From patchwork Mon Mar 29 06:09:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alain Volmat X-Patchwork-Id: 412046 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 8DD40C433E4 for ; Mon, 29 Mar 2021 06:10:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E3CD6196C for ; Mon, 29 Mar 2021 06:10:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230248AbhC2GKU (ORCPT ); Mon, 29 Mar 2021 02:10:20 -0400 Received: from mx07-00178001.pphosted.com ([185.132.182.106]:36488 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230226AbhC2GKB (ORCPT ); Mon, 29 Mar 2021 02:10:01 -0400 Received: from pps.filterd (m0241204.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12T5phSa015177; Mon, 29 Mar 2021 08:09:10 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=selector1; bh=cPJXGlx5Hs3xNFzQhMYTUi/aRSASy6bQtvoOjjtlKUA=; b=rgObmZhb3gvu/bFAx4ibpsD6QCTu2hUxt1Ds0TbQajSFwKKcGUYAON5zRGCtyDaoRnWa YRBmeY+yIFfCQAs3WDELX4o4VXQzijVEbB4UYXzw8R7t9Qog1AwXPur8sEJ5n87DNfae iGdYcH1ukuEk/lFLkR5KVikCURlnldukkQ76tw6NeSzJsqVIEq36rFSrKgUc4leKGWCj x5/khgD6jneZuWpoCNqVIJTJm5lS0G2en1tEQsz7q/fHIHcxjsdHWtePhcCPAnfejZE/ Y5vy2r6HHHKPoTCUQEcGzBmQ7u5X7RmE5Okvo0uWcLt37kRKLdxePAeA8/Kl++TKpSes JQ== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 37k04nhy7c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Mar 2021 08:09:10 +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 9C41F10003D; Mon, 29 Mar 2021 08:09:09 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node3.st.com [10.75.127.6]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 841A3221775; Mon, 29 Mar 2021 08:09:09 +0200 (CEST) Received: from localhost (10.75.127.44) by SFHDAG2NODE3.st.com (10.75.127.6) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 29 Mar 2021 08:09:09 +0200 From: Alain Volmat To: , CC: , , , , , , , , , , Subject: [PATCH v3 2/2] i2c: stm32f7: add SMBus-Alert support Date: Mon, 29 Mar 2021 08:09:05 +0200 Message-ID: <1616998145-28278-3-git-send-email-alain.volmat@foss.st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1616998145-28278-1-git-send-email-alain.volmat@foss.st.com> References: <1616998145-28278-1-git-send-email-alain.volmat@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.44] X-ClientProxiedBy: SFHDAG3NODE1.st.com (10.75.127.7) To SFHDAG2NODE3.st.com (10.75.127.6) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369, 18.0.761 definitions=2021-03-29_02:2021-03-26,2021-03-29 signatures=0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Add support for the SMBus-Alert protocol to the STM32F7 that has dedicated control and status logic. If SMBus-Alert is used, the SMBALERT# pin must be configured as alternate function for I2C Alert. Signed-off-by: Alain Volmat Reviewed-by: Pierre-Yves MORDRET --- v2: - rely on st,smbus-alert binding instead of smbus --- drivers/i2c/busses/i2c-stm32f7.c | 73 ++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index c62c815b88eb..bd840cd2b9e4 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -51,6 +51,7 @@ /* STM32F7 I2C control 1 */ #define STM32F7_I2C_CR1_PECEN BIT(23) +#define STM32F7_I2C_CR1_ALERTEN BIT(22) #define STM32F7_I2C_CR1_SMBHEN BIT(20) #define STM32F7_I2C_CR1_WUPEN BIT(18) #define STM32F7_I2C_CR1_SBC BIT(16) @@ -125,6 +126,7 @@ (((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17) #define STM32F7_I2C_ISR_DIR BIT(16) #define STM32F7_I2C_ISR_BUSY BIT(15) +#define STM32F7_I2C_ISR_ALERT BIT(13) #define STM32F7_I2C_ISR_PECERR BIT(11) #define STM32F7_I2C_ISR_ARLO BIT(9) #define STM32F7_I2C_ISR_BERR BIT(8) @@ -138,6 +140,7 @@ #define STM32F7_I2C_ISR_TXE BIT(0) /* STM32F7 I2C Interrupt Clear */ +#define STM32F7_I2C_ICR_ALERTCF BIT(13) #define STM32F7_I2C_ICR_PECCF BIT(11) #define STM32F7_I2C_ICR_ARLOCF BIT(9) #define STM32F7_I2C_ICR_BERRCF BIT(8) @@ -283,6 +286,17 @@ struct stm32f7_i2c_msg { u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4); }; +/** + * struct stm32f7_i2c_alert - SMBus alert specific data + * @setup: platform data for the smbus_alert i2c client + * @ara: I2C slave device used to respond to the SMBus Alert with Alert + * Response Address + */ +struct stm32f7_i2c_alert { + struct i2c_smbus_alert_setup setup; + struct i2c_client *ara; +}; + /** * struct stm32f7_i2c_dev - private data of the controller * @adap: I2C adapter for this controller @@ -312,6 +326,7 @@ struct stm32f7_i2c_msg { * @wakeup_src: boolean to know if the device is a wakeup source * @smbus_mode: states that the controller is configured in SMBus mode * @host_notify_client: SMBus host-notify client + * @alert: SMBus alert specific data */ struct stm32f7_i2c_dev { struct i2c_adapter adap; @@ -340,6 +355,7 @@ struct stm32f7_i2c_dev { bool wakeup_src; bool smbus_mode; struct i2c_client *host_notify_client; + struct stm32f7_i2c_alert *alert; }; /* @@ -1616,6 +1632,13 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) f7_msg->result = -EINVAL; } + if (status & STM32F7_I2C_ISR_ALERT) { + dev_dbg(dev, "<%s>: SMBus alert received\n", __func__); + writel_relaxed(STM32F7_I2C_ICR_ALERTCF, base + STM32F7_I2C_ICR); + i2c_handle_smbus_alert(i2c_dev->alert->ara); + return IRQ_HANDLED; + } + if (!i2c_dev->slave_running) { u32 mask; /* Disable interrupts */ @@ -1982,6 +2005,42 @@ static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev) } } +static int stm32f7_i2c_enable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_alert *alert; + struct i2c_adapter *adap = &i2c_dev->adap; + struct device *dev = i2c_dev->dev; + void __iomem *base = i2c_dev->base; + + alert = devm_kzalloc(dev, sizeof(*alert), GFP_KERNEL); + if (!alert) + return -ENOMEM; + + alert->ara = i2c_new_smbus_alert_device(adap, &alert->setup); + if (IS_ERR(alert->ara)) + return PTR_ERR(alert->ara); + + i2c_dev->alert = alert; + + /* Enable SMBus Alert */ + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_ALERTEN); + + return 0; +} + +static void stm32f7_i2c_disable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_alert *alert = i2c_dev->alert; + void __iomem *base = i2c_dev->base; + + if (alert) { + /* Disable SMBus Alert */ + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_ALERTEN); + i2c_unregister_device(alert->ara); + } +} + static u32 stm32f7_i2c_func(struct i2c_adapter *adap) { struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap); @@ -2169,6 +2228,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) } } + if (of_property_read_bool(pdev->dev.of_node, "st,smbus-alert")) { + ret = stm32f7_i2c_enable_smbus_alert(i2c_dev); + if (ret) { + dev_err(i2c_dev->dev, + "failed to enable SMBus alert protocol (%d)\n", + ret); + goto i2c_disable_smbus_host; + } + } + dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr); pm_runtime_mark_last_busy(i2c_dev->dev); @@ -2176,6 +2245,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) return 0; +i2c_disable_smbus_host: + stm32f7_i2c_disable_smbus_host(i2c_dev); + i2c_adapter_remove: i2c_del_adapter(adap); @@ -2210,6 +2282,7 @@ static int stm32f7_i2c_remove(struct platform_device *pdev) { struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev); + stm32f7_i2c_disable_smbus_alert(i2c_dev); stm32f7_i2c_disable_smbus_host(i2c_dev); i2c_del_adapter(&i2c_dev->adap);