drm/i915: Move SKL/KLB pll selection logic to intel_dpll_mgr.c

Move the code for selecting plls for SKL/KLB into the shared dpll code,
so that the platform specific details are hidden behind that interface.

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457451987-17466-11-git-send-email-ander.conselvan.de.oliveira@intel.com

1 files changed, 305 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
index 224c8965ec95..61887ae82b31 100644
--- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -837,16 +837,319 @@ out:
 	return ret;
 }
 
+struct skl_wrpll_context {
+	uint64_t min_deviation;		/* current minimal deviation */
+	uint64_t central_freq;		/* chosen central freq */
+	uint64_t dco_freq;		/* chosen dco freq */
+	unsigned int p;			/* chosen divider */
+};
+
+static void skl_wrpll_context_init(struct skl_wrpll_context *ctx)
+{
+	memset(ctx, 0, sizeof(*ctx));
+
+	ctx->min_deviation = U64_MAX;
+}
+
+/* DCO freq must be within +1%/-6%  of the DCO central freq */
+#define SKL_DCO_MAX_PDEVIATION	100
+#define SKL_DCO_MAX_NDEVIATION	600
+
+static void skl_wrpll_try_divider(struct skl_wrpll_context *ctx,
+				  uint64_t central_freq,
+				  uint64_t dco_freq,
+				  unsigned int divider)
+{
+	uint64_t deviation;
+
+	deviation = div64_u64(10000 * abs_diff(dco_freq, central_freq),
+			      central_freq);
+
+	/* positive deviation */
+	if (dco_freq >= central_freq) {
+		if (deviation < SKL_DCO_MAX_PDEVIATION &&
+		    deviation < ctx->min_deviation) {
+			ctx->min_deviation = deviation;
+			ctx->central_freq = central_freq;
+			ctx->dco_freq = dco_freq;
+			ctx->p = divider;
+		}
+	/* negative deviation */
+	} else if (deviation < SKL_DCO_MAX_NDEVIATION &&
+		   deviation < ctx->min_deviation) {
+		ctx->min_deviation = deviation;
+		ctx->central_freq = central_freq;
+		ctx->dco_freq = dco_freq;
+		ctx->p = divider;
+	}
+}
+
+static void skl_wrpll_get_multipliers(unsigned int p,
+				      unsigned int *p0 /* out */,
+				      unsigned int *p1 /* out */,
+				      unsigned int *p2 /* out */)
+{
+	/* even dividers */
+	if (p % 2 == 0) {
+		unsigned int half = p / 2;
+
+		if (half == 1 || half == 2 || half == 3 || half == 5) {
+			*p0 = 2;
+			*p1 = 1;
+			*p2 = half;
+		} else if (half % 2 == 0) {
+			*p0 = 2;
+			*p1 = half / 2;
+			*p2 = 2;
+		} else if (half % 3 == 0) {
+			*p0 = 3;
+			*p1 = half / 3;
+			*p2 = 2;
+		} else if (half % 7 == 0) {
+			*p0 = 7;
+			*p1 = half / 7;
+			*p2 = 2;
+		}
+	} else if (p == 3 || p == 9) {  /* 3, 5, 7, 9, 15, 21, 35 */
+		*p0 = 3;
+		*p1 = 1;
+		*p2 = p / 3;
+	} else if (p == 5 || p == 7) {
+		*p0 = p;
+		*p1 = 1;
+		*p2 = 1;
+	} else if (p == 15) {
+		*p0 = 3;
+		*p1 = 1;
+		*p2 = 5;
+	} else if (p == 21) {
+		*p0 = 7;
+		*p1 = 1;
+		*p2 = 3;
+	} else if (p == 35) {
+		*p0 = 7;
+		*p1 = 1;
+		*p2 = 5;
+	}
+}
+
+struct skl_wrpll_params {
+	uint32_t        dco_fraction;
+	uint32_t        dco_integer;
+	uint32_t        qdiv_ratio;
+	uint32_t        qdiv_mode;
+	uint32_t        kdiv;
+	uint32_t        pdiv;
+	uint32_t        central_freq;
+};
+
+static void skl_wrpll_params_populate(struct skl_wrpll_params *params,
+				      uint64_t afe_clock,
+				      uint64_t central_freq,
+				      uint32_t p0, uint32_t p1, uint32_t p2)
+{
+	uint64_t dco_freq;
+
+	switch (central_freq) {
+	case 9600000000ULL:
+		params->central_freq = 0;
+		break;
+	case 9000000000ULL:
+		params->central_freq = 1;
+		break;
+	case 8400000000ULL:
+		params->central_freq = 3;
+	}
+
+	switch (p0) {
+	case 1:
+		params->pdiv = 0;
+		break;
+	case 2:
+		params->pdiv = 1;
+		break;
+	case 3:
+		params->pdiv = 2;
+		break;
+	case 7:
+		params->pdiv = 4;
+		break;
+	default:
+		WARN(1, "Incorrect PDiv\n");
+	}
+
+	switch (p2) {
+	case 5:
+		params->kdiv = 0;
+		break;
+	case 2:
+		params->kdiv = 1;
+		break;
+	case 3:
+		params->kdiv = 2;
+		break;
+	case 1:
+		params->kdiv = 3;
+		break;
+	default:
+		WARN(1, "Incorrect KDiv\n");
+	}
+
+	params->qdiv_ratio = p1;
+	params->qdiv_mode = (params->qdiv_ratio == 1) ? 0 : 1;
+
+	dco_freq = p0 * p1 * p2 * afe_clock;
+
+	/*
+	 * Intermediate values are in Hz.
+	 * Divide by MHz to match bsepc
+	 */
+	params->dco_integer = div_u64(dco_freq, 24 * MHz(1));
+	params->dco_fraction =
+		div_u64((div_u64(dco_freq, 24) -
+			 params->dco_integer * MHz(1)) * 0x8000, MHz(1));
+}
+
+static bool
+skl_ddi_calculate_wrpll(int clock /* in Hz */,
+			struct skl_wrpll_params *wrpll_params)
+{
+	uint64_t afe_clock = clock * 5; /* AFE Clock is 5x Pixel clock */
+	uint64_t dco_central_freq[3] = {8400000000ULL,
+					9000000000ULL,
+					9600000000ULL};
+	static const int even_dividers[] = {  4,  6,  8, 10, 12, 14, 16, 18, 20,
+					     24, 28, 30, 32, 36, 40, 42, 44,
+					     48, 52, 54, 56, 60, 64, 66, 68,
+					     70, 72, 76, 78, 80, 84, 88, 90,
+					     92, 96, 98 };
+	static const int odd_dividers[] = { 3, 5, 7, 9, 15, 21, 35 };
+	static const struct {
+		const int *list;
+		int n_dividers;
+	} dividers[] = {
+		{ even_dividers, ARRAY_SIZE(even_dividers) },
+		{ odd_dividers, ARRAY_SIZE(odd_dividers) },
+	};
+	struct skl_wrpll_context ctx;
+	unsigned int dco, d, i;
+	unsigned int p0, p1, p2;
+
+	skl_wrpll_context_init(&ctx);
+
+	for (d = 0; d < ARRAY_SIZE(dividers); d++) {
+		for (dco = 0; dco < ARRAY_SIZE(dco_central_freq); dco++) {
+			for (i = 0; i < dividers[d].n_dividers; i++) {
+				unsigned int p = dividers[d].list[i];
+				uint64_t dco_freq = p * afe_clock;
+
+				skl_wrpll_try_divider(&ctx,
+						      dco_central_freq[dco],
+						      dco_freq,
+						      p);
+				/*
+				 * Skip the remaining dividers if we're sure to
+				 * have found the definitive divider, we can't
+				 * improve a 0 deviation.
+				 */
+				if (ctx.min_deviation == 0)
+					goto skip_remaining_dividers;
+			}
+		}
+
+skip_remaining_dividers:
+		/*
+		 * If a solution is found with an even divider, prefer
+		 * this one.
+		 */
+		if (d == 0 && ctx.p)
+			break;
+	}
+
+	if (!ctx.p) {
+		DRM_DEBUG_DRIVER("No valid divider found for %dHz\n", clock);
+		return false;
+	}
+
+	/*
+	 * gcc incorrectly analyses that these can be used without being
+	 * initialized. To be fair, it's hard to guess.
+	 */
+	p0 = p1 = p2 = 0;
+	skl_wrpll_get_multipliers(ctx.p, &p0, &p1, &p2);
+	skl_wrpll_params_populate(wrpll_params, afe_clock, ctx.central_freq,
+				  p0, p1, p2);
+
+	return true;
+}
+
 static struct intel_shared_dpll *
 skl_get_dpll(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state,
 	     struct intel_encoder *encoder)
 {
 	struct intel_shared_dpll *pll;
+	uint32_t ctrl1, cfgcr1, cfgcr2;
+	int clock = crtc_state->port_clock;
+
+	/*
+	 * See comment in intel_dpll_hw_state to understand why we always use 0
+	 * as the DPLL id in this function.
+	 */
+
+	ctrl1 = DPLL_CTRL1_OVERRIDE(0);
+
+	if (encoder->type == INTEL_OUTPUT_HDMI) {
+		struct skl_wrpll_params wrpll_params = { 0, };
+
+		ctrl1 |= DPLL_CTRL1_HDMI_MODE(0);
+
+		if (!skl_ddi_calculate_wrpll(clock * 1000, &wrpll_params))
+			return false;
+
+		cfgcr1 = DPLL_CFGCR1_FREQ_ENABLE |
+			 DPLL_CFGCR1_DCO_FRACTION(wrpll_params.dco_fraction) |
+			 wrpll_params.dco_integer;
+
+		cfgcr2 = DPLL_CFGCR2_QDIV_RATIO(wrpll_params.qdiv_ratio) |
+			 DPLL_CFGCR2_QDIV_MODE(wrpll_params.qdiv_mode) |
+			 DPLL_CFGCR2_KDIV(wrpll_params.kdiv) |
+			 DPLL_CFGCR2_PDIV(wrpll_params.pdiv) |
+			 wrpll_params.central_freq;
+	} else if (encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
+		   encoder->type == INTEL_OUTPUT_DP_MST) {
+		switch (crtc_state->port_clock / 2) {
+		case 81000:
+			ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_810, 0);
+			break;
+		case 135000:
+			ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1350, 0);
+			break;
+		case 270000:
+			ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2700, 0);
+			break;
+		}
+
+		cfgcr1 = cfgcr2 = 0;
+	} else {
+		return NULL;
+	}
+
+	memset(&crtc_state->dpll_hw_state, 0,
+	       sizeof(crtc_state->dpll_hw_state));
+
+	crtc_state->dpll_hw_state.ctrl1 = ctrl1;
+	crtc_state->dpll_hw_state.cfgcr1 = cfgcr1;
+	crtc_state->dpll_hw_state.cfgcr2 = cfgcr2;
 
 	pll = intel_find_shared_dpll(crtc, crtc_state,
 				     DPLL_ID_SKL_DPLL1, DPLL_ID_SKL_DPLL3);
-	if (pll)
-		intel_reference_shared_dpll(pll, crtc_state);
+	if (!pll)
+		return NULL;
+
+	/* shared DPLL id 0 is DPLL 1 */
+	crtc_state->ddi_pll_sel = pll->id + 1;
+
+	intel_reference_shared_dpll(pll, crtc_state);
 
 	return pll;
 }