From patchwork Fri Jul 12 15:26:19 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerhard Sittig X-Patchwork-Id: 258770 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 207112C0690 for ; Sat, 13 Jul 2013 01:33:32 +1000 (EST) Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 727712C03A5; Sat, 13 Jul 2013 01:28:03 +1000 (EST) Received: from frontend1.mail.m-online.net (frontend1.mail.intern.m-online.net [192.168.8.180]) by mail-out.m-online.net (Postfix) with ESMTP id 3bsJ1C6Q3Qz3hhbQ; Fri, 12 Jul 2013 17:27:59 +0200 (CEST) Received: from localhost (dynscan1.mnet-online.de [192.168.6.68]) by mail.m-online.net (Postfix) with ESMTP id 3bsJ1C64XKzbbp0; Fri, 12 Jul 2013 17:27:59 +0200 (CEST) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.180]) by localhost (dynscan1.mail.m-online.net [192.168.6.68]) (amavisd-new, port 10024) with ESMTP id I6GUl9zcal_k; Fri, 12 Jul 2013 17:27:58 +0200 (CEST) X-Auth-Info: dMFVBW1VhNVhOxaMFTT347eTA0ymO1Q7RhN3zt0yips= Received: from localhost (kons-4d03eed5.pool.mediaWays.net [77.3.238.213]) by mail.mnet-online.de (Postfix) with ESMTPA; Fri, 12 Jul 2013 17:27:58 +0200 (CEST) From: Gerhard Sittig To: linuxppc-dev@lists.ozlabs.org, devicetree-discuss@lists.ozlabs.org, Alexander Popov Subject: [PATCH RFC 6/8] dma: of: Add common xlate function for matching by channel id Date: Fri, 12 Jul 2013 17:26:19 +0200 Message-Id: <1373642781-32631-7-git-send-email-gsi@denx.de> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1373642781-32631-1-git-send-email-gsi@denx.de> References: <1373642781-32631-1-git-send-email-gsi@denx.de> Cc: Vinod Koul , Lars-Peter Clausen , Anatolij Gustschin , Arnd Bergmann , Dan Williams X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 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" From: Lars-Peter Clausen From: Lars-Peter Clausen 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. The filter function will use this pointer to match only channels which belong to the specified DMA controller. Signed-off-by: Lars-Peter Clausen --- drivers/dma/of-dma.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_dma.h | 4 ++++ 2 files changed, 51 insertions(+) diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index 7aa0864..d5d528e 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -229,3 +229,50 @@ struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, &dma_spec->args[0]); } EXPORT_SYMBOL_GPL(of_dma_simple_xlate); + +struct of_dma_filter_by_chan_id_args { + struct dma_device *dev; + unsigned int chan_id; +}; + +static bool of_dma_filter_by_chan_id(struct dma_chan *chan, void *params) +{ + struct of_dma_filter_by_chan_id_args *args = params; + + return chan->device == args->dev && chan->chan_id == args->chan_id; +} + +/** + * 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 of_dma_filter_by_chan_id_args args; + dma_cap_mask_t cap; + + args.dev = ofdma->of_dma_data; + if (!args.dev) + return NULL; + + if (dma_spec->args_count != 1) + return NULL; + + dma_cap_zero(cap); + dma_cap_set(DMA_SLAVE, cap); + + args.chan_id = dma_spec->args[0]; + + return dma_request_channel(cap, of_dma_filter_by_chan_id, &args); +} +EXPORT_SYMBOL_GPL(of_dma_xlate_by_chan_id); diff --git a/include/linux/of_dma.h b/include/linux/of_dma.h index 364dda7..b7cf614 100644 --- a/include/linux/of_dma.h +++ b/include/linux/of_dma.h @@ -42,6 +42,8 @@ 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) @@ -67,6 +69,8 @@ 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 */