[PATCH 2/2] drm/i915: add fast boot support for Haswell

[Furquan Shaikh <furquan@google.com>]

Enables getting correct mode clock when reading pipe config
This patch has been tested successfully on top of drm-intel-nightly tree

Signed-off-by: Furquan Shaikh <furquan@google.com>
---
 drivers/gpu/drm/i915/i915_reg.h      |  6 ++++
 drivers/gpu/drm/i915/intel_ddi.c     | 70 ++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_display.c |  1 +
 3 files changed, 77 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2b96d6b..9511129 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4970,6 +4970,7 @@
 #define  SPLL_PLL_NON_SSC		(2<<28)
 #define  SPLL_PLL_FREQ_810MHz		(0<<26)
 #define  SPLL_PLL_FREQ_1350MHz		(1<<26)
+#define  SPLL_PLL_FREQ_MASK             (3<<26)
 
 /* WRPLL */
 #define WRPLL_CTL1			0x46040
@@ -4983,6 +4984,10 @@
 #define  WRPLL_DIVIDER_POST(x)		((x)<<8)
 #define  WRPLL_DIVIDER_FEEDBACK(x)	((x)<<16)
 
+#define WRPLL_DIVIDER_REFERENCE_BITS(reg)    (reg & 0xff)
+#define WRPLL_DIVIDER_POST_BITS(reg)         ((reg >> 8) & 0x3f)
+#define WRPLL_DIVIDER_FEEDBACK_BITS(reg)     ((reg >> 16) & 0xff)
+
 /* Port clock selection */
 #define PORT_CLK_SEL_A			0x46100
 #define PORT_CLK_SEL_B			0x46104
@@ -4994,6 +4999,7 @@
 #define  PORT_CLK_SEL_WRPLL1		(4<<29)
 #define  PORT_CLK_SEL_WRPLL2		(5<<29)
 #define  PORT_CLK_SEL_NONE		(7<<29)
+#define  PORT_CLK_SEL_MASK              (7<<29)
 
 /* Transcoder clock selection */
 #define TRANS_CLK_SEL_A			0x46140
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index b8c096b..a24a375 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1246,6 +1246,74 @@ static void intel_ddi_hot_plug(struct intel_encoder *intel_encoder)
 		intel_dp_check_link_status(intel_dp);
 }
 
+static void intel_ddi_get_clock(struct intel_encoder *encoder,
+				struct intel_crtc_config *pipe_config)
+{
+	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+	int port = intel_ddi_get_encoder_port(encoder);
+	u32 temp = I915_READ(PORT_CLK_SEL(port)) & PORT_CLK_SEL_MASK;
+	u8 link_bw;
+
+	if ((temp == PORT_CLK_SEL_LCPLL_810) ||
+	    (temp == PORT_CLK_SEL_LCPLL_1350) ||
+	    (temp == PORT_CLK_SEL_LCPLL_2700)) {
+
+		switch (temp) {
+		case PORT_CLK_SEL_LCPLL_810:
+			link_bw = DP_LINK_BW_1_62;
+			break;
+		case PORT_CLK_SEL_LCPLL_1350:
+			link_bw = DP_LINK_BW_2_7;
+			break;
+		case PORT_CLK_SEL_LCPLL_2700:
+			link_bw = DP_LINK_BW_5_4;
+			break;
+		}
+		pipe_config->port_clock = drm_dp_bw_code_to_link_rate(link_bw);
+	} else if ((temp == PORT_CLK_SEL_WRPLL1) ||
+		   (temp == PORT_CLK_SEL_WRPLL2)) {
+		uint64_t p, n2, r2;
+		u32 val, reg;
+		uint64_t freq2k;
+
+		switch (temp) {
+		case PORT_CLK_SEL_WRPLL1:
+			reg = WRPLL_CTL1;
+			break;
+		case PORT_CLK_SEL_WRPLL2:
+			reg = WRPLL_CTL2;
+			break;
+		}
+		val = I915_READ(reg);
+		r2 = WRPLL_DIVIDER_REFERENCE_BITS(val);
+		p = WRPLL_DIVIDER_POST_BITS(val);
+		n2 = WRPLL_DIVIDER_FEEDBACK_BITS(val);
+
+		freq2k = DIV_ROUND_UP_ULL(LC_FREQ * n2, r2 * p);
+		pipe_config->port_clock = freq2k / 10;
+	} else if (temp == PORT_CLK_SEL_SPLL) {
+		u32 val;
+
+		val = I915_READ(PORT_CLK_SEL_SPLL);
+
+		switch (val & SPLL_PLL_FREQ_MASK) {
+		case SPLL_PLL_FREQ_810MHz:
+			pipe_config->port_clock = 810000;
+			break;
+		case SPLL_PLL_FREQ_1350MHz:
+			pipe_config->port_clock = 1350000;
+			break;
+		default:
+			WARN(1, "Invalid pll freq %d\n",
+			     val & SPLL_PLL_FREQ_MASK);
+			return;
+		}
+	} else {
+		WARN(1, "Invalid clock selection %d\n", temp);
+		return;
+	}
+}
+
 static void intel_ddi_get_config(struct intel_encoder *encoder,
 				 struct intel_crtc_config *pipe_config)
 {
@@ -1265,6 +1333,8 @@ static void intel_ddi_get_config(struct intel_encoder *encoder,
 		flags |= DRM_MODE_FLAG_NVSYNC;
 
 	pipe_config->adjusted_mode.flags |= flags;
+
+	intel_ddi_get_clock(encoder, pipe_config);
 }
 
 static void intel_ddi_destroy(struct drm_encoder *encoder)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e0069f4..1c6a3d2 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9579,6 +9579,7 @@ static void intel_init_display(struct drm_device *dev)
 
 	if (HAS_DDI(dev)) {
 		dev_priv->display.get_pipe_config = haswell_get_pipe_config;
+		dev_priv->display.get_clock = ironlake_crtc_clock_get;
 		dev_priv->display.crtc_mode_set = haswell_crtc_mode_set;
 		dev_priv->display.crtc_enable = haswell_crtc_enable;
 		dev_priv->display.crtc_disable = haswell_crtc_disable;
-- 
1.8.3