From patchwork Tue Jul 23 20:37:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 1135918 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=lucaceresoli.net Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45tWQ269GJz9s3l for ; Wed, 24 Jul 2019 07:12:10 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731744AbfGWVMK (ORCPT ); Tue, 23 Jul 2019 17:12:10 -0400 Received: from hostingweb31-40.netsons.net ([89.40.174.40]:38497 "EHLO hostingweb31-40.netsons.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728921AbfGWVMK (ORCPT ); Tue, 23 Jul 2019 17:12:10 -0400 X-Greylist: delayed 2071 seconds by postgrey-1.27 at vger.kernel.org; Tue, 23 Jul 2019 17:12:08 EDT Received: from [88.149.224.16] (port=34022 helo=melee.fritz.box) by hostingweb31.netsons.net with esmtpa (Exim 4.92) (envelope-from ) id 1hq1XU-007idA-Tw; Tue, 23 Jul 2019 22:37:37 +0200 From: Luca Ceresoli To: linux-media@vger.kernel.org, linux-i2c@vger.kernel.org Cc: Luca Ceresoli , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Mauro Carvalho Chehab , Rob Herring , Mark Rutland , Wolfram Sang , Sakari Ailus , Hans Verkuil , Laurent Pinchart , Kieran Bingham , Jacopo Mondi , Vladimir Zapolskiy , Peter Rosin Subject: [RFC, v2 1/6] i2c: core: let adapters be notified of client attach/detach Date: Tue, 23 Jul 2019 22:37:18 +0200 Message-Id: <20190723203723.11730-2-luca@lucaceresoli.net> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190723203723.11730-1-luca@lucaceresoli.net> References: <20190723203723.11730-1-luca@lucaceresoli.net> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - hostingweb31.netsons.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lucaceresoli.net X-Get-Message-Sender-Via: hostingweb31.netsons.net: authenticated_id: luca+lucaceresoli.net/only user confirmed/virtual account not confirmed X-Authenticated-Sender: hostingweb31.netsons.net: luca@lucaceresoli.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org An adapter might need to know when a new device is about to be added. This will soon bee needed to implement an "I2C address translator" (ATR for short), a device that propagates I2C transactions with a different slave address (an "alias" address). An ATR driver needs to know when a slave is being added to find a suitable alias and program the device translation map. Add an attach/detach callback pair to allow adapter drivers to be notified of clients being added and removed. Signed-off-by: Luca Ceresoli --- Changes RFCv1 -> RFCv2: - Document struct i2c_attach_operations --- drivers/i2c/i2c-core-base.c | 16 ++++++++++++++++ include/linux/i2c.h | 16 ++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index f26ed495d384..c08ca4bca9c1 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -776,6 +776,11 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf } } + if (adap->attach_ops && + adap->attach_ops->attach_client && + adap->attach_ops->attach_client(adap, info, client) != 0) + goto err_attach_client; + status = device_register(&client->dev); if (status) goto out_free_props; @@ -786,6 +791,9 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf return client; out_free_props: + if (adap->attach_ops && adap->attach_ops->detach_client) + adap->attach_ops->detach_client(adap, client); +err_attach_client: if (info->properties) device_remove_properties(&client->dev); out_err_put_of_node: @@ -832,9 +840,17 @@ EXPORT_SYMBOL_GPL(i2c_new_device); */ void i2c_unregister_device(struct i2c_client *client) { + struct i2c_adapter *adap; + if (!client) return; + adap = client->adapter; + + if (adap->attach_ops && + adap->attach_ops->detach_client) + adap->attach_ops->detach_client(adap, client); + if (client->dev.of_node) { of_node_clear_flag(client->dev.of_node, OF_POPULATED); of_node_put(client->dev.of_node); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index fa5552c2307b..ebc372a0e537 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -567,6 +567,21 @@ struct i2c_lock_operations { void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); }; +/** + * struct i2c_attach_operations - callbacks to notify client attach/detach + * @attach_client: Notify of new client being attached + * @detach_client: Notify of new client being detached + * + * Both ops are optional. + */ +struct i2c_attach_operations { + int (*attach_client)(struct i2c_adapter *adapter, + const struct i2c_board_info *info, + const struct i2c_client *client); + void (*detach_client)(struct i2c_adapter *adapter, + const struct i2c_client *client); +}; + /** * struct i2c_timings - I2C timing information * @bus_freq_hz: the bus frequency in Hz @@ -690,6 +705,7 @@ struct i2c_adapter { /* data fields that are valid for all devices */ const struct i2c_lock_operations *lock_ops; + const struct i2c_attach_operations *attach_ops; struct rt_mutex bus_lock; struct rt_mutex mux_lock;