diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_early.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c index 5cd8c36c8fcc..70d7826788f5 100644 --- a/drivers/tty/serial/8250/8250_early.c +++ b/drivers/tty/serial/8250/8250_early.c @@ -109,6 +109,28 @@ static void early_serial8250_write(struct console *console, uart_console_write(port, s, count, serial_putc); } +#ifdef CONFIG_CONSOLE_POLL +static int early_serial8250_read(struct console *console, + char *s, unsigned int count) +{ + struct earlycon_device *device = console->data; + struct uart_port *port = &device->port; + unsigned int status; + int num_read = 0; + + while (num_read < count) { + status = serial8250_early_in(port, UART_LSR); + if (!(status & UART_LSR_DR)) + break; + s[num_read++] = serial8250_early_in(port, UART_RX); + } + + return num_read; +} +#else +#define early_serial8250_read NULL +#endif + static void __init init_port(struct earlycon_device *device) { struct uart_port *port = &device->port; @@ -149,6 +171,7 @@ int __init early_serial8250_setup(struct earlycon_device *device, init_port(device); device->con->write = early_serial8250_write; + device->con->read = early_serial8250_read; return 0; } EARLYCON_DECLARE(uart8250, early_serial8250_setup); |