From 85d8775d4c29be10ca437324785e76ff5949db29 Mon Sep 17 00:00:00 2001
From: Frank Mori Hess <fmhess@speakeasy.net>
Date: Tue, 18 Jul 2006 02:31:50 +0000
Subject: [PATCH] turn pcmcia support on or off by default depending on whether
 the kernel's pcmcia_driver struct has a probe function pointer.

---
 configure.ac   |  3 ++-
 m4/as-linux.m4 | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 7fa375c5..54ebdeaa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -66,8 +66,9 @@ CC=$LINUX_CC
  -DKBUILD_BASENAME=\$(shell basename \$< .c)"]
 AC_SUBST(COMEDI_CFLAGS)
 
+COMEDI_CHECK_PCMCIA_PROBE([$LINUX_DIR], [ENABLE_PCMCIA="yes"], [ENABLE_PCMCIA="no"])
 AC_ARG_ENABLE([pcmcia],[  --disable-pcmcia	Disable support for PCMCIA devices],
-	[ENABLE_PCMCIA=$enableval],[ENABLE_PCMCIA="yes"])
+	[ENABLE_PCMCIA=$enableval],[])
 if test "$ENABLE_PCMCIA" = "yes" ; then
 	AS_LINUX_CONFIG_OPTION_MODULE(CONFIG_PCMCIA)
 else
diff --git a/m4/as-linux.m4 b/m4/as-linux.m4
index 0d9ba40b..de6e0986 100644
--- a/m4/as-linux.m4
+++ b/m4/as-linux.m4
@@ -698,3 +698,22 @@ AC_DEFUN([COMEDI_CHECK_LINUX_KBUILD],
 	fi
 	fi
 ])
+
+# COMEDI_CHECK_PCMCIA_PROBE([LINUX_SOURCE_PATH], [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+# -------------------------------------------------------------
+#
+# Check if kernel pcmcia support is new enough to have a probe member in the pcmcia_driver
+# struct.
+AC_DEFUN([COMEDI_CHECK_PCMCIA_PROBE],
+[
+	AC_REQUIRE([AC_PROG_EGREP])
+	AC_MSG_CHECKING([$1 for probe in pcmcia_driver struct])
+	cat "$1/include/pcmcia/ds.h" | tr \\n ' ' | [$EGREP "struct[[:space:]]+pcmcia_driver[[:space:]]*[{][^}]*probe"] > /dev/null
+	if (($?)); then
+		AC_MSG_RESULT([no])
+		$3
+	else
+		AC_MSG_RESULT([yes])
+		$2
+	fi
+])
-- 
2.26.2