Chang <jun.chang at metanoia-comm.com>
Signed-off-by: Benoît Monin <benoit.monin at bootlin.com>
---
 drivers/phy/Kconfig             |  1 +
 drivers/phy/Makefile            |  1 +
 drivers/phy/metanoia/Kconfig    | 16 ++++++++
 drivers/phy/metanoia/Makefile   |  3 ++
 drivers/phy/metanoia/phy-usb2.c | 88 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 109 insertions(+)

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 105fbe408aa2..73ef61f1f53d 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -184,6 +184,7 @@ source "drivers/phy/intel/Kconfig"
 source "drivers/phy/lantiq/Kconfig"
 source "drivers/phy/marvell/Kconfig"
 source "drivers/phy/mediatek/Kconfig"
+source "drivers/phy/metanoia/Kconfig"
 source "drivers/phy/microchip/Kconfig"
 source "drivers/phy/motorola/Kconfig"
 source "drivers/phy/mscc/Kconfig"
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index c6dd02003bbe..57991b50978c 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_GENERIC_PHY)		+= allwinner/	\
 					   lantiq/	\
 					   marvell/	\
 					   mediatek/	\
+					   metanoia/	\
 					   microchip/	\
 					   motorola/	\
 					   mscc/	\
diff --git a/drivers/phy/metanoia/Kconfig b/drivers/phy/metanoia/Kconfig
new file mode 100644
index 000000000000..b8a49085bb95
--- /dev/null
+++ b/drivers/phy/metanoia/Kconfig
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Metanoia platforms
+#
+
+config PHY_METANOIA_USB2
+	tristate "Metanoia USB2 PHY reset support"
+	depends on OF && (ARCH_METANOIA || COMPILE_TEST)
+	depends on RESET_CONTROLLER
+	select GENERIC_PHY
+	help
+	  Enable this to support the USB2 PHY reset block that is part
+	  of Metanoia SoCs.
+
+	  This driver only toggles the reset line of the PHY needed by
+	  the DWC2 USB controller.
diff --git a/drivers/phy/metanoia/Makefile b/drivers/phy/metanoia/Makefile
new file mode 100644
index 000000000000..ce1b5f8af15d
--- /dev/null
+++ b/drivers/phy/metanoia/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_PHY_METANOIA_USB2)	+= phy-usb2.o
diff --git a/drivers/phy/metanoia/phy-usb2.c b/drivers/phy/metanoia/phy-usb2.c
new file mode 100644
index 000000000000..b06d423eada7
--- /dev/null
+++ b/drivers/phy/metanoia/phy-usb2.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026 Metanoia Communications Inc.
+ *
+ * Author: Jun Chang <jun.chang at metanoia-comm.com>
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+struct metanoia_usb2phy {
+	struct reset_control *reset;
+};
+
+static int metanoia_usb2phy_init(struct phy *phy)
+{
+	struct metanoia_usb2phy *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = reset_control_deassert(priv->reset);
+	if (ret)
+		dev_err(&phy->dev, "failed to reset phy: %d\n", ret);
+
+	return ret;
+}
+
+static int metanoia_usb2phy_exit(struct phy *phy)
+{
+	struct metanoia_usb2phy *priv = phy_get_drvdata(phy);
+
+	return reset_control_assert(priv->reset);
+}
+
+static const struct phy_ops metanoia_usb2phy_ops = {
+	.init = metanoia_usb2phy_init,
+	.exit = metanoia_usb2phy_exit,
+	.owner = THIS_MODULE,
+};
+
+static int metanoia_usb2phy_probe(struct platform_device *pdev)
+{
+	struct phy_provider *phy_provider;
+	struct device *dev = &pdev->dev;
+	struct metanoia_usb2phy *priv;
+	struct phy *phy;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->reset = devm_reset_control_get_exclusive(dev, "usb2-phy");
+	if (IS_ERR(priv->reset))
+		return dev_err_probe(dev, PTR_ERR(priv->reset),
+				     "failed to get usb2-phy reset\n");
+
+	phy = devm_phy_create(dev, NULL, &metanoia_usb2phy_ops);
+	if (IS_ERR(phy))
+		return dev_err_probe(dev, PTR_ERR(phy),
+				     "failed to create usb2 phy\n");
+
+	phy_set_drvdata(phy, priv);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct of_device_id metanoia_usb2phy_of_match[] = {
+	{ .compatible = "metanoia,mt2824-usb2-phy" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, metanoia_usb2phy_of_match);
+
+static struct platform_driver metanoia_usb2phy_driver = {
+	.probe = metanoia_usb2phy_probe,
+	.driver = {
+		.name = "metanoia-usb2-phy",
+		.of_match_table = metanoia_usb2phy_of_match,
+	},
+};
+module_platform_driver(metanoia_usb2phy_driver);
+
+MODULE_DESCRIPTION("Metanoia USB2 PHY driver");
+MODULE_AUTHOR("Jun Chang <jun.chang at metanoia-comm.com>");
+MODULE_LICENSE("GPL");

-- 
2.56.0