aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--drivers/tty/serial/amba-pl011.c157
1 files changed, 66 insertions, 91 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index cb45136..faa16ee 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);
/*