From patchwork Tue Jan 23 21:25:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank Li X-Patchwork-Id: 765560 Received: from EUR05-DB8-obe.outbound.protection.outlook.com (mail-db8eur05on2046.outbound.protection.outlook.com [40.107.20.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E01FA3D96B; Tue, 23 Jan 2024 21:26:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.20.46 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706045185; cv=fail; b=NfofUSldvzaZjFQiDQ57cLK15gfFI+rN0iS3q3O9cep1/kVg4NM16zQ/wHYS7uVL3CVDkhjZFPkfBmuEsKzn7Key0Xh6BUPyHbJjZele4c/BMslySbFfwkMQIwt6VylP9eWQUsD4bt2nqqKUiuLTsLeJ8uXuMAx0NrtyujD30B0= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706045185; c=relaxed/simple; bh=cbqJ8B8zoNb1wL5cvsafYdWHOXGpucToAPhTV87jaLA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: Content-Type:MIME-Version; b=ozOByGrtClf2X1ryl3XTyjwaEyDgbr0tdqnEJ9ysTgIebIxA5V0tvvwHRyykQ4AphzLaYuhZxYOvpo218xkAwnz6FYn3T6+YoH54tbP2ZKxa8brDkSYRahDVolg2Nojvq20bF3VbzErzaCWWNIYmPDOY3yYLw1IzzdLPZoCZ1yA= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nxp.com; spf=pass smtp.mailfrom=nxp.com; dkim=pass (1024-bit key) header.d=nxp.com header.i=@nxp.com header.b=La4XnIXC; arc=fail smtp.client-ip=40.107.20.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nxp.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nxp.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=nxp.com header.i=@nxp.com header.b="La4XnIXC" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=khDyxHkj9dE6PeQiXk9kJmXEuO7ORcQOQEEWvBxz35XXpHvKUi+4WqpK2ad4PKCT7ltbAJtuY0RHYCuszp9LPEP59m3vmaFqTIRSaxk57X1AUhI2tZHzNBttCIe94EaOXJI+cK70teIibFqCaI54/ppcXnCuQA/n9CTm1tQxlX+JgQXm5M2mRRNlxtM/r2WShogNmwwQaEHb7qKo5GEcHtJiunQXmfMYRSe+A1bpGxVJYaI0/y1yMJd0GJ/fHh1hrPqMdZwn5uJ8zYdEVcoQ8TEen8zoh1In8qiDWZew1sH9KSUIlN+ks6liERGUa7Z0B6Cmz1aZ5425cF1wchn3Lg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=NcAD7n5DFC8zY5SMsqG6DN1S/Q3hAt3IaNHuvXjxowM=; b=dsKD3ydmeESuFWY0AAv1/MlZJn3WELzrgJBSnmhjks2ncMZbwO0cwdDKggew57YVELwZL870GMPSl5qhBQJdfF09RvAHFazM8L/2UCuw57XKooHzX5tcU9D4gRwzl44/LF4NSCw0i22N89sIlN1kkm6+3O3/kJ3DCO6ss3qGivrccjTyL8bW68A9CRPsjwe2DjNW/uHyYSI5EnpqVjonDDIxhL/+5e+apnhjV7M3fccL08wHpLns+sbPVR9JzpUTHWqRyb5wCIz3oG76I+Wo4wx5/mji2lJKtNNtHUPgOBI+WaCKlATJH2s0FMf4lXoNv72zpwXGvyORH3MWFVj5tQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nxp.com; dmarc=pass action=none header.from=nxp.com; dkim=pass header.d=nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxp.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=NcAD7n5DFC8zY5SMsqG6DN1S/Q3hAt3IaNHuvXjxowM=; b=La4XnIXC0IIxAUHYbxjX7BiodW+cftZV1oJoT7rj6LU118T/MzVxNMy95qEJZqs4+d0nqWbeFmUFGeb5ZPIPV2h+FPVHVZvrPKUgztGST7K3faVnl+SLGe1zA359VficS7Rh6XNPS5v85u88SmugHAHIJdx+Fx63krYsZkrN0/0= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nxp.com; Received: from PAXPR04MB9642.eurprd04.prod.outlook.com (2603:10a6:102:240::14) by PA4PR04MB7616.eurprd04.prod.outlook.com (2603:10a6:102:e7::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7202.33; Tue, 23 Jan 2024 21:26:18 +0000 Received: from PAXPR04MB9642.eurprd04.prod.outlook.com ([fe80::c8b4:5648:8948:e85c]) by PAXPR04MB9642.eurprd04.prod.outlook.com ([fe80::c8b4:5648:8948:e85c%3]) with mapi id 15.20.7202.035; Tue, 23 Jan 2024 21:26:18 +0000 From: Frank Li To: frank.li@nxp.com Cc: alexandre.belloni@bootlin.com, conor.culhane@silvaco.com, devicetree@vger.kernel.org, gregkh@linuxfoundation.org, imx@lists.linux.dev, jirislaby@kernel.org, joe@perches.com, krzysztof.kozlowski+dt@linaro.org, krzysztof.kozlowski@linaro.org, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, miquel.raynal@bootlin.com, robh@kernel.org, zbigniew.lukwinski@linux.intel.com Subject: [PATCH v3 3/8] Documentation: i3c: Add I3C target mode controller and function Date: Tue, 23 Jan 2024 16:25:44 -0500 Message-Id: <20240123212549.3858137-4-Frank.Li@nxp.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240123212549.3858137-1-Frank.Li@nxp.com> References: <20240123212549.3858137-1-Frank.Li@nxp.com> X-ClientProxiedBy: SJ0PR13CA0081.namprd13.prod.outlook.com (2603:10b6:a03:2c4::26) To PAXPR04MB9642.eurprd04.prod.outlook.com (2603:10a6:102:240::14) Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PAXPR04MB9642:EE_|PA4PR04MB7616:EE_ X-MS-Office365-Filtering-Correlation-Id: b6cfe34b-4733-41e1-56a5-08dc1c59f017 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:PAXPR04MB9642.eurprd04.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230031)(396003)(39860400002)(136003)(346002)(366004)(376002)(230922051799003)(451199024)(186009)(1800799012)(64100799003)(1076003)(26005)(2616005)(478600001)(52116002)(6666004)(6506007)(6512007)(83380400001)(5660300002)(30864003)(7416002)(41300700001)(2906002)(6486002)(4326008)(8676002)(37006003)(34206002)(66946007)(66476007)(66556008)(316002)(8936002)(36756003)(86362001)(38100700002)(38350700005); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: b6cfe34b-4733-41e1-56a5-08dc1c59f017 X-MS-Exchange-CrossTenant-AuthSource: PAXPR04MB9642.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Jan 2024 21:26:18.7864 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: DFeEAn41sipYiQ0xnXr6D9FpoOTrRAR7L6NaaSjEv0WkqaT7It3dVFSIPszsWAkoJ6rAIHjYonM+ABDDxteivQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PA4PR04MB7616 Add I3C target mode and tty over i3c func driver document. Signed-off-by: Frank Li --- Documentation/driver-api/i3c/index.rst | 1 + .../driver-api/i3c/target/i3c-target-cfs.rst | 109 ++++++++++ .../driver-api/i3c/target/i3c-target.rst | 189 ++++++++++++++++++ .../driver-api/i3c/target/i3c-tty-howto.rst | 109 ++++++++++ Documentation/driver-api/i3c/target/index.rst | 13 ++ 5 files changed, 421 insertions(+) create mode 100644 Documentation/driver-api/i3c/target/i3c-target-cfs.rst create mode 100644 Documentation/driver-api/i3c/target/i3c-target.rst create mode 100644 Documentation/driver-api/i3c/target/i3c-tty-howto.rst create mode 100644 Documentation/driver-api/i3c/target/index.rst diff --git a/Documentation/driver-api/i3c/index.rst b/Documentation/driver-api/i3c/index.rst index 783d6dad054b6..345a43c9f61b0 100644 --- a/Documentation/driver-api/i3c/index.rst +++ b/Documentation/driver-api/i3c/index.rst @@ -9,3 +9,4 @@ I3C subsystem protocol device-driver-api master-driver-api + target/index diff --git a/Documentation/driver-api/i3c/target/i3c-target-cfs.rst b/Documentation/driver-api/i3c/target/i3c-target-cfs.rst new file mode 100644 index 0000000000000..1fcf829dc4ae2 --- /dev/null +++ b/Documentation/driver-api/i3c/target/i3c-target-cfs.rst @@ -0,0 +1,109 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================================= +Configuring I3C Target Using CONFIGFS +======================================= + +:Author: Frank Li + +The I3C Target Core exposes configfs entry (i3c_target) to configure the I3C +target function and to bind the target function with the target controller. +(For introducing other mechanisms to configure the I3C Target Function refer to +[1]). + +Mounting configfs +================= + +The I3C Target Core layer creates i3c_target directory in the mounted configfs +directory. configfs can be mounted using the following command:: + + mount -t configfs none /sys/kernel/config + +Directory Structure +=================== + +The i3c_target configfs has two directories at its root: controllers and +functions. Every Controller device present in the system will have an entry in +the *controllers* directory and every Function driver present in the system will +have an entry in the *functions* directory. +:: + + /sys/kernel/config/i3c_target/ + .. controllers/ + .. functions/ + +Creating Function Device +=================== + +Every registered Function driver will be listed in controllers directory. The +entries corresponding to Function driver will be created by the Function core. +:: + + /sys/kernel/config/i3c_target/functions/ + .. / + ... / + ... / + ... / + .. / + ... / + ... / + +In order to create a of the type probed by , +the user has to create a directory inside . + +Every directory consists of the following entries that can be +used to configure the standard configuration header of the target function. +(These entries are created by the framework when any new is +created) +:: + + .. / + ... / + ... vendor_id + ... part_id + ... bcr + ... dcr + ... ext_id + ... instance_id + ... max_read_len + ... max_write_len + ... vendor_info + +Controller Device +========== + +Every registered Controller device will be listed in controllers directory. The +entries corresponding to Controller device will be created by the Controller +core. +:: + + /sys/kernel/config/i3c_target/controllers/ + .. / + ... / + .. / + ... / + +The directory will have a list of symbolic links to +. These symbolic links should be created by the user to +represent the functions present in the target device. Only +that represents a physical function can be linked to a Controller device. + +:: + + | controllers/ + | / + | + | functions/ + | / + | / + | vendor_id + | part_id + | bcr + | dcr + | ext_id + | instance_id + | max_read_len + | max_write_len + | vendor_info + +[1] Documentation/I3C/target/pci-target.rst diff --git a/Documentation/driver-api/i3c/target/i3c-target.rst b/Documentation/driver-api/i3c/target/i3c-target.rst new file mode 100644 index 0000000000000..09ae26b1f311a --- /dev/null +++ b/Documentation/driver-api/i3c/target/i3c-target.rst @@ -0,0 +1,189 @@ +.. SPDX-License-Identifier: GPL-2.0 + +:Author: Frank Li + +This document is a guide to use the I3C Target Framework in order to create +target controller driver, target function driver, and using configfs interface +to bind the function driver to the controller driver. + +Introduction +============ + +Linux has a comprehensive I3C subsystem to support I3C controllers that +operates in master mode. The subsystem has capability to scan I3C bus,assign +i3c device address, load I3C driver (based on Manufacturer ID, part ID), +support other services like hot-join, In-Band Interrupt(IBI). + +However the I3C controller IP integrated in some SoCs is capable of operating +either in Master mode or Target mode. I3C Target Framework will add target mode +support in Linux. This will help to run Linux in an target system which can +have a wide variety of use cases from testing or validation, co-processor +accelerator, etc. + +I3C Target Core +================= + +The I3C Target Core layer comprises 3 components: the Target Controller +library, the Target Function library, and the configfs layer to bind the target +function with the target controller. + +I3C Target Controller Library +------------------------------------ + +The Controller library provides APIs to be used by the controller that can +operate in target mode. It also provides APIs to be used by function +driver/library in order to implement a particular target function. + +APIs for the I3C Target controller Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the I3C Target core provides to be used by the +I3C controller driver. + +* devm_i3c_target_ctrl_create()/i3c_target_ctrl_create() + + The I3C controller driver should implement the following ops: + + * set_config: ops to set i3c configuration + * enable: ops to enable controller + * disable: ops to disable controller + * raise_ibi: ops to raise IBI to master controller + * alloc_request: ops to alloc a transfer request + * free_request: ops to free a transfer request + * queue: ops to queue a request to transfer queue + * dequeue: ops to dequeue a request from transfer queue + * cancel_all_reqs: ops to cancel all request from transfer queue + * fifo_status: ops to get fifo status + * fifo_flush: ops to flush hardware fifo + * get_features: ops to get controller supported features + + The I3C controller driver can then create a new Controller device by + invoking devm_i3c_target_ctrl_create()/i3c_target_ctrl_create(). + +* devm_i3c_target_ctrl_destroy()/i3c_target_ctrl_destroy() + + The I3C controller driver can destroy the Controller device created by + either devm_i3c_target_ctrl_create() or i3c_target_ctrl_create() using + devm_i3c_target_ctrl_destroy() or i3c_target_ctrl_destroy(). + +I3C Target Controller APIs for the I3C Target Function Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the I3C Target core provides to be used by the +I3C target function driver. + +* i3c_target_ctrl_set_config() + + The I3C target function driver should use i3c_target_ctrl_set_config() to + write i3c configuration to the target controller. + +* i3c_target_ctrl_enable()/i3c_target_ctrl_disable() + + The I3C target function driver should use i3c_target_ctrl_enable()/ + i3c_target_ctrl_disable() to enable/disable i3c target controller. + +* i3c_target_ctrl_alloc_request()/i3c_target_ctrl_free_request() + + The I3C target function driver should usei3c_target_ctrl_alloc_request() / + i3c_target_ctrl_free_request() to alloc/free a i3c request. + +* i3c_target_ctrl_raise_ibi() + + The I3C target function driver should use i3c_target_ctrl_raise_ibi() to + raise IBI. + +* i3c_target_ctrl_queue()/i3c_target_ctrl_dequeue() + + The I3C target function driver should use i3c_target_ctrl_queue()/ + i3c_target_ctrl_dequeue(), to queue/dequeue I3C transfer to/from transfer + queue. + +* i3c_target_ctrl_get_features() + + The I3C target function driver should use i3c_target_ctrl_get_features() to + get I3C target controller supported features. + +Other I3C Target Controller APIs +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +There are other APIs provided by the Controller library. These are used for +binding the I3C Target Function device with Controlller device. i3c-cfs.c can +be used as reference for using these APIs. + +* i3c_target_ctrl_get() + + Get a reference to the I3C target controller based on the device name of + the controller. + +* i3c_target_ctrl_put() + + Release the reference to the I3C target controller obtained using + i3c_target_ctrl_get() + +* i3c_target_ctrl_add_func() + + Add a I3C target function to a I3C target controller. + +* i3c_target_ctrl_remove_func() + + Remove the I3C target function from I3C target controller. + +I3C Target Function Library +---------------------------------- + +The I3C Target Function library provides APIs to be used by the function driver +and the Controller library to provide target mode functionality. + +I3C Target Function APIs for the I3C Target Function Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the I3C Target core provides to be used +by the I3C target function driver. + +* i3c_target_func_register_driver() + + The I3C Target Function driver should implement the following ops: + * bind: ops to perform when a Controller device has been bound to + Function device + * unbind: ops to perform when a binding has been lost between a + Controller device and Function device + + The I3C Function driver can then register the I3C Function driver by using + i3c_target_func_register_driver(). + +* i3c_target_func_unregister_driver() + + The I3C Function driver can unregister the I3C Function driver by using + i3c_epf_unregister_driver(). + +APIs for the I3C Target Controller Library +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the I3C Target core provides to be used by the +I3C target controller library. + +Other I3C Target APIs +~~~~~~~~~~~~~~~~~~~~ + +There are other APIs provided by the Function library. These are used to notify +the function driver when the Function device is bound to the EPC device. +i3c-cfs.c can be used as reference for using these APIs. + +* i3c_target_func_create() + + Create a new I3C Function device by passing the name of the I3C EPF device. + This name will be used to bind the Function device to a Function driver. + +* i3c_target_func_destroy() + + Destroy the created I3C Function device. + +* i3c_target_func_bind() + + i3c_target_func_bind() should be invoked when the EPF device has been bound + to a Controller device. + +* i3c_target_func_unbind() + + i3c_target_func_unbind() should be invoked when the binding between EPC + device and function device is lost. diff --git a/Documentation/driver-api/i3c/target/i3c-tty-howto.rst b/Documentation/driver-api/i3c/target/i3c-tty-howto.rst new file mode 100644 index 0000000000000..43a129b18e938 --- /dev/null +++ b/Documentation/driver-api/i3c/target/i3c-tty-howto.rst @@ -0,0 +1,109 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=================== +I3C TTY User Guide +=================== + +:Author: Frank Li + +This document is a guide to help users use i3c-target-tty function driver and +i3ctty master driver for testing I3C. The list of steps to be followed in the +master side and target side is given below. + +Endpoint Device +=============== + +Endpoint Controller Devices +--------------------------- + +To find the list of target controller devices in the system:: + + # ls /sys/class/i3c_target/ + 44330000.i3c-target + +If CONFIG_I3C_SLAVE_CONFIGFS is enabled:: + + # ls /sys/kernel/config/i3c_target/controllers/ + 44330000.i3c-target + + +Endpoint Function Drivers +------------------------- + +To find the list of target function drivers in the system:: + + # ls /sys/bus/i3c_target_func/drivers + tty + +If CONFIG_I3C_SLAVE_CONFIGFS is enabled:: + + # ls /sys/kernel/config/i3c_target/functions + tty + + +Creating i3c-target-tty Device +---------------------------- + +I3C target function device can be created using the configfs. To create +i3c-target-tty device, the following commands can be used:: + + # mount -t configfs none /sys/kernel/config + # cd /sys/kernel/config/i3c_target/ + # mkdir functions/tty/func1 + +The "mkdir func1" above creates the i3c-target-tty function device that will +be probed by i3c tty driver. + +The I3C target framework populates the directory with the following +configurable fields:: + + # ls functions/tty/func1 + bcr dcr ext_id instance_id max_read_len max_write_len + part_id vendor_id vendor_info + +The I3C target function driver populates these entries with default values when +the device is bound to the driver. The i3c-target-tty driver populates vendorid +with 0xffff and interrupt_pin with 0x0001:: + + # cat functions/tty/func1/vendor_id + 0x0 + +Configuring i3c-target-tty Device +------------------------------- + +The user can configure the i3c-target-tty device using configfs entry. In order +to change the vendorid, the following commands can be used:: + + # echo 0x011b > functions/tty/func1/vendor_id + # echo 0x1000 > functions/tty/func1/part_id + # echo 0x6 > functions/tty/t/bcr + +Binding i3c-target-tty Device to target Controller +------------------------------------------------ + +In order for the target function device to be useful, it has to be bound to a +I3C target controller driver. Use the configfs to bind the function device to +one of the controller driver present in the system:: + + # ln -s functions/tty/func1 controllers/44330000.i3c-target/ + +I3C Master Device +================ + +Check I3C tty device is probed + + # ls /sys/bus/i3c/devices/0-23610000000 + 0-23610000000:0 bcr dcr driver dynamic_address hdrcap + modalias pid power subsystem tty uevent + +Using Target TTY function Device +----------------------------------- + +Host side: + cat /dev/ttyI3C0 +Target side + echo abc >/dev/ttyI3C0 + +You will see "abc" show at console. + +You can use other tty tool to test I3C target tty device. diff --git a/Documentation/driver-api/i3c/target/index.rst b/Documentation/driver-api/i3c/target/index.rst new file mode 100644 index 0000000000000..56eabfae83aa4 --- /dev/null +++ b/Documentation/driver-api/i3c/target/index.rst @@ -0,0 +1,13 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================== +I3C Target Framework +====================== + +.. toctree:: + :maxdepth: 2 + + i3c-target + i3c-target-cfs + i3c-tty-howto +