mxser: extract mxser_ioctl_op_mode

This ioctl code sets RS232, RS422 or RS485 mode. Move the code to a
separate function (mxser_ioctl_op_mode) with a note that these
mxser-special ioctls should be likely replaced eventually by TIOCGRS485
and TIOCSRS485.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-39-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 2a8bbce..4a584db 100644 (file)
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1407,6 +1407,48 @@ static int mxser_cflags_changed(struct mxser_port *info, unsigned long arg,
        return ret;
 }
 
+/* We should likely switch to TIOCGRS485/TIOCSRS485. */
+static int mxser_ioctl_op_mode(struct mxser_port *port, int index, bool set,
+               int __user *u_opmode)
+{
+       static const unsigned char ModeMask[] = { 0xfc, 0xf3, 0xcf, 0x3f };
+       int opmode, p = index % 4;
+       int shiftbit = p * 2;
+       unsigned char val, mask;
+
+       if (port->board->must_hwid != MOXA_MUST_MU860_HWID)
+               return -EFAULT;
+
+       if (set) {
+               if (get_user(opmode, u_opmode))
+                       return -EFAULT;
+
+               if (opmode != RS232_MODE && opmode != RS485_2WIRE_MODE &&
+                               opmode != RS422_MODE &&
+                               opmode != RS485_4WIRE_MODE)
+                       return -EFAULT;
+
+               mask = ModeMask[p];
+
+               spin_lock_irq(&port->slock);
+               val = inb(port->opmode_ioaddr);
+               val &= mask;
+               val |= (opmode << shiftbit);
+               outb(val, port->opmode_ioaddr);
+               spin_unlock_irq(&port->slock);
+       } else {
+               spin_lock_irq(&port->slock);
+               opmode = inb(port->opmode_ioaddr) >> shiftbit;
+               spin_unlock_irq(&port->slock);
+
+               opmode &= OP_MODE_MASK;
+               if (put_user(opmode, u_opmode))
+                       return -EFAULT;
+       }
+
+       return 0;
+}
+
 static int mxser_ioctl(struct tty_struct *tty,
                unsigned int cmd, unsigned long arg)
 {
@@ -1415,44 +1457,9 @@ static int mxser_ioctl(struct tty_struct *tty,
        unsigned long flags;
        void __user *argp = (void __user *)arg;
 
-       if (cmd == MOXA_SET_OP_MODE || cmd == MOXA_GET_OP_MODE) {
-               int p;
-               unsigned long opmode;
-               static unsigned char ModeMask[] = { 0xfc, 0xf3, 0xcf, 0x3f };
-               int shiftbit;
-               unsigned char val, mask;
-
-               if (info->board->must_hwid != MOXA_MUST_MU860_HWID)
-                       return -EFAULT;
-
-               p = tty->index % 4;
-               if (cmd == MOXA_SET_OP_MODE) {
-                       if (get_user(opmode, (int __user *) argp))
-                               return -EFAULT;
-                       if (opmode != RS232_MODE &&
-                                       opmode != RS485_2WIRE_MODE &&
-                                       opmode != RS422_MODE &&
-                                       opmode != RS485_4WIRE_MODE)
-                               return -EFAULT;
-                       mask = ModeMask[p];
-                       shiftbit = p * 2;
-                       spin_lock_irq(&info->slock);
-                       val = inb(info->opmode_ioaddr);
-                       val &= mask;
-                       val |= (opmode << shiftbit);
-                       outb(val, info->opmode_ioaddr);
-                       spin_unlock_irq(&info->slock);
-               } else {
-                       shiftbit = p * 2;
-                       spin_lock_irq(&info->slock);
-                       opmode = inb(info->opmode_ioaddr) >> shiftbit;
-                       spin_unlock_irq(&info->slock);
-                       opmode &= OP_MODE_MASK;
-                       if (put_user(opmode, (int __user *)argp))
-                               return -EFAULT;
-               }
-               return 0;
-       }
+       if (cmd == MOXA_SET_OP_MODE || cmd == MOXA_GET_OP_MODE)
+               return mxser_ioctl_op_mode(info, tty->index,
+                               cmd == MOXA_SET_OP_MODE, argp);
 
        if (cmd != TIOCMIWAIT && tty_io_error(tty))
                return -EIO;