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

Hal Feng
2025-12-02T03:38:33Z

> On 02.12.25 04:53, Bjorn Helgaas wrote:
> [+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?

Yes, "enable-gpios" or "enable-gpio" is never used in any DTs, and pcie->power_gpio
related code is never run actually. Even the "enable-gpios" or "enable-gpio"
property was not added in the dt-bindings
Documentation/devicetree/bindings/pci/starfive,jh7110-pcie.yaml.

Suggested by Manivannan in the previous version [1], let's use regulator APIs instead.

[1] https://lore.kernel.org/all/xxswzi4v6gpuqbe3cczj2yjmprhvln26fl5ligsp5vkiogrnwk@hpifxivaps6j/

Best regards,
Hal

>
> 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@suse.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@starfivetech.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
> >
> >
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