From patchwork Thu Mar 5 02:01:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suman Anna X-Patchwork-Id: 5943101 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id B8C74BF440 for ; Thu, 5 Mar 2015 02:43:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id BC24720148 for ; Thu, 5 Mar 2015 02:43:33 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AE9DE201CE for ; Thu, 5 Mar 2015 02:43:32 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YTLiF-0003fh-PI; Thu, 05 Mar 2015 02:40:35 +0000 Received: from bear.ext.ti.com ([192.94.94.41]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YTL6f-0007lw-3l for linux-arm-kernel@lists.infradead.org; Thu, 05 Mar 2015 02:01:49 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id t2521Kia005745; Wed, 4 Mar 2015 20:01:20 -0600 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 t2521IXG023032; Wed, 4 Mar 2015 20:01:19 -0600 Received: from dlep32.itg.ti.com (157.170.170.100) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.224.2; Wed, 4 Mar 2015 20:01:18 -0600 Received: from legion.dal.design.ti.com (legion.dal.design.ti.com [128.247.22.53]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id t2521I2X008392; Wed, 4 Mar 2015 20:01:18 -0600 Received: from localhost (irmo.am.dhcp.ti.com [128.247.71.175]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id t2521I902614; Wed, 4 Mar 2015 20:01:18 -0600 (CST) From: Suman Anna To: Ohad Ben-Cohen , Mark Rutland Subject: [PATCH v8 2/4] hwspinlock/core: add device tree support Date: Wed, 4 Mar 2015 20:01:14 -0600 Message-ID: <1425520876-37826-3-git-send-email-s-anna@ti.com> X-Mailer: git-send-email 2.3.0 In-Reply-To: <1425520876-37826-1-git-send-email-s-anna@ti.com> References: <1425520876-37826-1-git-send-email-s-anna@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150304_180145_339279_E20DED94 X-CRM114-Status: GOOD ( 20.77 ) X-Spam-Score: -5.0 (-----) Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Andersson , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 This patch adds a new OF-friendly API of_hwspin_lock_get_id() for hwspinlock clients to use/request locks from a hwspinlock device instantiated through a device-tree blob. This new API can be used by hwspinlock clients to get the id for a specific lock using the phandle + args specifier, so that it can be requested using the available hwspin_lock_request_specific() API. Signed-off-by: Suman Anna Reviewed-by: Bjorn Andersson --- v8: Removed the previous OF helpers of_hwspin_lock_get_num_locks() & of_hwspin_lock_get_base_id() due to the revised generic bindings. Added back the support for deferred probing and pargs specifier validation like in v6, but without using an added list for storing registered hwspinlock devices. Documentation/hwspinlock.txt | 10 +++++ drivers/hwspinlock/hwspinlock_core.c | 79 ++++++++++++++++++++++++++++++++++++ include/linux/hwspinlock.h | 7 ++++ 3 files changed, 96 insertions(+) diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt index 62f7d4ea6e26..61c1ee98e59f 100644 --- a/Documentation/hwspinlock.txt +++ b/Documentation/hwspinlock.txt @@ -48,6 +48,16 @@ independent, drivers. ids for predefined purposes. Should be called from a process context (might sleep). + int of_hwspin_lock_get_id(struct device_node *np, int index); + - retrieve the global lock id for an OF phandle-based specific lock. + This function provides a means for DT users of a hwspinlock module + to get the global lock id of a specific hwspinlock, so that it can + be requested using the normal hwspin_lock_request_specific() API. + The function returns a lock id number on success, -EPROBE_DEFER if + the hwspinlock device is not yet registered with the core, or other + error values. + Should be called from a process context (might sleep). + int hwspin_lock_free(struct hwspinlock *hwlock); - free a previously-assigned hwspinlock; returns 0 on success, or an appropriate error code on failure (e.g. -EINVAL if the hwspinlock diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 461a0d739d75..f8539f624e3d 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "hwspinlock_internal.h" @@ -257,6 +258,84 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) } EXPORT_SYMBOL_GPL(__hwspin_unlock); +/** + * of_hwspin_lock_simple_xlate - translate hwlock_spec to return a lock id + * @bank: the hwspinlock device bank + * @hwlock_spec: hwlock specifier as found in the device tree + * + * This is a simple translation function, suitable for hwspinlock platform + * drivers that only has a lock specifier length of 1. + * + * Returns a relative index of the lock within a specified bank on success, + * or -EINVAL on invalid specifier cell count. + */ +static inline int +of_hwspin_lock_simple_xlate(const struct of_phandle_args *hwlock_spec) +{ + if (WARN_ON(hwlock_spec->args_count != 1)) + return -EINVAL; + + return hwlock_spec->args[0]; +} + +/** + * of_hwspin_lock_get_id() - get lock id for an OF phandle-based specific lock + * @np: device node from which to request the specific hwlock + * @index: index of the hwlock in the list of values + * + * This function provides a means for DT users of the hwspinlock module to + * get the global lock id of a specific hwspinlock using the phandle of the + * hwspinlock device, so that it can be requested using the normal + * hwspin_lock_request_specific() API. + * + * Returns the global lock id number on success, -EPROBE_DEFER if the hwspinlock + * device is not yet registered, -EINVAL on invalid args specifier value or an + * appropriate error as returned from the OF parsing of the DT client node. + */ +int of_hwspin_lock_get_id(struct device_node *np, int index) +{ + struct of_phandle_args args; + struct hwspinlock *hwlock; + struct radix_tree_iter iter; + void **slot; + int id; + int ret; + + ret = of_parse_phandle_with_args(np, "hwlocks", "#hwlock-cells", index, + &args); + if (ret) + return ret; + + /* perform a sanity check of the hwspinlock device */ + ret = -EPROBE_DEFER; + rcu_read_lock(); + radix_tree_for_each_slot(slot, &hwspinlock_tree, &iter, 0) { + hwlock = radix_tree_deref_slot(slot); + if (unlikely(!hwlock)) + continue; + + if (hwlock->bank->dev->of_node == args.np) { + ret = 0; + break; + } + } + rcu_read_unlock(); + if (ret < 0) + goto out; + + id = of_hwspin_lock_simple_xlate(&args); + if (id < 0 || id >= hwlock->bank->num_locks) { + ret = -EINVAL; + goto out; + } + id += hwlock->bank->base_id; + +out: + of_node_put(args.np); + return ret ? ret : id; +} +EXPORT_SYMBOL_GPL(of_hwspin_lock_get_id); + static int hwspin_lock_register_single(struct hwspinlock *hwlock, int id) { struct hwspinlock *tmp; diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index 3343298e40e8..859d673d98c8 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -26,6 +26,7 @@ #define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */ struct device; +struct device_node; struct hwspinlock; struct hwspinlock_device; struct hwspinlock_ops; @@ -66,6 +67,7 @@ int hwspin_lock_unregister(struct hwspinlock_device *bank); struct hwspinlock *hwspin_lock_request(void); struct hwspinlock *hwspin_lock_request_specific(unsigned int id); int hwspin_lock_free(struct hwspinlock *hwlock); +int of_hwspin_lock_get_id(struct device_node *np, int index); int hwspin_lock_get_id(struct hwspinlock *hwlock); int __hwspin_lock_timeout(struct hwspinlock *, unsigned int, int, unsigned long *); @@ -120,6 +122,11 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) { } +static inline int of_hwspin_lock_get_id(struct device_node *np, int index) +{ + return 0; +} + static inline int hwspin_lock_get_id(struct hwspinlock *hwlock) { return 0;