diff options
Diffstat (limited to 'drivers/serial/ns16550.c')
| -rw-r--r-- | drivers/serial/ns16550.c | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index ed3428d7d8..71c523dfeb 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -6,6 +6,7 @@ #include <common.h> #include <config.h> +#include <common.h> #include <ns16550.h> #include <watchdog.h> #include <linux/types.h> @@ -31,6 +32,16 @@ DECLARE_GLOBAL_DATA_PTR; #define CONFIG_SYS_NS16550_IER 0x00 #endif /* CONFIG_SYS_NS16550_IER */ +/* + * Signal that we are about to use the UART. This unfortunate hack is + * required by Seaboard, which cannot use its console and SPI at the same + * time. If the board file provides this, the board config will declare it. + * Let this be a lesson for others. + */ +#ifndef CONFIG_SPI_CORRUPTS_UART +inline void uart_enable(void) {} +#endif + void NS16550_init (NS16550_t com_port, int baud_divisor) { serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier); @@ -71,10 +82,12 @@ void NS16550_reinit (NS16550_t com_port, int baud_divisor) serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm); serial_out(UART_LCRVAL, &com_port->lcr); } + #endif /* CONFIG_NS16550_MIN_FUNCTIONS */ void NS16550_putc (NS16550_t com_port, char c) { + uart_enable(); while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0); serial_out(c, &com_port->thr); @@ -92,6 +105,7 @@ void NS16550_putc (NS16550_t com_port, char c) static char NS16550_raw_getc(NS16550_t regs) { + uart_enable(); while ((serial_in(®s->lsr) & UART_LSR_DR) == 0) { #ifdef CONFIG_USB_TTY extern void usbtty_poll(void); @@ -107,7 +121,6 @@ static int NS16550_raw_tstc(NS16550_t regs) return ((serial_in(®s->lsr) & UART_LSR_DR) != 0); } - #ifdef CONFIG_NS16550_BUFFER_READS #define BUF_SIZE 256 @@ -185,8 +198,37 @@ char NS16550_getc(NS16550_t regs, unsigned int port) int NS16550_tstc(NS16550_t regs, unsigned int port) { + uart_enable(); return NS16550_raw_tstc(regs); } #endif /* CONFIG_NS16550_BUFFER_READS */ + +/* Clear the UART's RX FIFO */ + +void NS16550_clear(NS16550_t regs, unsigned port) +{ + /* Reset RX fifo */ + serial_out(UART_FCR_FIFO_EN | UART_FCR_RXSR, ®s->fcr); + + /* Remove any pending characters */ + while (NS16550_raw_tstc(regs)) + NS16550_raw_getc(regs); +} + +/* Wait for the UART's output buffer and holding register to drain */ + +void NS16550_drain(NS16550_t regs, unsigned port) +{ + u32 mask = UART_LSR_TEMT | UART_LSR_THRE; + + /* Wait for the UART to finish sending */ + while ((serial_in(®s->lsr) & mask) != mask) + udelay(100); +#ifdef CONFIG_NS16550_BUFFER_READS + /* Quickly grab any incoming data while we can */ + fill_rx_buf(regs, port); +#endif +} + #endif /* CONFIG_NS16550_MIN_FUNCTIONS */ |