From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754198AbcDYIsy (ORCPT ); Mon, 25 Apr 2016 04:48:54 -0400 Received: from foss.arm.com ([217.140.101.70]:43940 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754142AbcDYIsJ (ORCPT ); Mon, 25 Apr 2016 04:48:09 -0400 From: Vladimir Murzin To: gregkh@linuxfoundation.org Cc: jslaby@suse.com, arnd@arndb.de, sudeep.holla@arm.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.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> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 -- 1.7.9.5