From patchwork Tue Feb 12 00:48:04 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 2126711 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 93881DF2A1 for ; Tue, 12 Feb 2013 00:48:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932865Ab3BLAsR (ORCPT ); Mon, 11 Feb 2013 19:48:17 -0500 Received: from mail-gg0-f202.google.com ([209.85.161.202]:40620 "EHLO mail-gg0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932674Ab3BLAsQ (ORCPT ); Mon, 11 Feb 2013 19:48:16 -0500 Received: by mail-gg0-f202.google.com with SMTP id l4so405311ggi.1 for ; Mon, 11 Feb 2013 16:48:15 -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=cnluqTHdpJmRrrBnymyAXGYw5o55BbhN2fG5bP8zjfc=; b=nGvsqeAkzhGhLC7ipK8iYYYl/k8zXBvSVDyGdvXIo5ePsu6xsWg7Wnc0yNEA/p/sav cA/210V/96TPOh+P+Egvz4aKiyU3AVTmNoGqf4D7Rm/3NqkwwlBa2crRisNFYyuFAA52 1aS11+wcZSygqUhDrE+jpl4e2+liUEDosIcgFUBB6XdIfo1JWTlY8uaZS5T70hlA3lq1 PS5SzTyNrAkXs4WmFBqlePPlKGUUsrm59TxiFCgLAsT95RFgsyr71n6kkVX/kIqWhlvS Ov2kbbY5dm2gQkxcIM1O2KP+rpaZwrwnrxJ0/dUNOXuc6Csnq1yJ664sLjkOJicIMTBf 7ROw== X-Received: by 10.236.59.8 with SMTP id r8mr7432588yhc.8.1360630095786; Mon, 11 Feb 2013 16:48:15 -0800 (PST) Received: from corp2gmr1-2.hot.corp.google.com (corp2gmr1-2.hot.corp.google.com [172.24.189.93]) by gmr-mx.google.com with ESMTPS id f47si1342546yhg.4.2013.02.11.16.48.15 (version=TLSv1.1 cipher=AES128-SHA bits=128/128); Mon, 11 Feb 2013 16:48:15 -0800 (PST) Received: from tictac.mtv.corp.google.com (tictac.mtv.corp.google.com [172.22.73.80]) by corp2gmr1-2.hot.corp.google.com (Postfix) with ESMTP id 6F0225A40A5; Mon, 11 Feb 2013 16:48:15 -0800 (PST) Received: by tictac.mtv.corp.google.com (Postfix, from userid 121310) id 30EA480563; Mon, 11 Feb 2013 16:48:15 -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 v3 1/2] i2c-core: dt: Pick i2c bus number from i2c alias if present Date: Mon, 11 Feb 2013 16:48:04 -0800 Message-Id: <1360630085-26874-2-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.8.1 In-Reply-To: <1360630085-26874-1-git-send-email-dianders@chromium.org> References: <1360630085-26874-1-git-send-email-dianders@chromium.org> X-Gm-Message-State: ALoCoQn7zr32fhtKSpjtVm/orc2FY8cbtH79XGO2x9f30bndHAzYLid3XJq9/Lduwrbdj1PusAbg8BvUPFn5M1zgjBS2f05ctXr70T65XOvuM7ZrHGhltnqgHJnGqU3h4zaQm6jHhJmjW0M1fGiGfNfYgBChvfy7ju14Mh9ul0YtBAjwWiMixzIFdgxg+qlbUORPfYuf91EzxNbi82XzHuWcYGzUklTXag== 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 v3: - Addressed Wolfram's feedback; rebased atop idr-cleanup series. Changes in v2: None drivers/i2c/i2c-core.c | 54 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 40 insertions(+), 14 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 0b599f2..5204818 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -921,13 +921,41 @@ 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; + + if (adap->nr & ~MAX_IDR_MASK) + 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 +963,17 @@ out_list: */ int i2c_add_adapter(struct i2c_adapter *adapter) { + struct device *dev = &adapter->dev; int res; + if (dev->of_node) { + res = of_alias_get_id(dev->of_node, "i2c"); + if (res >= 0) { + adapter->nr = res; + return __i2c_add_numbered_adapter(adapter); + } + } + mutex_lock(&core_lock); res = idr_alloc(&i2c_adapter_idr, adapter, __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); @@ -974,20 +1011,9 @@ 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); - if (adap->nr & ~MAX_IDR_MASK) - 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); + return __i2c_add_numbered_adapter(adap); } EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);