drm/i915: calculate the port clock rate along with other PLL params

Depending on the platform the port clock fed to the pipe can be the PLL's
post-divided fast clock rate or a /5 divided version of it. To make this
more obvious across the platforms calculate this port clock along with
the rest of the PLL parameters.

This is also needed by the next patch where we can reuse the CHV helper
for the BXT PLL HW readout code; so export the corresponding helper.

While at it also add a more descriptive name to the helpers and a
comment explaining what's being calculated.

No functional change.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index bb52620..3f0a890 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1140,6 +1140,8 @@ ironlake_check_encoder_dotclock(const struct intel_crtc_state *pipe_config,
 				int dotclock);
 bool bxt_find_best_dpll(struct intel_crtc_state *crtc_state, int target_clock,
 			intel_clock_t *best_clock);
+int chv_calc_dpll_params(int refclk, intel_clock_t *pll_clock);
+
 bool intel_crtc_active(struct drm_crtc *crtc);
 void hsw_enable_ips(struct intel_crtc *crtc);
 void hsw_disable_ips(struct intel_crtc *crtc);