Message-ID: <20251201205236.GA3023515@bhelgaas>
Date: Mon, 1 Dec 2025 14:52:36 -0600
From: Bjorn Helgaas <helgaas@...nel.org>
To: 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,
	linux-pci@...r.kernel.org, linux-riscv@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	Kevin Xie <kevin.xie@...rfivetech.com>
Subject: 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?

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

Powered by blists - more mailing lists