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

Kevin Xie
2025-12-02T03:03:22Z

> Krzysztof Kozlowski <krzk+dt@kernel.org>; Palmer Dabbelt
> <palmer@dabbelt.com>; Paul Walmsley <pjw@kernel.org>; Albert Ou
> <aou@eecs.berkeley.edu>; Rafael J . Wysocki <rafael@kernel.org>; Viresh
> Kumar <viresh.kumar@linaro.org>; Lorenzo Pieralisi <lpieralisi@kernel.org>;
> Krzysztof Wilczyński <kwilczynski@kernel.org>; Manivannan Sadhasivam
> <mani@kernel.org>; Bjorn Helgaas <bhelgaas@google.com>; Liam Girdwood
> <lgirdwood@gmail.com>; Mark Brown <broonie@kernel.org>; Emil Renner
> Berthing <emil.renner.berthing@canonical.com>; Heinrich Schuchardt
> <heinrich.schuchardt@canonical.com>; E Shattow <e@freeshell.de>;
> devicetree@vger.kernel.org; linux-pci@vger.kernel.org;
> linux-riscv@lists.infradead.org; linux-kernel@vger.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@kernel.org>; Palmer Dabbelt
> > <palmer@dabbelt.com>; Paul Walmsley <pjw@kernel.org>; Albert Ou
> > <aou@eecs.berkeley.edu>; Rafael J . Wysocki <rafael@kernel.org>;
> > Viresh Kumar <viresh.kumar@linaro.org>; Lorenzo Pieralisi
> > <lpieralisi@kernel.org>; Krzysztof Wilczyński
> > <kwilczynski@kernel.org>; Manivannan Sadhasivam <mani@kernel.org>;
> > Bjorn Helgaas <bhelgaas@google.com>; Liam Girdwood
> > <lgirdwood@gmail.com>; Mark Brown <broonie@kernel.org>; Emil Renner
> > Berthing <emil.renner.berthing@canonical.com>; Heinrich Schuchardt
> > <heinrich.schuchardt@canonical.com>; E Shattow <e@freeshell.de>;
> > devicetree@vger.kernel.org; linux-pci@vger.kernel.org;
> > linux-riscv@lists.infradead.org; linux-kernel@vger.kernel.org; Kevin
> > Xie <kevin.xie@starfivetech.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@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
> > >
> > >
> > > _______________________________________________
> > > linux-riscv mailing list
> > > linux-riscv@lists.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-riscv