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authorRussell King <rmk+kernel@arm.linux.org.uk>2014-01-02 21:27:33 +0000
committerThierry Reding <treding@nvidia.com>2014-01-14 14:35:02 +0100
commitdb5f7a6e78303fd96dc87487d6976145f70ab84a (patch)
tree67e1794359724795088e92c4ded11fff46e58007 /drivers/gpu/drm/drm_crtc.c
parentff5009ef8df87908a956412619e4f1bf1078ef5d (diff)
drm: provide a helper for the encoder possible_crtcs mask
The encoder possible_crtcs mask identifies which CRTCs can be bound to a particular encoder. Each bit from bit 0 defines an index in the list of CRTCs held in the DRM mode_config crtc_list. Rather than having drivers trying to track the position of their CRTCs in the list, expose the code which already exists for calculating the appropriate mask bit for a CRTC. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> [treding@nvidia.com: add drm_crtc_index(), move to core] Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/gpu/drm/drm_crtc.c')
-rw-r--r--drivers/gpu/drm/drm_crtc.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index d6cf77c472e7..452bcbd0eab9 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -675,6 +675,29 @@ void drm_crtc_cleanup(struct drm_crtc *crtc)
EXPORT_SYMBOL(drm_crtc_cleanup);
/**
+ * drm_crtc_index - find the index of a registered CRTC
+ * @crtc: CRTC to find index for
+ *
+ * Given a registered CRTC, return the index of that CRTC within a DRM
+ * device's list of CRTCs.
+ */
+unsigned int drm_crtc_index(struct drm_crtc *crtc)
+{
+ unsigned int index = 0;
+ struct drm_crtc *tmp;
+
+ list_for_each_entry(tmp, &crtc->dev->mode_config.crtc_list, head) {
+ if (tmp == crtc)
+ return index;
+
+ index++;
+ }
+
+ BUG();
+}
+EXPORT_SYMBOL(drm_crtc_index);
+
+/**
* drm_mode_probed_add - add a mode to a connector's probed mode list
* @connector: connector the new mode
* @mode: mode data