From patchwork Thu Dec 8 10:39:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 13068219 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87785C6370C for ; Thu, 8 Dec 2022 10:43:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230266AbiLHKnp (ORCPT ); Thu, 8 Dec 2022 05:43:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230096AbiLHKnT (ORCPT ); Thu, 8 Dec 2022 05:43:19 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DD9BD4A; Thu, 8 Dec 2022 02:40:27 -0800 (PST) Received: from desky.lan (91-154-32-225.elisa-laajakaista.fi [91.154.32.225]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id EE32B9D9; Thu, 8 Dec 2022 11:40:23 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1670496025; bh=qqlP9y4CxrbgrpwUUQtSV2m4Q9RgrkWSjW1olrXBJFA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CQkedEqPUuFFPv87Gd/8wD85ZblpiG5JbFMhLP9siK7EJ62KJmi7fMpz1mdGnqrZz 2kAWJltrhhHX5saJ8Kssqb/hB7dO1dlU5qS0FObnh+StI6kxHYXQ/6XN3wP4JuBmft vf+lkBlx+mfWiMrqu0Y4nZq5pfeqIyfkI0SlrHE4= From: Tomi Valkeinen To: linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Wolfram Sang , Luca Ceresoli , Andy Shevchenko , Matti Vaittinen Cc: Mauro Carvalho Chehab , Peter Rosin , Liam Girdwood , Mark Brown , Sakari Ailus , Laurent Pinchart , Michael Tretter , Shawn Tu , Hans Verkuil , Mike Pagano , =?utf-8?q?Krzysztof_Ha=C5=82asa?= , Marek Vasut , Luca Ceresoli , Tomi Valkeinen Subject: [PATCH v5 1/8] i2c: core: let adapters be notified of client attach/detach Date: Thu, 8 Dec 2022 12:39:59 +0200 Message-Id: <20221208104006.316606-2-tomi.valkeinen@ideasonboard.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221208104006.316606-1-tomi.valkeinen@ideasonboard.com> References: <20221208104006.316606-1-tomi.valkeinen@ideasonboard.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Luca Ceresoli 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 Signed-off-by: Tomi Valkeinen --- drivers/i2c/i2c-core-base.c | 18 +++++++++++++++++- include/linux/i2c.h | 16 ++++++++++++++++ 2 files changed, 33 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index b4edf10e8fd0..c8bc71b1db82 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -966,15 +966,23 @@ 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 out_remove_swnode; + status = device_register(&client->dev); if (status) - goto out_remove_swnode; + goto out_detach_client; dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", client->name, dev_name(&client->dev)); return client; +out_detach_client: + if (adap->attach_ops && adap->attach_ops->detach_client) + adap->attach_ops->detach_client(adap, client); out_remove_swnode: device_remove_software_node(&client->dev); out_err_put_of_node: @@ -996,9 +1004,17 @@ EXPORT_SYMBOL_GPL(i2c_new_client_device); */ void i2c_unregister_device(struct i2c_client *client) { + struct i2c_adapter *adap; + if (IS_ERR_OR_NULL(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 f7c49bbdb8a1..9a385b6de388 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -584,6 +584,21 @@ 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 @@ -726,6 +741,7 @@ 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;