From patchwork Tue May 5 05:51:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alain Volmat X-Patchwork-Id: 207654 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59282C4725D for ; Tue, 5 May 2020 05:52:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3708121775 for ; Tue, 5 May 2020 05:52:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="QHNuk5ZV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728271AbgEEFww (ORCPT ); Tue, 5 May 2020 01:52:52 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:32240 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726610AbgEEFwg (ORCPT ); Tue, 5 May 2020 01:52:36 -0400 Received: from pps.filterd (m0046668.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0455l5f1027091; Tue, 5 May 2020 07:52:20 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=STMicroelectronics; bh=GopKOZPzu+8i/oUoqkNnJs4tklyiulsTc+pEfuMGGk8=; b=QHNuk5ZVdOMBd9RvPTw24x7ky1r6ZeUp2u6qCEDCZduimczmozXcQKCQVZnHOxeBVsrh aWmKI7ULZMFPvN+e66DYgdIg7rP5ERVFkobb1uE4c8twWy4FMAJBVo313r7EEvrO2qCr 2aFj6CIG+/lrFsWn/kmyYCpvw0QTBLjmUxDd5xBk0DhcO8Z5SDZUS6/MQb95zNDr36Ce UhkPwla4miEe3eckeSRdxvhKuwgub7vUfFBb49SAje9IfeSVkRdAHzWxC97h+aW1AA7f Ng7e+eZvjEqFDQeaErDS6rOaNmMzQtQjf9EDqnCJ674lc3j4F/itODP1YEXKv7AvBoaR ew== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 30rxb1wy0n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 05 May 2020 07:52:20 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 7A35F100034; Tue, 5 May 2020 07:52:20 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag3node2.st.com [10.75.127.8]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 6948021CA80; Tue, 5 May 2020 07:52:20 +0200 (CEST) Received: from localhost (10.75.127.50) by SFHDAG3NODE2.st.com (10.75.127.8) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Tue, 5 May 2020 07:52:20 +0200 From: Alain Volmat To: , CC: , , , , , , , , , , Subject: [PATCH 1/4] i2c: smbus: add core function handling SMBus host-notify Date: Tue, 5 May 2020 07:51:08 +0200 Message-ID: <1588657871-14747-2-git-send-email-alain.volmat@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1588657871-14747-1-git-send-email-alain.volmat@st.com> References: <1588657871-14747-1-git-send-email-alain.volmat@st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG6NODE1.st.com (10.75.127.16) To SFHDAG3NODE2.st.com (10.75.127.8) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.676 definitions=2020-05-05_02:2020-05-04,2020-05-05 signatures=0 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org SMBus Host-Notify protocol, from the adapter point of view consist of receiving a message from a client, including the client address and some other data. It can be simply handled by creating a new slave device and registering a callback performing the parsing of the message received from the client. This commit introduces two new core functions * i2c_new_smbus_host_notify_device * i2c_free_smbus_host_notify_device that take care of registration of the new slave device and callback and will call i2c_handle_smbus_host_notify once a Host-Notify event is received. Signed-off-by: Alain Volmat --- drivers/i2c/i2c-core-smbus.c | 105 +++++++++++++++++++++++++++++++++++ include/linux/i2c-smbus.h | 2 + 2 files changed, 107 insertions(+) diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c index b34d2ff06931..0c7e135c73e1 100644 --- a/drivers/i2c/i2c-core-smbus.c +++ b/drivers/i2c/i2c-core-smbus.c @@ -708,3 +708,108 @@ int of_i2c_setup_smbus_alert(struct i2c_adapter *adapter) } EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert); #endif + +struct i2c_smbus_host_notify_status { + bool notify_start; + u8 addr; +}; + +static int i2c_smbus_host_notify_cb(struct i2c_client *client, + enum i2c_slave_event event, u8 *val) +{ + struct i2c_smbus_host_notify_status *status = client->dev.platform_data; + int ret; + + switch (event) { + case I2C_SLAVE_WRITE_REQUESTED: + status->notify_start = true; + break; + case I2C_SLAVE_WRITE_RECEIVED: + /* We only retrieve the first byte received (addr) + * since there is currently no way to retrieve the data + * parameter from the client. + */ + if (!status->notify_start) + break; + status->addr = *val; + status->notify_start = false; + break; + case I2C_SLAVE_STOP: + ret = i2c_handle_smbus_host_notify(client->adapter, + status->addr); + if (ret < 0) { + dev_warn(&client->adapter->dev, "failed to handle host_notify (%d)\n", + ret); + return ret; + } + break; + default: + /* Only handle necessary events */ + break; + } + + return 0; +} + +/** + * i2c_new_smbus_host_notify_device - get a client for SMBus host-notify support + * @adapter: the target adapter + * Context: can sleep + * + * Setup handling of the SMBus host-notify protocol on a given I2C bus segment. + * + * Handling is done by creating a device and its callback and handling data + * received via the SMBus host-notify address (0x8) + * + * This returns the client, which should be ultimately freed using + * i2c_free_smbus_host_notify_device(); or an ERRPTR to indicate an error. + */ +struct i2c_client *i2c_new_smbus_host_notify_device(struct i2c_adapter *adapter) +{ + struct i2c_board_info host_notify_board_info = { + I2C_BOARD_INFO("smbus_host_notify", 0x08), + .flags = I2C_CLIENT_SLAVE, + }; + struct i2c_smbus_host_notify_status *status; + struct i2c_client *client; + int ret; + + status = kzalloc(sizeof(struct i2c_smbus_host_notify_status), + GFP_KERNEL); + if (!status) + return ERR_PTR(-ENOMEM); + + host_notify_board_info.platform_data = status; + + client = i2c_new_client_device(adapter, &host_notify_board_info); + if (IS_ERR(client)) { + kfree(status); + return client; + } + + ret = i2c_slave_register(client, i2c_smbus_host_notify_cb); + if (ret) { + i2c_unregister_device(client); + kfree(status); + return ERR_PTR(ret); + } + + return client; +} +EXPORT_SYMBOL_GPL(i2c_new_smbus_host_notify_device); + +/** + * i2c_free_smbus_host_notify_device - free the client for SMBus host-notify + * support + * @client: the client to free + * Context: can sleep + * + * Free the i2c_client allocated via i2c_new_smbus_host_notify_device + */ +void i2c_free_smbus_host_notify_device(struct i2c_client *client) +{ + i2c_slave_unregister(client); + kfree(client->dev.platform_data); + i2c_unregister_device(client); +} +EXPORT_SYMBOL_GPL(i2c_free_smbus_host_notify_device); diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h index 8c5459034f92..926f6d8ae30d 100644 --- a/include/linux/i2c-smbus.h +++ b/include/linux/i2c-smbus.h @@ -38,5 +38,7 @@ static inline int of_i2c_setup_smbus_alert(struct i2c_adapter *adap) return 0; } #endif +struct i2c_client *i2c_new_smbus_host_notify_device(struct i2c_adapter *adapter); +void i2c_free_smbus_host_notify_device(struct i2c_client *client); #endif /* _LINUX_I2C_SMBUS_H */