AVIVO: add new PLL code

This should hopefully help the problems with flickering
and blinking monitors reported on some systems.  If there
are problems, the old PLL algorithm can be selected with:
Option "NewPLL" "FALSE"
in the device section of your X config.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>

5 files changed, 98 insertions, 4 deletions

diff --git a/src/atombios_crtc.c b/src/atombios_crtc.c
index f9698f3f..8cccba62 100644
--- a/src/atombios_crtc.c
+++ b/src/atombios_crtc.c
@@ -407,7 +407,13 @@ atombios_crtc_set_pll(xf86CrtcPtr crtc, DisplayModePtr mode)
 	ErrorF("after %d\n", adjust_pll_param.usPixelClock);
     }
 
-    RADEONComputePLL(&info->pll, sclock, &temp, &fb_div, &frac_fb_div, &ref_div, &post_div, pll_flags);
+    if (IS_AVIVO_VARIANT) {
+	if (xf86ReturnOptValBool(info->Options, OPTION_NEW_PLL, TRUE))
+	    RADEONComputePLL_AVIVO(&info->pll, sclock, &temp, &fb_div, &frac_fb_div, &ref_div, &post_div, pll_flags);
+	else
+	    RADEONComputePLL(&info->pll, sclock, &temp, &fb_div, &frac_fb_div, &ref_div, &post_div, pll_flags);
+    } else
+	RADEONComputePLL(&info->pll, sclock, &temp, &fb_div, &frac_fb_div, &ref_div, &post_div, pll_flags);
     sclock = temp; /* 10 khz */
 
     xf86DrvMsg(crtc->scrn->scrnIndex, X_INFO,
diff --git a/src/radeon.h b/src/radeon.h
index 182e946e..10710a83 100644
--- a/src/radeon.h
+++ b/src/radeon.h
@@ -222,7 +222,8 @@ typedef enum {
     OPTION_ATOM_TVOUT,
     OPTION_R4XX_ATOM,
     OPTION_FORCE_LOW_POWER,
-    OPTION_DYNAMIC_PM
+    OPTION_DYNAMIC_PM,
+    OPTION_NEW_PLL
 } RADEONOpts;
 
 
@@ -1164,6 +1165,14 @@ extern void RADEONComputePLL(RADEONPLLPtr pll, unsigned long freq,
 			     uint32_t *chosen_frac_feedback_div,
 			     uint32_t *chosen_reference_div,
 			     uint32_t *chosen_post_div, int flags);
+extern void RADEONComputePLL_AVIVO(RADEONPLLPtr pll,
+				   unsigned long freq,
+				   uint32_t *chosen_dot_clock_freq,
+				   uint32_t *chosen_feedback_div,
+				   uint32_t *chosen_frac_feedback_div,
+				   uint32_t *chosen_reference_div,
+				   uint32_t *chosen_post_div,
+				   int flags);
 extern DisplayModePtr RADEONCrtcFindClosestMode(xf86CrtcPtr crtc,
 						DisplayModePtr pMode);
 extern void RADEONUnblank(ScrnInfoPtr pScrn);
diff --git a/src/radeon_atombios.c b/src/radeon_atombios.c
index 72fbe214..c272c9a5 100644
--- a/src/radeon_atombios.c
+++ b/src/radeon_atombios.c
@@ -2204,14 +2204,17 @@ RADEONGetATOMClockInfo(ScrnInfoPtr pScrn)
     if (pll->pll_out_min == 0)
 	pll->pll_out_min = 64800;
 
+
     /* limiting the range is a good thing in most cases
      * as it limits the number of matching pll combinations,
      * however, some duallink DVI monitors seem to prefer combinations that
      * would be limited by this.  This may need to be revisited
      * per chip family.
      */
-    if (pll->pll_out_min > 64800)
-	pll->pll_out_min = 64800;
+    if (!xf86ReturnOptValBool(info->Options, OPTION_NEW_PLL, TRUE)) {
+	if (pll->pll_out_min > 64800)
+	    pll->pll_out_min = 64800;
+    }
 
     return TRUE;
 }
diff --git a/src/radeon_crtc.c b/src/radeon_crtc.c
index 3899064f..4e8b490b 100644
--- a/src/radeon_crtc.c
+++ b/src/radeon_crtc.c
@@ -301,6 +301,81 @@ RADEONComputePLL(RADEONPLLPtr pll,
 
 }
 
+void
+RADEONComputePLL_AVIVO(RADEONPLLPtr pll,
+		       unsigned long freq,
+		       uint32_t *chosen_dot_clock_freq,
+		       uint32_t *chosen_feedback_div,
+		       uint32_t *chosen_frac_feedback_div,
+		       uint32_t *chosen_reference_div,
+		       uint32_t *chosen_post_div,
+		       int flags)
+{
+    float m, n, frac_n, p, f_vco, f_pclk, best_freq;
+    float pll_out_max = pll->pll_out_max;
+    float pll_out_min = pll->pll_out_min;
+    float reference_freq = pll->reference_freq;
+    float pll_in_max = pll->pll_in_max;
+    float pll_in_min = pll->pll_in_min;
+    float ffreq = freq / 10;
+    float error = 100;
+
+    ErrorF("ffreq: %f\n", ffreq * 10);
+
+    /* 1 - max p */
+    p = floor(pll_out_max / ffreq);
+
+    /* 2 - min m */
+    m = ceil(reference_freq / pll_in_max);
+
+    while (error > 0.25) {
+	/* 3 - n */
+	n = (ffreq / reference_freq) * m * p;
+
+	/* 4 - vco out freq */
+	f_vco = (n / m) * reference_freq;
+
+	/* 5 - pclk freq */
+	f_pclk = f_vco / p;
+
+	/* 6 - error */
+	error = (abs(f_pclk - ffreq) / f_pclk) * 100;
+
+	best_freq = reference_freq * (n / (m * p));
+
+	/* min error 0.25% */
+	if (error < 0.25)
+	    break;
+
+	/* 7 - check m */
+	m++;
+	if ((reference_freq / m) >= pll_in_min)
+	    continue;
+
+	/* 8 - check p */
+	m = ceil(reference_freq / pll_in_max);
+	p--;
+	if ((p * ffreq) >= pll_out_min)
+	    continue;
+	else
+	    FatalError("Couldn't find valid PLL dividers\n");
+    }
+
+    frac_n = (n - (int)n) * 10;
+
+    ErrorF("best_freq: %u\n", (unsigned int)best_freq * 10);
+    ErrorF("best_feedback_div: %d.%d\n", (int)n, (int)frac_n);
+    ErrorF("best_ref_div: %d\n", (int)m);
+    ErrorF("best_post_div: %d\n", (int)p);
+
+    *chosen_dot_clock_freq = best_freq;
+    *chosen_feedback_div = (uint32_t)n;
+    *chosen_frac_feedback_div = (uint32_t)frac_n;
+    *chosen_reference_div = (uint32_t)m;
+    *chosen_post_div = (uint32_t)p;
+
+}
+
 static void
 radeon_crtc_mode_set(xf86CrtcPtr crtc, DisplayModePtr mode,
 		     DisplayModePtr adjusted_mode, int x, int y)
diff --git a/src/radeon_driver.c b/src/radeon_driver.c
index bf560f7d..ae4993bc 100644
--- a/src/radeon_driver.c
+++ b/src/radeon_driver.c
@@ -205,6 +205,7 @@ static const OptionInfoRec RADEONOptions[] = {
     { OPTION_R4XX_ATOM,	        "R4xxATOM",	   OPTV_BOOLEAN, {0}, FALSE },
     { OPTION_FORCE_LOW_POWER,	"ForceLowPowerMode", OPTV_BOOLEAN, {0}, FALSE },
     { OPTION_DYNAMIC_PM,	"DynamicPM",       OPTV_BOOLEAN, {0}, FALSE },
+    { OPTION_NEW_PLL,	        "NewPLL",        OPTV_BOOLEAN, {0}, FALSE },
     { -1,                    NULL,               OPTV_NONE,    {0}, FALSE }
 };