From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 900EEC07D5C for ; Thu, 14 Jun 2018 03:32:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D29620864 for ; Thu, 14 Jun 2018 03:32:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D29620864 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936022AbeFNDcD (ORCPT ); Wed, 13 Jun 2018 23:32:03 -0400 Received: from gate.crashing.org ([63.228.1.57]:39893 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935858AbeFNDcB (ORCPT ); Wed, 13 Jun 2018 23:32:01 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id w5E3VmZu023537; Wed, 13 Jun 2018 22:31:49 -0500 Message-ID: Subject: [PATCH] devres: Add devm_of_iomap() From: Benjamin Herrenschmidt To: Rob Herring Cc: "linux-kernel@vger.kernel.org" , devicetree@vger.kernel.org Date: Thu, 14 Jun 2018 13:31:48 +1000 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.1 (3.28.1-2.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are still quite a few cases where a device might want to get to a different node of the device-tree, obtain the resources and map them. This is generally open coded in drivers which is quite error prone We have of_iomap() and of_io_request_and_map() but they both have shortcomings, such as not returning the size of the resource found (which can be useful) and not being "managed". This adds a devm_of_iomap() that provides all of these and should probably replace uses of the above in most drivers. Signed-off-by: Benjamin Herrenschmidt --- include/linux/device.h | 4 ++++ lib/devres.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/include/linux/device.h b/include/linux/device.h index beabdbc08420..1529775ecb36 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -686,6 +686,10 @@ extern void devm_free_pages(struct device *dev, unsigned long addr); void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res); +void __iomem *devm_of_iomap(struct device *dev, + struct device_node *node, int index, + resource_size_t *size); + /* allows to add/remove a custom action to devres stack */ int devm_add_action(struct device *dev, void (*action)(void *), void *data); void devm_remove_action(struct device *dev, void (*action)(void *), void *data); diff --git a/lib/devres.c b/lib/devres.c index 78eca713b1d9..e320f80c1c4e 100644 --- a/lib/devres.c +++ b/lib/devres.c @@ -3,6 +3,7 @@ #include #include #include +#include void devm_ioremap_release(struct device *dev, void *res) { @@ -163,6 +164,41 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res) } EXPORT_SYMBOL(devm_ioremap_resource); +/* + * devm_of_iomap - Requests a resource and maps the memory mapped IO + * for a given device_node managed by a given device + * + * Checks that a resource is a valid memory region, requests the memory + * region and ioremaps it. All operations are managed and will be undone + * on driver detach of the device. + * + * This is to be used when a device requests/maps resources described + * by other device tree nodes (children or otherwise). + * + * @dev: The device "managing" the resource + * @node: The device-tree node where the resource resides + * @index: index of the MMIO range in the "reg" property + * @size: Returns the size of the resource (pass NULL if not needed) + * Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded + * error code on failure. Usage example: + * + * base = devm_of_iomap(&pdev->dev, node, 0, NULL); + * if (IS_ERR(base)) + * return PTR_ERR(base); + */ +void __iomem *devm_of_iomap(struct device *dev, struct device_node *node, int index, + resource_size_t *size) +{ + struct resource res; + + if (of_address_to_resource(node, index, &res)) + return IOMEM_ERR_PTR(-EINVAL); + if (size) + *size = resource_size(&res); + return devm_ioremap_resource(dev, &res); +} +EXPORT_SYMBOL(devm_of_iomap); + #ifdef CONFIG_HAS_IOPORT_MAP /* * Generic iomap devres