From patchwork Mon Mar 26 06:41:29 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Looijmans X-Patchwork-Id: 890776 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=topic.nl Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 408l1F0dv5z9s1R for ; Mon, 26 Mar 2018 17:41:53 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752007AbeCZGln (ORCPT ); Mon, 26 Mar 2018 02:41:43 -0400 Received: from atl4mhob16.registeredsite.com ([209.17.115.109]:55592 "EHLO atl4mhob16.registeredsite.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751162AbeCZGlm (ORCPT ); Mon, 26 Mar 2018 02:41:42 -0400 Received: from mailpod.hostingplatform.com (atl4qobmail02.registeredsite.com [10.30.71.204]) by atl4mhob16.registeredsite.com (8.14.4/8.14.4) with ESMTP id w2Q6fbrg018190 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 26 Mar 2018 02:41:37 -0400 Received: (qmail 26533 invoked by uid 0); 26 Mar 2018 06:41:37 -0000 X-TCPREMOTEIP: 37.74.225.130 X-Authenticated-UID: mike@milosoftware.com Received: from unknown (HELO mikebuntu.TOPIC.LOCAL) (mike@milosoftware.com@37.74.225.130) by 0 with ESMTPA; 26 Mar 2018 06:41:36 -0000 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 v2] of_net: Implement of_get_nvmem_mac_address helper Date: Mon, 26 Mar 2018 08:41:29 +0200 Message-Id: <1522046489-19652-1-git-send-email-mike.looijmans@topic.nl> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1521815074-30424-1-git-send-email-mike.looijmans@topic.nl> References: <1521815074-30424-1-git-send-email-mike.looijmans@topic.nl> <20180323151101.GB24361@lunn.ch> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@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. Tested by adapting the cadence macb driver to call this instead of of_get_mac_address(). Signed-off-by: Mike Looijmans --- v2: Use of_nvmem_cell_get to avoid needing the assiciated device Use void* instead of char* Add devicetree binding doc Documentation/devicetree/bindings/net/ethernet.txt | 2 + drivers/of/of_net.c | 47 ++++++++++++++++++++++ include/linux/of_net.h | 6 +++ 3 files changed, 55 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..8999745 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 +81,49 @@ const void *of_get_mac_address(struct device_node *np) return of_get_mac_addr(np, "address"); } EXPORT_SYMBOL(of_get_mac_address); + +/** + * Search the device tree for a MAC address, by calling of_get_mac_address + * and if that doesn't provide an address, fetch it from an nvmem provider + * using the name 'mac-address'. + * On success, copies the new address is into memory pointed to by addr and + * returns 0. Returns a negative error code otherwise. + * @dev: Pointer to the device containing the device_node + * @addr: Pointer to receive the MAC address using ether_addr_copy() + */ +int of_get_nvmem_mac_address(struct device_node *np, void *addr) +{ + const void *mac; + struct nvmem_cell *cell; + size_t len; + int ret; + + mac = of_get_mac_address(np); + if (mac) { + ether_addr_copy(addr, mac); + return 0; + } + + 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 < 6 || !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;