Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752801AbbKYKi3 (ORCPT ); Wed, 25 Nov 2015 05:38:29 -0500 Received: from eu-smtp-delivery-143.mimecast.com ([207.82.80.143]:38899 "EHLO eu-smtp-delivery-143.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752655AbbKYKgQ (ORCPT ); Wed, 25 Nov 2015 05:36:16 -0500 From: Vladimir Murzin To: arnd@arndb.de, linux@arm.linux.org.uk, gregkh@linuxfoundation.org, daniel.lezcano@linaro.org, tglx@linutronix.de, u.kleine-koenig@pengutronix.de, afaerber@suse.de, mcoquelin.stm32@gmail.com Cc: Mark.Rutland@arm.com, Pawel.Moll@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, jslaby@suse.cz, robh+dt@kernel.org, devicetree@vger.kernel.org, linux-serial@vger.kernel.org, linux-api@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 05/10] serial: mps2-uart: add support for early console Date: Wed, 25 Nov 2015 10:33:36 +0000 Message-Id: <1448447621-17900-6-git-send-email-vladimir.murzin@arm.com> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1448447621-17900-1-git-send-email-vladimir.murzin@arm.com> References: <1448447621-17900-1-git-send-email-vladimir.murzin@arm.com> X-OriginalArrivalTime: 25 Nov 2015 10:35:53.0166 (UTC) FILETIME=[0F469EE0:01D1276D] X-MC-Unique: LprC3iOdQG-OUUQQwqSGgA-11 Content-Type: text/plain; charset=WINDOWS-1252 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id tAPAcYgw027336 Content-Length: 2051 Lines: 70 This adds support early console for MPS2 UART which can be enabled via earlycon=mps2,0x40004000 Signed-off-by: Vladimir Murzin --- drivers/tty/serial/Kconfig | 1 + drivers/tty/serial/mps2-uart.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index b47f8fc..bb8c66b 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1477,6 +1477,7 @@ 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 tristate "MPS2 UART port" diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c index 00e882e..c2f530e 100644 --- a/drivers/tty/serial/mps2-uart.c +++ b/drivers/tty/serial/mps2-uart.c @@ -445,6 +445,36 @@ 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 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; +} +EARLYCON_DECLARE(mps2, mps2_early_console_setup); +OF_EARLYCON_DECLARE(mps2, "arm,mps2-uart", mps2_early_console_setup); + #else #define MPS2_SERIAL_CONSOLE NULL #endif -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/