linux-kernel - Re: [PATCH 02/10] PCI: imx6: Add support for parsing the reset property in new Root Port binding

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aW5aQK2z92tBxIIV@lizhi-Precision-Tower-5810>
Date: Mon, 19 Jan 2026 11:22:24 -0500
From: Frank Li <Frank.li@....com>
To: Sherry Sun <sherry.sun@....com>
Cc: hongxing.zhu@....com, l.stach@...gutronix.de, bhelgaas@...gle.com,
	lpieralisi@...nel.org, kwilczynski@...nel.org, mani@...nel.org,
	robh@...nel.org, krzk+dt@...nel.org, conor+dt@...nel.org,
	shawnguo@...nel.org, s.hauer@...gutronix.de, festevam@...il.com,
	kernel@...gutronix.de, linux-pci@...r.kernel.org,
	devicetree@...r.kernel.org, imx@...ts.linux.dev,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 02/10] PCI: imx6: Add support for parsing the reset
 property in new Root Port binding

On Mon, Jan 19, 2026 at 06:02:27PM +0800, Sherry Sun wrote:
> DT binding allows specifying 'reset' property in both host bridge and
> Root Port nodes, but specifying in the host bridge node is marked as
> deprecated. So add support for parsing the new binding that uses
> 'reset-gpios' property for PERST#.
>
> To maintain DT backwards compatibility, fallback to the legacy method of
> parsing the host bridge node if the reset property is not present in the
> Root Port node.
>
> Signed-off-by: Sherry Sun <sherry.sun@....com>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 128 +++++++++++++++++++++++---
>  1 file changed, 114 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 1d8677d7de04..0592b24071bc 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -147,10 +147,15 @@ struct imx_lut_data {
>  	u32 data2;
>  };
>
> +
> +static int imx_pcie_parse_ports(struct imx_pcie *pcie)
> +{
> +	struct device *dev = pcie->pci->dev;
> +	struct imx_pcie_port *port, *tmp;
> +	int ret = -ENOENT;
> +
> +	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> +		if (!of_node_is_type(of_port, "pci"))
> +			continue;
> +		ret = imx_pcie_parse_port(pcie, of_port);
> +		if (ret)
> +			goto err_port_del;
> +	}
> +
> +	return ret;
> +
> +err_port_del:
> +	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
> +		list_del(&port->list);

you can call helper imx_pcie_delete_ports()

Frank
> +
> +	return ret;
> +}
> +
> +static int imx_pcie_parse_legacy_binding(struct imx_pcie *pcie)
> +{
> +	struct device *dev = pcie->pci->dev;
> +	struct imx_pcie_port *port;
> +	struct gpio_desc *reset;
> +
> +	reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> +	if (IS_ERR(reset))
> +		return PTR_ERR(reset);
> +
> +	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> +	if (!port)
> +		return -ENOMEM;
> +
> +	port->reset = reset;
> +	INIT_LIST_HEAD(&port->list);
> +	list_add_tail(&port->list, &pcie->ports);
> +
> +	return 0;
> +}
> +
> +static void imx_pcie_delete_ports(void *data)
> +{
> +	struct imx_pcie *pcie = data;
> +	struct imx_pcie_port *port, *tmp;
> +
> +	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
> +		list_del(&port->list);
> +}
> +
>  static int imx_pcie_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> @@ -1656,6 +1742,8 @@ static int imx_pcie_probe(struct platform_device *pdev)
>  	if (!pci)
>  		return -ENOMEM;
>
> +	INIT_LIST_HEAD(&imx_pcie->ports);
> +
>  	pci->dev = dev;
>  	pci->ops = &dw_pcie_ops;
>
> @@ -1684,12 +1772,24 @@ static int imx_pcie_probe(struct platform_device *pdev)
>  			return PTR_ERR(imx_pcie->phy_base);
>  	}
>
> -	/* Fetch GPIOs */
> -	imx_pcie->reset_gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> -	if (IS_ERR(imx_pcie->reset_gpiod))
> -		return dev_err_probe(dev, PTR_ERR(imx_pcie->reset_gpiod),
> -				     "unable to get reset gpio\n");
> -	gpiod_set_consumer_name(imx_pcie->reset_gpiod, "PCIe reset");
> +	ret = imx_pcie_parse_ports(imx_pcie);
> +	if (ret) {
> +		if (ret != -ENOENT)
> +			return dev_err_probe(dev, ret, "Failed to parse Root Port: %d\n", ret);
> +
> +		/*
> +		 * In the case of properties not populated in Root Port node,
> +		 * fallback to the legacy method of parsing the Host Bridge
> +		 * node. This is to maintain DT backwards compatibility.
> +		 */
> +		ret = imx_pcie_parse_legacy_binding(imx_pcie);
> +		if (ret)
> +			return dev_err_probe(dev, ret, "Unable to get reset gpio: %d\n", ret);
> +	}
> +
> +	ret = devm_add_action_or_reset(dev, imx_pcie_delete_ports, imx_pcie);
> +	if (ret)
> +		return ret;
>
>  	/* Fetch clocks */
>  	imx_pcie->num_clks = devm_clk_bulk_get_all(dev, &imx_pcie->clks);
> --
> 2.37.1
>