[PATCH v12 0/1] Add USB2.0 VBUS mux driver for RZ/G3E

[PATCH v12 0/1] Add USB2.0 VBUS mux driver for RZ/G3E

[Tommaso Merciai]

Dear All,

This patch adds a new mux driver for RZ/V2H USB VBENCTL VBUS_SEL.

All patches in the original series ([0]) have been merged except this one,
so this is just a follow-up patch to add the mux driver.

[0] https://patchwork.kernel.org/project/linux-renesas-soc/cover/cover.1775047175.git.tommaso.merciai.xr@bp.renesas.com/

Thanks & Regards,
Tommaso

v11->v12
 - No changes, just rebased on top of next-20260714

v10->v11:
 - Rebased on top of next-20260424
 - PATCHES 2,3,4,5 of [0] have been merged except this one,
   so this is just a follow-up patch to add the mux driver.

v9->v10:
 - Rebased on top of next-20260331
 - PATCH 4/5: Use struct reg_sequence and regmap_multi_reg_write()
   to handle initialization, assert and deassert sequences and drop
   custom struct rzv2h_usb2phy_regval.

v8->v9
 - Rebased on top of next-20260326
 - PATCH 1/6: Fixed driver comment year (2025 -> 2026)
     - Switch from devm_regmap_init_mmio() to dev_get_regmap().
     - Drop unnecessasry include bitops.h, of.h, property.h and
       drivers/reset/reset-rzv2h-usb2phy.h headers, driver is now based on
       regmap.
     - Collected PZabel tag.
 - PATCH 4/6: Collected PZabel tag.
 - PATCH 5/6: New patch.
 - PATCH 6/6: Drop linux/reset/reset_rzv2h_usb2phy.h dependecy as the
              driver is now based on regmap and does not need the
              reset driver's private header, update driver accordingly.
     - Collected PZabel tag.
 - Update cover letter.

v7->v8:
 - Rebased on top of next-20260311
 - Updated series cover letter as part of the series was already merged.

v6->v7:
  - Rebased on top of next-20260128
  - Split series into per subsystem series, no changes.

v5->v6:
 - Rebased on top of next-20251219
 - Re-arranged series order per subsystem patches.
 - Patch: 3/14: Collected tag.
 - Patch: 4/14: Fixed commit message.
 - Split from dts patches will send separate series.
 - Added merge strategy in cover letter.

v4->v5:
 - Rebased on top of next-20251127
 - Patch 01/22: Added Reviewed-by tag from Conor Dooley.
 - Patch 06/22: Changed file name to rzv2h-usb-vbenctl.c and Fixed
   Makefile, Kconfig, function names accordingly.
   Changed driver .name to "vbenctl" and fix auxiliary_device_id name.
   Updated commit msg.
 - Patch 07/22: Update mux_name to "vbenctl" to match the driver name.
   Updated commit message.
 - Patch 11/22: Fixed if statement for mux_state error check.

v3->v4:
 - Rebased on top of next-20251121
 - Added patch 01/22 to remove nodename pattern from mux-controller schema.
 - Switch back to v2 implementation for mux controller in patches
   5/22, 15/22, 16/22, 21/22.
 - Improved commit bodies for patches 5/22, 15/22, 16/22, 21/22.
 - Removed mux_chip->dev.of_node not needed in patch 06/22.
 - Collected CDooley tag in patch 09/22.
 - Added missing select MULTIPLEXER into Kconfig in patch 11/22.

v2->v3:
 - Rebased on top of next-20251110 + [1] + [2]
 - Add missing Cc: stable@vger.kernel.org in patch 03/21
 - Patch 03/21: Added missing Cc: stable@vger.kernel.org.
   Improved commit body describing the removal of rzv2h_usbphy_assert_helper()
   from rzv2h_usb2phy_reset_probe().
 - Patch 04/21: Manipulate mux-controller as an internal node.
   Improved commit body.
 - Patch 05/21: The main driver is using now __devm_auxiliary_device_create()
   then update the aux driver accordingly.
 - Patch 06/21: Use __devm_auxiliary_device_create() to create the aux device.
 - Patch 08/21: Improved commit body and mux-states description.
 - Patch 14/21: Manipulate the mux controller as an internal node,
   and update commit body accordingly.
 - Patch 15/21: Manipulate the mux controller as an internal node,
   and update commit body accordingly.
 - Patch 20/21: Manipulate the mux controller as an internal node.

v1->v2:
 - Rebased on top of next-20251103 + [1] + [2]
 - Reworked series to use mux-state for controlling VBUS_SEL
   as suggested by PZabel added also mux bindings documentation
   on phy and rst side.
 - Collected Conor Dooley tags
 - Dropped unnecessary rzv2h_usbphy_assert_helper() function from
   rzv2h_usb2phy_reset_probe()

Tommaso Merciai (1):
  mux: Add driver for Renesas RZ/V2H USB VBENCTL VBUS_SEL mux

 drivers/mux/Kconfig             | 11 +++++
 drivers/mux/Makefile            |  2 +
 drivers/mux/rzv2h-usb-vbenctl.c | 85 +++++++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+)
 create mode 100644 drivers/mux/rzv2h-usb-vbenctl.c

-- 
2.54.0

[PATCH v12 1/1] mux: Add driver for Renesas RZ/V2H USB VBENCTL VBUS_SEL mux

[Tommaso Merciai]

As per the RZ/V2H(P) HW manual, VBUSEN can be controlled by the VBUS_SEL
bit of the VBENCTL Control Register. This register is mapped in the
reset framework. The reset driver expose this register as mux-controller
and instantiates this driver. The consumer will use the mux API to
control the VBUS_SEL bit.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
---
v11->v12
 - No changes, just rebased on top of next-20260714

v10->v11:
 - No changes.

v9->v10:
 - No changes.

v8->v9:
 - Fixed driver comment year (2025 -> 2026)
 - Switch from devm_regmap_init_mmio() to dev_get_regmap().
 - Drop unnecessasry include bitops.h, of.h, property.h and
   drivers/reset/reset-rzv2h-usb2phy.h headers, driver is now based on regmap.
 - Collected PZabel tag.

v7->v8:
 - No changes.

v6->v7:
 - No changes.

v5->v6:
 - No changes.

v4->v5:
 - Changed file name to rzv2h-usb-vbenctl.c and Fixed
   Makefile, Kconfig, function names accordingly.
 - Changed driver .name to "vbenctl" and fix auxiliary_device_id name.
 - Updated commit msg.

v3->v4:
 - Removed mux_chip->dev.of_node not needed.

v2->v3:
 - Added mux_chip->dev.of_node = dev->of_node->child as the mux-controller
   is an internal node.
 - Fixed auxiliary_device_id name.
 - Get rdev using from platform_data.
 - Drop struct auxiliary_device adev from reset_rzv2h_usb2phy_adev
   as it is needed.
 - Drop to_reset_rzv2h_usb2phy_adev() as it is not needed.

v1->v2:
 - New patch

 drivers/mux/Kconfig             | 11 +++++
 drivers/mux/Makefile            |  2 +
 drivers/mux/rzv2h-usb-vbenctl.c | 85 +++++++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+)
 create mode 100644 drivers/mux/rzv2h-usb-vbenctl.c

diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
index 6d17dfa25dad..7f334540c189 100644
--- a/drivers/mux/Kconfig
+++ b/drivers/mux/Kconfig
@@ -70,6 +70,17 @@ config MUX_MMIO
 	  To compile the driver as a module, choose M here: the module will
 	  be called mux-mmio.
 
+config MUX_RZV2H_USB_VBENCTL
+	tristate "Renesas RZ/V2H USB VBENCTL VBUS_SEL mux driver"
+	depends on RESET_RZV2H_USB2PHY || COMPILE_TEST
+	depends on OF
+	select REGMAP
+	select AUXILIARY_BUS
+	default RESET_RZV2H_USB2PHY
+	help
+	  Support for USB VBENCTL VBUS_SEL mux implemented on Renesas
+	  RZ/V2H SoCs.
+
 endmenu
 
 endif # MULTIPLEXER
diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
index 6e9fa47daf56..3bd9b3846835 100644
--- a/drivers/mux/Makefile
+++ b/drivers/mux/Makefile
@@ -8,9 +8,11 @@ mux-adg792a-objs		:= adg792a.o
 mux-adgs1408-objs		:= adgs1408.o
 mux-gpio-objs			:= gpio.o
 mux-mmio-objs			:= mmio.o
+mux-rzv2h-usb-vbenctl-objs	:= rzv2h-usb-vbenctl.o
 
 obj-$(CONFIG_MULTIPLEXER)	+= mux-core.o
 obj-$(CONFIG_MUX_ADG792A)	+= mux-adg792a.o
 obj-$(CONFIG_MUX_ADGS1408)	+= mux-adgs1408.o
 obj-$(CONFIG_MUX_GPIO)		+= mux-gpio.o
 obj-$(CONFIG_MUX_MMIO)		+= mux-mmio.o
+obj-$(CONFIG_MUX_RZV2H_USB_VBENCTL)	+= mux-rzv2h-usb-vbenctl.o
diff --git a/drivers/mux/rzv2h-usb-vbenctl.c b/drivers/mux/rzv2h-usb-vbenctl.c
new file mode 100644
index 000000000000..79197fddbf74
--- /dev/null
+++ b/drivers/mux/rzv2h-usb-vbenctl.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/V2H(P) USB VBENCTL VBUS_SEL mux driver
+ *
+ * Copyright (C) 2026 Renesas Electronics Corp.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/mux/driver.h>
+#include <linux/regmap.h>
+
+#define RZV2H_VBENCTL		0xf0c
+
+struct mux_rzv2h_usb_vbenctl_priv {
+	struct regmap_field *field;
+};
+
+static int mux_rzv2h_usb_vbenctl_set(struct mux_control *mux, int state)
+{
+	struct mux_rzv2h_usb_vbenctl_priv *priv = mux_chip_priv(mux->chip);
+
+	return regmap_field_write(priv->field, state);
+}
+
+static const struct mux_control_ops mux_rzv2h_usb_vbenctl_ops = {
+	.set = mux_rzv2h_usb_vbenctl_set,
+};
+
+static int mux_rzv2h_usb_vbenctl_probe(struct auxiliary_device *adev,
+				       const struct auxiliary_device_id *id)
+{
+	struct mux_rzv2h_usb_vbenctl_priv *priv;
+	struct device *dev = &adev->dev;
+	struct mux_chip *mux_chip;
+	struct regmap *regmap;
+	struct reg_field reg_field = {
+		.reg = RZV2H_VBENCTL,
+		.lsb = 0,
+		.msb = 0,
+	};
+	int ret;
+
+	regmap = dev_get_regmap(adev->dev.parent, NULL);
+	if (!regmap)
+		return -ENODEV;
+
+	mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*priv));
+	if (IS_ERR(mux_chip))
+		return PTR_ERR(mux_chip);
+
+	priv = mux_chip_priv(mux_chip);
+
+	priv->field = devm_regmap_field_alloc(dev, regmap, reg_field);
+	if (IS_ERR(priv->field))
+		return PTR_ERR(priv->field);
+
+	mux_chip->ops = &mux_rzv2h_usb_vbenctl_ops;
+	mux_chip->mux[0].states = 2;
+	mux_chip->mux[0].idle_state = MUX_IDLE_AS_IS;
+
+	ret = devm_mux_chip_register(dev, mux_chip);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to register mux chip\n");
+
+	return 0;
+}
+
+static const struct auxiliary_device_id mux_rzv2h_usb_vbenctl_ids[] = {
+	{ .name = "rzv2h_usb2phy_reset.vbenctl" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(auxiliary, mux_rzv2h_usb_vbenctl_ids);
+
+static struct auxiliary_driver mux_rzv2h_usb_vbenctl_driver = {
+	.name		= "vbenctl",
+	.probe		= mux_rzv2h_usb_vbenctl_probe,
+	.id_table	= mux_rzv2h_usb_vbenctl_ids,
+};
+module_auxiliary_driver(mux_rzv2h_usb_vbenctl_driver);
+
+MODULE_DESCRIPTION("RZ/V2H USB VBENCTL VBUS_SEL mux driver");
+MODULE_AUTHOR("Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>");
+MODULE_LICENSE("GPL");
-- 
2.54.0

Re: [PATCH v12 1/1] mux: Add driver for Renesas RZ/V2H USB VBENCTL VBUS_SEL mux

[Alvin Šipraga]

On Wed, Jul 15, 2026 at 12:12:46PM +0200, Tommaso Merciai wrote:
> As per the RZ/V2H(P) HW manual, VBUSEN can be controlled by the VBUS_SEL
> bit of the VBENCTL Control Register. This register is mapped in the
> reset framework. The reset driver expose this register as mux-controller
> and instantiates this driver. The consumer will use the mux API to
> control the VBUS_SEL bit.
> 
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
> Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>

Reviewed-by: Alvin Šipraga <alvin.sipraga@analog.com>

Re: [PATCH v12 1/1] mux: Add driver for Renesas RZ/V2H USB VBENCTL VBUS_SEL mux

[Lad, Prabhakar]

On Wed, Jul 15, 2026 at 11:19 AM Tommaso Merciai
<tommaso.merciai.xr@bp.renesas.com> wrote:
>
> As per the RZ/V2H(P) HW manual, VBUSEN can be controlled by the VBUS_SEL
> bit of the VBENCTL Control Register. This register is mapped in the
> reset framework. The reset driver expose this register as mux-controller
> and instantiates this driver. The consumer will use the mux API to
> control the VBUS_SEL bit.
>
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
> Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> ---
> v11->v12
>  - No changes, just rebased on top of next-20260714
>
> v10->v11:
>  - No changes.
>
> v9->v10:
>  - No changes.
>
> v8->v9:
>  - Fixed driver comment year (2025 -> 2026)
>  - Switch from devm_regmap_init_mmio() to dev_get_regmap().
>  - Drop unnecessasry include bitops.h, of.h, property.h and
>    drivers/reset/reset-rzv2h-usb2phy.h headers, driver is now based on regmap.
>  - Collected PZabel tag.
>
> v7->v8:
>  - No changes.
>
> v6->v7:
>  - No changes.
>
> v5->v6:
>  - No changes.
>
> v4->v5:
>  - Changed file name to rzv2h-usb-vbenctl.c and Fixed
>    Makefile, Kconfig, function names accordingly.
>  - Changed driver .name to "vbenctl" and fix auxiliary_device_id name.
>  - Updated commit msg.
>
> v3->v4:
>  - Removed mux_chip->dev.of_node not needed.
>
> v2->v3:
>  - Added mux_chip->dev.of_node = dev->of_node->child as the mux-controller
>    is an internal node.
>  - Fixed auxiliary_device_id name.
>  - Get rdev using from platform_data.
>  - Drop struct auxiliary_device adev from reset_rzv2h_usb2phy_adev
>    as it is needed.
>  - Drop to_reset_rzv2h_usb2phy_adev() as it is not needed.
>
> v1->v2:
>  - New patch
>
>  drivers/mux/Kconfig             | 11 +++++
>  drivers/mux/Makefile            |  2 +
>  drivers/mux/rzv2h-usb-vbenctl.c | 85 +++++++++++++++++++++++++++++++++
>  3 files changed, 98 insertions(+)
>  create mode 100644 drivers/mux/rzv2h-usb-vbenctl.c
>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Cheers,
Prabhakar

Re: [PATCH v12 1/1] mux: Add driver for Renesas RZ/V2H USB VBENCTL VBUS_SEL mux

[Peter Rosin]

Hi!

Sorry for the late reply.

On 2026-07-15 12:12, Tommaso Merciai wrote:
> As per the RZ/V2H(P) HW manual, VBUSEN can be controlled by the VBUS_SEL
> bit of the VBENCTL Control Register. This register is mapped in the
> reset framework. The reset driver expose this register as mux-controller
> and instantiates this driver. The consumer will use the mux API to
> control the VBUS_SEL bit.
> 
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
> Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> ---
> v11->v12
>  - No changes, just rebased on top of next-20260714
> 
> v10->v11:
>  - No changes.
> 
> v9->v10:
>  - No changes.
> 
> v8->v9:
>  - Fixed driver comment year (2025 -> 2026)
>  - Switch from devm_regmap_init_mmio() to dev_get_regmap().
>  - Drop unnecessasry include bitops.h, of.h, property.h and
>    drivers/reset/reset-rzv2h-usb2phy.h headers, driver is now based on regmap.
>  - Collected PZabel tag.
> 
> v7->v8:
>  - No changes.
> 
> v6->v7:
>  - No changes.
> 
> v5->v6:
>  - No changes.
> 
> v4->v5:
>  - Changed file name to rzv2h-usb-vbenctl.c and Fixed
>    Makefile, Kconfig, function names accordingly.
>  - Changed driver .name to "vbenctl" and fix auxiliary_device_id name.
>  - Updated commit msg.
> 
> v3->v4:
>  - Removed mux_chip->dev.of_node not needed.
> 
> v2->v3:
>  - Added mux_chip->dev.of_node = dev->of_node->child as the mux-controller
>    is an internal node.
>  - Fixed auxiliary_device_id name.
>  - Get rdev using from platform_data.
>  - Drop struct auxiliary_device adev from reset_rzv2h_usb2phy_adev
>    as it is needed.
>  - Drop to_reset_rzv2h_usb2phy_adev() as it is not needed.
> 
> v1->v2:
>  - New patch
> 
>  drivers/mux/Kconfig             | 11 +++++
>  drivers/mux/Makefile            |  2 +
>  drivers/mux/rzv2h-usb-vbenctl.c | 85 +++++++++++++++++++++++++++++++++
>  3 files changed, 98 insertions(+)
>  create mode 100644 drivers/mux/rzv2h-usb-vbenctl.c
> 
> diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
> index 6d17dfa25dad..7f334540c189 100644
> --- a/drivers/mux/Kconfig
> +++ b/drivers/mux/Kconfig
> @@ -70,6 +70,17 @@ config MUX_MMIO
>  	  To compile the driver as a module, choose M here: the module will
>  	  be called mux-mmio.
>  
> +config MUX_RZV2H_USB_VBENCTL

Do we really need such a long name? Can we skip at least some part
of it, e.g. "USB_"? I see little in this driver that relates to
USB. And then propagate the shorter name to the file name and
various identifiers of course. Please?

> +	tristate "Renesas RZ/V2H USB VBENCTL VBUS_SEL mux driver"
> +	depends on RESET_RZV2H_USB2PHY || COMPILE_TEST
> +	depends on OF

Why OF?

> +	select REGMAP
> +	select AUXILIARY_BUS
> +	default RESET_RZV2H_USB2PHY
> +	help
> +	  Support for USB VBENCTL VBUS_SEL mux implemented on Renesas
> +	  RZ/V2H SoCs.

All the other drivers have a boilerplate "module paragraph" here:

	  To compile the driver as a module, choose M here: the module will
	  be called mux-<gazonk>.

I see no reason to exclude it here.

> +
>  endmenu
>  
>  endif # MULTIPLEXER
> diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
> index 6e9fa47daf56..3bd9b3846835 100644
> --- a/drivers/mux/Makefile
> +++ b/drivers/mux/Makefile
> @@ -8,9 +8,11 @@ mux-adg792a-objs		:= adg792a.o
>  mux-adgs1408-objs		:= adgs1408.o
>  mux-gpio-objs			:= gpio.o
>  mux-mmio-objs			:= mmio.o
> +mux-rzv2h-usb-vbenctl-objs	:= rzv2h-usb-vbenctl.o
>  
>  obj-$(CONFIG_MULTIPLEXER)	+= mux-core.o
>  obj-$(CONFIG_MUX_ADG792A)	+= mux-adg792a.o
>  obj-$(CONFIG_MUX_ADGS1408)	+= mux-adgs1408.o
>  obj-$(CONFIG_MUX_GPIO)		+= mux-gpio.o
>  obj-$(CONFIG_MUX_MMIO)		+= mux-mmio.o
> +obj-$(CONFIG_MUX_RZV2H_USB_VBENCTL)	+= mux-rzv2h-usb-vbenctl.o
> diff --git a/drivers/mux/rzv2h-usb-vbenctl.c b/drivers/mux/rzv2h-usb-vbenctl.c
> new file mode 100644
> index 000000000000..79197fddbf74
> --- /dev/null
> +++ b/drivers/mux/rzv2h-usb-vbenctl.c
> @@ -0,0 +1,85 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Renesas RZ/V2H(P) USB VBENCTL VBUS_SEL mux driver
> + *
> + * Copyright (C) 2026 Renesas Electronics Corp.
> + */
> +
> +#include <linux/auxiliary_bus.h>
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/mux/driver.h>
> +#include <linux/regmap.h>
> +
> +#define RZV2H_VBENCTL		0xf0c
> +
> +struct mux_rzv2h_usb_vbenctl_priv {
> +	struct regmap_field *field;
> +};
> +
> +static int mux_rzv2h_usb_vbenctl_set(struct mux_control *mux, int state)
> +{
> +	struct mux_rzv2h_usb_vbenctl_priv *priv = mux_chip_priv(mux->chip);
> +
> +	return regmap_field_write(priv->field, state);
> +}
> +
> +static const struct mux_control_ops mux_rzv2h_usb_vbenctl_ops = {
> +	.set = mux_rzv2h_usb_vbenctl_set,
> +};
> +
> +static int mux_rzv2h_usb_vbenctl_probe(struct auxiliary_device *adev,
> +				       const struct auxiliary_device_id *id)
> +{
> +	struct mux_rzv2h_usb_vbenctl_priv *priv;
> +	struct device *dev = &adev->dev;
> +	struct mux_chip *mux_chip;
> +	struct regmap *regmap;
> +	struct reg_field reg_field = {
> +		.reg = RZV2H_VBENCTL,
> +		.lsb = 0,
> +		.msb = 0,
> +	};

Perhaps

	struct reg_field reg_field = REG_FIELD(RZV2H_VBENCTL, 0, 0);

> +	int ret;
> +
> +	regmap = dev_get_regmap(adev->dev.parent, NULL);

Perhaps

	regmap = dev_get_regmap(dev->parent, NULL);

> +	if (!regmap)
> +		return -ENODEV;
> +
> +	mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*priv));
> +	if (IS_ERR(mux_chip))
> +		return PTR_ERR(mux_chip);
> +
> +	priv = mux_chip_priv(mux_chip);
> +
> +	priv->field = devm_regmap_field_alloc(dev, regmap, reg_field);
> +	if (IS_ERR(priv->field))
> +		return PTR_ERR(priv->field);
> +
> +	mux_chip->ops = &mux_rzv2h_usb_vbenctl_ops;
> +	mux_chip->mux[0].states = 2;
> +	mux_chip->mux[0].idle_state = MUX_IDLE_AS_IS;
> +
> +	ret = devm_mux_chip_register(dev, mux_chip);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "Failed to register mux chip\n");
> +
> +	return 0;
> +}
> +
> +static const struct auxiliary_device_id mux_rzv2h_usb_vbenctl_ids[] = {
> +	{ .name = "rzv2h_usb2phy_reset.vbenctl" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(auxiliary, mux_rzv2h_usb_vbenctl_ids);
> +
> +static struct auxiliary_driver mux_rzv2h_usb_vbenctl_driver = {
> +	.name		= "vbenctl",
> +	.probe		= mux_rzv2h_usb_vbenctl_probe,
> +	.id_table	= mux_rzv2h_usb_vbenctl_ids,
> +};
> +module_auxiliary_driver(mux_rzv2h_usb_vbenctl_driver);
> +

I'm not previously familiar with the auxiliary bus. When I read about
it I find this:

	"A key requirement for utilizing the auxiliary bus is that
	there is no dependency on a physical bus, device, register
	accesses or regmap support."

That seems to contradict this driver with its dependency on regmap,
thus violating the above key requirement?

Cheers,
Peter

> +MODULE_DESCRIPTION("RZ/V2H USB VBENCTL VBUS_SEL mux driver");
> +MODULE_AUTHOR("Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>");
> +MODULE_LICENSE("GPL");

Re: [PATCH v12 1/1] mux: Add driver for Renesas RZ/V2H USB VBENCTL VBUS_SEL mux

[Tommaso Merciai]

Hi Peter,
Thanks for your review.

On Fri, Aug 07, 2026 at 08:23:13AM +0200, Peter Rosin wrote:
> Hi!
> 
> Sorry for the late reply.
> 
> On 2026-07-15 12:12, Tommaso Merciai wrote:
> > As per the RZ/V2H(P) HW manual, VBUSEN can be controlled by the VBUS_SEL
> > bit of the VBENCTL Control Register. This register is mapped in the
> > reset framework. The reset driver expose this register as mux-controller
> > and instantiates this driver. The consumer will use the mux API to
> > control the VBUS_SEL bit.
> > 
> > Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> > ---
> > v11->v12
> >  - No changes, just rebased on top of next-20260714
> > 
> > v10->v11:
> >  - No changes.
> > 
> > v9->v10:
> >  - No changes.
> > 
> > v8->v9:
> >  - Fixed driver comment year (2025 -> 2026)
> >  - Switch from devm_regmap_init_mmio() to dev_get_regmap().
> >  - Drop unnecessasry include bitops.h, of.h, property.h and
> >    drivers/reset/reset-rzv2h-usb2phy.h headers, driver is now based on regmap.
> >  - Collected PZabel tag.
> > 
> > v7->v8:
> >  - No changes.
> > 
> > v6->v7:
> >  - No changes.
> > 
> > v5->v6:
> >  - No changes.
> > 
> > v4->v5:
> >  - Changed file name to rzv2h-usb-vbenctl.c and Fixed
> >    Makefile, Kconfig, function names accordingly.
> >  - Changed driver .name to "vbenctl" and fix auxiliary_device_id name.
> >  - Updated commit msg.
> > 
> > v3->v4:
> >  - Removed mux_chip->dev.of_node not needed.
> > 
> > v2->v3:
> >  - Added mux_chip->dev.of_node = dev->of_node->child as the mux-controller
> >    is an internal node.
> >  - Fixed auxiliary_device_id name.
> >  - Get rdev using from platform_data.
> >  - Drop struct auxiliary_device adev from reset_rzv2h_usb2phy_adev
> >    as it is needed.
> >  - Drop to_reset_rzv2h_usb2phy_adev() as it is not needed.
> > 
> > v1->v2:
> >  - New patch
> > 
> >  drivers/mux/Kconfig             | 11 +++++
> >  drivers/mux/Makefile            |  2 +
> >  drivers/mux/rzv2h-usb-vbenctl.c | 85 +++++++++++++++++++++++++++++++++
> >  3 files changed, 98 insertions(+)
> >  create mode 100644 drivers/mux/rzv2h-usb-vbenctl.c
> > 
> > diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
> > index 6d17dfa25dad..7f334540c189 100644
> > --- a/drivers/mux/Kconfig
> > +++ b/drivers/mux/Kconfig
> > @@ -70,6 +70,17 @@ config MUX_MMIO
> >  	  To compile the driver as a module, choose M here: the module will
> >  	  be called mux-mmio.
> >  
> > +config MUX_RZV2H_USB_VBENCTL
> 
> Do we really need such a long name? Can we skip at least some part
> of it, e.g. "USB_"? I see little in this driver that relates to
> USB. And then propagate the shorter name to the file name and
> various identifiers of course. Please?

Ok we can go with:

	MUX_RZV2H_VBENCTL

Then propagating:

	rzv2h-vbenctl.c

And functions prefix:

	mux_rzv2h_vbenctl_*


I will do this in v13.


> 
> > +	tristate "Renesas RZ/V2H USB VBENCTL VBUS_SEL mux driver"
> > +	depends on RESET_RZV2H_USB2PHY || COMPILE_TEST
> > +	depends on OF
> 
> Why OF?

Good catch, will drop this in v13.

> 
> > +	select REGMAP
> > +	select AUXILIARY_BUS
> > +	default RESET_RZV2H_USB2PHY
> > +	help
> > +	  Support for USB VBENCTL VBUS_SEL mux implemented on Renesas
> > +	  RZ/V2H SoCs.
> 
> All the other drivers have a boilerplate "module paragraph" here:
> 
> 	  To compile the driver as a module, choose M here: the module will
> 	  be called mux-<gazonk>.
> 
> I see no reason to exclude it here.

Will add this section in v13.

> 
> > +
> >  endmenu
> >  
> >  endif # MULTIPLEXER
> > diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
> > index 6e9fa47daf56..3bd9b3846835 100644
> > --- a/drivers/mux/Makefile
> > +++ b/drivers/mux/Makefile
> > @@ -8,9 +8,11 @@ mux-adg792a-objs		:= adg792a.o
> >  mux-adgs1408-objs		:= adgs1408.o
> >  mux-gpio-objs			:= gpio.o
> >  mux-mmio-objs			:= mmio.o
> > +mux-rzv2h-usb-vbenctl-objs	:= rzv2h-usb-vbenctl.o
> >  
> >  obj-$(CONFIG_MULTIPLEXER)	+= mux-core.o
> >  obj-$(CONFIG_MUX_ADG792A)	+= mux-adg792a.o
> >  obj-$(CONFIG_MUX_ADGS1408)	+= mux-adgs1408.o
> >  obj-$(CONFIG_MUX_GPIO)		+= mux-gpio.o
> >  obj-$(CONFIG_MUX_MMIO)		+= mux-mmio.o
> > +obj-$(CONFIG_MUX_RZV2H_USB_VBENCTL)	+= mux-rzv2h-usb-vbenctl.o
> > diff --git a/drivers/mux/rzv2h-usb-vbenctl.c b/drivers/mux/rzv2h-usb-vbenctl.c
> > new file mode 100644
> > index 000000000000..79197fddbf74
> > --- /dev/null
> > +++ b/drivers/mux/rzv2h-usb-vbenctl.c
> > @@ -0,0 +1,85 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Renesas RZ/V2H(P) USB VBENCTL VBUS_SEL mux driver
> > + *
> > + * Copyright (C) 2026 Renesas Electronics Corp.
> > + */
> > +
> > +#include <linux/auxiliary_bus.h>
> > +#include <linux/err.h>
> > +#include <linux/module.h>
> > +#include <linux/mux/driver.h>
> > +#include <linux/regmap.h>
> > +
> > +#define RZV2H_VBENCTL		0xf0c
> > +
> > +struct mux_rzv2h_usb_vbenctl_priv {
> > +	struct regmap_field *field;
> > +};
> > +
> > +static int mux_rzv2h_usb_vbenctl_set(struct mux_control *mux, int state)
> > +{
> > +	struct mux_rzv2h_usb_vbenctl_priv *priv = mux_chip_priv(mux->chip);
> > +
> > +	return regmap_field_write(priv->field, state);
> > +}
> > +
> > +static const struct mux_control_ops mux_rzv2h_usb_vbenctl_ops = {
> > +	.set = mux_rzv2h_usb_vbenctl_set,
> > +};
> > +
> > +static int mux_rzv2h_usb_vbenctl_probe(struct auxiliary_device *adev,
> > +				       const struct auxiliary_device_id *id)
> > +{
> > +	struct mux_rzv2h_usb_vbenctl_priv *priv;
> > +	struct device *dev = &adev->dev;
> > +	struct mux_chip *mux_chip;
> > +	struct regmap *regmap;
> > +	struct reg_field reg_field = {
> > +		.reg = RZV2H_VBENCTL,
> > +		.lsb = 0,
> > +		.msb = 0,
> > +	};
> 
> Perhaps
> 
> 	struct reg_field reg_field = REG_FIELD(RZV2H_VBENCTL, 0, 0);

Ok will use this in v13.

> 
> > +	int ret;
> > +
> > +	regmap = dev_get_regmap(adev->dev.parent, NULL);
> 
> Perhaps
> 
> 	regmap = dev_get_regmap(dev->parent, NULL);

Ok, will use this in v13.


> 
> > +	if (!regmap)
> > +		return -ENODEV;
> > +
> > +	mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*priv));
> > +	if (IS_ERR(mux_chip))
> > +		return PTR_ERR(mux_chip);
> > +
> > +	priv = mux_chip_priv(mux_chip);
> > +
> > +	priv->field = devm_regmap_field_alloc(dev, regmap, reg_field);
> > +	if (IS_ERR(priv->field))
> > +		return PTR_ERR(priv->field);
> > +
> > +	mux_chip->ops = &mux_rzv2h_usb_vbenctl_ops;
> > +	mux_chip->mux[0].states = 2;
> > +	mux_chip->mux[0].idle_state = MUX_IDLE_AS_IS;
> > +
> > +	ret = devm_mux_chip_register(dev, mux_chip);
> > +	if (ret < 0)
> > +		return dev_err_probe(dev, ret, "Failed to register mux chip\n");
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct auxiliary_device_id mux_rzv2h_usb_vbenctl_ids[] = {
> > +	{ .name = "rzv2h_usb2phy_reset.vbenctl" },
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(auxiliary, mux_rzv2h_usb_vbenctl_ids);
> > +
> > +static struct auxiliary_driver mux_rzv2h_usb_vbenctl_driver = {
> > +	.name		= "vbenctl",
> > +	.probe		= mux_rzv2h_usb_vbenctl_probe,
> > +	.id_table	= mux_rzv2h_usb_vbenctl_ids,
> > +};
> > +module_auxiliary_driver(mux_rzv2h_usb_vbenctl_driver);
> > +
> 
> I'm not previously familiar with the auxiliary bus. When I read about
> it I find this:
> 
> 	"A key requirement for utilizing the auxiliary bus is that
> 	there is no dependency on a physical bus, device, register
> 	accesses or regmap support."
> 
> That seems to contradict this driver with its dependency on regmap,
> thus violating the above key requirement?

I'm seeing a very close pattern in [1]. clk-imx8ulp-sim-lpav.c create a
regmap for its auxiliary reset and mux driver. 

The parent driver is creating the axuiliary device in [2], this create
"clk_imx8ulp_sim_lpav.reset".

Then later reset-imx8mp-audiomix.c into
imx8mp_audiomix_reset_get_regmap() [3] take the rgmap from the parent.

Also reset-meson-aux.c [4] is aux device and is taking the regmap
from the parent.

IMHO the doc paragraph share why such a device can't be a platform
device or an MFD, matching on the auxiliary bus is a plain
string compare, so no register access is involved in match or bind.

[1] https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/clk/imx/clk-imx8ulp-sim-lpav.c#L95
[2] https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/clk/imx/clk-imx8ulp-sim-lpav.c#L123
[3] https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/reset/reset-imx8mp-audiomix.c#L162
[4] https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/reset/amlogic/reset-meson-aux.c#L65


Kind regards,
Tommaso

> 
> Cheers,
> Peter
> 
> > +MODULE_DESCRIPTION("RZ/V2H USB VBENCTL VBUS_SEL mux driver");
> > +MODULE_AUTHOR("Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>");
> > +MODULE_LICENSE("GPL");
> 

Re: [PATCH v12 1/1] mux: Add driver for Renesas RZ/V2H USB VBENCTL VBUS_SEL mux

[Peter Rosin]

On 2026-08-07 12:05, Tommaso Merciai wrote:
> On Fri, Aug 07, 2026 at 08:23:13AM +0200, Peter Rosin wrote:
>> I'm not previously familiar with the auxiliary bus. When I read about
>> it I find this:
>>
>> 	"A key requirement for utilizing the auxiliary bus is that
>> 	there is no dependency on a physical bus, device, register
>> 	accesses or regmap support."
>>
>> That seems to contradict this driver with its dependency on regmap,
>> thus violating the above key requirement?
> 
> I'm seeing a very close pattern in [1]. clk-imx8ulp-sim-lpav.c create a
> regmap for its auxiliary reset and mux driver. 
> 
> The parent driver is creating the axuiliary device in [2], this create
> "clk_imx8ulp_sim_lpav.reset".
> 
> Then later reset-imx8mp-audiomix.c into
> imx8mp_audiomix_reset_get_regmap() [3] take the rgmap from the parent.
> 
> Also reset-meson-aux.c [4] is aux device and is taking the regmap
> from the parent.
> 
> IMHO the doc paragraph share why such a device can't be a platform
> device or an MFD, matching on the auxiliary bus is a plain
> string compare, so no register access is involved in match or bind.
> 
> [1] https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/clk/imx/clk-imx8ulp-sim-lpav.c#L95
> [2] https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/clk/imx/clk-imx8ulp-sim-lpav.c#L123
> [3] https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/reset/reset-imx8mp-audiomix.c#L162
> [4] https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/reset/amlogic/reset-meson-aux.c#L65
Yes, agreed, regmap usage from the aux bus seem pretty widespread, and
not being allowed to touch regmap would be quite odd...

Looking forward to v13, thanks!

Cheers,
Peter