--- src/rhd_acpi.c.orig	2009-10-06 07:36:07.000000000 -0400
+++ src/rhd_acpi.c	2009-10-27 02:44:10.000000000 -0400
@@ -47,6 +47,54 @@
 #include "rhd_acpi.h"
 
 
+#if defined(__FreeBSD__)
+
+#include <stdlib.h>
+#include <sys/sysctl.h>
+
+/*
+ * Get/Set LCD backlight brightness via acpi_video(4).
+ */
+static Bool
+rhdDoBacklight(struct rhdOutput *Output, Bool do_write, int *val)
+{
+    int *levels;
+    size_t len;
+    int level, num_levels;
+    RHDFUNC(Output);
+
+    if (sysctlbyname("hw.acpi.video.lcd0.levels", NULL, &len, NULL, 0) != 0 || len == 0)
+	return FALSE;
+
+    if (do_write) {
+	levels = (int *)malloc(len);
+	if (levels == NULL)
+	    return FALSE;
+	if (sysctlbyname("hw.acpi.video.lcd0.levels", levels, &len, NULL, 0) != 0) {
+	    free(levels);
+	    return FALSE;
+	}
+	num_levels = len / sizeof(*levels);
+	for (level = 0; level < num_levels; level++)
+	    if (levels[level] == *val)
+		break;
+	free(levels);
+	if (level >= num_levels)
+	    return FALSE;
+	if (sysctlbyname("hw.acpi.video.lcd0.brightness", NULL, 0, val, sizeof(*val)) != 0)
+	    return FALSE;
+	    RHDDebug(Output->scrnIndex,"%s: Set brightness value %i\n", __func__, *val);
+    } else {
+	if (sysctlbyname("hw.acpi.video.lcd0.brightness", val, &len, NULL, 0) != 0)
+	    return FALSE;
+	RHDDebug(Output->scrnIndex,"%s: Get brightness value %i\n", __func__, *val);
+    }
+
+    return TRUE;
+}
+
+#elif defined(__linux__)
+
 #define ACPI_PATH "/sys/class/backlight"
 
 /*
@@ -120,6 +168,7 @@
 
     return FALSE;
 }
+#endif
 
 /*
  * RhdACPIGetBacklightControl(): return backlight value in range 0..255;
@@ -128,7 +177,7 @@
 int
 RhdACPIGetBacklightControl(struct rhdOutput *Output)
 {
-#ifdef __linux__
+#if defined(__FreeBSD__) || defined(__linux__)
     int ret;
     RHDFUNC(Output);
     if (rhdDoBacklight(Output, FALSE, &ret))
@@ -144,7 +193,7 @@
 RhdACPISetBacklightControl(struct rhdOutput *Output, int val)
 {
     RHDFUNC(Output);
-#ifdef __linux__
+#if defined(__FreeBSD__) || defined(__linux__)
     rhdDoBacklight(Output, TRUE, &val);
 #endif
 }