[PATCH 2/3] drm/i915/cnl: use previous pll hw readout

[Lucas De Marchi <lucas.demarchi@intel.com>]

By the time cnl_ddi_clock_get() is called we've just got the hw state
from the pll registers. We don't need to read them again: we can rather
reuse what was cached in the dpll_hw_state.

This also affects the code for ICL since it partially reuses the CNL
code. However the more intricate part on ICL is left for another patch.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
---
 drivers/gpu/drm/i915/icl_dsi.c   |  5 ++-
 drivers/gpu/drm/i915/intel_ddi.c | 53 +++++++++++++++++---------------
 drivers/gpu/drm/i915/intel_drv.h |  2 +-
 3 files changed, 31 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/i915/icl_dsi.c b/drivers/gpu/drm/i915/icl_dsi.c
index beb30d9a855c..c7dcd783d986 100644
--- a/drivers/gpu/drm/i915/icl_dsi.c
+++ b/drivers/gpu/drm/i915/icl_dsi.c
@@ -1179,11 +1179,10 @@ static void gen11_dsi_get_config(struct intel_encoder *encoder,
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
-	u32 pll_id;
 
 	/* FIXME: adapt icl_ddi_clock_get() for DSI and use that? */
-	pll_id = intel_get_shared_dpll_id(dev_priv, pipe_config->shared_dpll);
-	pipe_config->port_clock = cnl_calc_wrpll_link(dev_priv, pll_id);
+	pipe_config->port_clock =
+		cnl_calc_wrpll_link(dev_priv, &pipe_config->dpll_hw_state);
 	pipe_config->base.adjusted_mode.crtc_clock = intel_dsi->pclk;
 	pipe_config->output_types |= BIT(INTEL_OUTPUT_DSI);
 }
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 644541924208..fe52af9fa4aa 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1294,25 +1294,17 @@ static int skl_calc_wrpll_link(struct intel_dpll_hw_state *state)
 	return dco_freq / (p0 * p1 * p2 * 5);
 }
 
+
 int cnl_calc_wrpll_link(struct drm_i915_private *dev_priv,
-			enum intel_dpll_id pll_id)
+			struct intel_dpll_hw_state *state)
 {
-	u32 cfgcr0, cfgcr1;
 	u32 p0, p1, p2, dco_freq, ref_clock;
 
-	if (INTEL_GEN(dev_priv) >= 11) {
-		cfgcr0 = I915_READ(ICL_DPLL_CFGCR0(pll_id));
-		cfgcr1 = I915_READ(ICL_DPLL_CFGCR1(pll_id));
-	} else {
-		cfgcr0 = I915_READ(CNL_DPLL_CFGCR0(pll_id));
-		cfgcr1 = I915_READ(CNL_DPLL_CFGCR1(pll_id));
-	}
-
-	p0 = cfgcr1 & DPLL_CFGCR1_PDIV_MASK;
-	p2 = cfgcr1 & DPLL_CFGCR1_KDIV_MASK;
+	p0 = state->cfgcr1 & DPLL_CFGCR1_PDIV_MASK;
+	p2 = state->cfgcr1 & DPLL_CFGCR1_KDIV_MASK;
 
-	if (cfgcr1 & DPLL_CFGCR1_QDIV_MODE(1))
-		p1 = (cfgcr1 & DPLL_CFGCR1_QDIV_RATIO_MASK) >>
+	if (state->cfgcr1 & DPLL_CFGCR1_QDIV_MODE(1))
+		p1 = (state->cfgcr1 & DPLL_CFGCR1_QDIV_RATIO_MASK) >>
 			DPLL_CFGCR1_QDIV_RATIO_SHIFT;
 	else
 		p1 = 1;
@@ -1347,9 +1339,9 @@ int cnl_calc_wrpll_link(struct drm_i915_private *dev_priv,
 
 	ref_clock = cnl_hdmi_pll_ref_clock(dev_priv);
 
-	dco_freq = (cfgcr0 & DPLL_CFGCR0_DCO_INTEGER_MASK) * ref_clock;
+	dco_freq = (state->cfgcr0 & DPLL_CFGCR0_DCO_INTEGER_MASK) * ref_clock;
 
-	dco_freq += (((cfgcr0 & DPLL_CFGCR0_DCO_FRACTION_MASK) >>
+	dco_freq += (((state->cfgcr0 & DPLL_CFGCR0_DCO_FRACTION_MASK) >>
 		      DPLL_CFGCR0_DCO_FRACTION_SHIFT) * ref_clock) / 0x8000;
 
 	if (WARN_ON(p0 == 0 || p1 == 0 || p2 == 0))
@@ -1462,13 +1454,21 @@ static void icl_ddi_clock_get(struct intel_encoder *encoder,
 			      struct intel_crtc_state *pipe_config)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	struct intel_dpll_hw_state *state;
 	enum port port = encoder->port;
 	int link_clock = 0;
 	u32 pll_id;
 
 	pll_id = intel_get_shared_dpll_id(dev_priv, pipe_config->shared_dpll);
+
+	/* For DDI ports we always use a shared PLL. */
+	if (WARN_ON(!pipe_config->shared_dpll))
+		goto end;
+
+	state = &pipe_config->dpll_hw_state;
+
 	if (intel_port_is_combophy(dev_priv, port)) {
-		link_clock = cnl_calc_wrpll_link(dev_priv, pll_id);
+		link_clock = cnl_calc_wrpll_link(dev_priv, state);
 	} else {
 		if (pll_id == DPLL_ID_ICL_TBTPLL)
 			link_clock = icl_calc_tbt_pll_link(dev_priv, port);
@@ -1476,7 +1476,9 @@ static void icl_ddi_clock_get(struct intel_encoder *encoder,
 			link_clock = icl_calc_mg_pll_link(dev_priv, port);
 	}
 
+end:
 	pipe_config->port_clock = link_clock;
+
 	ddi_dotclock_get(pipe_config);
 }
 
@@ -1484,18 +1486,18 @@ static void cnl_ddi_clock_get(struct intel_encoder *encoder,
 			      struct intel_crtc_state *pipe_config)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	struct intel_dpll_hw_state *state;
 	int link_clock = 0;
-	u32 cfgcr0;
-	enum intel_dpll_id pll_id;
-
-	pll_id = intel_get_shared_dpll_id(dev_priv, pipe_config->shared_dpll);
 
-	cfgcr0 = I915_READ(CNL_DPLL_CFGCR0(pll_id));
+	/* For DDI ports we always use a shared PLL. */
+	if (WARN_ON(!pipe_config->shared_dpll))
+		goto end;
 
-	if (cfgcr0 & DPLL_CFGCR0_HDMI_MODE) {
-		link_clock = cnl_calc_wrpll_link(dev_priv, pll_id);
+	state = &pipe_config->dpll_hw_state;
+	if (state->cfgcr0 & DPLL_CFGCR0_HDMI_MODE) {
+		link_clock = cnl_calc_wrpll_link(dev_priv, state);
 	} else {
-		link_clock = cfgcr0 & DPLL_CFGCR0_LINK_RATE_MASK;
+		link_clock = state->cfgcr0 & DPLL_CFGCR0_LINK_RATE_MASK;
 
 		switch (link_clock) {
 		case DPLL_CFGCR0_LINK_RATE_810:
@@ -1529,6 +1531,7 @@ static void cnl_ddi_clock_get(struct intel_encoder *encoder,
 		link_clock *= 2;
 	}
 
+end:
 	pipe_config->port_clock = link_clock;
 
 	ddi_dotclock_get(pipe_config);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 4d7ae579fc92..65ab0f90ce6a 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1659,7 +1659,7 @@ int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder,
 				     bool enable);
 void icl_sanitize_encoder_pll_mapping(struct intel_encoder *encoder);
 int cnl_calc_wrpll_link(struct drm_i915_private *dev_priv,
-			enum intel_dpll_id pll_id);
+			struct intel_dpll_hw_state *state);
 
 unsigned int intel_fb_align_height(const struct drm_framebuffer *fb,
 				   int color_plane, unsigned int height);
-- 
2.20.1

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