Re: [PATCH V8 02/13] PCI: host-generic: Add common helpers for parsing Root Port properties

[Manivannan Sadhasivam]

On Fri, Mar 13, 2026 at 10:08:12AM +0800, Sherry Sun wrote:
> Introduce generic helper functions to parse Root Port device tree nodes
> and extract common properties like reset GPIOs. This allows multiple
> PCI host controller drivers to share the same parsing logic.
> 
> Define struct pci_host_port to hold common Root Port properties
> (currently only reset GPIO descriptor) and add
> pci_host_common_parse_ports() to parse Root Port nodes from device tree.
> 
> Also add the 'ports' list to struct pci_host_bridge for better maintain
> parsed Root Port information.
> 
> Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
> ---
>  drivers/pci/controller/pci-host-common.c | 78 ++++++++++++++++++++++++
>  drivers/pci/controller/pci-host-common.h | 15 +++++
>  drivers/pci/probe.c                      |  1 +
>  include/linux/pci.h                      |  1 +
>  4 files changed, 95 insertions(+)
> 
> diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
> index d6258c1cffe5..2f012cf80463 100644
> --- a/drivers/pci/controller/pci-host-common.c
> +++ b/drivers/pci/controller/pci-host-common.c
> @@ -9,6 +9,7 @@
>  
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/of.h>
>  #include <linux/of_address.h>
>  #include <linux/of_pci.h>
> @@ -17,6 +18,83 @@
>  
>  #include "pci-host-common.h"
>  
> +/**
> + * pci_host_common_delete_ports - Cleanup function for port list
> + * @data: Pointer to the port list head
> + */
> +static void pci_host_common_delete_ports(void *data)
> +{
> +	struct list_head *ports = data;
> +	struct pci_host_port *port, *tmp;
> +
> +	list_for_each_entry_safe(port, tmp, ports, list)
> +		list_del(&port->list);
> +}
> +
> +/**
> + * pci_host_common_parse_port - Parse a single Root Port node
> + * @dev: Device pointer
> + * @bridge: PCI host bridge
> + * @node: Device tree node of the Root Port
> + *
> + * Returns: 0 on success, negative error code on failure
> + */
> +static int pci_host_common_parse_port(struct device *dev,
> +				      struct pci_host_bridge *bridge,
> +				      struct device_node *node)
> +{
> +	struct pci_host_port *port;
> +	struct gpio_desc *reset;
> +
> +	reset = devm_fwnode_gpiod_get(dev, of_fwnode_handle(node),
> +				      "reset", GPIOD_ASIS, "PERST#");
> +	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, &bridge->ports);
> +
> +	return 0;
> +}
> +
> +/**
> + * pci_host_common_parse_ports - Parse Root Port nodes from device tree
> + * @dev: Device pointer
> + * @bridge: PCI host bridge
> + *
> + * This function iterates through child nodes of the host bridge and parses
> + * Root Port properties (currently only reset GPIO).
> + *
> + * Returns: 0 on success, -ENOENT if no ports found, other negative error codes
> + * on failure
> + */
> +int pci_host_common_parse_ports(struct device *dev, struct pci_host_bridge *bridge)
> +{
> +	int ret = -ENOENT;
> +	int err;
> +
> +	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> +		if (!of_node_is_type(of_port, "pci"))
> +			continue;
> +		ret = pci_host_common_parse_port(dev, bridge, of_port);
> +		if (ret)
> +			return ret;
> +	}
> +

I think you should just do:

	if (ret)
		return ret;

and get rid of 'err'.

> +	err = devm_add_action_or_reset(dev, pci_host_common_delete_ports,
> +				       &bridge->ports);
> +	if (err)
> +		return err;
> +
> +	return ret;

return 0;

- Mani

-- 
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