drm/radeon/kms: add new pll algo for avivo asics

Based on the vbios code.  This should hopefully
fix the pll problems on a number of avivo asics
once it's enabled.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/atombios_crtc.c

@@ -951,7 +951,7 @@ static void atombios_crtc_set_pll(struct drm_crtc *crtc, struct drm_display_mode
 	/* adjust pixel clock as needed */
 	adjusted_clock = atombios_adjust_pll(crtc, mode, pll, ss_enabled, &ss);
 
-	radeon_compute_pll(pll, adjusted_clock, &pll_clock, &fb_div, &frac_fb_div,
+	radeon_compute_pll_legacy(pll, adjusted_clock, &pll_clock, &fb_div, &frac_fb_div,
 				  &ref_div, &post_div);
 
 	atombios_crtc_program_ss(crtc, ATOM_DISABLE, radeon_crtc->pll_id, &ss);

drivers/gpu/drm/radeon/radeon_display.c

@@ -780,6 +780,115 @@ static int radeon_ddc_dump(struct drm_connector *connector)
 	return ret;
 }
 
+/* avivo */
+static void avivo_get_fb_div(struct radeon_pll *pll,
+			     u32 target_clock,
+			     u32 post_div,
+			     u32 ref_div,
+			     u32 *fb_div,
+			     u32 *frac_fb_div)
+{
+	u32 tmp = post_div * ref_div;
+
+	tmp *= target_clock;
+	*fb_div = tmp / pll->reference_freq;
+	*frac_fb_div = tmp % pll->reference_freq;
+}
+
+static u32 avivo_get_post_div(struct radeon_pll *pll,
+			      u32 target_clock)
+{
+	u32 vco, post_div, tmp;
+
+	if (pll->flags & RADEON_PLL_USE_POST_DIV)
+		return pll->post_div;
+
+	if (pll->flags & RADEON_PLL_PREFER_MINM_OVER_MAXP) {
+		if (pll->flags & RADEON_PLL_IS_LCD)
+			vco = pll->lcd_pll_out_min;
+		else
+			vco = pll->pll_out_min;
+	} else {
+		if (pll->flags & RADEON_PLL_IS_LCD)
+			vco = pll->lcd_pll_out_max;
+		else
+			vco = pll->pll_out_max;
+	}
+
+	post_div = vco / target_clock;
+	tmp = vco % target_clock;
+
+	if (pll->flags & RADEON_PLL_PREFER_MINM_OVER_MAXP) {
+		if (tmp)
+			post_div++;
+	} else {
+		if (!tmp)
+			post_div--;
+	}
+
+	return post_div;
+}
+
+#define MAX_TOLERANCE 10
+
+void radeon_compute_pll_avivo(struct radeon_pll *pll,
+			      u32 freq,
+			      u32 *dot_clock_p,
+			      u32 *fb_div_p,
+			      u32 *frac_fb_div_p,
+			      u32 *ref_div_p,
+			      u32 *post_div_p)
+{
+	u32 target_clock = freq / 10;
+	u32 post_div = avivo_get_post_div(pll, target_clock);
+	u32 ref_div = pll->min_ref_div;
+	u32 fb_div = 0, frac_fb_div = 0, tmp;
+
+	if (pll->flags & RADEON_PLL_USE_REF_DIV)
+		ref_div = pll->reference_div;
+
+	if (pll->flags & RADEON_PLL_USE_FRAC_FB_DIV) {
+		avivo_get_fb_div(pll, target_clock, post_div, ref_div, &fb_div, &frac_fb_div);
+		frac_fb_div = (100 * frac_fb_div) / pll->reference_freq;
+		if (frac_fb_div >= 5) {
+			frac_fb_div -= 5;
+			frac_fb_div = frac_fb_div / 10;
+			frac_fb_div++;
+		}
+		if (frac_fb_div >= 10) {
+			fb_div++;
+			frac_fb_div = 0;
+		}
+	} else {
+		while (ref_div <= pll->max_ref_div) {
+			avivo_get_fb_div(pll, target_clock, post_div, ref_div,
+					 &fb_div, &frac_fb_div);
+			if (frac_fb_div >= (pll->reference_freq / 2))
+				fb_div++;
+			frac_fb_div = 0;
+			tmp = (pll->reference_freq * fb_div) / (post_div * ref_div);
+			tmp = (tmp * 10000) / target_clock;
+
+			if (tmp > (10000 + MAX_TOLERANCE))
+				ref_div++;
+			else if (tmp >= (10000 - MAX_TOLERANCE))
+				break;
+			else
+				ref_div++;
+		}
+	}
+
+	*dot_clock_p = ((pll->reference_freq * fb_div * 10) + (pll->reference_freq * frac_fb_div)) /
+		(ref_div * post_div * 10);
+	*fb_div_p = fb_div;
+	*frac_fb_div_p = frac_fb_div;
+	*ref_div_p = ref_div;
+	*post_div_p = post_div;
+	DRM_DEBUG_KMS("%d, pll dividers - fb: %d.%d ref: %d, post %d\n",
+		      *dot_clock_p, fb_div, frac_fb_div, ref_div, post_div);
+}
+
+/* pre-avivo */
 static inline uint32_t radeon_div(uint64_t n, uint32_t d)
 {
 	uint64_t mod;
@@ -790,7 +899,7 @@ static inline uint32_t radeon_div(uint64_t n, uint32_t d)
 	return n;
 }
 
-void radeon_compute_pll(struct radeon_pll *pll,
+void radeon_compute_pll_legacy(struct radeon_pll *pll,
 			       uint64_t freq,
 			       uint32_t *dot_clock_p,
 			       uint32_t *fb_div_p,

drivers/gpu/drm/radeon/radeon_legacy_crtc.c

@@ -778,7 +778,7 @@ static void radeon_set_pll(struct drm_crtc *crtc, struct drm_display_mode *mode)
 	DRM_DEBUG_KMS("\n");
 
 	if (!use_bios_divs) {
-		radeon_compute_pll(pll, mode->clock,
+		radeon_compute_pll_legacy(pll, mode->clock,
 					  &freq, &feedback_div, &frac_fb_div,
 					  &reference_div, &post_divider);
 

drivers/gpu/drm/radeon/radeon_mode.h

@@ -149,6 +149,7 @@ struct radeon_tmds_pll {
 #define RADEON_PLL_PREFER_CLOSEST_LOWER (1 << 11)
 #define RADEON_PLL_USE_POST_DIV         (1 << 12)
 #define RADEON_PLL_IS_LCD               (1 << 13)
+#define RADEON_PLL_PREFER_MINM_OVER_MAXP (1 << 14)
 
 struct radeon_pll {
 	/* reference frequency */
@@ -510,7 +511,7 @@ extern bool radeon_atombios_get_asic_ss_info(struct radeon_device *rdev,
 					     struct radeon_atom_ss *ss,
 					     int id, u32 clock);
 
-extern void radeon_compute_pll(struct radeon_pll *pll,
+extern void radeon_compute_pll_legacy(struct radeon_pll *pll,
 				      uint64_t freq,
 				      uint32_t *dot_clock_p,
 				      uint32_t *fb_div_p,
@@ -518,6 +519,14 @@ extern void radeon_compute_pll(struct radeon_pll *pll,
 				      uint32_t *ref_div_p,
 				      uint32_t *post_div_p);
 
+extern void radeon_compute_pll_avivo(struct radeon_pll *pll,
+				     u32 freq,
+				     u32 *dot_clock_p,
+				     u32 *fb_div_p,
+				     u32 *frac_fb_div_p,
+				     u32 *ref_div_p,
+				     u32 *post_div_p);
+
 extern void radeon_setup_encoder_clones(struct drm_device *dev);
 
 struct drm_encoder *radeon_encoder_legacy_lvds_add(struct drm_device *dev, int bios_index);