diff options
| author | Tobias Klauser <tklauser@distanz.ch> | 2017-03-22 13:50:13 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-31 16:56:10 +0200 |
| commit | 4d9d7d896d77e70e6868cfe681e7fcd58dc9526d (patch) | |
| tree | e51c87225e31ee349087ecc0e65d3103463bb54f /drivers/tty/serial/altera_uart.c | |
| parent | tty: Disable default console blanking interval (diff) | |
| download | linux-4d9d7d896d77e70e6868cfe681e7fcd58dc9526d.tar.xz linux-4d9d7d896d77e70e6868cfe681e7fcd58dc9526d.zip | |
serial: altera_uart: add earlycon support
Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_uart.
Add earlycon support to altera_uart so that other archs may use it.
Also, this (together with the corresponding patch for altera_jtaguart)
will allow the early printk implementation in arch/nios2 to be removed
in a future patch.
Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/altera_uart.c')
| -rw-r--r-- | drivers/tty/serial/altera_uart.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c index 820a74208696..46d3438a0d27 100644 --- a/drivers/tty/serial/altera_uart.c +++ b/drivers/tty/serial/altera_uart.c @@ -489,6 +489,38 @@ console_initcall(altera_uart_console_init); #define ALTERA_UART_CONSOLE (&altera_uart_console) +static void altera_uart_earlycon_write(struct console *co, const char *s, + unsigned int count) +{ + struct earlycon_device *dev = co->data; + + uart_console_write(&dev->port, s, count, altera_uart_console_putc); +} + +static int __init altera_uart_earlycon_setup(struct earlycon_device *dev, + const char *options) +{ + struct uart_port *port = &dev->port; + + if (!port->membase) + return -ENODEV; + + /* Enable RX interrupts now */ + writel(ALTERA_UART_CONTROL_RRDY_MSK, + port->membase + ALTERA_UART_CONTROL_REG); + + if (dev->baud) { + unsigned int baudclk = port->uartclk / dev->baud; + + writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG); + } + + dev->con->write = altera_uart_earlycon_write; + return 0; +} + +OF_EARLYCON_DECLARE(uart, "altr,uart-1.0", altera_uart_earlycon_setup); + #else #define ALTERA_UART_CONSOLE NULL |