[src/trunk]: src/sys Add device_compatible_match(), a generalized routine for...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3dde85f86db9
branches:  trunk
changeset: 362631:3dde85f86db9
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Mon Jun 18 15:36:54 2018 +0000

description:
Add device_compatible_match(), a generalized routine for weighted
matching of device_compatible_entry data to a device's "compatible"
strings.

diffstat:

 sys/kern/subr_autoconf.c |  67 ++++++++++++++++++++++++++++++++++++++++++++++-
 sys/sys/device.h         |   7 ++++-
 2 files changed, 71 insertions(+), 3 deletions(-)

diffs (109 lines):

diff -r 1455a5b825bb -r 3dde85f86db9 sys/kern/subr_autoconf.c
--- a/sys/kern/subr_autoconf.c  Mon Jun 18 14:56:24 2018 +0000
+++ b/sys/kern/subr_autoconf.c  Mon Jun 18 15:36:54 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_autoconf.c,v 1.257 2018/03/04 07:12:18 mlelstv Exp $ */
+/* $NetBSD: subr_autoconf.c,v 1.258 2018/06/18 15:36:54 thorpej Exp $ */
 
 /*
  * Copyright (c) 1996, 2000 Christopher G. Demetriou
@@ -77,7 +77,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.257 2018/03/04 07:12:18 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.258 2018/06/18 15:36:54 thorpej Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -2275,6 +2275,69 @@
 }
 
 /*
+ * device_compatible_entry_matches:
+ *
+ *     Helper function to determine if a device_compatible_entry
+ *     contains a match for the specified "compatible" string.
+ */
+static bool
+device_compatible_entry_matches(const struct device_compatible_entry *dce,
+                               const char *compatible)
+{
+       const char **cpp = DEVICE_COMPAT_ENTRY_GET_STRINGS(dce);
+
+       if (cpp == NULL)
+               return false;
+       
+       while (*cpp != NULL)
+               if (strcmp(*cpp, compatible) == 0)
+                       return true;
+
+       return false;
+}
+
+/*
+ * device_compatible_match:
+ *
+ *     Match a driver's "compatible" data against a device's
+ *     "compatible" strings.  If a match is found, we return
+ *     the matching device_compatible_entry, along with a
+ *     matching weight.
+ */
+const struct device_compatible_entry *
+device_compatible_match(const char **device_compats, int ndevice_compats,
+                       const struct device_compatible_entry *driver_compats,
+                       int *match_weightp)
+{
+       const struct device_compatible_entry *dce = NULL;
+       int i, match_weight;
+
+       if (ndevice_compats == 0 || device_compats == NULL ||
+           driver_compats == NULL)
+               return NULL;
+       
+       /*
+        * We take the first match because we start with the most-specific
+        * device compatible string.
+        */
+       for (i = 0, match_weight = ndevice_compats - 1;
+            i < ndevice_compats;
+            i++, match_weight--) {
+               for (dce = driver_compats;
+                    DEVICE_COMPAT_ENTRY_IS_TERMINATOR(dce) == false; dce++) {
+                       if (device_compatible_entry_matches(dce,
+                                                        device_compats[i])) {
+                               KASSERT(match_weight >= 0);
+                               if (match_weightp)
+                                       *match_weightp = match_weight;
+                               return dce;
+                       }
+               }
+       }
+       return NULL;
+}
+
+/*
  * Power management related functions.
  */
 
diff -r 1455a5b825bb -r 3dde85f86db9 sys/sys/device.h
--- a/sys/sys/device.h  Mon Jun 18 14:56:24 2018 +0000
+++ b/sys/sys/device.h  Mon Jun 18 15:36:54 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: device.h,v 1.152 2018/06/17 15:06:27 thorpej Exp $ */
+/* $NetBSD: device.h,v 1.153 2018/06/18 15:36:54 thorpej Exp $ */
 
 /*
  * Copyright (c) 1996, 2000 Christopher G. Demetriou
@@ -552,6 +552,11 @@
 device_t       device_find_by_xname(const char *);
 device_t       device_find_by_driver_unit(const char *, int);
 
+const struct device_compatible_entry *
+               device_compatible_match(const char **, int,
+                                       const struct device_compatible_entry *,
+                                       int *);
+
 bool           device_pmf_is_registered(device_t);
 
 bool           device_pmf_driver_suspend(device_t, const pmf_qual_t *);