synclink_gt: add compat_ioctl

Add support for 32 bit ioctl on 64 bit systems for synclink_gt

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 2a7736b..02b49bc 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -1171,6 +1171,112 @@
 }
 
 /*
+ * support for 32 bit ioctl calls on 64 bit systems
+ */
+#ifdef CONFIG_COMPAT
+static long get_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *user_params)
+{
+	struct MGSL_PARAMS32 tmp_params;
+
+	DBGINFO(("%s get_params32\n", info->device_name));
+	tmp_params.mode            = (compat_ulong_t)info->params.mode;
+	tmp_params.loopback        = info->params.loopback;
+	tmp_params.flags           = info->params.flags;
+	tmp_params.encoding        = info->params.encoding;
+	tmp_params.clock_speed     = (compat_ulong_t)info->params.clock_speed;
+	tmp_params.addr_filter     = info->params.addr_filter;
+	tmp_params.crc_type        = info->params.crc_type;
+	tmp_params.preamble_length = info->params.preamble_length;
+	tmp_params.preamble        = info->params.preamble;
+	tmp_params.data_rate       = (compat_ulong_t)info->params.data_rate;
+	tmp_params.data_bits       = info->params.data_bits;
+	tmp_params.stop_bits       = info->params.stop_bits;
+	tmp_params.parity          = info->params.parity;
+	if (copy_to_user(user_params, &tmp_params, sizeof(struct MGSL_PARAMS32)))
+		return -EFAULT;
+	return 0;
+}
+
+static long set_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *new_params)
+{
+	struct MGSL_PARAMS32 tmp_params;
+
+	DBGINFO(("%s set_params32\n", info->device_name));
+	if (copy_from_user(&tmp_params, new_params, sizeof(struct MGSL_PARAMS32)))
+		return -EFAULT;
+
+	spin_lock(&info->lock);
+	info->params.mode            = tmp_params.mode;
+	info->params.loopback        = tmp_params.loopback;
+	info->params.flags           = tmp_params.flags;
+	info->params.encoding        = tmp_params.encoding;
+	info->params.clock_speed     = tmp_params.clock_speed;
+	info->params.addr_filter     = tmp_params.addr_filter;
+	info->params.crc_type        = tmp_params.crc_type;
+	info->params.preamble_length = tmp_params.preamble_length;
+	info->params.preamble        = tmp_params.preamble;
+	info->params.data_rate       = tmp_params.data_rate;
+	info->params.data_bits       = tmp_params.data_bits;
+	info->params.stop_bits       = tmp_params.stop_bits;
+	info->params.parity          = tmp_params.parity;
+	spin_unlock(&info->lock);
+
+ 	change_params(info);
+
+	return 0;
+}
+
+static long slgt_compat_ioctl(struct tty_struct *tty, struct file *file,
+			 unsigned int cmd, unsigned long arg)
+{
+	struct slgt_info *info = tty->driver_data;
+	int rc = -ENOIOCTLCMD;
+
+	if (sanity_check(info, tty->name, "compat_ioctl"))
+		return -ENODEV;
+	DBGINFO(("%s compat_ioctl() cmd=%08X\n", info->device_name, cmd));
+
+	switch (cmd) {
+
+	case MGSL_IOCSPARAMS32:
+		rc = set_params32(info, compat_ptr(arg));
+		break;
+
+	case MGSL_IOCGPARAMS32:
+		rc = get_params32(info, compat_ptr(arg));
+		break;
+
+	case MGSL_IOCGPARAMS:
+	case MGSL_IOCSPARAMS:
+	case MGSL_IOCGTXIDLE:
+	case MGSL_IOCGSTATS:
+	case MGSL_IOCWAITEVENT:
+	case MGSL_IOCGIF:
+	case MGSL_IOCSGPIO:
+	case MGSL_IOCGGPIO:
+	case MGSL_IOCWAITGPIO:
+	case TIOCGICOUNT:
+		rc = ioctl(tty, file, cmd, (unsigned long)(compat_ptr(arg)));
+		break;
+
+	case MGSL_IOCSTXIDLE:
+	case MGSL_IOCTXENABLE:
+	case MGSL_IOCRXENABLE:
+	case MGSL_IOCTXABORT:
+	case TIOCMIWAIT:
+	case MGSL_IOCSIF:
+		rc = ioctl(tty, file, cmd, arg);
+		break;
+	}
+
+	DBGINFO(("%s compat_ioctl() cmd=%08X rc=%d\n", info->device_name, cmd, rc));
+	return rc;
+}
+#else
+#define slgt_compat_ioctl NULL
+#endif /* ifdef CONFIG_COMPAT */
+
+/*
  * proc fs support
  */
 static inline int line_info(char *buf, struct slgt_info *info)
@@ -3446,6 +3552,7 @@
 	.chars_in_buffer = chars_in_buffer,
 	.flush_buffer = flush_buffer,
 	.ioctl = ioctl,
+	.compat_ioctl = slgt_compat_ioctl,
 	.throttle = throttle,
 	.unthrottle = unthrottle,
 	.send_xchar = send_xchar,