[Intel-gfx] [PATCH 28/29] drm/i915: prepare HDMI link for Haswell

[Eugeni Dodonov]

On Haswell, we need to properly train the DDI buffers prior to enabling
HDMI, and enable the required clocks with correct dividers for the desired
frequency.

Also, we cannot simple reuse HDMI routines from previous generations of
GPU, as most of HDMI-specific stuff is being done via the DDI port
programming instead of HDMI-specific registers.

This commit take advantage of the WR PLL clock table which is in a
separate (previous) commit to select the right divisors for each mode.

Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
---
 drivers/gpu/drm/i915/intel_hdmi.c |  129 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 128 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index d2f278f..e2b8847 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -665,6 +665,98 @@ static const struct wrpll_tmds_clock wrpll_tmds_clock_table[] = {
 	{298000,	2,	21,	19},
 };
 
+static void intel_hdmi_mode_set_hsw(struct drm_encoder *encoder,
+				struct drm_display_mode *mode,
+				struct drm_display_mode *adjusted_mode)
+{
+	struct drm_device *dev = encoder->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_crtc *crtc = encoder->crtc;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
+	int port = intel_hdmi->ddi_port;
+	int pipe = intel_crtc->pipe;
+	int p, n2, r2, valid=0;
+	u32 temp, i;
+
+	/* On Haswell, we need to enable the clocks and prepare DDI function to
+	 * work in HDMI mode for this pipe.
+	 */
+	DRM_DEBUG_KMS("Preparing HDMI DDI mode for Haswell on port %c, pipe %c\n", port_name(port), pipe_name(pipe));
+
+	for (i=0; i < ARRAY_SIZE(wrpll_tmds_clock_table); i++) {
+		if (crtc->mode.clock == wrpll_tmds_clock_table[i].clock) {
+			p = wrpll_tmds_clock_table[i].p;
+			n2 = wrpll_tmds_clock_table[i].n2;
+			r2 = wrpll_tmds_clock_table[i].r2;
+
+			DRM_INFO("Found clock settings for %dKHz refresh rate: p=%d, n2=%d, r2=%d\n",
+					crtc->mode.clock,
+					p, n2, r2);
+
+			valid = 1;
+			break;
+		}
+	}
+
+	if (!valid) {
+		DRM_ERROR("Unable to find WRPLL clock settings for %dKHz refresh rate\n",
+				crtc->mode.clock);
+		return;
+	}
+
+	/* Enable LCPLL if disabled */
+	temp = I915_READ(LCPLL_CTL);
+	if (temp & LCPLL_PLL_DISABLE)
+		I915_WRITE(LCPLL_CTL,
+				temp & ~LCPLL_PLL_DISABLE);
+
+	/* Configure WR PLL 1, program the correct divider values for
+	 * the desired frequency and wait for warmup */
+	I915_WRITE(WRPLL_CTL1,
+			WRPLL_PLL_ENABLE |
+			WRPLL_PLL_SELECT_LCPLL_2700 |
+			WRPLL_DIVIDER_REFERENCE(r2) |
+			WRPLL_DIVIDER_FEEDBACK(n2) |
+			WRPLL_DIVIDER_POST(p));
+
+	udelay(20);
+
+	/* Use WRPLL1 clock to drive the output to the port, and tell the pipe to use
+	 * this port for connection.
+	 */
+	I915_WRITE(PORT_CLK_SEL(port),
+			PORT_CLK_SEL_WRPLL1);
+	I915_WRITE(PIPE_CLK_SEL(pipe),
+			PIPE_CLK_SEL_PORT(port));
+
+	udelay(20);
+
+	if (intel_hdmi->has_audio) {
+		/* Proper support for digital audio needs a new logic and a new set
+		 * of registers, so we leave it for future patch bombing.
+		 */
+		DRM_DEBUG_DRIVER("HDMI audio on pipe %c not yet supported on DDI\n",
+				 pipe_name(intel_crtc->pipe));
+	}
+
+	/* Enable PIPE_DDI_FUNC_CTL for the pipe to work in HDMI mode */
+	temp = I915_READ(DDI_FUNC_CTL(pipe));
+	temp &= ~PIPE_DDI_PORT_MASK;
+	temp &= ~PIPE_DDI_BPC_12;
+	temp |= PIPE_DDI_SELECT_PORT(port) |
+			PIPE_DDI_MODE_SELECT_HDMI |
+			((intel_crtc->bpp > 24) ?
+				PIPE_DDI_BPC_12 :
+				PIPE_DDI_BPC_8) |
+			PIPE_DDI_FUNC_ENABLE;
+
+	I915_WRITE(DDI_FUNC_CTL(pipe), temp);
+
+	intel_hdmi_set_avi_infoframe(encoder);
+	intel_hdmi_set_spd_infoframe(encoder);
+}
+
 static void intel_hdmi_mode_set(struct drm_encoder *encoder,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode)
@@ -713,6 +805,30 @@ static void intel_hdmi_mode_set(struct drm_encoder *encoder,
 	intel_hdmi_set_spd_infoframe(encoder);
 }
 
+static void intel_hdmi_dpms_hsw(struct drm_encoder *encoder, int mode)
+{
+	struct drm_device *dev = encoder->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
+	int port = intel_hdmi->ddi_port;
+	u32 temp;
+
+	temp = I915_READ(DDI_BUF_CTL(port));
+
+	if (mode != DRM_MODE_DPMS_ON) {
+		temp &= ~DDI_BUF_CTL_ENABLE;
+	} else {
+		temp |= DDI_BUF_CTL_ENABLE;
+	}
+
+	/* Enable DDI_BUF_CTL. In HDMI/DVI mode, the port width,
+	 * and swing/emphasis values are ignored so nothing special needs
+	 * to be done besides enabling the port.
+	 */
+	I915_WRITE(DDI_BUF_CTL(port),
+			temp);
+}
+
 static void intel_hdmi_dpms(struct drm_encoder *encoder, int mode)
 {
 	struct drm_device *dev = encoder->dev;
@@ -914,6 +1030,14 @@ static void intel_hdmi_destroy(struct drm_connector *connector)
 	kfree(connector);
 }
 
+static const struct drm_encoder_helper_funcs intel_hdmi_helper_funcs_hsw = {
+	.dpms = intel_hdmi_dpms_hsw,
+	.mode_fixup = intel_hdmi_mode_fixup,
+	.prepare = intel_encoder_prepare,
+	.mode_set = intel_hdmi_mode_set_hsw,
+	.commit = intel_encoder_commit,
+};
+
 static const struct drm_encoder_helper_funcs intel_hdmi_helper_funcs = {
 	.dpms = intel_hdmi_dpms,
 	.mode_fixup = intel_hdmi_mode_fixup,
@@ -1044,7 +1168,10 @@ void intel_hdmi_init(struct drm_device *dev, int sdvox_reg)
 			I915_WRITE(TVIDEO_DIP_CTL(i), 0);
 	}
 
-	drm_encoder_helper_add(&intel_encoder->base, &intel_hdmi_helper_funcs);
+	if (IS_HASWELL(dev))
+		drm_encoder_helper_add(&intel_encoder->base, &intel_hdmi_helper_funcs_hsw);
+	else
+		drm_encoder_helper_add(&intel_encoder->base, &intel_hdmi_helper_funcs);
 
 	intel_hdmi_add_properties(intel_hdmi, connector);
 
-- 
1.7.10