drm/i915: extract common link_m_n helpers

Both the dp and fdi code use the exact same computations (ignore minor
differences in conversion between bits and bytes).

This makes it even more apparent that we have a _massive_ mess between
cpu transcoder/fdi link/pch transcoder and pch link settings. And also
that we have hilarious amounts of confusion between edp and dp
(despite that they're identical at a link level).

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a00ee3da632f..e9ac3603fbdb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -107,6 +107,19 @@ struct intel_pch_pll {
 };
 #define I915_NUM_PLLS 2
 
+/* Used by dp and fdi links */
+struct intel_link_m_n {
+        uint32_t        tu;
+        uint32_t        gmch_m;
+        uint32_t        gmch_n;
+        uint32_t        link_m;
+        uint32_t        link_n;
+};
+
+void intel_link_compute_m_n(int bpp, int nlanes,
+                            int pixel_clock, int link_clock,
+                            struct intel_link_m_n *m_n);
+
 struct intel_ddi_plls {
         int spll_refcount;
         int wrpll1_refcount;