From patchwork Fri Mar 1 16:57:31 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 2202411 Return-Path: X-Original-To: patchwork-linux-samsung-soc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id CAFCBDF24C for ; Fri, 1 Mar 2013 17:06:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751060Ab3CARGY (ORCPT ); Fri, 1 Mar 2013 12:06:24 -0500 Received: from mail-qe0-f74.google.com ([209.85.128.74]:51117 "EHLO mail-qe0-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750879Ab3CARGX (ORCPT ); Fri, 1 Mar 2013 12:06:23 -0500 X-Greylist: delayed 496 seconds by postgrey-1.27 at vger.kernel.org; Fri, 01 Mar 2013 12:06:23 EST Received: by mail-qe0-f74.google.com with SMTP id 9so351634qea.1 for ; Fri, 01 Mar 2013 09:06:23 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references:x-gm-message-state; bh=uEjN43UyHK/JTyBPqcNqE0WX2Q79fiXbpkOh48eswYY=; b=nWtAUqfdX7LkZ3DA9J4DJ9A38PMtIJrgtQcKTHP/WJYve6RikPQTKskwxponQXldGg MuWnP90+7LLofmQmWd16TnqApBwAdsXODgc6rqLlLvbtu+ZzwPM8N30UQCX2KGs73B/I mdWTpKURfRwtkmEET0E0TeIDvDMZhEVOPwtAED0WVz6Hn93zS2igKiqVjOnZQjb3+Mc2 wtLPtSaxv5XmiTEumBKOblKXX/uvmCSylRlZFOfJCzmTemdjeOU2lXT54OqL8wtqJUtV Vi/44HA6Fz0+Tpe28SNc3RoU+o8Yrs+b79w/Z/EfXg7STxlvySIsktm8sHcS3fZJGrgj DuTQ== X-Received: by 10.236.92.115 with SMTP id i79mr6385530yhf.49.1362157085815; Fri, 01 Mar 2013 08:58:05 -0800 (PST) Received: from corp2gmr1-1.hot.corp.google.com (corp2gmr1-1.hot.corp.google.com [172.24.189.92]) by gmr-mx.google.com with ESMTPS id u21si815200yhj.0.2013.03.01.08.58.05 (version=TLSv1.1 cipher=AES128-SHA bits=128/128); Fri, 01 Mar 2013 08:58:05 -0800 (PST) Received: from tictac.mtv.corp.google.com (tictac.mtv.corp.google.com [172.22.73.80]) by corp2gmr1-1.hot.corp.google.com (Postfix) with ESMTP id 7C2B531C1F0; Fri, 1 Mar 2013 08:58:05 -0800 (PST) Received: by tictac.mtv.corp.google.com (Postfix, from userid 121310) id 25FFF8155F; Fri, 1 Mar 2013 08:58:04 -0800 (PST) From: Doug Anderson To: linux-i2c@vger.kernel.org, Wolfram Sang Cc: Mark Brown , Kukjin Kim , Olof Johansson , Thomas Abraham , Padmavathi Venna , Ben Dooks , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, Haojian Zhuang , Arnd Bergmann , Sylwester Nawrocki , Doug Anderson , linux-kernel@vger.kernel.org Subject: [PATCH v4 1/2] i2c-core: dt: Pick i2c bus number from i2c alias if present Date: Fri, 1 Mar 2013 08:57:31 -0800 Message-Id: <1362157052-16738-2-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.8.1.3 In-Reply-To: <1362157052-16738-1-git-send-email-dianders@chromium.org> References: <1360630085-26874-1-git-send-email-dianders@chromium.org> <1362157052-16738-1-git-send-email-dianders@chromium.org> X-Gm-Message-State: ALoCoQlZ3TDKDhDyDJYPpLSGHHcC+/XPyPQ+UAzuWLIoFzj+liYCx/LDTl4XYN2oW44UcoSjyCI250vsIOZMx8g+RXuNaYTxos806ST9xBjbNLK6JWdYkzJg/JTmwspzU6n+GrGZzllrNkcBcwWEBpd4gHToV9VhkgyeXBsCMfvV/l9bkrj4BU/U57I5tooK+fy8plsV5D4yo2Zu+VcSPeHpj7HiEFLuDw== Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org This allows you to get the equivalent functionality of i2c_add_numbered_adapter() with all data in the device tree and no special case code in your driver. This is a common device tree technique. For quick reference, the FDT syntax for using an alias to provide an ID looks like: aliases { i2c0 = &i2c_0; i2c1 = &i2c_1; }; Signed-off-by: Doug Anderson --- Changes in v4: - Rebased atop the removal of MAX_IDR_MASK. Changes in v3: - Addressed Wolfram's feedback; rebased atop idr-cleanup series. Changes in v2: None drivers/i2c/i2c-core.c | 49 +++++++++++++++++++++++++++++++++++++------------ 1 file changed, 37 insertions(+), 12 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 991d38d..66c5252 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -921,13 +921,38 @@ out_list: } /** + * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 + * @adap: the adapter to register (with adap->nr initialized) + * Context: can sleep + * + * See i2c_add_numbered_adapter() for details. + */ +static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) +{ + int id; + + /* Handled by wrappers */ + if (WARN_ON(adap->nr == -1)) + return -EINVAL; + + mutex_lock(&core_lock); + id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, + GFP_KERNEL); + mutex_unlock(&core_lock); + if (id < 0) + return id == -ENOSPC ? -EBUSY : id; + return i2c_register_adapter(adap); +} + +/** * i2c_add_adapter - declare i2c adapter, use dynamic bus number * @adapter: the adapter to add * Context: can sleep * * This routine is used to declare an I2C adapter when its bus number - * doesn't matter. Examples: for I2C adapters dynamically added by - * USB links or PCI plugin cards. + * doesn't matter or when its bus number is specified by an dt alias. + * Examples of bases when the bus number doesn't matter: I2C adapters + * dynamically added by USB links or PCI plugin cards. * * When this returns zero, a new bus number was allocated and stored * in adap->nr, and the specified adapter became available for clients. @@ -935,8 +960,17 @@ out_list: */ int i2c_add_adapter(struct i2c_adapter *adapter) { + struct device *dev = &adapter->dev; int id; + if (dev->of_node) { + id = of_alias_get_id(dev->of_node, "i2c"); + if (id >= 0) { + adapter->nr = id; + return __i2c_add_numbered_adapter(adapter); + } + } + mutex_lock(&core_lock); id = idr_alloc(&i2c_adapter_idr, adapter, __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); @@ -975,18 +1009,9 @@ EXPORT_SYMBOL(i2c_add_adapter); */ int i2c_add_numbered_adapter(struct i2c_adapter *adap) { - int id; - if (adap->nr == -1) /* -1 means dynamically assign bus id */ return i2c_add_adapter(adap); - - mutex_lock(&core_lock); - id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, - GFP_KERNEL); - mutex_unlock(&core_lock); - if (id < 0) - return id == -ENOSPC ? -EBUSY : id; - return i2c_register_adapter(adap); + return __i2c_add_numbered_adapter(adap); } EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);