[Patch 3/3] edid override: make edid writable in sysfs

[Thorsten Schoel <tschoel@web.de>]

From: Thorsten Schoel <tschoel at web.de>

Makes class/drm/[CONNECTOR]/edid writable for adding edid overrides.

Signed-off-by: Thorsten Schoel <tschoel at web.de>
---
diff -Nurp infra/drivers/gpu/drm/drm_sysfs.c sysfs/drivers/gpu/drm/drm_sysfs.c
--- infra/drivers/gpu/drm/drm_sysfs.c	2012-01-12 20:42:45.000000000 +0100
+++ sysfs/drivers/gpu/drm/drm_sysfs.c	2012-01-25 22:13:08.000000000 +0100
@@ -21,6 +21,8 @@
 #include "drm_sysfs.h"
 #include "drm_core.h"
 #include "drmP.h"
+#include "drm_edid.h"
+#include "drm_crtc.h"
 
 #define to_drm_minor(d) container_of(d, struct drm_minor, kdev)
 #define to_drm_connector(d) container_of(d, struct drm_connector, kdev)
@@ -228,6 +230,44 @@ static ssize_t edid_show(struct file *fi
 	return count;
 }
 
+static ssize_t edid_override(struct file *filp, struct kobject *kobj,
+			     struct bin_attribute *attr, char *buf, loff_t off,
+			     size_t count)
+{
+	struct device *connector_dev = container_of(kobj, struct device, kobj);
+	struct drm_connector *connector = to_drm_connector(connector_dev);
+	char *connector_name;
+	unsigned char *edid_new;
+
+	connector_name = drm_get_connector_name(connector);
+	
+	if (!count) {
+		drm_edid_override_remove(connector_name);
+		return 0;
+	}
+	
+	/* Only support writing the whole EDID in one piece */
+	if (off)
+		return 0;
+
+	if (count < EDID_LENGTH)
+		return 0;
+	if (count != (buf[0x7e] + 1) * EDID_LENGTH)
+		return 0;
+	
+	edid_new = kmalloc(count, GFP_KERNEL);
+	if (!edid_new)
+		return 0;
+	
+	memcpy(edid_new,  buf, count);
+
+	if (drm_edid_override_set(connector_name, (struct edid *)edid_new) < 0)
+		count = 0;
+	
+	kfree(edid_new);
+	return count;
+}
+
 static ssize_t modes_show(struct device *device,
 			   struct device_attribute *attr,
 			   char *buf)
@@ -341,9 +381,10 @@ static struct device_attribute connector
 
 static struct bin_attribute edid_attr = {
 	.attr.name = "edid",
-	.attr.mode = 0444,
+	.attr.mode = 0644,
 	.size = 0,
 	.read = edid_show,
+	.write = edid_override,
 };
 
 /**
---