From patchwork Fri Mar 27 12:26:47 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 6106841 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 [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 974EA9F2A9 for ; Fri, 27 Mar 2015 12:31:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AE53020439 for ; Fri, 27 Mar 2015 12:31:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E403B20429 for ; Fri, 27 Mar 2015 12:31:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753163AbbC0MbL (ORCPT ); Fri, 27 Mar 2015 08:31:11 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:57933 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752631AbbC0M1k (ORCPT ); Fri, 27 Mar 2015 08:27:40 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id t2RCR3CJ031285; Fri, 27 Mar 2015 07:27:03 -0500 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id t2RCR1Rf029225; Fri, 27 Mar 2015 07:27:02 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.224.2; Fri, 27 Mar 2015 07:27:01 -0500 Received: from dlep32.itg.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id t2RCQsHk017958; Fri, 27 Mar 2015 07:26:58 -0500 From: Peter Ujfalusi To: , , CC: , , , , , , , Subject: [PATCH v3 1/7] dmaengine: of_dma: Support for DMA routers Date: Fri, 27 Mar 2015 14:26:47 +0200 Message-ID: <1427459213-14611-2-git-send-email-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.3.3 In-Reply-To: <1427459213-14611-1-git-send-email-peter.ujfalusi@ti.com> References: <1427459213-14611-1-git-send-email-peter.ujfalusi@ti.com> MIME-Version: 1.0 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 DMA routers are transparent devices used to mux DMA requests from peripherals to DMA controllers. They are used when the SoC integrates more devices with DMA requests then their controller can handle. DRA7x is one example of such SoC, where the sDMA can hanlde 128 DMA request lines, but in SoC level it has 205 DMA requests. The of_dma_router will be registered as of_dma_controller with special xlate function and additional parameters and the code will translate and requests a DMA channel from the real DMA controller. This way the router can be transparent for the system while remaining generic enough to be used in different environments. Signed-off-by: Peter Ujfalusi --- Documentation/devicetree/bindings/dma/dma.txt | 28 ++++++++ drivers/dma/dmaengine.c | 7 ++ drivers/dma/of-dma.c | 92 +++++++++++++++++++++++++++ include/linux/dmaengine.h | 17 +++++ include/linux/of_dma.h | 21 ++++++ 5 files changed, 165 insertions(+) diff --git a/Documentation/devicetree/bindings/dma/dma.txt b/Documentation/devicetree/bindings/dma/dma.txt index 82104271e754..f728b978178e 100644 --- a/Documentation/devicetree/bindings/dma/dma.txt +++ b/Documentation/devicetree/bindings/dma/dma.txt @@ -31,6 +31,34 @@ Example: dma-requests = <127>; }; +* DMA router + +DMA routers are transparent IP blocks used to route DMA request lines from +devices to the DMA controller. Some SoCs (like TI DRA7x) have more peripherals +integrated with DMA requests than what the DMA controller can handle directly. + +Required property: +- dma-device: phandle of the DMA controller. The router is modifying + the DMA requests for this controller. +- #dma-cells: Must be at least 1. Used to provide DMA router specific + information. See DMA client binding below for more + details. + +Optional properties: +- dma-requests: Number of incoming request lines the router can handle. +- dma-device + - dma-requests: The router driver might need to look for this in order + to configure the routing. + +Example: + sdma_xbar: dma-router@4a002b78 { + compatible = "ti,dra7-dma-crossbar"; + reg = <0x4a002b78 0xfc>; + #dma-cells = <1>; + dma-requests = <205>; + ti,dma-safe-map = <0>; + dma-device = <&sdma>; + }; * DMA client diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 24967c89f5d4..c7aa232b4a59 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -267,6 +267,13 @@ static void dma_chan_put(struct dma_chan *chan) /* This channel is not in use anymore, free it */ if (!chan->client_count && chan->device->device_free_chan_resources) chan->device->device_free_chan_resources(chan); + + /* If the channel is used via a DMA request router, free the mapping */ + if (chan->router && chan->router->route_free) { + chan->router->route_free(chan->router->dev, chan->route_data); + chan->router = NULL; + chan->route_data = NULL; + } } enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index cbd4a8aff120..37acdc2cce58 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -45,6 +45,53 @@ static struct of_dma *of_dma_find_controller(struct of_phandle_args *dma_spec) } /** + * of_dma_router_xlate - translation function for router devices + * @dma_spec: pointer to DMA specifier as found in the device tree + * @of_dma: pointer to DMA controller data (router information) + * + * The function creates new dma_spec to be passed to the router driver's + * of_dma_route_allocate() function to prepare a dma_spec which will be used + * to request channel from the real DMA controller. + */ +static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct dma_chan *chan; + struct of_dma *ofdma_target; + struct device_node *dma_target; + struct of_phandle_args dma_spec_target; + void *route_data; + + dma_target = of_parse_phandle(dma_spec->np, "dma-device", 0); + if (!dma_target) { + pr_err("%s: Can't get target DMA\n", __func__); + return NULL; + } + + /* translate the request for the real DMA controller */ + memcpy(&dma_spec_target, dma_spec, sizeof(dma_spec_target)); + dma_spec_target.np = dma_target; + route_data = ofdma->of_dma_route_allocate(&dma_spec_target, ofdma); + + ofdma_target = of_dma_find_controller(&dma_spec_target); + if (!ofdma_target) { + pr_err("%s: Can't get target ofDMA\n", __func__); + return NULL; + } + + chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target); + if (chan) { + chan->router = ofdma->dma_router; + chan->route_data = route_data; + } else { + ofdma->dma_router->route_free(ofdma->dma_router->dev, route_data); + } + + of_node_put(dma_target); + return chan; +} + +/** * of_dma_controller_register - Register a DMA controller to DT DMA helpers * @np: device node of DMA controller * @of_dma_xlate: translation function which converts a phandle @@ -110,6 +157,51 @@ void of_dma_controller_free(struct device_node *np) EXPORT_SYMBOL_GPL(of_dma_controller_free); /** + * of_dma_router_register - Register a DMA router to DT DMA helpers as a + * controller + * @np: device node of DMA router + * @of_dma_route_allocate: setup function for the router which need to + * modify the dma_spec for the DMA controller to + * use and to set up the requested route. + * @dma_router: pointer to dma_router structure to be used when + * the route need to be free up. + * + * Returns 0 on success or appropriate errno value on error. + * + * Allocated memory should be freed with appropriate of_dma_controller_free() + * call. + */ +int of_dma_router_register(struct device_node *np, + void *(*of_dma_route_allocate) + (struct of_phandle_args *, struct of_dma *), + struct dma_router *dma_router) +{ + struct of_dma *ofdma; + + if (!np || !of_dma_route_allocate || !dma_router) { + pr_err("%s: not enough information provided\n", __func__); + return -EINVAL; + } + + ofdma = kzalloc(sizeof(*ofdma), GFP_KERNEL); + if (!ofdma) + return -ENOMEM; + + ofdma->of_node = np; + ofdma->of_dma_xlate = of_dma_router_xlate; + ofdma->of_dma_route_allocate = of_dma_route_allocate; + ofdma->dma_router = dma_router; + + /* Now queue of_dma controller structure in list */ + mutex_lock(&of_dma_lock); + list_add_tail(&ofdma->of_dma_controllers, &of_dma_list); + mutex_unlock(&of_dma_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(of_dma_router_register); + +/** * of_dma_match_channel - Check if a DMA specifier matches name * @np: device node to look for DMA channels * @name: channel name to be matched diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index ad419757241f..abf63ceabef9 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -222,6 +222,16 @@ struct dma_chan_percpu { }; /** + * struct dma_router - DMA router structure + * @dev: pointer to the DMA router device + * @route_free: function to be called when the route can be disconnected + */ +struct dma_router { + struct device *dev; + void (*route_free)(struct device *dev, void *route_data); +}; + +/** * struct dma_chan - devices supply DMA channels, clients use them * @device: ptr to the dma device who supplies this channel, always !%NULL * @cookie: last cookie value returned to client @@ -232,6 +242,8 @@ struct dma_chan_percpu { * @local: per-cpu pointer to a struct dma_chan_percpu * @client_count: how many clients are using this channel * @table_count: number of appearances in the mem-to-mem allocation table + * @router: pointer to the DMA router structure + * @route_data: channel specific data for the router * @private: private data for certain client-channel associations */ struct dma_chan { @@ -247,6 +259,11 @@ struct dma_chan { struct dma_chan_percpu __percpu *local; int client_count; int table_count; + + /* DMA router */ + struct dma_router *router; + void *route_data; + void *private; }; diff --git a/include/linux/of_dma.h b/include/linux/of_dma.h index 56bc026c143f..734e449f87c1 100644 --- a/include/linux/of_dma.h +++ b/include/linux/of_dma.h @@ -23,6 +23,9 @@ struct of_dma { struct device_node *of_node; struct dma_chan *(*of_dma_xlate) (struct of_phandle_args *, struct of_dma *); + void *(*of_dma_route_allocate) + (struct of_phandle_args *, struct of_dma *); + struct dma_router *dma_router; void *of_dma_data; }; @@ -37,12 +40,20 @@ extern int of_dma_controller_register(struct device_node *np, (struct of_phandle_args *, struct of_dma *), void *data); extern void of_dma_controller_free(struct device_node *np); + +extern int of_dma_router_register(struct device_node *np, + void *(*of_dma_route_allocate) + (struct of_phandle_args *, struct of_dma *), + struct dma_router *dma_router); +#define of_dma_router_free of_dma_controller_free + 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) @@ -56,6 +67,16 @@ static inline void of_dma_controller_free(struct device_node *np) { } +static inline int of_dma_router_register(struct device_node *np, + void *(*of_dma_route_allocate) + (struct of_phandle_args *, struct of_dma *), + struct dma_router *dma_router) +{ + return -ENODEV; +} + +#define of_dma_router_free of_dma_controller_free + static inline struct dma_chan *of_dma_request_slave_channel(struct device_node *np, const char *name) {