From: Rodolfo Giometti <giometti@xxxxxxxx>
This patch adds multidrop support for atmel serial controllers and it
has been tested by using a SAMA5D3 CPU.
Signed-off-by: Rodolfo Giometti <giometti@xxxxxxxx>
Signed-off-by: Joshua Henderson <joshua.henderson@xxxxxxxxxxxxx>
---
drivers/tty/serial/atmel_serial.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 0b4f36905321..b30b4a336907 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2178,7 +2178,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
unsigned long flags;
- unsigned int old_mode, mode, imr, quot, baud, div, cd, fp = 0;
+ unsigned int old_mode, mode, mdrop, imr, quot, baud, div, cd, fp = 0;
/* save the current mode register */
mode = old_mode = atmel_uart_readl(port, ATMEL_US_MR);
@@ -2211,9 +2211,11 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
/* parity */
if (termios->c_cflag & PARENB) {
- /* Mark or Space parity */
+ /* Mark, Space or Multidrop parity */
if (termios->c_cflag & CMSPAR) {
- if (termios->c_cflag & PARODD)
+ if (termios->c_cflag & PARMD)
+ mode |= ATMEL_US_PAR_MULTI_DROP;
+ else if (termios->c_cflag & PARODD)
mode |= ATMEL_US_PAR_MARK;
else
mode |= ATMEL_US_PAR_SPACE;
@@ -2221,8 +2223,11 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
mode |= ATMEL_US_PAR_ODD;
else
mode |= ATMEL_US_PAR_EVEN;
+
} else
mode |= ATMEL_US_PAR_NONE;
+ mdrop = termios->c_cflag & SENDA ? ATMEL_US_SENDA : 0;
+ termios->c_cflag &= ~SENDA; /* SENDA bit must be cleared once used */
spin_lock_irqsave(&port->lock, flags);
@@ -2363,7 +2368,8 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
if (!(port->iso7816.flags & SER_ISO7816_ENABLED))
atmel_uart_writel(port, ATMEL_US_BRGR, quot);
atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
- atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
+ atmel_uart_writel(port, ATMEL_US_CR,
+ mdrop | ATMEL_US_TXEN | ATMEL_US_RXEN);
atmel_port->tx_stopped = false;
/* restore interrupts */
--
2.17.1
