drm/i915/cdclk: abstract intel_cdclk_logical()

Add intel_cdclk_logical() helper to avoid looking at struct
intel_cdclk_state internals outside of intel_cdclk.c.

Reviewed-by: Imre Deak <[e-mail]>
Link: https://lore.kernel.org/r/e96[e-mail]
Signed-off-by: Jani Nikula <[e-mail]>

drivers/gpu/drm/i915/display/hsw_ips.c

···
 			return PTR_ERR(cdclk_state);
 
 		/* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
-		if (crtc_state->pixel_rate > cdclk_state->logical.cdclk * 95 / 100)
+		if (crtc_state->pixel_rate > intel_cdclk_logical(cdclk_state) * 95 / 100)
 			return 0;
 	}
 

drivers/gpu/drm/i915/display/intel_cdclk.c

···
 		     "Unknown platform. Assuming i830\n"))
 		display->funcs.cdclk = &i830_cdclk_funcs;
 }
+
+int intel_cdclk_logical(const struct intel_cdclk_state *cdclk_state)
+{
+	return cdclk_state->logical.cdclk;
+}

drivers/gpu/drm/i915/display/intel_cdclk.h

···
 int intel_cdclk_init(struct intel_display *display);
 void intel_cdclk_debugfs_register(struct intel_display *display);
 
+int intel_cdclk_logical(const struct intel_cdclk_state *cdclk_state);
+
 #endif /* __INTEL_CDCLK_H__ */

drivers/gpu/drm/i915/display/intel_display.c

···
 		return 0;
 
 	linetime_wm = DIV_ROUND_CLOSEST(pipe_mode->crtc_htotal * 1000 * 8,
-					cdclk_state->logical.cdclk);
+					intel_cdclk_logical(cdclk_state));
 
 	return min(linetime_wm, 0x1ff);
 }

drivers/gpu/drm/i915/display/intel_fbc.c

···
 		if (IS_ERR(cdclk_state))
 			return PTR_ERR(cdclk_state);
 
-		if (crtc_state->pixel_rate >= cdclk_state->logical.cdclk * 95 / 100) {
+		if (crtc_state->pixel_rate >= intel_cdclk_logical(cdclk_state) * 95 / 100) {
 			plane_state->no_fbc_reason = "pixel rate too high";
 			return 0;
 		}

drivers/gpu/drm/i915/display/skl_watermark.c

···
 	}
 
 	return min(1, DIV_ROUND_UP(crtc_state->pixel_rate,
-				   2 * cdclk_state->logical.cdclk));
+				   2 * intel_cdclk_logical(cdclk_state)));
 }
 
 static int