Re: [RFC PATCH 05/21] PCI: endpoint: Add API to get reference to EPC from device-tree

From: Jon Mason <jdmason@kudzu.us>
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Rob Herring <robh+dt@kernel.org>,
	Dave Jiang <dave.jiang@intel.com>,
	Allen Hubbe <allenbh@gmail.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-pci@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel <linux-kernel@vger.kernel.org>,
	devicetree@vger.kernel.org,
	linux-ntb <linux-ntb@googlegroups.com>
Subject: Re: [RFC PATCH 05/21] PCI: endpoint: Add API to get reference to EPC from device-tree
Date: Sun, 17 Nov 2019 18:28:36 -0500	[thread overview]
Message-ID: <CAPoiz9yRemT5Q4FYCgx-mmkhywG2TP_OUU_tfLGWJXfO6KRwDA@mail.gmail.com> (raw)
In-Reply-To: <20190926112933.8922-6-kishon@ti.com>

On Thu, Sep 26, 2019 at 7:31 AM 'Kishon Vijay Abraham I' via linux-ntb
<linux-ntb@googlegroups.com> wrote:
>
> Add of_pci_epc_get() and of_pci_epc_get_by_name() to get reference
> to EPC from device-tree. This is added in preparation to define
> an endpoint function from device tree.

I can't get this patch to apply cleanly to my git tree (for the
current or any of the previous kernels I tried).  Please rebase this
series when you send it out as a patch.

Thanks,
Jon

> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  drivers/pci/endpoint/pci-epc-core.c | 61 +++++++++++++++++++++++++++++
>  include/linux/pci-epc.h             |  4 +-
>  2 files changed, 64 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index 5bc094093a47..0c2fdd39090c 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -83,6 +83,66 @@ struct pci_epc *pci_epc_get(const char *epc_name)
>  }
>  EXPORT_SYMBOL_GPL(pci_epc_get);
>
> +/**
> + * of_pci_epc_get() - get PCI endpoint controller from device node and index
> + * @node: device node which contains the phandle to endpoint controller
> + * @index: index of the endpoint controller in "epcs" property
> + *
> + * Returns the EPC corresponding to the _index_ entry in "epcs" property
> + * present in device node, after getting a refcount  to it or -ENODEV if
> + * there is no such EPC or -EPROBE_DEFER if there is a phandle to the phy,
> + * but the device is not yet loaded.
> + */
> +struct pci_epc *of_pci_epc_get(struct device_node *node, int index)
> +{
> +       struct device_node *epc_node;
> +       struct class_dev_iter iter;
> +       struct pci_epc *epc;
> +       struct device *dev;
> +
> +       epc_node = of_parse_phandle(node, "epcs", index);
> +       if (!epc_node)
> +               return ERR_PTR(-ENODEV);
> +
> +       class_dev_iter_init(&iter, pci_epc_class, NULL, NULL);
> +       while ((dev = class_dev_iter_next(&iter))) {
> +               epc = to_pci_epc(dev);
> +               if (epc_node != epc->dev.of_node)
> +                       continue;
> +
> +               of_node_put(epc_node);
> +               class_dev_iter_exit(&iter);
> +               get_device(&epc->dev);
> +               return epc;
> +       }
> +
> +       of_node_put(node);
> +       class_dev_iter_exit(&iter);
> +       return ERR_PTR(-EPROBE_DEFER);
> +}
> +EXPORT_SYMBOL_GPL(of_pci_epc_get);
> +
> +/**
> + * of_pci_epc_get_by_name() - get PCI endpoint controller from device node
> + *                            and string
> + * @node: device node which contains the phandle to endpoint controller
> + * @epc_name: name of endpoint controller as present in "epc-names" property
> + *
> + * Returns the EPC corresponding to the epc_name in "epc-names" property
> + * present in device node.
> + */
> +struct pci_epc *of_pci_epc_get_by_name(struct device_node *node,
> +                                      const char *epc_name)
> +{
> +       int index = 0;
> +
> +       if (epc_name)
> +               index = of_property_match_string(node, "epc-names", epc_name);
> +
> +       return of_pci_epc_get(node, index);
> +}
> +EXPORT_SYMBOL_GPL(of_pci_epc_get_by_name);
> +
>  /**
>   * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
>   * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
> @@ -661,6 +721,7 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
>         device_initialize(&epc->dev);
>         epc->dev.class = pci_epc_class;
>         epc->dev.parent = dev;
> +       epc->dev.of_node = dev->of_node;
>         epc->ops = ops;
>
>         ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> index 0fff52675a6b..ef6531af6ed2 100644
> --- a/include/linux/pci-epc.h
> +++ b/include/linux/pci-epc.h
> @@ -202,7 +202,9 @@ unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
>                                         *epc_features);
>  struct pci_epc *pci_epc_get(const char *epc_name);
>  void pci_epc_put(struct pci_epc *epc);
> -
> +struct pci_epc *of_pci_epc_get(struct device_node *node, int index);
> +struct pci_epc *of_pci_epc_get_by_name(struct device_node *node,
> +                                      const char *epc_name);
>  int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_addr, size_t size,
>                        size_t page_size);
>  void pci_epc_mem_exit(struct pci_epc *epc);
> --
> 2.17.1
>
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