modesetting: implement the backlight atom with the drm backlight propertybacklight

With the drm backlight property, backlight interaction will
work automatically if applications use an "BRIGHTNESS" atom.
For backward compatibility, this patch maps the drm backlight property
values to the "Backlight" atom, allowing existing applications
to use the backlight.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96572

Signed-off-by: Marta Lofstedt <marta.lofstedt@intel.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 6e755e948..41fc680fc 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -54,6 +54,10 @@ static Bool drmmode_xf86crtc_resize(ScrnInfoPtr scrn, int width, int height);
 static PixmapPtr drmmode_create_pixmap_header(ScreenPtr pScreen, int width, int height,
                                               int depth, int bitsPerPixel, int devKind,
                                               void *pPixData);
+
+#define BACKLIGHT_NAME             "Backlight"
+static Atom backlight_atom;
+
 static Bool
 drmmode_zaphod_string_matches(ScrnInfoPtr scrn, const char *s, char *output_name)
 {
@@ -1493,6 +1497,22 @@ drmmode_output_create_resources(xf86OutputPtr output)
                 xf86DrvMsg(output->scrn->scrnIndex, X_ERROR,
                            "RRChangeOutputProperty error, %d\n", err);
             }
+            /* associate the backlight atom with the BRIGHTNESS property */
+            if (!strcmp(drmmode_prop->name, "BRIGHTNESS")) {
+                backlight_atom = MakeAtom(BACKLIGHT_NAME, strlen(BACKLIGHT_NAME), TRUE);
+                err = RRConfigureOutputProperty(output->randr_output, backlight_atom, FALSE,
+                                                TRUE, FALSE, 2, prop_range);
+                if (err != 0)
+                    xf86DrvMsg(output->scrn->scrnIndex, X_WARNING,
+                               "RRConfigureOutputProperty error, %d\n", err);
+
+                err = RRChangeOutputProperty(output->randr_output, backlight_atom, XA_INTEGER,
+                                             32, PropModeReplace, 1, &value,
+                                             FALSE, FALSE);
+                if (err != 0)
+                    xf86DrvMsg(output->scrn->scrnIndex, X_WARNING,
+                               "RRConfigureOutputProperty error, %d\n", err);
+            }
         }
         else if (drmmode_prop->flags & DRM_MODE_PROP_ENUM) {
             p->num_atoms = drmmode_prop->count_enums + 1;
@@ -1542,6 +1562,20 @@ drmmode_output_set_property(xf86OutputPtr output, Atom property,
     for (i = 0; i < drmmode_output->num_props; i++) {
         drmmode_prop_ptr p = &drmmode_output->props[i];
 
+        if (property == backlight_atom &&
+            !strcmp(p->mode_prop->name, "BRIGHTNESS")) {
+            uint32_t val;
+
+            if (value->type != XA_INTEGER || value->format != 32 ||
+                value->size != 1)
+	        return FALSE;
+
+            val = *(uint32_t *) value->data;
+	    drmModeConnectorSetProperty(drmmode->fd, drmmode_output->output_id,
+					p->mode_prop->prop_id, (uint64_t) val);
+            return TRUE;
+        }
+
         if (p->atoms[0] != property)
             continue;
 
@@ -1587,6 +1621,37 @@ drmmode_output_set_property(xf86OutputPtr output, Atom property,
 static Bool
 drmmode_output_get_property(xf86OutputPtr output, Atom property)
 {
+    if (property == backlight_atom ) {
+        drmmode_output_private_ptr drmmode_output = output->driver_private;
+        drmModeConnectorPtr koutput = drmmode_output->mode_output;
+        drmmode_ptr drmmode = drmmode_output->drmmode;
+        int err, i;
+
+        for (i = 0; i < koutput->count_props; i++) {
+            uint32_t id = koutput-> connector_id;
+            drmModePropertyPtr prop = drmModeGetProperty(drmmode->fd, koutput->props[i]);
+            drmModeObjectPropertiesPtr props = drmModeObjectGetProperties(drmmode->fd, id, DRM_MODE_OBJECT_CONNECTOR);
+
+            if (!prop)
+                continue;
+            if (!strcmp(prop->name, "BRIGHTNESS"))
+                {
+                    INT32 value = props->prop_values[i];
+                    err = RRChangeOutputProperty(output->randr_output, property,
+                                                 XA_INTEGER, 32, PropModeReplace, 1, &value,
+                                                 FALSE, FALSE);
+                    drmModeFreeProperty(prop);
+                    if (err != 0) {
+                        xf86DrvMsg(output->scrn->scrnIndex, X_ERROR,
+                                   "RRChangeOutputProperty error, %d\n", err);
+                        return FALSE;
+                    }
+                    return TRUE;
+                }
+            drmModeFreeProperty(prop);
+        }
+        return FALSE;
+    }
     return TRUE;
 }