diff options
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 157 |
1 files changed, 66 insertions, 91 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index cb45136f686..faa16ee6b02 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -144,6 +144,62 @@ struct uart_amba_port { }; /* + * Reads up to 256 characters from the FIFO or until it's empty and + * inserts them into the TTY layer. Returns the number of characters + * read from the FIFO. + */ +static int pl011_fifo_to_tty(struct uart_amba_port *uap) +{ + u16 status, ch; + unsigned int flag, max_count = 256; + int fifotaken = 0; + + while (max_count--) { + status = readw(uap->port.membase + UART01x_FR); + if (status & UART01x_FR_RXFE) + break; + + /* Take chars from the FIFO and update status */ + ch = readw(uap->port.membase + UART01x_DR) | + UART_DUMMY_DR_RX; + flag = TTY_NORMAL; + uap->port.icount.rx++; + fifotaken++; + + if (unlikely(ch & UART_DR_ERROR)) { + if (ch & UART011_DR_BE) { + ch &= ~(UART011_DR_FE | UART011_DR_PE); + uap->port.icount.brk++; + if (uart_handle_break(&uap->port)) + continue; + } else if (ch & UART011_DR_PE) + uap->port.icount.parity++; + else if (ch & UART011_DR_FE) + uap->port.icount.frame++; + if (ch & UART011_DR_OE) + uap->port.icount.overrun++; + + ch &= uap->port.read_status_mask; + + if (ch & UART011_DR_BE) + flag = TTY_BREAK; + else if (ch & UART011_DR_PE) + flag = TTY_PARITY; + else if (ch & UART011_DR_FE) + flag = TTY_FRAME; + } + + if (uart_handle_sysrq_char(&uap->port, ch & 255)) + continue; + + uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); + } + + return fifotaken; +} + + +/* * All the DMA operation mode stuff goes inside this ifdef. * This assumes that you have a generic DMA device interface, * no custom DMA interfaces are supported. @@ -634,7 +690,6 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap, struct pl011_sgbuf *sgbuf = use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; struct device *dev = uap->dmarx.chan->device->dev; - unsigned int status, ch, flag; int dma_count = 0; u32 fifotaken = 0; /* only used for vdbg() */ @@ -671,56 +726,16 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap, /* * If we read all the DMA'd characters, and we had an - * incomplete buffer, that could be due to an rx error, - * or maybe we just timed out. Read any pending chars - * and check the error status. + * incomplete buffer, that could be due to an rx error, or + * maybe we just timed out. Read any pending chars and check + * the error status. + * + * Error conditions will only occur in the FIFO, these will + * trigger an immediate interrupt and stop the DMA job, so we + * will always find the error in the FIFO, never in the DMA + * buffer. */ - while (1) { - status = readw(uap->port.membase + UART01x_FR); - if (status & UART01x_FR_RXFE) - break; - - /* Take chars from the FIFO and update status */ - ch = readw(uap->port.membase + UART01x_DR) | - UART_DUMMY_DR_RX; - flag = TTY_NORMAL; - uap->port.icount.rx++; - fifotaken++; - - /* - * Error conditions will only occur in the FIFO, - * these will trigger an immediate interrupt and - * stop the DMA job, so we will always find the - * error in the FIFO, never in the DMA buffer. - */ - if (unlikely(ch & UART_DR_ERROR)) { - if (ch & UART011_DR_BE) { - ch &= ~(UART011_DR_FE | UART011_DR_PE); - uap->port.icount.brk++; - if (uart_handle_break(&uap->port)) - continue; - } else if (ch & UART011_DR_PE) - uap->port.icount.parity++; - else if (ch & UART011_DR_FE) - uap->port.icount.frame++; - if (ch & UART011_DR_OE) - uap->port.icount.overrun++; - - ch &= uap->port.read_status_mask; - - if (ch & UART011_DR_BE) - flag = TTY_BREAK; - else if (ch & UART011_DR_PE) - flag = TTY_PARITY; - else if (ch & UART011_DR_FE) - flag = TTY_FRAME; - } - - if (uart_handle_sysrq_char(&uap->port, ch & 255)) - continue; - - uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); - } + fifotaken = pl011_fifo_to_tty(uap); } spin_unlock(&uap->port.lock); @@ -1036,49 +1051,9 @@ static void pl011_enable_ms(struct uart_port *port) static void pl011_rx_chars(struct uart_amba_port *uap) { struct tty_struct *tty = uap->port.state->port.tty; - unsigned int status, ch, flag, max_count = 256; - status = readw(uap->port.membase + UART01x_FR); - while ((status & UART01x_FR_RXFE) == 0 && max_count--) { - ch = readw(uap->port.membase + UART01x_DR) | UART_DUMMY_DR_RX; - flag = TTY_NORMAL; - uap->port.icount.rx++; + pl011_fifo_to_tty(uap); - /* - * Note that the error handling code is - * out of the main execution path - */ - if (unlikely(ch & UART_DR_ERROR)) { - if (ch & UART011_DR_BE) { - ch &= ~(UART011_DR_FE | UART011_DR_PE); - uap->port.icount.brk++; - if (uart_handle_break(&uap->port)) - goto ignore_char; - } else if (ch & UART011_DR_PE) - uap->port.icount.parity++; - else if (ch & UART011_DR_FE) - uap->port.icount.frame++; - if (ch & UART011_DR_OE) - uap->port.icount.overrun++; - - ch &= uap->port.read_status_mask; - - if (ch & UART011_DR_BE) - flag = TTY_BREAK; - else if (ch & UART011_DR_PE) - flag = TTY_PARITY; - else if (ch & UART011_DR_FE) - flag = TTY_FRAME; - } - - if (uart_handle_sysrq_char(&uap->port, ch & 255)) - goto ignore_char; - - uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); - - ignore_char: - status = readw(uap->port.membase + UART01x_FR); - } spin_unlock(&uap->port.lock); tty_flip_buffer_push(tty); /* |