From patchwork Wed Jan 9 20:43:02 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [02/14] of/pci: Add of_pci_get_devfn() function From: Thierry Reding X-Patchwork-Id: 210869 Message-Id: <1357764194-12677-3-git-send-email-thierry.reding@avionic-design.de> To: linux-tegra@vger.kernel.org Cc: Grant Likely , Rob Herring , Russell King , Stephen Warren , Bjorn Helgaas , Andrew Murray , Jason Gunthorpe , Arnd Bergmann , Thomas Petazzoni , devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org Date: Wed, 9 Jan 2013 21:43:02 +0100 This function can be used to parse the device and function number from a standard 5-cell PCI resource. PCI_SLOT() and PCI_FUNC() can be used on the returned value obtain the device and function numbers respectively. Signed-off-by: Thierry Reding --- drivers/of/of_pci.c | 32 ++++++++++++++++++++++++++++---- include/linux/of_pci.h | 1 + 2 files changed, 29 insertions(+), 4 deletions(-) diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index 13e37e2..0dd52df 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -7,12 +7,13 @@ static inline int __of_pci_pci_compare(struct device_node *node, unsigned int devfn) { - unsigned int size; - const __be32 *reg = of_get_property(node, "reg", &size); + int err; - if (!reg || size < 5 * sizeof(__be32)) + err = of_pci_get_devfn(node); + if (err < 0) return 0; - return ((be32_to_cpup(®[0]) >> 8) & 0xff) == devfn; + + return devfn == err; } struct device_node *of_pci_find_child_device(struct device_node *parent, @@ -40,3 +41,26 @@ struct device_node *of_pci_find_child_device(struct device_node *parent, return NULL; } EXPORT_SYMBOL_GPL(of_pci_find_child_device); + +/** + * of_pci_get_devfn() - Get device and function numbers for a device node + * @np: device node + * + * Parses a standard 5-cell PCI resource and returns an 8-bit value that can + * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device + * and function numbers respectively. On error a negative error code is + * returned. + */ +int of_pci_get_devfn(struct device_node *np) +{ + unsigned int size; + const __be32 *reg; + + reg = of_get_property(np, "reg", &size); + + if (!reg || size < 5 * sizeof(__be32)) + return -EINVAL; + + return (be32_to_cpup(reg) >> 8) & 0xff; +} +EXPORT_SYMBOL_GPL(of_pci_get_devfn); diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h index bb115de..91ec484 100644 --- a/include/linux/of_pci.h +++ b/include/linux/of_pci.h @@ -10,5 +10,6 @@ int of_irq_map_pci(const struct pci_dev *pdev, struct of_irq *out_irq); struct device_node; struct device_node *of_pci_find_child_device(struct device_node *parent, unsigned int devfn); +int of_pci_get_devfn(struct device_node *np); #endif