From patchwork Thu Jan 26 17:45:32 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis de Oliveira X-Patchwork-Id: 720320 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3v8Tth5ggQz9sD6 for ; Fri, 27 Jan 2017 04:49:00 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754054AbdAZRsh (ORCPT ); Thu, 26 Jan 2017 12:48:37 -0500 Received: from smtprelay2.synopsys.com ([198.182.60.111]:43365 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754039AbdAZRsg (ORCPT ); Thu, 26 Jan 2017 12:48:36 -0500 Received: from mailhost.synopsys.com (mailhost1.synopsys.com [10.12.238.239]) by smtprelay.synopsys.com (Postfix) with ESMTP id 7E20D10C0591; Thu, 26 Jan 2017 09:48:17 -0800 (PST) Received: from mailhost.synopsys.com (localhost [127.0.0.1]) by mailhost.synopsys.com (Postfix) with ESMTP id 537A964D; Thu, 26 Jan 2017 09:48:17 -0800 (PST) Received: from lolivei-VirtualBox.internal.synopsys.com (lolivei-840g2.internal.synopsys.com [10.107.25.85]) by mailhost.synopsys.com (Postfix) with ESMTP id 5BC645F6; Thu, 26 Jan 2017 09:48:14 -0800 (PST) From: Luis Oliveira To: wsa@the-dreams.de, robh+dt@kernel.org, mark.rutland@arm.com, jarkko.nikula@linux.intel.com, andriy.shevchenko@linux.intel.com, mika.westerberg@linux.intel.com, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, vz@mleia.com Cc: Luis.Oliveira@synopsys.com, Ramiro.Oliveira@synopsys.com, Joao.Pinto@synopsys.com, CARLOS.PALMINHA@synopsys.com Subject: [PATCH v4] i2c: core: helper function to detect slave mode Date: Thu, 26 Jan 2017 17:45:32 +0000 Message-Id: X-Mailer: git-send-email 2.11.0 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org This function has the purpose of mode detection by checking the device nodes for a reg matching with the I2C_OWN_SLAVE_ADDREESS flag. Currently only checks using OF functions (ACPI slave not supported yet). Signed-off-by: Luis Oliveira Suggested-by: Andy Shevchenko Reviewed-by: Andy Shevchenko --- Changes V3->V4: (@Wolfram) - Rename of the function - Reword of the function description drivers/i2c/i2c-core.c | 33 +++++++++++++++++++++++++++++++++ include/linux/i2c.h | 1 + 2 files changed, 34 insertions(+) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 583e95042a21..408de741fec5 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -3690,6 +3690,39 @@ int i2c_slave_unregister(struct i2c_client *client) return ret; } EXPORT_SYMBOL_GPL(i2c_slave_unregister); + +/** + * i2c_detect_slave_mode - detect operation mode + * @dev: The device owning the bus + * + * This checks the device nodes for an I2C slave by checking the address + * used in the reg property. If the address match the I2C_OWN_SLAVE_ADDRESS + * flag this means the device is configured to act as a I2C slave and it will + * be listening at that address. + * + * Returns true if an I2C own slave address is detected, otherwise returns + * false. + */ +bool i2c_detect_slave_mode(struct device *dev) +{ + if (IS_BUILTIN(CONFIG_OF) && dev->of_node) { + struct device_node *child; + u32 reg; + + for_each_child_of_node(dev->of_node, child) { + of_property_read_u32(child, "reg", ®); + if (reg & I2C_OWN_SLAVE_ADDRESS) { + of_node_put(child); + return true; + } + } + } else if (IS_BUILTIN(CONFIG_ACPI) && ACPI_HANDLE(dev)) { + dev_dbg(dev, "ACPI slave is not supported yet\n"); + } + return false; +} +EXPORT_SYMBOL_GPL(i2c_detect_slave_mode); + #endif MODULE_AUTHOR("Simon G. Vogl "); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 4b45ec46161f..f0ba4bac7452 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -282,6 +282,7 @@ enum i2c_slave_event { extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); extern int i2c_slave_unregister(struct i2c_client *client); +extern bool i2c_detect_slave_mode(struct device *dev); static inline int i2c_slave_event(struct i2c_client *client, enum i2c_slave_event event, u8 *val)