linux-kernel - Re: [PATCH v4 1/6] PCI: starfive: Use regulator APIs instead of GPIO APIs to enable the 3V3 power supply of PCIe slots

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 <ZQ0PR01MB09816DBC8A88CEC939C8968482D82@ZQ0PR01MB0981.CHNPR01.prod.partner.outlook.cn>
Date: Tue, 2 Dec 2025 03:02:48 +0000
From: Kevin Xie <kevin.xie@...rfivetech.com>
To: Bjorn Helgaas <helgaas@...nel.org>, Hal Feng <hal.feng@...rfivetech.com>
CC: Conor Dooley <conor+dt@...nel.org>, Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Palmer Dabbelt
	<palmer@...belt.com>, Paul Walmsley <pjw@...nel.org>, Albert Ou
	<aou@...s.berkeley.edu>, "Rafael J . Wysocki" <rafael@...nel.org>, Viresh
 Kumar <viresh.kumar@...aro.org>, Lorenzo Pieralisi <lpieralisi@...nel.org>,
	Krzysztof Wilczyński <kwilczynski@...nel.org>, Manivannan
 Sadhasivam <mani@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>, Liam
 Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, Emil Renner
 Berthing <emil.renner.berthing@...onical.com>, Heinrich Schuchardt
	<heinrich.schuchardt@...onical.com>, E Shattow <e@...eshell.de>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 1/6] PCI: starfive: Use regulator APIs instead of GPIO
 APIs to enable the 3V3 power supply of PCIe slots

> Krzysztof Kozlowski <krzk+dt@...nel.org>; Palmer Dabbelt
> <palmer@...belt.com>; Paul Walmsley <pjw@...nel.org>; Albert Ou
> <aou@...s.berkeley.edu>; Rafael J . Wysocki <rafael@...nel.org>; Viresh
> Kumar <viresh.kumar@...aro.org>; Lorenzo Pieralisi <lpieralisi@...nel.org>;
> Krzysztof Wilczyński <kwilczynski@...nel.org>; Manivannan Sadhasivam
> <mani@...nel.org>; Bjorn Helgaas <bhelgaas@...gle.com>; Liam Girdwood
> <lgirdwood@...il.com>; Mark Brown <broonie@...nel.org>; Emil Renner
> Berthing <emil.renner.berthing@...onical.com>; Heinrich Schuchardt
> <heinrich.schuchardt@...onical.com>; E Shattow <e@...eshell.de>;
> devicetree@...r.kernel.org; linux-pci@...r.kernel.org;
> linux-riscv@...ts.infradead.org; linux-kernel@...r.kernel.org
>Re: [PATCH v4 1/6] PCI: starfive: Use regulator APIs instead of GPIO
> APIs to enable the 3V3 power supply of PCIe slots
> 
> > Krzysztof Kozlowski <krzk+dt@...nel.org>; Palmer Dabbelt
> > <palmer@...belt.com>; Paul Walmsley <pjw@...nel.org>; Albert Ou
> > <aou@...s.berkeley.edu>; Rafael J . Wysocki <rafael@...nel.org>;
> > Viresh Kumar <viresh.kumar@...aro.org>; Lorenzo Pieralisi
> > <lpieralisi@...nel.org>; Krzysztof Wilczyński
> > <kwilczynski@...nel.org>; Manivannan Sadhasivam <mani@...nel.org>;
> > Bjorn Helgaas <bhelgaas@...gle.com>; Liam Girdwood
> > <lgirdwood@...il.com>; Mark Brown <broonie@...nel.org>; Emil Renner
> > Berthing <emil.renner.berthing@...onical.com>; Heinrich Schuchardt
> > <heinrich.schuchardt@...onical.com>; E Shattow <e@...eshell.de>;
> > devicetree@...r.kernel.org; linux-pci@...r.kernel.org;
> > linux-riscv@...ts.infradead.org; linux-kernel@...r.kernel.org; Kevin
> > Xie <kevin.xie@...rfivetech.com>
> >Re: [PATCH v4 1/6] PCI: starfive: Use regulator APIs instead of
> > GPIO APIs to enable the 3V3 power supply of PCIe slots
> >
> > [+cc Kevin, pcie-starfive.c maintainer; will need his ack]
> >
> > Subject line is excessively long.
> >
> > On Tue, Nov 25, 2025 at 03:55:59PM +0800, Hal Feng wrote:
> > > The "enable-gpio" property is not documented in the dt-bindings and
> > > using GPIO APIs is not a standard method to enable or disable PCIe
> > > slot power, so use regulator APIs to replace them.
> >
> > I can't tell from this whether existing DTs will continue to work
> > after this change.  It looks like previously we looked for an
> > "enable-gpios" or "enable-gpio" property and now we'll look for a
> > "vpcie3v3-supply" regulator property.
> >
> > I don't see "enable-gpios" or "enable-gpio" mentioned in any of the DT
> > patches in this series, so maybe that property was never actually used
> > before, and the code for pcie->power_gpio was actually dead?
> >
> 
> pcie->power_gpio is used in the our JH7110 EVB, it share the same pcie
> pcie->controller
> driver with VisionFive2 board. Although JH7110 was not upstreamed, we still
> hope to maintain the compatibility of the driver.
> 

Sorry, I missed the background information regarding replacing enable_gpio with
regulator APIs. I agree with this change.

> > Please add something here about how we know this won't break any
> > existing setups using DTs that are already in the field.
> >
> > > Tested-by: Matthias Brugger <mbrugger@...e.com>
> > > Fixes: 39b91eb40c6a ("PCI: starfive: Add JH7110 PCIe controller")
> >
> > Based on the cover letter, it looks like the point of this is to add
> > support for a new device, which I don't think really qualifies as a "fix".
> >
> > > Signed-off-by: Hal Feng <hal.feng@...rfivetech.com>
> > > ---
> > >  drivers/pci/controller/plda/pcie-starfive.c | 25
> > > ++++++++++++---------
> > >  1 file changed, 15 insertions(+), 10 deletions(-)
> > >
> > > diff --git a/drivers/pci/controller/plda/pcie-starfive.c
> > > b/drivers/pci/controller/plda/pcie-starfive.c
> > > index 3caf53c6c082..298036c3e7f9 100644
> > > --- a/drivers/pci/controller/plda/pcie-starfive.c
> > > +++ b/drivers/pci/controller/plda/pcie-starfive.c
> > > @@ -55,7 +55,7 @@ struct starfive_jh7110_pcie {
> > >  	struct reset_control *resets;
> > >  	struct clk_bulk_data *clks;
> > >  	struct regmap *reg_syscon;
> > > -	struct gpio_desc *power_gpio;
> > > +	struct regulator *vpcie3v3;
> > >  	struct gpio_desc *reset_gpio;
> > >  	struct phy *phy;
> > >
> > > @@ -153,11 +153,13 @@ static int starfive_pcie_parse_dt(struct
> > starfive_jh7110_pcie *pcie,
> > >  		return dev_err_probe(dev, PTR_ERR(pcie->reset_gpio),
> > >  				     "failed to get perst-gpio\n");
> > >
> > > -	pcie->power_gpio = devm_gpiod_get_optional(dev, "enable",
> > > -						   GPIOD_OUT_LOW);
> > > -	if (IS_ERR(pcie->power_gpio))
> > > -		return dev_err_probe(dev, PTR_ERR(pcie->power_gpio),
> > > -				     "failed to get power-gpio\n");
> > > +	pcie->vpcie3v3 = devm_regulator_get_optional(dev, "vpcie3v3");
> > > +	if (IS_ERR(pcie->vpcie3v3)) {
> > > +		if (PTR_ERR(pcie->vpcie3v3) != -ENODEV)
> > > +			return dev_err_probe(dev, PTR_ERR(pcie->vpcie3v3),
> > > +					     "failed to get vpcie3v3 regulator\n");
> > > +		pcie->vpcie3v3 = NULL;
> > > +	}
> > >
> > >  	return 0;
> > >  }
> > > @@ -270,8 +272,8 @@ static void starfive_pcie_host_deinit(struct
> > plda_pcie_rp *plda)
> > >  		container_of(plda, struct starfive_jh7110_pcie, plda);
> > >
> > >  	starfive_pcie_clk_rst_deinit(pcie);
> > > -	if (pcie->power_gpio)
> > > -		gpiod_set_value_cansleep(pcie->power_gpio, 0);
> > > +	if (pcie->vpcie3v3)
> > > +		regulator_disable(pcie->vpcie3v3);
> > >  	starfive_pcie_disable_phy(pcie);
> > >  }
> > >
> > > @@ -304,8 +306,11 @@ static int starfive_pcie_host_init(struct
> > plda_pcie_rp *plda)
> > >  	if (ret)
> > >  		return ret;
> > >
> > > -	if (pcie->power_gpio)
> > > -		gpiod_set_value_cansleep(pcie->power_gpio, 1);
> > > +	if (pcie->vpcie3v3) {
> > > +		ret = regulator_enable(pcie->vpcie3v3);
> > > +		if (ret)
> > > +			dev_err_probe(dev, ret, "failed to enable vpcie3v3 regulator\n");
> > > +	}
> > >
> > >  	if (pcie->reset_gpio)
> > >  		gpiod_set_value_cansleep(pcie->reset_gpio, 1);
> > > --
> > > 2.43.2
> > >
> > >
> > > _______________________________________________
> > > linux-riscv mailing list
> > > linux-riscv@...ts.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-riscv

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