From patchwork Wed Aug 17 11:47:27 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jamie Iles X-Patchwork-Id: 1073682 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7HBmMPw021407 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 17 Aug 2011 11:48:43 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QtebC-0006VB-Tb; Wed, 17 Aug 2011 11:47:56 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QtebC-0003ih-Ae; Wed, 17 Aug 2011 11:47:54 +0000 Received: from mail-ww0-f49.google.com ([74.125.82.49]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qteat-0003ey-Cw for linux-arm-kernel@lists.infradead.org; Wed, 17 Aug 2011 11:47:37 +0000 Received: by wwf10 with SMTP id 10so646816wwf.18 for ; Wed, 17 Aug 2011 04:47:33 -0700 (PDT) Received: by 10.217.3.17 with SMTP id q17mr3917242wes.107.1313581653672; Wed, 17 Aug 2011 04:47:33 -0700 (PDT) Received: from localhost (gw-ba1.picochip.com [94.175.234.108]) by mx.google.com with ESMTPS id z74sm708134weq.23.2011.08.17.04.47.32 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 17 Aug 2011 04:47:33 -0700 (PDT) From: Jamie Iles To: devicetree-discuss@lists.ozlabs.org Subject: [RFC PATCH 1/2] of: add a generic pinmux helper Date: Wed, 17 Aug 2011 12:47:27 +0100 Message-Id: <1313581648-22303-2-git-send-email-jamie@jamieiles.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1313581648-22303-1-git-send-email-jamie@jamieiles.com> References: <1313581648-22303-1-git-send-email-jamie@jamieiles.com> X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110817_074735_762562_88D06CEA X-CRM114-Status: GOOD ( 24.60 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [74.125.82.49 listed in list.dnswl.org] Cc: linux@arm.linux.org.uk, sshtylyov@mvista.com, konkers@android.com, marek.belisko@gmail.com, linus.walleij@linaro.org, Jamie Iles , grant.likely@secretlab.ca, linux-arm-kernel@lists.infradead.org, ccross@android.com, swarren@nvidia.com, shawn.guo@freescale.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Wed, 17 Aug 2011 11:48:43 +0000 (UTC) This patch adds a helper function of_pinmux_parse() that can be used to extract common pinmux configuration to avoid each platform implementing a parsing loop. Platforms supply the node containing the pinmux definitions and a platform specific callback for configuring a pingroup. Cc: Stephen Warren Signed-off-by: Jamie Iles --- drivers/of/Kconfig | 5 +++ drivers/of/Makefile | 1 + drivers/of/of_pinmux.c | 80 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_pinmux.h | 67 +++++++++++++++++++++++++++++++++++++ 4 files changed, 153 insertions(+), 0 deletions(-) create mode 100644 drivers/of/of_pinmux.c create mode 100644 include/linux/of_pinmux.h diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index b3bfea5..d300c02 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -87,4 +87,9 @@ config OF_PCI_IRQ help OpenFirmware PCI IRQ routing helpers +config OF_PINMUX + def_bool y + help + OpenFirmware pin multiplexing helpers + endmenu # OF diff --git a/drivers/of/Makefile b/drivers/of/Makefile index 74b959c..04d7fa9 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -12,3 +12,4 @@ obj-$(CONFIG_OF_SPI) += of_spi.o obj-$(CONFIG_OF_MDIO) += of_mdio.o obj-$(CONFIG_OF_PCI) += of_pci.o obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o +obj-$(CONFIG_OF_PINMUX) += of_pinmux.o diff --git a/drivers/of/of_pinmux.c b/drivers/of/of_pinmux.c new file mode 100644 index 0000000..adfdfc0 --- /dev/null +++ b/drivers/of/of_pinmux.c @@ -0,0 +1,80 @@ +/* + * Copyright (c) 2011 Picochip Ltd., Jamie Iles + * + * Generic pinmux bindings for device tree. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include +#include +#include +#include +#include + +/** + * of_pinmux_parse - configure a set of pinmux groups for a pinmux controller + * + * @controller: the controller to configure the pinmux entries for. This + * defines the controller device node and the callback for configuring + * the pingroups. + * + * This helper loops over all of the child nodes of a pinmux controller and + * collects the configuration for each pinmux group. A pinmux group is + * defined as one or more pins that are configured to a common function. This + * handles common properties that many platforms may implement, but for + * platform specific properties these may be handled in the configure + * callback. + */ +int of_pinmux_parse(const struct of_pinmux_ctrl *controller) +{ + struct device_node *np; + + if (!controller || !controller->pinmux || !controller->configure) + return -EINVAL; + + for_each_child_of_node(controller->pinmux, np) { + struct of_pinmux_cfg config = { + .pin = np, + }; + int ret; + + ret = of_property_read_string(np, "function", + &config.function); + if (ret < 0) { + pr_err("no function for pingroup %s\n", np->name); + continue; + } + + if (of_find_property(np, "pull-up", NULL)) + config.flags |= OF_PINMUX_PULL_UP; + if (of_find_property(np, "pull-down", NULL)) + config.flags |= OF_PINMUX_PULL_DOWN; + + if ((config.flags & OF_PINMUX_PULL_MASK) == + OF_PINMUX_PULL_MASK) { + pr_warn("pingroup %s has both pull-up and pull-down properties - defaulting to no pull\n", + np->name); + config.flags &= ~OF_PINMUX_PULL_MASK; + } + + if (of_find_property(np, "tristate", NULL)) + config.flags |= OF_PINMUX_TRISTATE; + + pr_debug("configure pingroup %s, func=%s, flags=0x%lx\n", + np->name, config.function, config.flags); + if (controller->configure(controller, &config)) + pr_warn("failed to configure pingroup %s\n", np->name); + } + + return 0; +} +EXPORT_SYMBOL_GPL(of_pinmux_parse); diff --git a/include/linux/of_pinmux.h b/include/linux/of_pinmux.h new file mode 100644 index 0000000..61f2ab6 --- /dev/null +++ b/include/linux/of_pinmux.h @@ -0,0 +1,67 @@ +/* + * Copyright (c) 2011 Picochip Ltd., Jamie Iles + * + * Generic pinmux bindings for device tree. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#ifndef __OF_PINMUX_H__ +#define __OF_PINMUX_H__ + +struct device_node; + +#define OF_PINMUX_PULL_UP (1 << 0) +#define OF_PINMUX_PULL_DOWN (1 << 1) +#define OF_PINMUX_TRISTATE (1 << 2) + +#define OF_PINMUX_PULL_MASK (OF_PINMUX_PULL_UP | OF_PINMUX_PULL_DOWN) + +/** + * struct of_pinmux_cfg - configuration state for a single pinmux entry. + * + * @function: the name of the function that the pinmux entry should be + * configured to. + * @pin: the device_node of the pinmux entry that should be configured. + * Platform specific properties that aren't in the generic binding may be + * obtained from this device node. + * @flags: flags for common pinmux options such as pull and tristate. + */ +struct of_pinmux_cfg { + const char *function; + struct device_node *pin; + unsigned long flags; +}; + +/** + * struct of_pinmux_ctrl - platform specific pinmux control state. + * + * @pinmux: the pinmux device node. All child nodes are required to be the + * pinmux entry definitions. Depending on the platform, this may either be + * a single pin or a group of pins where they can be set to a common + * function. + * @configure: platform specific callback to configure the pinmux entry. + */ +struct of_pinmux_ctrl { + struct device_node *pinmux; + int (*configure)(const struct of_pinmux_ctrl *ctrl, + const struct of_pinmux_cfg *cfg); +}; + +#ifdef CONFIG_OF +extern int of_pinmux_parse(const struct of_pinmux_ctrl *controller); +#else +static inline int of_pinmux_parse(const struct of_pinmux_ctrl *controller) +{ + return -ENOSYS; +} +#endif /* CONFIG_OF */ + +#endif /* __OF_PINMUX_H__ */