[PATCH 0/2] Add USB2PHY control support for Renesas RZ/V2H(P) SoC

[PATCH 0/2] Add USB2PHY control support for Renesas RZ/V2H(P) SoC

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Hi All,

This patch series adds support for the USB2PHY control on the Renesas
RZ/V2H(P) SoC. The changes include documenting the USB2PHY control
bindings and adding the USB2PHY control driver.

These changes are necessary to support the USB2.0 on the RZ/V2H(P) SoC.

Cheers,
Prabhakar

Lad Prabhakar (2):
  dt-bindings: reset: Document RZ/V2H(P) USB2PHY Control bindings
  reset: Add USB2PHY control driver for Renesas RZ/V2H(P)

 .../reset/renesas,rzv2h-usb2phy-ctrl.yaml     |  56 +++++
 drivers/reset/Kconfig                         |   7 +
 drivers/reset/Makefile                        |   1 +
 drivers/reset/reset-rzv2h-usb2phy-ctrl.c      | 220 ++++++++++++++++++
 4 files changed, 284 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-ctrl.yaml
 create mode 100644 drivers/reset/reset-rzv2h-usb2phy-ctrl.c

-- 
2.43.0

[PATCH 1/2] dt-bindings: reset: Document RZ/V2H(P) USB2PHY Control bindings

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Add device tree binding document for the Renesas RZ/V2H(P) USB2PHY Control
Device. It mainly controls reset and power down of the USB2.0 PHY (for
both host and function).

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 .../reset/renesas,rzv2h-usb2phy-ctrl.yaml     | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-ctrl.yaml

diff --git a/Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-ctrl.yaml b/Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-ctrl.yaml
new file mode 100644
index 000000000000..ed156a1d3eb3
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-ctrl.yaml
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reset/renesas,rzv2h-usb2phy-ctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas RZ/V2H(P) USB2PHY Control
+
+maintainers:
+  - Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
+
+description:
+  The RZ/V2H(P) USB2PHY Control mainly controls reset and power down of the
+  USB2.0 PHY.
+
+properties:
+  compatible:
+    const: renesas,r9a09g057-usb2phy-ctrl  # RZ/V2H(P)
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+  '#reset-cells':
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - resets
+  - power-domains
+  - '#reset-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/renesas,r9a09g057-cpg.h>
+
+    usbphy-ctrl@15830000 {
+        compatible = "renesas,r9a09g057-usb2phy-ctrl";
+        reg = <0x15830000 0x10000>;
+        clocks = <&cpg CPG_MOD 0xb6>;
+        resets = <&cpg 0xaf>;
+        power-domains = <&cpg>;
+        #reset-cells = <0>;
+    };
-- 
2.43.0

[PATCH 2/2] reset: Add USB2PHY control driver for Renesas RZ/V2H(P)

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Add support for the USB2PHY control driver on the Renesas RZ/V2H(P) SoC.
Make the driver handle reset and power-down operations for the USB2PHY.

Pass OF data to support future SoCs with similar USB2PHY hardware but
different register configurations. Define device-specific initialization
values and control register settings in OF data to ensure flexibility
for upcoming SoCs.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/reset/Kconfig                    |   7 +
 drivers/reset/Makefile                   |   1 +
 drivers/reset/reset-rzv2h-usb2phy-ctrl.c | 220 +++++++++++++++++++++++
 3 files changed, 228 insertions(+)
 create mode 100644 drivers/reset/reset-rzv2h-usb2phy-ctrl.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 5b3abb6db248..bac08dae8905 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -218,6 +218,13 @@ config RESET_RZG2L_USBPHY_CTRL
 	  Support for USBPHY Control found on RZ/G2L family. It mainly
 	  controls reset and power down of the USB/PHY.
 
+config RESET_RZV2H_USB2PHY_CTRL
+	tristate "Renesas RZ/V2H(P) (and similar SoCs) USB2PHY control driver"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	help
+	  Support for USB2PHY Control found on the RZ/V2H(P) SoC (and similar SoCs).
+	  It mainly controls reset and power down of the USB2 PHY.
+
 config RESET_SCMI
 	tristate "Reset driver controlled via ARM SCMI interface"
 	depends on ARM_SCMI_PROTOCOL || COMPILE_TEST
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 677c4d1e2632..3cb3df018cf8 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o
 obj-$(CONFIG_RESET_QCOM_PDC) += reset-qcom-pdc.o
 obj-$(CONFIG_RESET_RASPBERRYPI) += reset-raspberrypi.o
 obj-$(CONFIG_RESET_RZG2L_USBPHY_CTRL) += reset-rzg2l-usbphy-ctrl.o
+obj-$(CONFIG_RESET_RZV2H_USB2PHY_CTRL) += reset-rzv2h-usb2phy-ctrl.o
 obj-$(CONFIG_RESET_SCMI) += reset-scmi.o
 obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
 obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
diff --git a/drivers/reset/reset-rzv2h-usb2phy-ctrl.c b/drivers/reset/reset-rzv2h-usb2phy-ctrl.c
new file mode 100644
index 000000000000..5b6ad5f6dc82
--- /dev/null
+++ b/drivers/reset/reset-rzv2h-usb2phy-ctrl.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/V2H(P) USB2PHY control driver
+ *
+ * Copyright (C) 2025 Renesas Electronics Corporation
+ */
+
+#include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/reset-controller.h>
+
+struct rzv2h_usb2phy_regval {
+	u16 reg;
+	u16 val;
+};
+
+struct rzv2h_usb2phy_data {
+	const struct rzv2h_usb2phy_regval *init_vals;
+	unsigned int init_val_count;
+
+	u16 ctrl_reg;
+	u16 ctrl_assert_val;
+	u16 ctrl_deassert_val;
+	u16 ctrl_status_bits;
+	u16 ctrl_release_val;
+
+	u16 ctrl2_reg;
+	u16 ctrl2_release_val;
+};
+
+struct rzv2h_usb2phy_ctrl_priv {
+	const struct rzv2h_usb2phy_data *data;
+	void __iomem *base;
+	struct device *dev;
+	struct reset_controller_dev rcdev;
+	spinlock_t lock;
+};
+
+#define rcdev_to_priv(x) container_of(x, struct rzv2h_usb2phy_ctrl_priv, rcdev)
+
+static int rzv2h_usbphy_ctrl_assert(struct reset_controller_dev *rcdev,
+				    unsigned long id)
+{
+	struct rzv2h_usb2phy_ctrl_priv *priv = rcdev_to_priv(rcdev);
+	const struct rzv2h_usb2phy_data *data = priv->data;
+	struct device *dev = priv->dev;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret) {
+		dev_err(dev, "pm_runtime_resume_and_get failed\n");
+		return ret;
+	}
+	scoped_guard(spinlock, &priv->lock)
+		writel(data->ctrl_assert_val, priv->base + data->ctrl_reg);
+
+	/* The reset line needs to be asserted for more than 10 microseconds. */
+	udelay(11);
+	pm_runtime_put(dev);
+
+	return 0;
+}
+
+static int rzv2h_usbphy_ctrl_deassert(struct reset_controller_dev *rcdev,
+				      unsigned long id)
+{
+	struct rzv2h_usb2phy_ctrl_priv *priv = rcdev_to_priv(rcdev);
+	const struct rzv2h_usb2phy_data *data = priv->data;
+	struct device *dev = priv->dev;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret) {
+		dev_err(dev, "pm_runtime_resume_and_get failed\n");
+		return ret;
+	}
+
+	scoped_guard(spinlock, &priv->lock) {
+		writel(data->ctrl_deassert_val, priv->base + data->ctrl_reg);
+		writel(data->ctrl2_release_val, priv->base + data->ctrl2_reg);
+		writel(data->ctrl_release_val, priv->base + data->ctrl_reg);
+	}
+
+	pm_runtime_put(dev);
+
+	return 0;
+}
+
+static int rzv2h_usbphy_ctrl_status(struct reset_controller_dev *rcdev,
+				    unsigned long id)
+{
+	struct rzv2h_usb2phy_ctrl_priv *priv = rcdev_to_priv(rcdev);
+	struct device *dev = priv->dev;
+	int ret;
+	u32 reg;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret) {
+		dev_err(dev, "pm_runtime_resume_and_get failed\n");
+		return ret;
+	}
+
+	scoped_guard(spinlock, &priv->lock)
+		reg = readl(priv->base + priv->data->ctrl_reg);
+
+	pm_runtime_put(dev);
+
+	return (reg & priv->data->ctrl_status_bits) == priv->data->ctrl_status_bits;
+}
+
+static const struct reset_control_ops rzv2h_usbphy_ctrl_reset_ops = {
+	.assert = rzv2h_usbphy_ctrl_assert,
+	.deassert = rzv2h_usbphy_ctrl_deassert,
+	.status = rzv2h_usbphy_ctrl_status,
+};
+
+static int rzv2h_reset_of_xlate(struct reset_controller_dev *rcdev,
+				const struct of_phandle_args *reset_spec)
+{
+	/* No special handling needed, we have only one reset line per device */
+	return 0;
+}
+
+static int rzv2h_usb2phy_ctrl_probe(struct platform_device *pdev)
+{
+	const struct rzv2h_usb2phy_data *data;
+	struct rzv2h_usb2phy_ctrl_priv *priv;
+	struct device *dev = &pdev->dev;
+	struct reset_control *rstc;
+	int error;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	data = of_device_get_match_data(dev);
+	if (!data)
+		return dev_err_probe(dev, -ENODEV,
+				     "failed to match device\n");
+
+	priv->data = data;
+	priv->dev = dev;
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	rstc = devm_reset_control_get_shared_deasserted(dev, NULL);
+	if (IS_ERR(rstc))
+		return dev_err_probe(dev, PTR_ERR(rstc),
+				     "failed to get deasserted reset\n");
+
+	spin_lock_init(&priv->lock);
+	dev_set_drvdata(dev, priv);
+
+	error = devm_pm_runtime_enable(dev);
+	if (error)
+		return dev_err_probe(dev, error, "Failed to enable pm_runtime\n");
+
+	error = pm_runtime_resume_and_get(dev);
+	if (error)
+		return dev_err_probe(dev, error, "pm_runtime_resume_and_get failed\n");
+
+	for (unsigned int i = 0; i < data->init_val_count; i++)
+		writel(data->init_vals[i].val, priv->base + data->init_vals[i].reg);
+
+	pm_runtime_put(dev);
+
+	priv->rcdev.ops = &rzv2h_usbphy_ctrl_reset_ops;
+	priv->rcdev.of_reset_n_cells = 0;
+	priv->rcdev.nr_resets = 1;
+	priv->rcdev.of_xlate = rzv2h_reset_of_xlate;
+	priv->rcdev.of_node = dev->of_node;
+	priv->rcdev.dev = dev;
+
+	return devm_reset_controller_register(dev, &priv->rcdev);
+}
+
+static const struct rzv2h_usb2phy_regval rzv2h_init_vals[] = {
+	{ .reg = 0xb04, .val = 0x303 },
+	{ .reg = 0xc10, .val = 0x67c },
+	{ .reg = 0xc14, .val = 0x1f },
+	{ .reg = 0x600, .val = 0x909 },
+};
+
+static const struct rzv2h_usb2phy_data rzv2h_of_data = {
+	.init_vals = rzv2h_init_vals,
+	.init_val_count = ARRAY_SIZE(rzv2h_init_vals),
+	.ctrl_reg = 0,
+	.ctrl_assert_val = 0x206,
+	.ctrl_status_bits = 0x204,
+	.ctrl_deassert_val = 0x200,
+	.ctrl_release_val = 0x0,
+	.ctrl2_reg = 0xb04,
+	.ctrl2_release_val = 0x3,
+};
+
+static const struct of_device_id rzv2h_usb2phy_ctrl_match_table[] = {
+	{ .compatible = "renesas,r9a09g057-usb2phy-ctrl", .data = &rzv2h_of_data },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzv2h_usb2phy_ctrl_match_table);
+
+static struct platform_driver rzv2h_usb2phy_ctrl_driver = {
+	.driver = {
+		.name		= "rzv2h_usb2phy_ctrl",
+		.of_match_table	= rzv2h_usb2phy_ctrl_match_table,
+	},
+	.probe = rzv2h_usb2phy_ctrl_probe,
+};
+module_platform_driver(rzv2h_usb2phy_ctrl_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/V2H(P) USB2PHY Control");
-- 
2.43.0

Re: [PATCH 1/2] dt-bindings: reset: Document RZ/V2H(P) USB2PHY Control bindings

[Krzysztof Kozlowski]

On 03/03/2025 21:12, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Add device tree binding document for the Renesas RZ/V2H(P) USB2PHY Control
> Device. It mainly controls reset and power down of the USB2.0 PHY (for
> both host and function).
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
A nit, subject: drop second/last, redundant "bindings". The
"dt-bindings" prefix is already stating that these are bindings.
See also:
https://elixir.bootlin.com/linux/v6.7-rc8/source/Documentation/devicetree/bindings/submitting-patches.rst#L18

<form letter>
Please use scripts/get_maintainers.pl to get a list of necessary people
and lists to CC. It might happen, that command when run on an older
kernel, gives you outdated entries. Therefore please be sure you base
your patches on recent Linux kernel.

Tools like b4 or scripts/get_maintainer.pl provide you proper list of
people, so fix your workflow. Tools might also fail if you work on some
ancient tree (don't, instead use mainline) or work on fork of kernel
(don't, instead use mainline). Just use b4 and everything should be
fine, although remember about `b4 prep --auto-to-cc` if you added new
patches to the patchset.

You missed at least devicetree list (maybe more), so this won't be
tested by automated tooling. Performing review on untested code might be
a waste of time.

Please kindly resend and include all necessary To/Cc entries.
</form letter>

Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: reset: Document RZ/V2H(P) USB2PHY Control bindings

[Lad, Prabhakar]

Hi Krzysztof,

On Tue, Mar 4, 2025 at 6:59 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On 03/03/2025 21:12, Prabhakar wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > Add device tree binding document for the Renesas RZ/V2H(P) USB2PHY Control
> > Device. It mainly controls reset and power down of the USB2.0 PHY (for
> > both host and function).
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> A nit, subject: drop second/last, redundant "bindings". The
> "dt-bindings" prefix is already stating that these are bindings.
> See also:
> https://elixir.bootlin.com/linux/v6.7-rc8/source/Documentation/devicetree/bindings/submitting-patches.rst#L18
>
OK, I will drop the bindings at the end.

> <form letter>
> Please use scripts/get_maintainers.pl to get a list of necessary people
> and lists to CC. It might happen, that command when run on an older
> kernel, gives you outdated entries. Therefore please be sure you base
> your patches on recent Linux kernel.
>
> Tools like b4 or scripts/get_maintainer.pl provide you proper list of
> people, so fix your workflow. Tools might also fail if you work on some
> ancient tree (don't, instead use mainline) or work on fork of kernel
> (don't, instead use mainline). Just use b4 and everything should be
> fine, although remember about `b4 prep --auto-to-cc` if you added new
> patches to the patchset.
>
> You missed at least devicetree list (maybe more), so this won't be
> tested by automated tooling. Performing review on untested code might be
> a waste of time.
>
Ouch I missed that, as I sent out a fix to one of the reset driver and
re-used the same command. I'll resend the series. Thanks for pointing
it out.

Cheers,
Prabhakar