blob: fb358c71a83ae701d699bb1f3214ab32e3f47d9e [file] [log] [blame]
From 842136d35ee243af59e692aeaa95d1a3d79b9a9e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Fri, 27 Sep 2013 16:54:19 +0300
Subject: drm/i915: Rewrite vlv_find_best_dpll()
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Rewrite vlv_find_best_dpll() to use intel_clock_t rather than
an army of local variables.
Also extract the code to calculate the derived values into
vlv_clock().
v2: Split up the earlier fixes, extract vlv_clock()
v3: Initialize best_clock
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 6b4bf1c4952a65fae6b4043054b146642f031f19)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
drivers/gpu/drm/i915/intel_display.c | 74 ++++++++++++++++--------------------
1 file changed, 33 insertions(+), 41 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 60aa0121d7b8..4b5ffb5b9288 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -335,6 +335,14 @@ static const intel_limit_t intel_limits_vlv_hdmi = {
.p2_slow = 2, .p2_fast = 20 },
};
+static void vlv_clock(int refclk, intel_clock_t *clock)
+{
+ clock->m = clock->m1 * clock->m2;
+ clock->p = clock->p1 * clock->p2;
+ clock->vco = refclk * clock->m / clock->n;
+ clock->dot = clock->vco / clock->p;
+}
+
/**
* Returns whether any output on the specified pipe is of the specified type
*/
@@ -669,66 +677,50 @@ vlv_find_best_dpll(const intel_limit_t *limit, struct drm_crtc *crtc,
int target, int refclk, intel_clock_t *match_clock,
intel_clock_t *best_clock)
{
- u32 p1, p2, m1, m2, vco, bestn, bestm1, bestm2, bestp1, bestp2;
- u32 m, n, fastclk;
- u32 updrate, minupdate, p;
+ intel_clock_t clock;
+ u32 minupdate = 19200;
unsigned int bestppm = 1000000;
- int dotclk, flag;
- flag = 0;
- dotclk = target * 1000;
- fastclk = dotclk / (2*100);
- updrate = 0;
- minupdate = 19200;
- n = p = p1 = p2 = m = m1 = m2 = vco = bestn = 0;
- bestm1 = bestm2 = bestp1 = bestp2 = 0;
+ target *= 5; /* fast clock */
+
+ memset(best_clock, 0, sizeof(*best_clock));
/* based on hardware requirement, prefer smaller n to precision */
- for (n = limit->n.min; n <= ((refclk) / minupdate); n++) {
- updrate = refclk / n;
- for (p1 = limit->p1.max; p1 > limit->p1.min; p1--) {
- for (p2 = limit->p2.p2_fast+1; p2 > 0; p2--) {
- if (p2 > 10)
- p2 = p2 - 1;
- p = p1 * p2;
+ for (clock.n = limit->n.min; clock.n <= ((refclk) / minupdate); clock.n++) {
+ for (clock.p1 = limit->p1.max; clock.p1 > limit->p1.min; clock.p1--) {
+ for (clock.p2 = limit->p2.p2_fast+1; clock.p2 > 0; clock.p2--) {
+ if (clock.p2 > 10)
+ clock.p2--;
+ clock.p = clock.p1 * clock.p2;
/* based on hardware requirement, prefer bigger m1,m2 values */
- for (m1 = limit->m1.min; m1 <= limit->m1.max; m1++) {
+ for (clock.m1 = limit->m1.min; clock.m1 <= limit->m1.max; clock.m1++) {
unsigned int ppm, diff;
- m2 = DIV_ROUND_CLOSEST(fastclk * p * n, refclk * m1);
- m = m1 * m2;
- vco = updrate * m;
+ clock.m2 = DIV_ROUND_CLOSEST(target * clock.p * clock.n,
+ refclk * clock.m1);
+
+ vlv_clock(refclk, &clock);
- if (vco < limit->vco.min || vco >= limit->vco.max)
+ if (clock.vco < limit->vco.min ||
+ clock.vco >= limit->vco.max)
continue;
- diff = abs(vco / p - fastclk);
- ppm = div_u64(1000000ULL * diff, fastclk);
- if (ppm < 100 && ((p1 * p2) > (bestp1 * bestp2))) {
+ diff = abs(clock.dot - target);
+ ppm = div_u64(1000000ULL * diff, target);
+
+ if (ppm < 100 && clock.p > best_clock->p) {
bestppm = 0;
- flag = 1;
+ *best_clock = clock;
}
+
if (bestppm >= 10 && ppm < bestppm - 10) {
bestppm = ppm;
- flag = 1;
- }
- if (flag) {
- bestn = n;
- bestm1 = m1;
- bestm2 = m2;
- bestp1 = p1;
- bestp2 = p2;
- flag = 0;
+ *best_clock = clock;
}
}
}
}
}
- best_clock->n = bestn;
- best_clock->m1 = bestm1;
- best_clock->m2 = bestm2;
- best_clock->p1 = bestp1;
- best_clock->p2 = bestp2;
return true;
}
--
1.8.5.rc3