From patchwork Tue Apr 15 10:54:08 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Popov X-Patchwork-Id: 3991141 X-Patchwork-Delegate: vinod.koul@intel.com Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2E15FBFF02 for ; Tue, 15 Apr 2014 10:54:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3246320211 for ; Tue, 15 Apr 2014 10:54:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F872201FA for ; Tue, 15 Apr 2014 10:54:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754552AbaDOKyk (ORCPT ); Tue, 15 Apr 2014 06:54:40 -0400 Received: from mail-lb0-f173.google.com ([209.85.217.173]:54361 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754549AbaDOKyh (ORCPT ); Tue, 15 Apr 2014 06:54:37 -0400 Received: by mail-lb0-f173.google.com with SMTP id p9so6645072lbv.4 for ; Tue, 15 Apr 2014 03:54:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=QSTAzL0NX76NzCCKRCQV9I5HZGVfIMHOPk+VLGSz52k=; b=IZ526rUTmLhX57OfcMpzuC2Ot3q+w7Tt+0aqNR0H5sVXLjsLqxPmilMDezzg6JtmM6 DjeIzyED4b/ZZ7kIusj5m7VgA5Zz2+MV9UNxXSJe+cddfRWMO4e95hgLJ/UkODMSxqEb Z3xFK+IBr2GlSKGzaHQ2NMWineenygXezNxB2luzaTVmaktLgV9KTRpk2SHXqT0dfszq o+D2u90U9XCyZV0hpwteXmvmK/yvhZB+gZKplke816SYD6rW9zsNgmZKiQovimhdh9rI RNhgBOKyQKjkAqmD2HEOX6mrYWEx31+ULKk/469buTnWxUDbQGW6YcbXlNiHq2fy9TvM /1xw== X-Received: by 10.112.141.10 with SMTP id rk10mr808106lbb.26.1397559276272; Tue, 15 Apr 2014 03:54:36 -0700 (PDT) Received: from a13xCCC.localdomain ([89.175.56.18]) by mx.google.com with ESMTPSA id bm3sm16946268lbb.12.2014.04.15.03.54.35 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 15 Apr 2014 03:54:35 -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 Cc: devicetree@vger.kernel.org Subject: [PATCH RFC v11 4/6] dma: of: Add common xlate function for matching by channel id Date: Tue, 15 Apr 2014 14:54:08 +0400 Message-Id: <1397559250-17680-5-git-send-email-a13xp0p0v88@gmail.com> X-Mailer: git-send-email 1.7.11.3 In-Reply-To: <1397559250-17680-1-git-send-email-a13xp0p0v88@gmail.com> References: <1397559250-17680-1-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 */