From patchwork Mon Apr 25 08:47:48 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Murzin X-Patchwork-Id: 8924541 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 329F39F441 for ; Mon, 25 Apr 2016 08:49:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 57B1520166 for ; Mon, 25 Apr 2016 08:49:52 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 86552200E6 for ; Mon, 25 Apr 2016 08:49:51 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aucCB-0000vR-2p; Mon, 25 Apr 2016 08:48:43 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aucBs-0000c7-Fz for linux-arm-kernel@lists.infradead.org; Mon, 25 Apr 2016 08:48:25 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1694B43B; Mon, 25 Apr 2016 01:46:50 -0700 (PDT) Received: from login1.euhpc.arm.com (login1.euhpc.arm.com [10.6.26.143]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A32923F218; Mon, 25 Apr 2016 01:48:07 -0700 (PDT) From: Vladimir Murzin To: gregkh@linuxfoundation.org Subject: [PATCH 3/3] serial: mps2-uart: add support for early console Date: Mon, 25 Apr 2016 09:47:48 +0100 Message-Id: <1461574068-14641-4-git-send-email-vladimir.murzin@arm.com> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1461574068-14641-1-git-send-email-vladimir.murzin@arm.com> References: <1461574068-14641-1-git-send-email-vladimir.murzin@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160425_014824_579816_1975E307 X-CRM114-Status: UNSURE ( 9.47 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -7.9 (-------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: arnd@arndb.de, jslaby@suse.com, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, sudeep.holla@arm.com, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This adds support early console for MPS2 UART which can be enabled via earlycon=mps2,0x40004000 Acked-by: Greg Kroah-Hartman Reviewed-by: Peter Hurley Signed-off-by: Vladimir Murzin --- drivers/tty/serial/Kconfig | 1 + drivers/tty/serial/mps2-uart.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 29 insertions(+) diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 3673ef0..4e6d2d1 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1450,6 +1450,7 @@ config SERIAL_MPS2_UART_CONSOLE bool "MPS2 UART console support" depends on SERIAL_MPS2_UART select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON config SERIAL_MPS2_UART bool "MPS2 UART port" diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c index e571e4c..da9e27d 100644 --- a/drivers/tty/serial/mps2-uart.c +++ b/drivers/tty/serial/mps2-uart.c @@ -450,6 +450,34 @@ static struct console mps2_uart_console = { #define MPS2_SERIAL_CONSOLE (&mps2_uart_console) +static void mps2_early_putchar(struct uart_port *port, int ch) +{ + while (readb(port->membase + UARTn_STATE) & UARTn_STATE_TX_FULL) + cpu_relax(); + + writeb((unsigned char)ch, port->membase + UARTn_DATA); +} + +static void mps2_early_write(struct console *con, const char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, mps2_early_putchar); +} + +static int __init mps2_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = mps2_early_write; + + return 0; +} + +OF_EARLYCON_DECLARE(mps2, "arm,mps2-uart", mps2_early_console_setup); + #else #define MPS2_SERIAL_CONSOLE NULL #endif