drm/sysfs: add current display mode to sysfs

Change-Id: I2a1a699bac74d9fe71151ba1eb8e33e0683a48a5
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>

diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index 79f747296868d374bb259e58c65c677f08973458..1dc9f304cc8ce77269ae492e0083706a1cbb0a2a 100644 (file)
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -296,6 +296,35 @@ static ssize_t modes_show(struct device *device,
        return written;
 }
 
+static ssize_t mode_show(struct device *device,
+                          struct device_attribute *attr,
+                          char *buf)
+{
+       struct drm_connector *connector = to_drm_connector(device);
+       struct drm_display_mode *mode;
+       struct drm_crtc_state *crtc_state;
+       bool interlaced;
+       int written = 0;
+
+       if (!connector->state || !connector->state->crtc)
+               return written;
+
+       crtc_state = connector->state->crtc->state;
+       if (!crtc_state)
+               return written;
+
+       mode = &crtc_state->mode;
+
+       interlaced = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
+       written += snprintf(buf + written, PAGE_SIZE - written,
+                           "%dx%d%s%d\n",
+                           mode->hdisplay, mode->vdisplay,
+                           interlaced ? "i" : "p",
+                           drm_mode_vrefresh(mode));
+
+       return written;
+}
+
 static ssize_t tv_subconnector_show(struct device *device,
                                    struct device_attribute *attr,
                                    char *buf)
@@ -396,12 +425,14 @@ static DEVICE_ATTR_RW(status);
 static DEVICE_ATTR_RO(enabled);
 static DEVICE_ATTR_RO(dpms);
 static DEVICE_ATTR_RO(modes);
+static DEVICE_ATTR_RO(mode);
 
 static struct attribute *connector_dev_attrs[] = {
        &dev_attr_status.attr,
        &dev_attr_enabled.attr,
        &dev_attr_dpms.attr,
        &dev_attr_modes.attr,
+       &dev_attr_mode.attr,
        NULL
 };