summaryrefslogtreecommitdiff
path: root/drivers/serial/bfin_5xx.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/serial/bfin_5xx.c')
-rw-r--r--drivers/serial/bfin_5xx.c77
1 files changed, 67 insertions, 10 deletions
diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index d86123e03391..e2f6b1bfac98 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -330,6 +330,11 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
/* Clear TFI bit */
UART_PUT_LSR(uart, TFI);
#endif
+ /* Anomaly notes:
+ * 05000215 - we always clear ETBEI within last UART TX
+ * interrupt to end a string. It is always set
+ * when start a new tx.
+ */
UART_CLEAR_IER(uart, ETBEI);
return;
}
@@ -415,6 +420,7 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
set_dma_x_modify(uart->tx_dma_channel, 1);
+ SSYNC();
enable_dma(uart->tx_dma_channel);
UART_SET_IER(uart, ETBEI);
@@ -473,27 +479,41 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
{
int x_pos, pos;
- unsigned long flags;
-
- spin_lock_irqsave(&uart->port.lock, flags);
+ dma_disable_irq(uart->rx_dma_channel);
+ spin_lock_bh(&uart->port.lock);
+
+ /* 2D DMA RX buffer ring is used. Because curr_y_count and
+ * curr_x_count can't be read as an atomic operation,
+ * curr_y_count should be read before curr_x_count. When
+ * curr_x_count is read, curr_y_count may already indicate
+ * next buffer line. But, the position calculated here is
+ * still indicate the old line. The wrong position data may
+ * be smaller than current buffer tail, which cause garbages
+ * are received if it is not prohibit.
+ */
uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
- if (uart->rx_dma_nrows == DMA_RX_YCOUNT)
+ if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0)
uart->rx_dma_nrows = 0;
x_pos = DMA_RX_XCOUNT - x_pos;
if (x_pos == DMA_RX_XCOUNT)
x_pos = 0;
pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
- if (pos != uart->rx_dma_buf.tail) {
+ /* Ignore receiving data if new position is in the same line of
+ * current buffer tail and small.
+ */
+ if (pos > uart->rx_dma_buf.tail ||
+ uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
uart->rx_dma_buf.head = pos;
bfin_serial_dma_rx_chars(uart);
uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
}
- spin_unlock_irqrestore(&uart->port.lock, flags);
+ spin_unlock_bh(&uart->port.lock);
+ dma_enable_irq(uart->rx_dma_channel);
mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES);
}
@@ -514,6 +534,11 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
disable_dma(uart->tx_dma_channel);
clear_dma_irqstat(uart->tx_dma_channel);
+ /* Anomaly notes:
+ * 05000215 - we always clear ETBEI within last UART TX
+ * interrupt to end a string. It is always set
+ * when start a new tx.
+ */
UART_CLEAR_IER(uart, ETBEI);
xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
uart->port.icount.tx += uart->tx_count;
@@ -532,11 +557,26 @@ static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
unsigned short irqstat;
+ int x_pos, pos;
spin_lock(&uart->port.lock);
irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
clear_dma_irqstat(uart->rx_dma_channel);
- bfin_serial_dma_rx_chars(uart);
+
+ uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
+ x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
+ uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
+ if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0)
+ uart->rx_dma_nrows = 0;
+
+ pos = uart->rx_dma_nrows * DMA_RX_XCOUNT;
+ if (pos > uart->rx_dma_buf.tail ||
+ uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
+ uart->rx_dma_buf.head = pos;
+ bfin_serial_dma_rx_chars(uart);
+ uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
+ }
+
spin_unlock(&uart->port.lock);
return IRQ_HANDLED;
@@ -789,8 +829,16 @@ bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
__func__);
}
- if (termios->c_cflag & CSTOPB)
- lcr |= STB;
+ /* Anomaly notes:
+ * 05000231 - STOP bit is always set to 1 whatever the user is set.
+ */
+ if (termios->c_cflag & CSTOPB) {
+ if (ANOMALY_05000231)
+ printk(KERN_WARNING "STOP bits other than 1 is not "
+ "supported in case of anomaly 05000231.\n");
+ else
+ lcr |= STB;
+ }
if (termios->c_cflag & PARENB)
lcr |= PEN;
if (!(termios->c_cflag & PARODD))
@@ -940,6 +988,10 @@ static void bfin_serial_reset_irda(struct uart_port *port)
}
#ifdef CONFIG_CONSOLE_POLL
+/* Anomaly notes:
+ * 05000099 - Because we only use THRE in poll_put and DR in poll_get,
+ * losing other bits of UART_LSR is not a problem here.
+ */
static void bfin_serial_poll_put_char(struct uart_port *port, unsigned char chr)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
@@ -1245,12 +1297,17 @@ static __init void early_serial_write(struct console *con, const char *s,
}
}
+/*
+ * This should have a .setup or .early_setup in it, but then things get called
+ * without the command line options, and the baud rate gets messed up - so
+ * don't let the common infrastructure play with things. (see calls to setup
+ * & earlysetup in ./kernel/printk.c:register_console()
+ */
static struct __initdata console bfin_early_serial_console = {
.name = "early_BFuart",
.write = early_serial_write,
.device = uart_console_device,
.flags = CON_PRINTBUFFER,
- .setup = bfin_serial_console_setup,
.index = -1,
.data = &bfin_serial_reg,
};