* [PATCH V3] serial: Add ioctl to enable auto rs485 mode with some Exar UARTs
@ 2009-01-15 19:23 Matthias Fuchs
2009-01-16 9:54 ` Laurent Pinchart
0 siblings, 1 reply; 2+ messages in thread
From: Matthias Fuchs @ 2009-01-15 19:23 UTC (permalink / raw)
To: linux-serial; +Cc: Laurent Pinchart
Some Exar UARTs support an auto rs485 mode. In this mode
the UART's RTS# pin is activated during transmitting and
can be used to enable a rs485 line driver. This has nothing
to do with attempts to do this by manually asserting/
deasserting handshake lines in software.
Signed-off-by: Matthias Fuchs <mfuchs@ma-fu.de>
---
drivers/serial/8250.c | 70 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/serial_reg.h | 1 +
2 files changed, 71 insertions(+), 0 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 0d934bf..9c986bd 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2580,6 +2580,75 @@ serial8250_type(struct uart_port *port)
return uart_config[type].name;
}
+static int
+serial8250_ioctl_port(struct uart_port *port,
+ unsigned int cmd, unsigned long arg)
+{
+ struct uart_8250_port *up = (struct uart_8250_port *)port;
+ unsigned long flags;
+
+ switch (cmd) {
+ case TIOCSRS485:
+ {
+ struct serial_rs485 rs485ctrl;
+ unsigned char fctr, lcr;
+
+ if (port->type != PORT_16850)
+ return -ENOTTY;
+
+ if (copy_from_user(&rs485ctrl,
+ (struct serial_rs485 *)arg,
+ sizeof(rs485ctrl)))
+ return -EFAULT;
+
+ spin_lock_irqsave(&up->port.lock, flags);
+ lcr = serial_inp(up, UART_LCR);
+ serial_outp(up, UART_LCR, 0xbf);
+ fctr = serial_inp(up, UART_FCTR);
+ if (rs485ctrl.flags & SER_RS485_ENABLED)
+ fctr |= UART_FCTR_RS485;
+ else
+ fctr &= ~UART_FCTR_RS485;
+ serial_outp(up, UART_FCTR, fctr);
+ serial_outp(up, UART_LCR, lcr);
+ spin_unlock_irqrestore(&up->port.lock, flags);
+ return 0;
+ }
+
+ case TIOCGRS485:
+ {
+ struct serial_rs485 rs485ctrl;
+ unsigned char lcr;
+
+ if (port->type != PORT_16850)
+ return -ENOTTY;
+
+ memset(&rs485ctrl, 0, sizeof(rs485ctrl));
+
+ spin_lock_irqsave(&up->port.lock, flags);
+ lcr = serial_inp(up, UART_LCR);
+ serial_outp(up, UART_LCR, 0xbf);
+ if (serial_inp(up, UART_FCTR) & UART_FCTR_RS485)
+ rs485ctrl.flags = SER_RS485_ENABLED;
+ else
+ rs485ctrl.flags = 0;
+ serial_outp(up, UART_LCR, lcr);
+ spin_unlock_irqrestore(&up->port.lock, flags);
+
+ if (copy_to_user((struct serial_rs485 *)arg,
+ &rs485ctrl,
+ sizeof(rs485ctrl)))
+ return -EFAULT;
+ return 0;
+ }
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ return 0;
+}
+
static struct uart_ops serial8250_pops = {
.tx_empty = serial8250_tx_empty,
.set_mctrl = serial8250_set_mctrl,
@@ -2598,6 +2667,7 @@ static struct uart_ops serial8250_pops = {
.request_port = serial8250_request_port,
.config_port = serial8250_config_port,
.verify_port = serial8250_verify_port,
+ .ioctl = serial8250_ioctl_port,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = serial8250_get_poll_char,
.poll_put_char = serial8250_put_poll_char,
diff --git a/include/linux/serial_reg.h b/include/linux/serial_reg.h
index 96c0d93..086c3e2 100644
--- a/include/linux/serial_reg.h
+++ b/include/linux/serial_reg.h
@@ -191,6 +191,7 @@
#define UART_FCTR_RTS_8DELAY 0x03
#define UART_FCTR_IRDA 0x04 /* IrDa data encode select */
#define UART_FCTR_TX_INT 0x08 /* Tx interrupt type select */
+#define UART_FCTR_RS485 0x08 /* Auto RS485 mode */
#define UART_FCTR_TRGA 0x00 /* Tx/Rx 550 trigger table select */
#define UART_FCTR_TRGB 0x10 /* Tx/Rx 650 trigger table select */
#define UART_FCTR_TRGC 0x20 /* Tx/Rx 654 trigger table select */
--
1.5.6.3
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V3] serial: Add ioctl to enable auto rs485 mode with some Exar UARTs
2009-01-15 19:23 [PATCH V3] serial: Add ioctl to enable auto rs485 mode with some Exar UARTs Matthias Fuchs
@ 2009-01-16 9:54 ` Laurent Pinchart
0 siblings, 0 replies; 2+ messages in thread
From: Laurent Pinchart @ 2009-01-16 9:54 UTC (permalink / raw)
To: Matthias Fuchs; +Cc: linux-serial
On Thursday 15 January 2009 20:23:15 Matthias Fuchs wrote:
> Some Exar UARTs support an auto rs485 mode. In this mode
> the UART's RTS# pin is activated during transmitting and
> can be used to enable a rs485 line driver. This has nothing
> to do with attempts to do this by manually asserting/
> deasserting handshake lines in software.
>
> Signed-off-by: Matthias Fuchs <mfuchs@ma-fu.de>
Acked-by: Laurent Pinchart <laurentp@cse-semaphore.com>
> ---
> drivers/serial/8250.c | 70
> ++++++++++++++++++++++++++++++++++++++++++++ include/linux/serial_reg.h |
> 1 +
> 2 files changed, 71 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
> index 0d934bf..9c986bd 100644
> --- a/drivers/serial/8250.c
> +++ b/drivers/serial/8250.c
> @@ -2580,6 +2580,75 @@ serial8250_type(struct uart_port *port)
> return uart_config[type].name;
> }
>
> +static int
> +serial8250_ioctl_port(struct uart_port *port,
> + unsigned int cmd, unsigned long arg)
> +{
> + struct uart_8250_port *up = (struct uart_8250_port *)port;
> + unsigned long flags;
> +
> + switch (cmd) {
> + case TIOCSRS485:
> + {
> + struct serial_rs485 rs485ctrl;
> + unsigned char fctr, lcr;
> +
> + if (port->type != PORT_16850)
> + return -ENOTTY;
> +
> + if (copy_from_user(&rs485ctrl,
> + (struct serial_rs485 *)arg,
> + sizeof(rs485ctrl)))
> + return -EFAULT;
> +
> + spin_lock_irqsave(&up->port.lock, flags);
> + lcr = serial_inp(up, UART_LCR);
> + serial_outp(up, UART_LCR, 0xbf);
> + fctr = serial_inp(up, UART_FCTR);
> + if (rs485ctrl.flags & SER_RS485_ENABLED)
> + fctr |= UART_FCTR_RS485;
> + else
> + fctr &= ~UART_FCTR_RS485;
> + serial_outp(up, UART_FCTR, fctr);
> + serial_outp(up, UART_LCR, lcr);
> + spin_unlock_irqrestore(&up->port.lock, flags);
> + return 0;
> + }
> +
> + case TIOCGRS485:
> + {
> + struct serial_rs485 rs485ctrl;
> + unsigned char lcr;
> +
> + if (port->type != PORT_16850)
> + return -ENOTTY;
> +
> + memset(&rs485ctrl, 0, sizeof(rs485ctrl));
> +
> + spin_lock_irqsave(&up->port.lock, flags);
> + lcr = serial_inp(up, UART_LCR);
> + serial_outp(up, UART_LCR, 0xbf);
> + if (serial_inp(up, UART_FCTR) & UART_FCTR_RS485)
> + rs485ctrl.flags = SER_RS485_ENABLED;
> + else
> + rs485ctrl.flags = 0;
> + serial_outp(up, UART_LCR, lcr);
> + spin_unlock_irqrestore(&up->port.lock, flags);
> +
> + if (copy_to_user((struct serial_rs485 *)arg,
> + &rs485ctrl,
> + sizeof(rs485ctrl)))
> + return -EFAULT;
> + return 0;
> + }
> +
> + default:
> + return -ENOIOCTLCMD;
> + }
> +
> + return 0;
> +}
> +
> static struct uart_ops serial8250_pops = {
> .tx_empty = serial8250_tx_empty,
> .set_mctrl = serial8250_set_mctrl,
> @@ -2598,6 +2667,7 @@ static struct uart_ops serial8250_pops = {
> .request_port = serial8250_request_port,
> .config_port = serial8250_config_port,
> .verify_port = serial8250_verify_port,
> + .ioctl = serial8250_ioctl_port,
> #ifdef CONFIG_CONSOLE_POLL
> .poll_get_char = serial8250_get_poll_char,
> .poll_put_char = serial8250_put_poll_char,
> diff --git a/include/linux/serial_reg.h b/include/linux/serial_reg.h
> index 96c0d93..086c3e2 100644
> --- a/include/linux/serial_reg.h
> +++ b/include/linux/serial_reg.h
> @@ -191,6 +191,7 @@
> #define UART_FCTR_RTS_8DELAY 0x03
> #define UART_FCTR_IRDA 0x04 /* IrDa data encode select */
> #define UART_FCTR_TX_INT 0x08 /* Tx interrupt type select */
> +#define UART_FCTR_RS485 0x08 /* Auto RS485 mode */
> #define UART_FCTR_TRGA 0x00 /* Tx/Rx 550 trigger table select */
> #define UART_FCTR_TRGB 0x10 /* Tx/Rx 650 trigger table select */
> #define UART_FCTR_TRGC 0x20 /* Tx/Rx 654 trigger table select */
--
Laurent Pinchart
CSE Semaphore Belgium
Chaussee de Bruxelles, 732A
B-1410 Waterloo
Belgium
T +32 (2) 387 42 59
F +32 (2) 387 42 75
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