From 498fa7c1f9c8fa941e443c8c11c280b1853d8557 Mon Sep 17 00:00:00 2001
From: Ian Lepore <ian@FreeBSD.org>
Date: Fri, 25 Oct 2013 19:15:21 +0000
Subject: [PATCH] Add a helper routine to search for a compat string in a table
 that associates compat strings with arbitrary values that mean something to
 the driver.  This is handy for drivers that support several variations of
 similar hardware and need to know which one matched.

Reviewed by:	imp, jmg, nwhitehorn
---
 sys/dev/ofw/ofw_bus_subr.c | 15 +++++++++++++++
 sys/dev/ofw/ofw_bus_subr.h | 15 +++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/sys/dev/ofw/ofw_bus_subr.c b/sys/dev/ofw/ofw_bus_subr.c
index 920912e4d06c..26a675937c12 100644
--- a/sys/dev/ofw/ofw_bus_subr.c
+++ b/sys/dev/ofw/ofw_bus_subr.c
@@ -197,6 +197,21 @@ ofw_bus_is_compatible_strict(device_t dev, const char *compatible)
 	return (0);
 }
 
+const struct ofw_compat_data *
+ofw_bus_search_compatible(device_t dev, const struct ofw_compat_data *compat)
+{
+
+	if (compat == NULL)
+		return NULL;
+
+	for (; compat->ocd_str != NULL; ++compat) {
+		if (ofw_bus_is_compatible(dev, compat->ocd_str))
+			break;
+	}
+
+	return (compat);
+}
+
 int
 ofw_bus_has_prop(device_t dev, const char *propname)
 {
diff --git a/sys/dev/ofw/ofw_bus_subr.h b/sys/dev/ofw/ofw_bus_subr.h
index b777f7781645..184ab07b2412 100644
--- a/sys/dev/ofw/ofw_bus_subr.h
+++ b/sys/dev/ofw/ofw_bus_subr.h
@@ -47,6 +47,11 @@ struct ofw_bus_iinfo {
 	pcell_t			opi_addrc;
 };
 
+struct ofw_compat_data {
+	const char	*ocd_str;
+	uintptr_t	 ocd_data;
+};
+
 /* Generic implementation of ofw_bus_if.m methods and helper routines */
 int	ofw_bus_gen_setup_devinfo(struct ofw_bus_devinfo *, phandle_t);
 void	ofw_bus_gen_destroy_devinfo(struct ofw_bus_devinfo *);
@@ -74,6 +79,16 @@ void	ofw_bus_find_iparent(phandle_t);
 int ofw_bus_is_compatible(device_t, const char *);
 int ofw_bus_is_compatible_strict(device_t, const char *);
 
+/* 
+ * Helper routine to search a list of compat properties.  The table is
+ * terminated by an entry with a NULL compat-string pointer; a pointer to that
+ * table entry is returned if none of the compat strings match for the device,
+ * giving you control over the not-found value.  Will not return NULL unless the
+ * provided table pointer is NULL.
+ */
+const struct ofw_compat_data *
+    ofw_bus_search_compatible(device_t, const struct ofw_compat_data *);
+
 /* Helper routine for checking existence of a prop */
 int ofw_bus_has_prop(device_t, const char *);