From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Murzin Subject: [PATCH v3 05/10] serial: mps2-uart: add support for early console Date: Tue, 16 Feb 2016 10:08:10 +0000 Message-ID: <1455617295-23736-6-git-send-email-vladimir.murzin@arm.com> References: <1455617295-23736-1-git-send-email-vladimir.murzin@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1455617295-23736-1-git-send-email-vladimir.murzin@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: arnd@arndb.de, linux@arm.linux.org.uk, gregkh@linuxfoundation.org, daniel.lezcano@linaro.org, tglx@linutronix.de, u.kleine-koenig@pengutronix.de Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, pawel.moll@arm.com, ijc+devicetree@hellion.org.uk, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, andy.shevchenko@gmail.com, robh+dt@kernel.org, linux-serial@vger.kernel.org, galak@codeaurora.org, jslaby@suse.cz, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org 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 3a248be..4ed6e51 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1454,6 +1454,7 @@ 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 d97f3a9..f3a3bd1 100644 --- a/drivers/tty/serial/mps2-uart.c +++ b/drivers/tty/serial/mps2-uart.c @@ -435,6 +435,36 @@ 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