From patchwork Thu Jun 25 07:39:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alain Volmat X-Patchwork-Id: 207475 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=-10.1 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, 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 D6165C433E0 for ; Thu, 25 Jun 2020 07:40:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BE7F20663 for ; Thu, 25 Jun 2020 07:40:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="V16HI0bN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390315AbgFYHkH (ORCPT ); Thu, 25 Jun 2020 03:40:07 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:16494 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390210AbgFYHkF (ORCPT ); Thu, 25 Jun 2020 03:40:05 -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 05P7RNra002366; Thu, 25 Jun 2020 09:39:52 +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=UxiAJfYSqeRtE5Buy1wLRF+37X+4vnnj/FDCmUq06mo=; b=V16HI0bNh2hmqlUOrv0wXzAsR7lqhmvz2BT02n0gpN3WY6jIB8HSDy/dOtwfaOsOTiv2 u8kG1NuZKnNtmEkZeyfDJ/MLvQuGbp1hD0VR7p0nt+25ywCZAMr0mz+1cpNOaDa2l6jM WuS0hp38t9nLJl4/TrfQec9q0r51L5LhYXx5fmo4XODZ9oZ6+1C09/eHL1GdudUDDEmP FEAv/ioKbtKXMFbl7FMazCZA3IM9tlahhTY0xwxA+uRP/YSlXUOQHDa6/Q3A7OOCeO4D 9ZIeNzV+V4eiMwX5KGtvCbnOsBKHNFyc3ffD12fbRvSmAd3oj2aPqTynbre9bYhDfb/l xQ== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 31uuucgkpr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 25 Jun 2020 09:39:52 +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 0DD39100034; Thu, 25 Jun 2020 09:39:52 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag3node2.st.com [10.75.127.8]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 018D42A82E2; Thu, 25 Jun 2020 09:39:52 +0200 (CEST) Received: from localhost (10.75.127.51) by SFHDAG3NODE2.st.com (10.75.127.8) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Thu, 25 Jun 2020 09:39:51 +0200 From: Alain Volmat To: , CC: , , , , , , , , , , Subject: [PATCH v2 4/4] i2c: stm32f7: Add SMBus-specific protocols support Date: Thu, 25 Jun 2020 09:39:29 +0200 Message-ID: <1593070769-9106-5-git-send-email-alain.volmat@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1593070769-9106-1-git-send-email-alain.volmat@st.com> References: <1593070769-9106-1-git-send-email-alain.volmat@st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.51] X-ClientProxiedBy: SFHDAG5NODE2.st.com (10.75.127.14) To SFHDAG3NODE2.st.com (10.75.127.8) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.687 definitions=2020-06-25_03:2020-06-25,2020-06-25 signatures=0 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org This patch adds the support for SMBus Host notify and SMBus Alert extensions protocols This patch introduces the st,smbus-alert binding in order to enable SMBus-Alert handling. Indeed, while the I2C/SMBUS framework already provide a mechanism to enable SMBus-Alert by naming an IRQ line "smbus_alert", on stm32 the SMBus-Alert is part of the i2c IRQ. Using the smbus_alert naming here would lead to having 2 handlers (the handler of the driver and the smbus_alert handler from I2C/SMBUS framework) on the unique i2c IRQ of the stm32. Meaning that the smbus_alert handler would get called for all IRQ generated by the stm32 I2C controller. Signed-off-by: Alain Volmat --- v2: adapt code to use reg_hnotify_cli / unreg_hnotify_cli instead of reg_client / unreg_client clarify commit message drivers/i2c/busses/Kconfig | 1 + drivers/i2c/busses/i2c-stm32f7.c | 194 +++++++++++++++++++++++++++++++++++++-- 2 files changed, 185 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 735bf31a3fdf..ae8671727a4c 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1036,6 +1036,7 @@ config I2C_STM32F7 tristate "STMicroelectronics STM32F7 I2C support" depends on ARCH_STM32 || COMPILE_TEST select I2C_SLAVE + select I2C_SMBUS help Enable this option to add support for STM32 I2C controller embedded in STM32F7 SoCs. diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index bff3479fe122..d8f483ceeabb 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -14,10 +14,12 @@ * This driver is based on i2c-stm32f4.c * */ +#include #include #include #include #include +#include #include #include #include @@ -50,6 +52,8 @@ /* 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) #define STM32F7_I2C_CR1_RXDMAEN BIT(15) @@ -121,6 +125,7 @@ (((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) @@ -134,6 +139,7 @@ #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) @@ -150,7 +156,7 @@ #define STM32F7_I2C_MAX_LEN 0xff #define STM32F7_I2C_DMA_LEN_MIN 0x16 -#define STM32F7_I2C_MAX_SLAVE 0x2 +#define STM32F7_I2C_MAX_SLAVE 0x3 #define STM32F7_I2C_DNF_DEFAULT 0 #define STM32F7_I2C_DNF_MAX 16 @@ -275,6 +281,29 @@ struct stm32f7_i2c_msg { }; /** + * struct stm32f7_i2c_host - SMBus host specific data + * @client: I2C slave device that represents SMBus host + * @notify_start: indicate that this is the start of the notify transaction + * @addr: device address of SMBus device that initiate SMBus host protocol + */ +struct stm32f7_i2c_host { + struct i2c_client *client; + bool notify_start; + u8 addr; +}; + +/** + * 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 * @dev: device for this controller @@ -301,6 +330,9 @@ struct stm32f7_i2c_msg { * @fmp_creg: register address for clearing Fast Mode Plus bits * @fmp_mask: mask for Fast Mode Plus bits in set register * @wakeup_src: boolean to know if the device is a wakeup source + * @host_notify_cnt: atomic to know number of host_notify enabled clients + * @host_notify_client: SMBus host-notify client + * @alert: SMBus alert specific data */ struct stm32f7_i2c_dev { struct i2c_adapter adap; @@ -327,6 +359,9 @@ struct stm32f7_i2c_dev { u32 fmp_creg; u32 fmp_mask; bool wakeup_src; + atomic_t host_notify_cnt; + struct i2c_client *host_notify_client; + struct stm32f7_i2c_alert *alert; }; /* @@ -1321,10 +1356,20 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev, int i; /* - * slave[0] supports 7-bit and 10-bit slave address - * slave[1] supports 7-bit slave address only + * slave[0] support only SMBus Host address (0x8) + * slave[1] supports 7-bit and 10-bit slave address + * slave[2] supports 7-bit slave address only */ - for (i = STM32F7_I2C_MAX_SLAVE - 1; i >= 0; i--) { + if (atomic_read(&i2c_dev->host_notify_cnt)) { + if (slave->addr == 0x08) { + if (i2c_dev->slave[0]) + goto fail; + *id = 0; + return 0; + } + } + + for (i = STM32F7_I2C_MAX_SLAVE - 1; i > 0; i--) { if (i == 1 && (slave->flags & I2C_CLIENT_TEN)) continue; if (!i2c_dev->slave[i]) { @@ -1333,6 +1378,7 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev, } } +fail: dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr); return -EINVAL; @@ -1586,6 +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 */ @@ -1776,7 +1829,13 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave) if (!stm32f7_i2c_is_slave_registered(i2c_dev)) stm32f7_i2c_enable_wakeup(i2c_dev, true); - if (id == 0) { + switch (id) { + case 0: + /* Slave SMBus Host */ + i2c_dev->slave[id] = slave; + break; + + case 1: /* Configure Own Address 1 */ oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1); oar1 &= ~STM32F7_I2C_OAR1_MASK; @@ -1789,7 +1848,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave) oar1 |= STM32F7_I2C_OAR1_OA1EN; i2c_dev->slave[id] = slave; writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1); - } else if (id == 1) { + break; + + case 2: /* Configure Own Address 2 */ oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2); oar2 &= ~STM32F7_I2C_OAR2_MASK; @@ -1802,7 +1863,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave) oar2 |= STM32F7_I2C_OAR2_OA2EN; i2c_dev->slave[id] = slave; writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2); - } else { + break; + + default: + dev_err(dev, "I2C slave id not supported\n"); ret = -ENODEV; goto pm_free; } @@ -1843,10 +1907,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave) if (ret < 0) return ret; - if (id == 0) { + if (id == 1) { mask = STM32F7_I2C_OAR1_OA1EN; stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask); - } else { + } else if (id == 2) { mask = STM32F7_I2C_OAR2_OA2EN; stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask); } @@ -1911,6 +1975,99 @@ static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev, &i2c_dev->fmp_mask); } +static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev) +{ + struct i2c_adapter *adap = &i2c_dev->adap; + void __iomem *base = i2c_dev->base; + struct i2c_client *client; + + client = i2c_new_smbus_host_notify_device(adap); + if (IS_ERR(client)) + return PTR_ERR(client); + + i2c_dev->host_notify_client = client; + + /* Enable SMBus Host address */ + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN); + + return 0; +} + +static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev) +{ + void __iomem *base = i2c_dev->base; + + if (i2c_dev->host_notify_client) { + /* Disable SMBus Host address */ + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_SMBHEN); + i2c_free_smbus_host_notify_device(i2c_dev->host_notify_client); + } +} + +static int stm32f7_i2c_reg_hnotify_client(struct i2c_client *client) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(client->adapter); + int ret; + + /* Only enable on the first device registration */ + if (atomic_inc_return(&i2c_dev->host_notify_cnt) == 1) { + ret = stm32f7_i2c_enable_smbus_host(i2c_dev); + if (ret) { + dev_err(i2c_dev->dev, + "failed to enable SMBus host notify (%d)\n", + ret); + return ret; + } + } + + return 0; +} + +static void stm32f7_i2c_unreg_hnotify_client(struct i2c_client *client) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(client->adapter); + + if (atomic_dec_return(&i2c_dev->host_notify_cnt) == 0) + stm32f7_i2c_disable_smbus_host(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) { return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE | @@ -1918,7 +2075,7 @@ static u32 stm32f7_i2c_func(struct i2c_adapter *adap) I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC | - I2C_FUNC_SMBUS_I2C_BLOCK; + I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_HOST_NOTIFY; } static const struct i2c_algorithm stm32f7_i2c_algo = { @@ -1927,6 +2084,8 @@ static const struct i2c_algorithm stm32f7_i2c_algo = { .functionality = stm32f7_i2c_func, .reg_slave = stm32f7_i2c_reg_slave, .unreg_slave = stm32f7_i2c_unreg_slave, + .reg_hnotify_cli = stm32f7_i2c_reg_hnotify_client, + .unreg_hnotify_cli = stm32f7_i2c_unreg_hnotify_client, }; static int stm32f7_i2c_probe(struct platform_device *pdev) @@ -2088,6 +2247,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) if (ret) goto pm_disable; + if (device_property_read_bool(&pdev->dev, "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_adapter_remove; + } + } + dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr); pm_runtime_mark_last_busy(i2c_dev->dev); @@ -2095,6 +2264,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) return 0; +i2c_adapter_remove: + i2c_del_adapter(adap); + pm_disable: pm_runtime_put_noidle(i2c_dev->dev); pm_runtime_disable(i2c_dev->dev); @@ -2126,6 +2298,8 @@ 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); + i2c_del_adapter(&i2c_dev->adap); pm_runtime_get_sync(i2c_dev->dev);