From patchwork Fri Apr 8 12:26:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Valentin Caron X-Patchwork-Id: 12806726 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C67AAC433F5 for ; Fri, 8 Apr 2022 13:03:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=eFLgI4CZsUMDV38HS+ujHnIyjzlWH7jRxY9m6pTZSRI=; b=YoeWjbFSS3qj8O Kmk5YTR6FfEFBrvrZwFXJZE/bQiYDwTqHvoxqCHBSrgegBvUWlMMXNuagaFlL3zKCZlnGe3Vw/7ek KxTTIP8CC9LBjuDXjoCbNxPR/U73a15AADHvY+KPhTlZDC3e95cNQNul0WeUVYCkBljmTHi+A9NdK kKcMds/DyWU2fX3055uK93gLgRtaSdavynK+1uccOw8z16mOSeEx7LTjXHFMoXpbM7mAFI2nnKbkx 41tkztu3g6ChosfwjgSRwBg9COmdA9B3sGd19GzFk/c3yJl3cgpLZB97kVg0MiNHDCA55IBMiHth7 jWm4MZb/kcxKPfQ35ozQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncoFF-00HEBb-8F; Fri, 08 Apr 2022 13:01:46 +0000 Received: from mx07-00178001.pphosted.com ([185.132.182.106]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncnhu-00GzVU-M5 for linux-arm-kernel@lists.infradead.org; Fri, 08 Apr 2022 12:27:22 +0000 Received: from pps.filterd (m0288072.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 2389i7HP000594; Fri, 8 Apr 2022 14:27:05 +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-transfer-encoding : content-type; s=selector1; bh=kl/405WO6BWkxCmfDNNimImVgYIdQ5yPoKlOLHS/+kc=; b=yjXu8DxGT9GVFUcdu8MFk0cHGGuYhB/tXiRBU3q8ICaJp+5a/oLaw5E6PAlAiXvEbRrA fEs6bgmd3k4/O2G3GfVHU2p6HKJkpzSbF7hTX9acyqHRKTxQ9zuAB2xjenwTAtQPiHqR ySb5z4ze8xkxUIP4JHcD4SutI4+yv/uDcgn+iWI6Q0ZNYF4wCw8MVIoiakN5Nfhv/q6j 0WypSfw5hWNSwmzZ0ckAHKVeDK10mguIGmzaWUl2mXVIiGLbXpPY4E9UBGjHDxouvXGe X7lKQRSjESg8IC9Av/PWp15FOqHN/akBb3nj1yKMFo6iw9hRVdAbhYA6vUgSMBNue+gd EQ== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3f9wr7r1pb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 08 Apr 2022 14:27:05 +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 9BDA310002A; Fri, 8 Apr 2022 14:27:04 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 9409221A21E; Fri, 8 Apr 2022 14:27:04 +0200 (CEST) Received: from localhost (10.75.127.51) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Fri, 8 Apr 2022 14:27:04 +0200 From: Valentin Caron To: Greg Kroah-Hartman , Jonathan Corbet CC: Jiri Slaby , Maxime Coquelin , Alexandre Torgue , Erwan Le Ray , Valentin Caron , , , , , Subject: [PATCH V2 3/3] serial: stm32: add earlycon support Date: Fri, 8 Apr 2022 14:26:36 +0200 Message-ID: <20220408122636.505737-4-valentin.caron@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220408122636.505737-1-valentin.caron@foss.st.com> References: <20220408122636.505737-1-valentin.caron@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.51] X-ClientProxiedBy: SFHDAG2NODE1.st.com (10.75.127.4) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-04-08_04,2022-04-08_01,2022-02-23_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220408_052719_104302_0CC51615 X-CRM114-Status: GOOD ( 17.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add early console support in stm32 uart driver. Signed-off-by: Alexandre Torgue Signed-off-by: Valentin Caron --- .../admin-guide/kernel-parameters.txt | 6 +++ drivers/tty/serial/Kconfig | 1 + drivers/tty/serial/stm32-usart.c | 51 +++++++++++++++++++ 3 files changed, 58 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3f1cc5e317ed..e941c3351c7a 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1264,6 +1264,12 @@ address must be provided, and the serial port must already be setup and configured. + stm32, + Use early console provided by ST Microelectronics + serial driver for STM32 SoCs. A valid base address + must be provided, and the serial port must already + be setup and configured. + earlyprintk= [X86,SH,ARM,M68k,S390] earlyprintk=vga earlyprintk=sclp diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 6949e883ffab..ed59de8d2e11 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1443,6 +1443,7 @@ config SERIAL_STM32_CONSOLE bool "Support for console on STM32" depends on SERIAL_STM32=y select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON config SERIAL_MVEBU_UART bool "Marvell EBU serial port support" diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 4307c822afe4..65988e6efaa2 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -1766,6 +1766,57 @@ static struct console stm32_console = { #define STM32_SERIAL_CONSOLE NULL #endif /* CONFIG_SERIAL_STM32_CONSOLE */ +#ifdef CONFIG_SERIAL_EARLYCON +static void early_stm32_usart_console_putchar(struct uart_port *port, unsigned char ch) +{ + struct stm32_usart_info *info = port->private_data; + + while (!(readl_relaxed(port->membase + info->ofs.isr) & USART_SR_TXE)) + cpu_relax(); + + writel_relaxed(ch, port->membase + info->ofs.tdr); +} + +static void early_stm32_serial_write(struct console *console, const char *s, unsigned int count) +{ + struct earlycon_device *device = console->data; + struct uart_port *port = &device->port; + + uart_console_write(port, s, count, early_stm32_usart_console_putchar); +} + +static int __init early_stm32_h7_serial_setup(struct earlycon_device *device, const char *options) +{ + if (!(device->port.membase || device->port.iobase)) + return -ENODEV; + device->port.private_data = &stm32h7_info; + device->con->write = early_stm32_serial_write; + return 0; +} + +static int __init early_stm32_f7_serial_setup(struct earlycon_device *device, const char *options) +{ + if (!(device->port.membase || device->port.iobase)) + return -ENODEV; + device->port.private_data = &stm32f7_info; + device->con->write = early_stm32_serial_write; + return 0; +} + +static int __init early_stm32_f4_serial_setup(struct earlycon_device *device, const char *options) +{ + if (!(device->port.membase || device->port.iobase)) + return -ENODEV; + device->port.private_data = &stm32f4_info; + device->con->write = early_stm32_serial_write; + return 0; +} + +OF_EARLYCON_DECLARE(stm32, "st,stm32h7-uart", early_stm32_h7_serial_setup); +OF_EARLYCON_DECLARE(stm32, "st,stm32f7-uart", early_stm32_f7_serial_setup); +OF_EARLYCON_DECLARE(stm32, "st,stm32-uart", early_stm32_f4_serial_setup); +#endif /* CONFIG_SERIAL_EARLYCON */ + static struct uart_driver stm32_usart_driver = { .driver_name = DRIVER_NAME, .dev_name = STM32_SERIAL_NAME,