From patchwork Fri Apr 8 12:26:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Valentin Caron X-Patchwork-Id: 12806724 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 1D3ABC433EF for ; Fri, 8 Apr 2022 13:02:37 +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=im0prCsc7YSqKc2UhvwnBZFckDubZbJfQiki0wXReB0=; b=V1smeM+mnv5xub V6VjnaIrSjzLFp6MZ3oxIOSKOodnbyHAh8Y1JDWfDgy9r3q4s8mZYFS7/pi2PVQ9ERDVmROOXwLiE Ppiq2ngbGZSTUUsbA8iG92vVnhm5pkAnze+st+WuYvDLHd6HM1K7n81pAk6LATnvt+zc3P9+42cUP ONhFB6z6UvmVbuwl8DvPHvYoD1wFNEJ3RC0E3U/Eo65ivoU9JysRYXWLfVNp+dqMuW6qIR53m/Pjl J6QdGCLryQt1fnLEMREyQGycKjR5pipNVTQBzdXLe4HbTTL8V+jhe4w9RIn9PGx4tesPJ8Jt+92DL +qAmf2/Ze4t5qs5F3hAg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncoEe-00HDwq-Re; Fri, 08 Apr 2022 13:01:09 +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-00GzVT-Kq for linux-arm-kernel@lists.infradead.org; Fri, 08 Apr 2022 12:27:20 +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 2389j3P9000551; 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-type : content-transfer-encoding; s=selector1; bh=OzzsSeRZXTJPRZje9ui1T8+kROrim9zZTezfZrmqwVA=; b=g9pEZNsoYYlGs5g2LsrK5fLiu589Fxw1KHMSO0CId/eEqsrdIBXj6aKTW+eD8ltMsGgE Lmo260J0JhOSP7+0q6M1B/R9dJ8DCktbMGqZ4jU2MR7bKblxcZXYXDj/HLenA4x6JuV1 GxpxUrt+JnIKxaEH85wK6gRR3zIVInqb0/T9CmSzK552YxFgLzHvfOtY4DTLLw1xbbZ5 UDIaiJV5O85hvXJlE1uKarAfUTL6j0LghhtsifE0PWAyBmwTkxVuycc8aH7RWkhJKjM4 kfPbnN04JyVNJ+xhM1hlbpHavSUKqxYxE4CW7HuDrOs7s5HvpWs8CQinBrJROwov5khc 7Q== 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 3f9wr7r1p9-1 (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 8EA7B100038; Fri, 8 Apr 2022 14:27:03 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 8666321A21E; Fri, 8 Apr 2022 14:27:03 +0200 (CEST) Received: from localhost (10.75.127.50) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Fri, 8 Apr 2022 14:27:03 +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 1/3] serial: stm32: remove infinite loop possibility in putchar function Date: Fri, 8 Apr 2022 14:26:34 +0200 Message-ID: <20220408122636.505737-2-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: [10.75.127.50] 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_036477_75C7D399 X-CRM114-Status: GOOD ( 18.26 ) 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 Rework stm32_usart_console_putchar() function in order to anticipate the case where the character can never be sent. Signed-off-by: Valentin Caron --- drivers/tty/serial/stm32-usart.c | 12 +++++++++--- drivers/tty/serial/stm32-usart.h | 2 ++ 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 87b5cd4c9743..83895da84891 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -1645,10 +1645,16 @@ static void stm32_usart_console_putchar(struct uart_port *port, unsigned char ch { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + u32 isr; + int ret; - while (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE)) - cpu_relax(); - + ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, isr, + (isr & USART_SR_TXE), 100, + STM32_USART_TIMEOUT_USEC); + if (ret != 0) { + dev_err(port->dev, "Error while sending data in UART TX : %d\n", ret); + return; + } writel_relaxed(ch, port->membase + ofs->tdr); } diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h index feab952aec16..d734c4a5fd24 100644 --- a/drivers/tty/serial/stm32-usart.h +++ b/drivers/tty/serial/stm32-usart.h @@ -251,6 +251,8 @@ struct stm32_usart_info stm32h7_info = { #define RX_BUF_P (RX_BUF_L / 2) /* dma rx buffer period */ #define TX_BUF_L RX_BUF_L /* dma tx buffer length */ +#define STM32_USART_TIMEOUT_USEC USEC_PER_SEC /* 1s timeout in µs */ + struct stm32_port { struct uart_port port; struct clk *clk; From patchwork Fri Apr 8 12:26:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Valentin Caron X-Patchwork-Id: 12806722 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 58473C433F5 for ; Fri, 8 Apr 2022 13:01:05 +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=vH66RRGQoBULbvxF7uyMKxoCAhQvAycNiTfh9qWoy60=; b=2Cm+cxCtH/jpxx ouW1wDj7QhUGfzMOQGk+rvvI+DvxBz1dnvSjhX2GyPfQ4fiJ0q7PpD4R8aBdM3M5DZ1KLZWw9uq/F 5lVC1K/Jm2iS40gp3R7ko4ldsFZBuXTng3u5vQvOELEmBX3OvvOqbbUQwJFfMpx8jBrZyoaYVZgfJ V+oviGS+rIGdl4XLHeYW0r8jMyJjPzuvSlso7nKNNPrDW+4D8VmVEkgpUCzWaPmNmxgELXVKR2qvJ EU3Xo/ES9Ve00ZloIcJF7ihMN2r0WHKg4E9l/VT5CT7lay3ZjW4Slhm6BmnUX4wvc0N5qoeFHZQVD EGdFXZqwY0z3Bcnzr+MA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncoDB-00HDJs-WB; Fri, 08 Apr 2022 12:59:38 +0000 Received: from mx08-00178001.pphosted.com ([91.207.212.93] helo=mx07-00178001.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncnht-00GzV8-Ip for linux-arm-kernel@lists.infradead.org; Fri, 08 Apr 2022 12:27:20 +0000 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 238A3ahR022061; Fri, 8 Apr 2022 14:27:04 +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=Z+C6qsQxHAO28SlPFqbWYQOw4PgvzJsq3Eypnf5gKzU=; b=DV8jPhv2oQFcW0JI70pCiV/+5meHiG3pEjC7Ya9T2rGFEtbfB/aq4J3XZI3LsJr24iwa UefdkkGMVb8BrdkdEpdj+1VeLYy8lTxGZPCqiCjfCgKvlprHZRPDFGrqC/6DscaqiO2p JH5Sx6SAKia4JYg/miMUr7h1KcWlRM5Wbaqosjx+8pjYtNccU10YSGSyLqgD0B5AaO/C nC18hPtVlNc8do5zy6QeJDu96FhNycWx39RNmzF2u6zbl03RWXRxDZUSwBJgIfS8RHAS JjM/3vXEadVxWNwcK/NMDa3h2lOQ/58G/8s12VPKzIzbRn54REl4wysAY+9Drc42P2cz ig== 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 3f8x9gu5ek-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 08 Apr 2022 14:27:04 +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 189A2100039; 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 105DD21A21E; Fri, 8 Apr 2022 14:27:04 +0200 (CEST) Received: from localhost (10.75.127.49) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Fri, 8 Apr 2022 14:27:03 +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 2/3] serial: stm32: add KGDB support Date: Fri, 8 Apr 2022 14:26:35 +0200 Message-ID: <20220408122636.505737-3-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: [10.75.127.49] 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_052718_316857_D16930E8 X-CRM114-Status: GOOD ( 18.72 ) 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 support for KGDB in stm32 serial driver by implementing characters polling callbacks (poll_init, poll_get_char and poll_put_char). Signed-off-by: Erwan Le Ray Signed-off-by: Jean Philippe Romain Signed-off-by: Valentin Caron --- drivers/tty/serial/stm32-usart.c | 37 ++++++++++++++++++++++++++++++-- 1 file changed, 35 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 83895da84891..4307c822afe4 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -37,6 +37,7 @@ static void stm32_usart_stop_tx(struct uart_port *port); static void stm32_usart_transmit_chars(struct uart_port *port); +static void __maybe_unused stm32_usart_console_putchar(struct uart_port *port, unsigned char ch); static inline struct stm32_port *to_stm32_port(struct uart_port *port) { @@ -1222,6 +1223,33 @@ static void stm32_usart_pm(struct uart_port *port, unsigned int state, } } +#if defined(CONFIG_CONSOLE_POLL) + + /* Callbacks for characters polling in debug context (i.e. KGDB). */ +static int stm32_usart_poll_init(struct uart_port *port) +{ + struct stm32_port *stm32_port = to_stm32_port(port); + + return clk_prepare_enable(stm32_port->clk); +} + +static int stm32_usart_poll_get_char(struct uart_port *port) +{ + struct stm32_port *stm32_port = to_stm32_port(port); + const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + + if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_RXNE)) + return NO_POLL_CHAR; + + return readl_relaxed(port->membase + ofs->rdr) & stm32_port->rdr_mask; +} + +static void stm32_usart_poll_put_char(struct uart_port *port, unsigned char ch) +{ + stm32_usart_console_putchar(port, ch); +} +#endif /* CONFIG_CONSOLE_POLL */ + static const struct uart_ops stm32_uart_ops = { .tx_empty = stm32_usart_tx_empty, .set_mctrl = stm32_usart_set_mctrl, @@ -1243,6 +1271,11 @@ static const struct uart_ops stm32_uart_ops = { .request_port = stm32_usart_request_port, .config_port = stm32_usart_config_port, .verify_port = stm32_usart_verify_port, +#if defined(CONFIG_CONSOLE_POLL) + .poll_init = stm32_usart_poll_init, + .poll_get_char = stm32_usart_poll_get_char, + .poll_put_char = stm32_usart_poll_put_char, +#endif /* CONFIG_CONSOLE_POLL */ }; /* @@ -1640,8 +1673,7 @@ static int stm32_usart_serial_remove(struct platform_device *pdev) return 0; } -#ifdef CONFIG_SERIAL_STM32_CONSOLE -static void stm32_usart_console_putchar(struct uart_port *port, unsigned char ch) +static void __maybe_unused stm32_usart_console_putchar(struct uart_port *port, unsigned char ch) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; @@ -1658,6 +1690,7 @@ static void stm32_usart_console_putchar(struct uart_port *port, unsigned char ch writel_relaxed(ch, port->membase + ofs->tdr); } +#ifdef CONFIG_SERIAL_STM32_CONSOLE static void stm32_usart_console_write(struct console *co, const char *s, unsigned int cnt) { 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,