diff options
| author | Lucas Stach <l.stach@pengutronix.de> | 2015-08-28 12:56:19 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-04 19:49:27 +0300 |
| commit | 913c6c0e947be8fb14d591be69e8966912af9c15 (patch) | |
| tree | 4d97dee417ea0025397e28d09ebfec5a513b9e5e /drivers | |
| parent | 4cad4c57e0b3e90555a81e79ac7e82b253979697 (diff) | |
| download | linux-913c6c0e947be8fb14d591be69e8966912af9c15.tar.xz | |
serial: imx: add earlycon support
Earlycon allows to have an early debugging console that doesn't need
to be statically configured in the kernel config, like earlyprintk,
but is set up through the stdout-path DT property.
This allows to have the early debugging always built into the
kernel and enabled on demand without clashing between different boards
or architectures.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/tty/serial/imx.c | 32 |
2 files changed, 33 insertions, 0 deletions
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index f57bb907dc54..9e2cc51d205a 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -582,6 +582,7 @@ config SERIAL_IMX_CONSOLE bool "Console on IMX serial port" depends on SERIAL_IMX=y select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON if OF help If you have enabled the serial port on the Freescale IMX CPU you can make it the console by answering Y to this option. diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index fe3d41cc8416..52629ca80437 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1795,6 +1795,38 @@ static struct console imx_console = { }; #define IMX_CONSOLE &imx_console + +#ifdef CONFIG_OF +static void imx_console_early_putchar(struct uart_port *port, int ch) +{ + while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL) + cpu_relax(); + + writel_relaxed(ch, port->membase + URTX0); +} + +static void imx_console_early_write(struct console *con, const char *s, + unsigned count) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, count, imx_console_early_putchar); +} + +static int __init +imx_console_early_setup(struct earlycon_device *dev, const char *opt) +{ + if (!dev->port.membase) + return -ENODEV; + + dev->con->write = imx_console_early_write; + + return 0; +} +OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup); +OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup); +#endif + #else #define IMX_CONSOLE NULL #endif |