From patchwork Sat May 24 09:33:28 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Popov X-Patchwork-Id: 4237331 X-Patchwork-Delegate: vinod.koul@intel.com Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 5102F9F1CD for ; Sat, 24 May 2014 09:33:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7238E203E6 for ; Sat, 24 May 2014 09:33:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A67D203DB for ; Sat, 24 May 2014 09:33:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750882AbaEXJdo (ORCPT ); Sat, 24 May 2014 05:33:44 -0400 Received: from mail-lb0-f180.google.com ([209.85.217.180]:49819 "EHLO mail-lb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751257AbaEXJdl (ORCPT ); Sat, 24 May 2014 05:33:41 -0400 Received: by mail-lb0-f180.google.com with SMTP id p9so3327928lbv.11 for ; Sat, 24 May 2014 02:33:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:subject:date:message-id:in-reply-to:references; bh=QSTAzL0NX76NzCCKRCQV9I5HZGVfIMHOPk+VLGSz52k=; b=f8zsqs5tTZY2HH8+Vbdy/0rA8jlf/Pdsfq7EbZlghi0hZy4MC2tnnth9q2tjL9ZVSW Tc9u/rTOzwYKp5Uteb37mSAnRNTM3ykYk12qymZM7V/yTdA9DqaTX/Z2djAZAAQVlahy g/FZtg+fO9q+IhkWPaXa441laRUHrZGPjiyV1NXfQhdBba7WSA0Azu15gTIRBLgZQOW5 jzyDVh2Ql8F6XCdkkHo0XnZwYfEqAeepE2q3scyqsfpuj05Ya5RVrKl7QOQGUNdxbcuZ w5KMNeCjbaAmajYAam3lNn+JjHHy0mp8jBonbzFVpuUMLDIlr2uJzOYCfMY5bdsZAGNM lVKw== X-Received: by 10.112.162.42 with SMTP id xx10mr7362072lbb.8.1400924019722; Sat, 24 May 2014 02:33:39 -0700 (PDT) Received: from a13xCCC.localdomain (mail.tecon.ru. [89.175.104.62]) by mx.google.com with ESMTPSA id a2sm5573462lbz.25.2014.05.24.02.33.38 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Sat, 24 May 2014 02:33:39 -0700 (PDT) From: Alexander Popov To: Gerhard Sittig , Dan Williams , Vinod Koul , Lars-Peter Clausen , Arnd Bergmann , Anatolij Gustschin , Andy Shevchenko , Alexander Popov , linuxppc-dev@lists.ozlabs.org, dmaengine@vger.kernel.org, devicetree@vger.kernel.org Subject: [PATCH 2/3] dmaengine: of: add common xlate function for matching by channel id Date: Sat, 24 May 2014 13:33:28 +0400 Message-Id: <1400924009-23992-3-git-send-email-a13xp0p0v88@gmail.com> X-Mailer: git-send-email 1.7.11.3 In-Reply-To: <1400924009-23992-1-git-send-email-a13xp0p0v88@gmail.com> References: <1400924009-23992-1-git-send-email-a13xp0p0v88@gmail.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds a new common OF dma xlate callback function which will match a channel by it's id. The binding expects one integer argument which it will use to lookup the channel by the id. Unlike of_dma_simple_xlate this function is able to handle a system with multiple DMA controllers. When registering the of dma provider with of_dma_controller_register a pointer to the dma_device struct which is associated with the dt node needs to passed as the data parameter. New function will use this pointer to match only channels which belong to the specified DMA controller. Signed-off-by: Alexander Popov --- drivers/dma/of-dma.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/of_dma.h | 4 ++++ 2 files changed, 39 insertions(+) diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index e8fe9dc..d5fbeaa 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -218,3 +218,38 @@ struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, &dma_spec->args[0]); } EXPORT_SYMBOL_GPL(of_dma_simple_xlate); + +/** + * of_dma_xlate_by_chan_id - Translate dt property to DMA channel by channel id + * @dma_spec: pointer to DMA specifier as found in the device tree + * @of_dma: pointer to DMA controller data + * + * This function can be used as the of xlate callback for DMA driver which wants + * to match the channel based on the channel id. When using this xlate function + * the #dma-cells propety of the DMA controller dt node needs to be set to 1. + * The data parameter of of_dma_controller_register must be a pointer to the + * dma_device struct the function should match upon. + * + * Returns pointer to appropriate dma channel on success or NULL on error. + */ +struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct dma_device *dev = ofdma->of_dma_data; + struct dma_chan *chan, *candidate = NULL; + + if (!dev || dma_spec->args_count != 1) + return NULL; + + list_for_each_entry(chan, &dev->channels, device_node) + if (chan->chan_id == dma_spec->args[0]) { + candidate = chan; + break; + } + + if (!candidate) + return NULL; + + return dma_get_slave_channel(candidate); +} +EXPORT_SYMBOL_GPL(of_dma_xlate_by_chan_id); diff --git a/include/linux/of_dma.h b/include/linux/of_dma.h index ae36298..56bc026 100644 --- a/include/linux/of_dma.h +++ b/include/linux/of_dma.h @@ -41,6 +41,8 @@ extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np, const char *name); extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma); +extern struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec, + struct of_dma *ofdma); #else static inline int of_dma_controller_register(struct device_node *np, struct dma_chan *(*of_dma_xlate) @@ -66,6 +68,8 @@ static inline struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_s return NULL; } +#define of_dma_xlate_by_chan_id NULL + #endif #endif /* __LINUX_OF_DMA_H */