linux-kernel - Re: [PATCH v2 06/21] reset: rzv2h-usb2phy: Add support for VBUS mux controller registration

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Message-ID: <aQuIU9C0A_JMEpAn@tom-desktop>
Date: Wed, 5 Nov 2025 18:24:35 +0100
From: Tommaso Merciai <tommaso.merciai.xr@...renesas.com>
To: Philipp Zabel <p.zabel@...gutronix.de>
Cc: tomm.merciai@...il.com, linux-renesas-soc@...r.kernel.org,
	biju.das.jz@...renesas.com, Vinod Koul <vkoul@...nel.org>,
	Kishon Vijay Abraham I <kishon@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Fabrizio Castro <fabrizio.castro.jz@...esas.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>,
	Peter Rosin <peda@...ntia.se>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
	Geert Uytterhoeven <geert+renesas@...der.be>,
	Magnus Damm <magnus.damm@...il.com>, Arnd Bergmann <arnd@...db.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-phy@...ts.infradead.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 06/21] reset: rzv2h-usb2phy: Add support for VBUS mux
 controller registration

Hi Philipp,
Thanks for your review!

On Wed, Nov 05, 2025 at 05:04:54PM +0100, Philipp Zabel wrote:
> On Mi, 2025-11-05 at 16:39 +0100, Tommaso Merciai wrote:
> > The RZ/V2H USB2 PHY requires control of the VBUS selection line
> > (VBENCTL) through a mux controller described in the device tree as
> > "mux-controller". This change adds support for registering
> > vbus-sel-mux auxiliary driver during probe.
> > 
> > This enables proper management of USB2.0 VBUS source selection on
> > platforms using the RZ/V2H SoC.
> > 
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@...renesas.com>
> > ---
> > v1->v2:
> >  - New patch
> > 
> >  drivers/reset/Kconfig               |  1 +
> >  drivers/reset/reset-rzv2h-usb2phy.c | 65 +++++++++++++++++++++++++++++
> >  2 files changed, 66 insertions(+)
> > 
> > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> > index e1ae624661f3..f54e216ca7f6 100644
> > --- a/drivers/reset/Kconfig
> > +++ b/drivers/reset/Kconfig
> > @@ -255,6 +255,7 @@ config RESET_RZG2L_USBPHY_CTRL
> >  config RESET_RZV2H_USB2PHY
> >  	tristate "Renesas RZ/V2H(P) (and similar SoCs) USB2PHY Reset driver"
> >  	depends on ARCH_RENESAS || COMPILE_TEST
> > +	select AUXILIARY_BUS
> >  	help
> >  	  Support for USB2PHY Port reset Control found on the RZ/V2H(P) SoC
> >  	  (and similar SoCs).
> > diff --git a/drivers/reset/reset-rzv2h-usb2phy.c b/drivers/reset/reset-rzv2h-usb2phy.c
> > index 5bdd39274612..6074aa8cc13a 100644
> > --- a/drivers/reset/reset-rzv2h-usb2phy.c
> > +++ b/drivers/reset/reset-rzv2h-usb2phy.c
> > @@ -5,8 +5,10 @@
> >   * Copyright (C) 2025 Renesas Electronics Corporation
> >   */
> >  
> > +#include <linux/auxiliary_bus.h>
> >  #include <linux/cleanup.h>
> >  #include <linux/delay.h>
> > +#include <linux/idr.h>
> >  #include <linux/io.h>
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> > @@ -14,6 +16,9 @@
> >  #include <linux/pm_runtime.h>
> >  #include <linux/reset.h>
> >  #include <linux/reset-controller.h>
> > +#include <linux/reset/reset_rzv2h_usb2phy.h>
> > +
> > +static DEFINE_IDA(auxiliary_ids);
> >  
> >  struct rzv2h_usb2phy_regval {
> >  	u16 reg;
> > @@ -104,6 +109,62 @@ static int rzv2h_usb2phy_reset_of_xlate(struct reset_controller_dev *rcdev,
> >  	return 0;
> >  }
> >  
> > +static void rzv2h_usb2phy_reset_adev_unregister(void *data)
> > +{
> > +	struct auxiliary_device *adev = data;
> > +
> > +	auxiliary_device_delete(adev);
> > +	auxiliary_device_uninit(adev);
> > +}
> > +
> > +static void rzv2h_usb2phy_reset_adev_release(struct device *dev)
> > +{
> > +	struct auxiliary_device *adev = to_auxiliary_dev(dev);
> > +
> > +	ida_free(&auxiliary_ids, adev->id);
> > +}
> > +
> > +static int rzv2h_usb2phy_reset_mux_register(struct device *dev,
> > +					    void __iomem *base,
> > +					    const char *mux_name)
> > +{
> > +	struct reset_rzv2h_usb2phy_adev *rdev;
> > +	struct auxiliary_device *adev;
> > +	int ret;
> > +
> > +	rdev = devm_kzalloc(dev, sizeof(*rdev), GFP_KERNEL);
> > +	if (!rdev)
> > +		return -ENOMEM;
> > +
> > +	rdev->base = base;
> > +
> > +	adev = &rdev->adev;
> > +	adev->name = mux_name;
> > +	adev->dev.parent = dev->parent;
> > +	adev->dev.release = rzv2h_usb2phy_reset_adev_release;
> > +	adev->dev.of_node = dev->of_node;
> > +	ret = ida_alloc(&auxiliary_ids, GFP_KERNEL);
> > +	if (ret < 0)
> > +		return ret;
> > +	adev->id = ret;
> > +
> > +	ret = auxiliary_device_init(adev);
> > +	if (ret)
> > +		goto cleanup_ida;
> > +
> > +	ret = auxiliary_device_add(adev);
> > +	if (ret) {
> > +		auxiliary_device_uninit(adev);
> > +		goto cleanup_ida;
> > +	}
> > +
> > +	return devm_add_action_or_reset(dev, rzv2h_usb2phy_reset_adev_unregister, adev);
> 
> Can't you use __devm_auxiliary_device_create()?

Ack Thanks.
We can do:

	adev = __devm_auxiliary_device_create(dev, dev->driver->name,
					      mux_name, rdev, id);
	if (!adev) {
		ida_free(&auxiliary_ids, id);
		return -ENOMEM;
	}

Then we can get base rdev from auxiliary driver just using:

	struct reset_rzv2h_usb2phy_adev *rdev = adev->dev.platform_data;

I will use this into the next versio.


Thanks & Regards,
Tommaso


> 
> regards
> Philipp