From patchwork Thu Mar 20 14:47:56 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Popov X-Patchwork-Id: 332210 X-Patchwork-Delegate: agust@denx.de Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 5FA4D2C02A8 for ; Fri, 21 Mar 2014 01:51:10 +1100 (EST) Received: from mail-lb0-x22e.google.com (mail-lb0-x22e.google.com [IPv6:2a00:1450:4010:c04::22e]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id B0A8A2C011D for ; Fri, 21 Mar 2014 01:48:25 +1100 (EST) Received: by mail-lb0-f174.google.com with SMTP id u14so689017lbd.33 for ; Thu, 20 Mar 2014 07:48:20 -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=RRxT7sOlZd6vhK+ZiSisVaxaAGdKuAmsuf0OVo6uF02YhAUIPJBtU134Fd5yVWd/fF kdLC78Vgc/bt2pRHShAZRq1Lfdd56SOI+sezmlIaioaplUwhB6ZaLdxmleinIoO+nclf seS7yHMqC8XmhlwvfoAfDvsIvsr3SC3R0c+fv1JQ048tvrmGdejCECRjoQiTpLvRxvlx 8DlnuiSgYbh5g4T5drOcqXwNHCWhbU7AD6suuvbV2lEpAJa2h9TJcRdsww2AnuyBCjBG isfRfQL4bfyqkk0jIxy+4Yt6dbahst3R1Dtcjx5B3iTVsdhZL3/TWi0m4WY344zB2r7a 3dww== X-Received: by 10.152.87.14 with SMTP id t14mr1333218laz.52.1395326900929; Thu, 20 Mar 2014 07:48:20 -0700 (PDT) Received: from a13xCCC.localdomain (mail.tecon.ru. [89.175.104.62]) by mx.google.com with ESMTPSA id qa7sm1398967lbb.6.2014.03.20.07.48.19 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 20 Mar 2014 07:48:19 -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 Subject: [PATCH RFC v10 4/6] dma: of: Add common xlate function for matching by channel id Date: Thu, 20 Mar 2014 18:47:56 +0400 Message-Id: <1395326878-25243-5-git-send-email-a13xp0p0v88@gmail.com> X-Mailer: git-send-email 1.7.11.3 In-Reply-To: <1395326878-25243-1-git-send-email-a13xp0p0v88@gmail.com> References: <1395326878-25243-1-git-send-email-a13xp0p0v88@gmail.com> Cc: devicetree@vger.kernel.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 */