diff options
Diffstat (limited to 'drivers/tty/serial/amba-pl011.c')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 9ae024025ff3..6800f5f26241 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -159,6 +159,7 @@ struct uart_amba_port { unsigned int fifosize; /* vendor-specific */ unsigned int lcrh_tx; /* vendor-specific */ unsigned int lcrh_rx; /* vendor-specific */ + unsigned int old_cr; /* state during shutdown */ bool autorts; char type[12]; bool interrupt_may_hang; /* vendor-specific */ @@ -1411,7 +1412,9 @@ static int pl011_startup(struct uart_port *port) while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY) barrier(); - cr = UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE; + /* restore RTS and DTR */ + cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR); + cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE; writew(cr, uap->port.membase + UART011_CR); /* Clear pending error interrupts */ @@ -1469,6 +1472,7 @@ static void pl011_shutdown_channel(struct uart_amba_port *uap, static void pl011_shutdown(struct uart_port *port) { struct uart_amba_port *uap = (struct uart_amba_port *)port; + unsigned int cr; /* * disable all interrupts @@ -1488,9 +1492,16 @@ static void pl011_shutdown(struct uart_port *port) /* * disable the port + * disable the port. It should not disable RTS and DTR. + * Also RTS and DTR state should be preserved to restore + * it during startup(). */ uap->autorts = false; - writew(UART01x_CR_UARTEN | UART011_CR_TXE, uap->port.membase + UART011_CR); + cr = readw(uap->port.membase + UART011_CR); + uap->old_cr = cr; + cr &= UART011_CR_RTS | UART011_CR_DTR; + cr |= UART01x_CR_UARTEN | UART011_CR_TXE; + writew(cr, uap->port.membase + UART011_CR); /* * disable break condition and fifos @@ -1740,9 +1751,19 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) { struct uart_amba_port *uap = amba_ports[co->index]; unsigned int status, old_cr, new_cr; + unsigned long flags; + int locked = 1; clk_enable(uap->clk); + local_irq_save(flags); + if (uap->port.sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock(&uap->port.lock); + else + spin_lock(&uap->port.lock); + /* * First save the CR then disable the interrupts */ @@ -1762,6 +1783,10 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) } while (status & UART01x_FR_BUSY); writew(old_cr, uap->port.membase + UART011_CR); + if (locked) + spin_unlock(&uap->port.lock); + local_irq_restore(flags); + clk_disable(uap->clk); } @@ -1905,6 +1930,7 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id) uap->vendor = vendor; uap->lcrh_rx = vendor->lcrh_rx; uap->lcrh_tx = vendor->lcrh_tx; + uap->old_cr = 0; uap->fifosize = vendor->fifosize; uap->interrupt_may_hang = vendor->interrupt_may_hang; uap->port.dev = &dev->dev; |