drm/i915: Document the find_pll() function

The proper use of find_pll() isn't always so easy to determine from the
code itself. Some documentation should help.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 878e1e3e066732f5148e8c4d8a3b084d15a9d351..b4482b22a1ac2167cd508cc2b18387d5dcc6a188 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -71,8 +71,24 @@ typedef struct intel_limit intel_limit_t;
 struct intel_limit {
        intel_range_t   dot, vco, n, m, m1, m2, p, p1;
        intel_p2_t          p2;
-       bool (* find_pll)(const intel_limit_t *, struct drm_crtc *,
-                       int, int, intel_clock_t *, intel_clock_t *);
+       /**
+        * find_pll() - Find the best values for the PLL
+        * @limit: limits for the PLL
+        * @crtc: current CRTC
+        * @target: target frequency in kHz
+        * @refclk: reference clock frequency in kHz
+        * @match_clock: if provided, @best_clock P divider must
+        *               match the P divider from @match_clock
+        *               used for LVDS downclocking
+        * @best_clock: best PLL values found
+        *
+        * Returns true on success, false on failure.
+        */
+       bool (*find_pll)(const intel_limit_t *limit,
+                        struct drm_crtc *crtc,
+                        int target, int refclk,
+                        intel_clock_t *match_clock,
+                        intel_clock_t *best_clock);
 };
 
 /* FDI */