From patchwork Wed Jan 31 02:36:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Boyd X-Patchwork-Id: 10193069 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 51EC960383 for ; Wed, 31 Jan 2018 02:37:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 42422283B0 for ; Wed, 31 Jan 2018 02:37:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 36C1B283BF; Wed, 31 Jan 2018 02:37:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9CFB0283B0 for ; Wed, 31 Jan 2018 02:37:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=MrWS6r0OX3162og/kfjPhhcY8Wl8ePQGPGGHYUtNnsM=; b=mwJXlpXA4xVV3x1Jme2JpWsQnk RXRwpFQVMDyhlxsZ0EcFlVQYVlCFyW01v5jU/YZvihBrk/TnMaZnE5EZJyE9svLntalhDLLsjnJAh HiLTQ0n+LGdM1H66cozTlruuuzRfIRSIsqf0nK+Vvr4In9neKlIgNBmqdr+dttzPNcTCBEov8cMIv cYBknSKoM7W/spse4JBkQCkSS/yTfEsnZniQgjBNFMlj/VHc4VeYKS/4evb70gc/PcgjuBL/Ux38s aASzQ9zRvy5gYgd87G9Oupmy1FCTmbFioJiHKfbWs8/JY7op6uasdgbpXDK2RUyn4iXuHkoXE3rfD a4CjmkBA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1egiGi-0002oW-7S; Wed, 31 Jan 2018 02:37:00 +0000 Received: from mail-pf0-x242.google.com ([2607:f8b0:400e:c00::242]) by bombadil.infradead.org with esmtps (Exim 4.89 #1 (Red Hat Linux)) id 1egiGO-0002VQ-WD for linux-arm-kernel@lists.infradead.org; Wed, 31 Jan 2018 02:36:42 +0000 Received: by mail-pf0-x242.google.com with SMTP id i66so11088972pfd.7 for ; Tue, 30 Jan 2018 18:36:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=+YGe5AfQMSsdI2+cZp6bKM76ra175J+uy5clIruW6EY=; b=QAjVXHfdZgv4bFCOMV6Bw9cY5kHLbx20wKLfHLq7lKyGrd5VBpKyRyaQI+wXq5DRgW voBDUeEM3k9eDQgycyl973iaIljRFep+Qa4YeZmVOzj+8fiXTmaql9CScNNqH6I3bJdK cFox6D2FVrlFGB1XiKDRxU/6oHwYhen4ELRI4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=+YGe5AfQMSsdI2+cZp6bKM76ra175J+uy5clIruW6EY=; b=dHXgJQZz8VMD17FUgb+gd2zFw2SDs4ADzFqCnd1XD7z6PweSiFSai+MhM4yMEyV2/I ZE/KjE+ZrkWMZZMDys5IkYjb8KDbFRUCFrU+cNg97yp0/s/OtZnH9B39QPplzpdjMUNB l1yOoExxfrnEL4Bo6n/A3h/WsurEk42sN/2Cl1TLrBww4L/DG/12jwo/WUhi6Ga/EKJH R4bPhZ0/W7wfW19IhnIipa47mcxgF0DVStsHLzd0lB/RdjUzDnkcCh8qvKOvqkAk6wKQ CVhDI3YqZsqU6DnZrJxgJme2TK1JHfbn6YUmP80VnwkOnwIUImjdFolhaws8eCUEby2/ Qv2A== X-Gm-Message-State: AKwxytc1pLlYypV+GEGKN1Aap+8RUQWV2VONo/IWEZSxpuMR0dNoUSEn gKZUc7yOpltSCqnNO+5YRXqbqw== X-Google-Smtp-Source: AH8x224byFv8Umq9mPGacwaX5hLLjk/MzdLKaVljg7pvqfktTUh55vIfgTNi9r+CpBM3Ro5Ooj0jFg== X-Received: by 2002:a17:902:8f90:: with SMTP id z16-v6mr27613005plo.370.1517366190205; Tue, 30 Jan 2018 18:36:30 -0800 (PST) Received: from localhost.localdomain (pat_11.qualcomm.com. [192.35.156.11]) by smtp.gmail.com with ESMTPSA id z2sm24126828pgz.22.2018.01.30.18.36.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 30 Jan 2018 18:36:29 -0800 (PST) From: Stephen Boyd To: Rob Herring , Frank Rowand Subject: [PATCH v5 2/4] of: Support parsing phandle argument lists through a nexus node Date: Tue, 30 Jan 2018 18:36:16 -0800 Message-Id: <20180131023618.14292-3-stephen.boyd@linaro.org> X-Mailer: git-send-email 2.14.GIT In-Reply-To: <20180131023618.14292-1-stephen.boyd@linaro.org> References: <20180131023618.14292-1-stephen.boyd@linaro.org> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, devicetree-spec@vger.kernel.org, Linus Walleij , Pantelis Antoniou , linux-kernel@vger.kernel.org, Russell King - ARM Linux , Mark Brown , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Platforms like 96boards have a standardized connector/expansion slot that exposes signals like GPIOs to expansion boards in an SoC agnostic way. We'd like the DT overlays for the expansion boards to be written once without knowledge of the SoC on the other side of the connector. This avoids the unscalable combinatorial explosion of a different DT overlay for each expansion board and SoC pair. We need a way to describe the GPIOs routed through the connector in an SoC agnostic way. Let's introduce nexus property parsing into the OF core to do this. This is largely based on the interrupt nexus support we already have. This allows us to remap a phandle list in a consumer node (e.g. reset-gpios) through a connector in a generic way (e.g. via gpio-map). Do this in a generic routine so that we can remap any sort of variable length phandle list. Taking GPIOs as an example, the connector would be a GPIO nexus, supporting the remapping of a GPIO specifier space to multiple GPIO providers on the SoC. DT would look as shown below, where 'soc_gpio1' and 'soc_gpio2' are inside the SoC, 'connector' is an expansion port where boards can be plugged in, and 'expansion_device' is a device on the expansion board. soc { soc_gpio1: gpio-controller1 { #gpio-cells = <2>; }; soc_gpio2: gpio-controller2 { #gpio-cells = <2>; }; }; connector: connector { #gpio-cells = <2>; gpio-map = <0 0 &soc_gpio1 1 0>, <1 0 &soc_gpio2 4 0>, <2 0 &soc_gpio1 3 0>, <3 0 &soc_gpio2 2 0>; gpio-map-mask = <0xf 0x0>; gpio-map-pass-thru = <0x0 0x1> }; expansion_device { reset-gpios = <&connector 2 GPIO_ACTIVE_LOW>; }; The GPIO core would use of_parse_phandle_with_args_map() instead of of_parse_phandle_with_args() and arrive at the same type of result, a phandle and argument list. The difference is that the phandle and arguments will be remapped through the nexus node to the underlying SoC GPIO controller node. In the example above, we would remap 'reset-gpios' from <&connector 2 GPIO_ACTIVE_LOW> to <&soc_gpio1 3 GPIO_ACTIVE_LOW>. Cc: Pantelis Antoniou Cc: Linus Walleij Cc: Mark Brown Signed-off-by: Stephen Boyd --- drivers/of/base.c | 184 +++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of.h | 12 ++++ 2 files changed, 196 insertions(+) diff --git a/drivers/of/base.c b/drivers/of/base.c index 26618ba8f92a..aab0fc9a70d7 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1261,6 +1261,190 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na } EXPORT_SYMBOL(of_parse_phandle_with_args); +/** + * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it + * @np: pointer to a device tree node containing a list + * @list_name: property name that contains a list + * @stem_name: stem of property names that specify phandles' arguments count + * @index: index of a phandle to parse out + * @out_args: optional pointer to output arguments structure (will be filled) + * + * This function is useful to parse lists of phandles and their arguments. + * Returns 0 on success and fills out_args, on error returns appropriate errno + * value. The difference between this function and of_parse_phandle_with_args() + * is that this API remaps a phandle if the node the phandle points to has + * a <@stem_name>-map property. + * + * Caller is responsible to call of_node_put() on the returned out_args->np + * pointer. + * + * Example: + * + * phandle1: node1 { + * #list-cells = <2>; + * } + * + * phandle2: node2 { + * #list-cells = <1>; + * } + * + * phandle3: node3 { + * #list-cells = <1>; + * list-map = <0 &phandle2 3>, + * <1 &phandle2 2>, + * <2 &phandle1 5 1>; + * list-map-mask = <0x3>; + * }; + * + * node4 { + * list = <&phandle1 1 2 &phandle3 0>; + * } + * + * To get a device_node of the `node2' node you may call this: + * of_parse_phandle_with_args(node4, "list", "list", 1, &args); + */ +int of_parse_phandle_with_args_map(const struct device_node *np, + const char *list_name, + const char *stem_name, + int index, struct of_phandle_args *out_args) +{ + char *cells_name, *map_name = NULL, *mask_name = NULL; + char *pass_name = NULL; + struct device_node *cur, *new = NULL; + const __be32 *map, *mask, *pass; + static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 }; + static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 }; + __be32 initial_match_array[MAX_PHANDLE_ARGS]; + const __be32 *match_array = initial_match_array; + int i, ret, map_len, match; + u32 list_size, new_size; + + if (index < 0) + return -EINVAL; + + cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name); + if (!cells_name) + return -ENOMEM; + + ret = -ENOMEM; + map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name); + if (!map_name) + goto free; + + mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name); + if (!mask_name) + goto free; + + pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name); + if (!pass_name) + goto free; + + ret = __of_parse_phandle_with_args(np, list_name, cells_name, 0, index, + out_args); + if (ret) + goto free; + + /* Get the #-cells property */ + cur = out_args->np; + ret = of_property_read_u32(cur, cells_name, &list_size); + if (ret < 0) + goto put; + + /* Precalculate the match array - this simplifies match loop */ + for (i = 0; i < list_size; i++) + initial_match_array[i] = cpu_to_be32(out_args->args[i]); + + ret = -EINVAL; + while (cur) { + /* Get the -map property */ + map = of_get_property(cur, map_name, &map_len); + if (!map) { + ret = 0; + goto free; + } + map_len /= sizeof(u32); + + /* Get the -map-mask property (optional) */ + mask = of_get_property(cur, mask_name, NULL); + if (!mask) + mask = dummy_mask; + /* Iterate through -map property */ + match = 0; + while (map_len > (list_size + 1) && !match) { + /* Compare specifiers */ + match = 1; + for (i = 0; i < list_size; i++, map_len--) + match &= !((match_array[i] ^ *map++) & mask[i]); + + of_node_put(new); + new = of_find_node_by_phandle(be32_to_cpup(map)); + map++; + map_len--; + + /* Check if not found */ + if (!new) + goto put; + + if (!of_device_is_available(new)) + match = 0; + + ret = of_property_read_u32(new, cells_name, &new_size); + if (ret) + goto put; + + /* Check for malformed properties */ + if (WARN_ON(new_size > MAX_PHANDLE_ARGS)) + goto put; + if (map_len < new_size) + goto put; + + /* Move forward by new node's #-cells amount */ + map += new_size; + map_len -= new_size; + } + if (!match) + goto put; + + /* Get the -map-pass-thru property (optional) */ + pass = of_get_property(cur, pass_name, NULL); + if (!pass) + pass = dummy_pass; + + /* + * Successfully parsed a -map translation; copy new + * specifier into the out_args structure, keeping the + * bits specified in -map-pass-thru. + */ + match_array = map - new_size; + for (i = 0; i < new_size; i++) { + __be32 val = *(map - new_size + i); + + if (i < list_size) { + val &= ~pass[i]; + val |= cpu_to_be32(out_args->args[i]) & pass[i]; + } + + out_args->args[i] = be32_to_cpu(val); + } + out_args->args_count = list_size = new_size; + /* Iterate again with new provider */ + out_args->np = new; + of_node_put(cur); + cur = new; + } +put: + of_node_put(cur); + of_node_put(new); +free: + kfree(mask_name); + kfree(map_name); + kfree(cells_name); + kfree(pass_name); + + return ret; +} +EXPORT_SYMBOL(of_parse_phandle_with_args_map); + /** * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list * @np: pointer to a device tree node containing a list diff --git a/include/linux/of.h b/include/linux/of.h index d3dea1d1e3a9..1bdf10118134 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -367,6 +367,9 @@ extern struct device_node *of_parse_phandle(const struct device_node *np, extern int of_parse_phandle_with_args(const struct device_node *np, const char *list_name, const char *cells_name, int index, struct of_phandle_args *out_args); +extern int of_parse_phandle_with_args_map(const struct device_node *np, + const char *list_name, const char *stem_name, int index, + struct of_phandle_args *out_args); extern int of_parse_phandle_with_fixed_args(const struct device_node *np, const char *list_name, int cells_count, int index, struct of_phandle_args *out_args); @@ -817,6 +820,15 @@ static inline int of_parse_phandle_with_args(const struct device_node *np, return -ENOSYS; } +static inline int of_parse_phandle_with_args_map(const struct device_node *np, + const char *list_name, + const char *stem_name, + int index, + struct of_phandle_args *out_args) +{ + return -ENOSYS; +} + static inline int of_parse_phandle_with_fixed_args(const struct device_node *np, const char *list_name, int cells_count, int index, struct of_phandle_args *out_args)