drm/i915: Use GPLL ref clock to calculate GPU freqs on VLV/CHV
Extract the GPLL reference frequency from CCK and use it in the
GPU freq<->opcode conversions on VLV/CHV. This eliminates all the
assumptions we have about which divider is used for which czclk
frequency.
Note that unlike most clocks from CCK, the GPLL ref clock is a divided
down version of the CZ clock rather than the HPLL clock. CZ clock itself
is a divided down version of the HPLL clock though, so in effect it just
gets divided down twice.
While at it, throw in a few comments explaining the remaining constants
for anyone who later wants to compare this to the spreadsheets.
v2: Add slow/fast notes for CHV clocks (Imre)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457120584-26080-2-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com> (v1)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 9255b56..e0fcfa1 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1104,6 +1104,8 @@
void i915_audio_component_cleanup(struct drm_i915_private *dev_priv);
/* intel_display.c */
+int vlv_get_cck_clock(struct drm_i915_private *dev_priv,
+ const char *name, u32 reg, int ref_freq);
extern const struct drm_plane_funcs intel_plane_funcs;
void intel_init_display_hooks(struct drm_i915_private *dev_priv);
unsigned int intel_rotation_info_size(const struct intel_rotation_info *rot_info);