From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751976AbeC2FaD (ORCPT ); Thu, 29 Mar 2018 01:30:03 -0400 Received: from atl4mhob11.registeredsite.com ([209.17.115.49]:51780 "EHLO atl4mhob11.registeredsite.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751183AbeC2F35 (ORCPT ); Thu, 29 Mar 2018 01:29:57 -0400 X-TCPREMOTEIP: 37.74.225.130 X-Authenticated-UID: mike@milosoftware.com From: Mike Looijmans To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, andrew@lunn.ch, f.fainelli@gmail.com, robh+dt@kernel.org, frowand.list@gmail.com, Mike Looijmans Subject: [PATCH v4 1/2] of_net: Implement of_get_nvmem_mac_address helper Date: Thu, 29 Mar 2018 07:29:48 +0200 Message-Id: <1522301389-11034-2-git-send-email-mike.looijmans@topic.nl> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1522301389-11034-1-git-send-email-mike.looijmans@topic.nl> References: <1522301389-11034-1-git-send-email-mike.looijmans@topic.nl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's common practice to store MAC addresses for network interfaces into nvmem devices. However the code to actually do this in the kernel lacks, so this patch adds of_get_nvmem_mac_address() for drivers to obtain the address from an nvmem cell provider. This is particulary useful on devices where the ethernet interface cannot be configured by the bootloader, for example because it's in an FPGA. Signed-off-by: Mike Looijmans Reviewed-by: Florian Fainelli Reviewed-by: Andrew Lunn --- Documentation/devicetree/bindings/net/ethernet.txt | 2 ++ drivers/of/of_net.c | 40 ++++++++++++++++++++++ include/linux/of_net.h | 6 ++++ 3 files changed, 48 insertions(+) diff --git a/Documentation/devicetree/bindings/net/ethernet.txt b/Documentation/devicetree/bindings/net/ethernet.txt index 2974e63..cfc376b 100644 --- a/Documentation/devicetree/bindings/net/ethernet.txt +++ b/Documentation/devicetree/bindings/net/ethernet.txt @@ -10,6 +10,8 @@ Documentation/devicetree/bindings/phy/phy-bindings.txt. the boot program; should be used in cases where the MAC address assigned to the device by the boot program is different from the "local-mac-address" property; +- nvmem-cells: phandle, reference to an nvmem node for the MAC address; +- nvmem-cell-names: string, should be "mac-address" if nvmem is to be used; - max-speed: number, specifies maximum speed in Mbit/s supported by the device; - max-frame-size: number, maximum transfer unit (IEEE defined MTU), rather than the maximum frame size (there's contradiction in the Devicetree diff --git a/drivers/of/of_net.c b/drivers/of/of_net.c index d820f3e..53189d4 100644 --- a/drivers/of/of_net.c +++ b/drivers/of/of_net.c @@ -7,6 +7,7 @@ */ #include #include +#include #include #include #include @@ -80,3 +81,42 @@ const void *of_get_mac_address(struct device_node *np) return of_get_mac_addr(np, "address"); } EXPORT_SYMBOL(of_get_mac_address); + +/** + * Obtain the MAC address from an nvmem provider named 'mac-address' through + * device tree. + * On success, copies the new address into memory pointed to by addr and + * returns 0. Returns a negative error code otherwise. + * @np: Device tree node containing the nvmem-cells phandle + * @addr: Pointer to receive the MAC address using ether_addr_copy() + */ +int of_get_nvmem_mac_address(struct device_node *np, void *addr) +{ + struct nvmem_cell *cell; + const void *mac; + size_t len; + int ret; + + cell = of_nvmem_cell_get(np, "mac-address"); + if (IS_ERR(cell)) + return PTR_ERR(cell); + + mac = nvmem_cell_read(cell, &len); + + nvmem_cell_put(cell); + + if (IS_ERR(mac)) + return PTR_ERR(mac); + + if (len < ETH_ALEN || !is_valid_ether_addr(mac)) { + ret = -EINVAL; + } else { + ether_addr_copy(addr, mac); + ret = 0; + } + + kfree(mac); + + return ret; +} +EXPORT_SYMBOL(of_get_nvmem_mac_address); diff --git a/include/linux/of_net.h b/include/linux/of_net.h index 9cd72aa..90d81ee 100644 --- a/include/linux/of_net.h +++ b/include/linux/of_net.h @@ -13,6 +13,7 @@ struct net_device; extern int of_get_phy_mode(struct device_node *np); extern const void *of_get_mac_address(struct device_node *np); +extern int of_get_nvmem_mac_address(struct device_node *np, void *addr); extern struct net_device *of_find_net_device_by_node(struct device_node *np); #else static inline int of_get_phy_mode(struct device_node *np) @@ -25,6 +26,11 @@ static inline const void *of_get_mac_address(struct device_node *np) return NULL; } +static inline int of_get_nvmem_mac_address(struct device_node *np, void *addr) +{ + return -ENODEV; +} + static inline struct net_device *of_find_net_device_by_node(struct device_node *np) { return NULL; -- 1.9.1