The following drivers: 8250_core, atmel_serial, max310x, mcf, omap-serial
and sci16is7xx implement code to handle RS485 ioctls.
In order to avoid code duplication, we implement a simple ioctl handler
on the serial_core layer.
This handler can be used by all the other drivers instead of duplicating
code.
Until this is the only RS485 ioctl handler, it will try first the
rs485_config callback and if it is not present it will call the driver
specific ioctl.
Reviewed-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
---
v3: Fix invalid length on copy_from_user
drivers/tty/serial/serial_core.c | 45 ++++++++++++++++++++++++++++++++++++++++
include/linux/serial_core.h | 3 +++
2 files changed, 48 insertions(+)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 1a2d90f..6f6f8dd 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1152,6 +1152,39 @@ static int uart_get_icount(struct tty_struct *tty,
return 0;
}
+static int uart_get_rs485_config(struct uart_port *port,
+ struct serial_rs485 __user *rs485)
+{
+ if (!port->rs485_config)
+ return -ENOIOCTLCMD;
+
+ if (copy_to_user(rs485, &port->rs485, sizeof(port->rs485)))
+ return -EFAULT;
+ return 0;
+}
+
+static int uart_set_rs485_config(struct uart_port *port,
+ struct serial_rs485 __user *rs485_user)
+{
+ struct serial_rs485 rs485;
+ int ret;
+
+ if (!port->rs485_config)
+ return -ENOIOCTLCMD;
+
+ if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
+ return -EFAULT;
+
+ ret = port->rs485_config(port, &rs485);
+ if (ret)
+ return ret;
+
+ if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
+ return -EFAULT;
+
+ return 0;
+}
+
/*
* Called via sys_ioctl. We can use spin_lock_irq() here.
*/
@@ -1223,6 +1256,18 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd,
* protected against the tty being hung up.
*/
switch (cmd) {
+ case TIOCGRS485:
+ ret = uart_get_rs485_config(state->uart_port, uarg);
+ break;
+
+ case TIOCSRS485:
+ ret = uart_set_rs485_config(state->uart_port, uarg);
+ break;
+ }
+ if (ret != -ENOIOCTLCMD)
+ goto out;
+
+ switch (cmd) {
case TIOCSERGETLSR: /* Get line status register */
ret = uart_get_lsr_info(tty, state, uarg);
break;
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index ad93296..95d3c92 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -131,6 +131,8 @@ struct uart_port {
void (*pm)(struct uart_port *, unsigned int state,
unsigned int old);
void (*handle_break)(struct uart_port *);
+ int (*rs485_config)(struct uart_port *,
+ struct serial_rs485 *rs485);
unsigned int irq; /* irq number */
unsigned long irqflags; /* irq flags */
unsigned int uartclk; /* base uart clock */
@@ -231,6 +233,7 @@ struct uart_port {
unsigned char unused[2];
struct attribute_group *attr_group; /* port specific attributes */
const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
+ struct serial_rs485 rs485;
void *private_data; /* generic platform data pointer */
};
--
2.1.1
--
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