tty/serial_core: add ISO7816 infrastructure

Add the ISO7816 ioctl and associated accessors and data structure.
Drivers can then use this common implementation to handle ISO7816
(smart cards).

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[ludovic.desroches@microchip.com: squash and rebase, removal of gpios, checkpatch fixes]
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 60 insertions, 0 deletions

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index ed0133395cc7..0a4e6eeb5ff3 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1308,6 +1308,58 @@ static int uart_set_rs485_config(struct uart_port *port,
 	return 0;
 }
 
+static int uart_get_iso7816_config(struct uart_port *port,
+				   struct serial_iso7816 __user *iso7816)
+{
+	unsigned long flags;
+	struct serial_iso7816 aux;
+
+	if (!port->iso7816_config)
+		return -ENOIOCTLCMD;
+
+	spin_lock_irqsave(&port->lock, flags);
+	aux = port->iso7816;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (copy_to_user(iso7816, &aux, sizeof(aux)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int uart_set_iso7816_config(struct uart_port *port,
+				   struct serial_iso7816 __user *iso7816_user)
+{
+	struct serial_iso7816 iso7816;
+	int i, ret;
+	unsigned long flags;
+
+	if (!port->iso7816_config)
+		return -ENOIOCTLCMD;
+
+	if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
+		return -EFAULT;
+
+	/*
+	 * There are 5 words reserved for future use. Check that userspace
+	 * doesn't put stuff in there to prevent breakages in the future.
+	 */
+	for (i = 0; i < 5; i++)
+		if (iso7816.reserved[i])
+			return -EINVAL;
+
+	spin_lock_irqsave(&port->lock, flags);
+	ret = port->iso7816_config(port, &iso7816);
+	spin_unlock_irqrestore(&port->lock, flags);
+	if (ret)
+		return ret;
+
+	if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
+		return -EFAULT;
+
+	return 0;
+}
+
 /*
  * Called via sys_ioctl.  We can use spin_lock_irq() here.
  */
@@ -1392,6 +1444,14 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
 	case TIOCSRS485:
 		ret = uart_set_rs485_config(uport, uarg);
 		break;
+
+	case TIOCSISO7816:
+		ret = uart_set_iso7816_config(state->uart_port, uarg);
+		break;
+
+	case TIOCGISO7816:
+		ret = uart_get_iso7816_config(state->uart_port, uarg);
+		break;
 	default:
 		if (uport->ops->ioctl)
 			ret = uport->ops->ioctl(uport, cmd, arg);