drm/i915: Move the hsw/bdw pc8 code to intel_runtime_pm.c

hsw_enable_pc8()/hsw_disable_pc8() are more less equivalent to
the display core init/unit functions of later platforms. Relocate
the hsw/bdw code into intel_runtime_pm.c so that it sits next to
its cousins.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190503193143.28240-2-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>

1 files changed, 223 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index b1fd2ae99199..b8fadd1b685c 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -3642,6 +3642,229 @@ static void hsw_assert_cdclk(struct drm_i915_private *dev_priv)
 		DRM_ERROR("LCPLL is disabled\n");
 }
 
+static void assert_can_disable_lcpll(struct drm_i915_private *dev_priv)
+{
+	struct drm_device *dev = &dev_priv->drm;
+	struct intel_crtc *crtc;
+
+	for_each_intel_crtc(dev, crtc)
+		I915_STATE_WARN(crtc->active, "CRTC for pipe %c enabled\n",
+				pipe_name(crtc->pipe));
+
+	I915_STATE_WARN(I915_READ(HSW_PWR_WELL_CTL2),
+			"Display power well on\n");
+	I915_STATE_WARN(I915_READ(SPLL_CTL) & SPLL_PLL_ENABLE,
+			"SPLL enabled\n");
+	I915_STATE_WARN(I915_READ(WRPLL_CTL(0)) & WRPLL_PLL_ENABLE,
+			"WRPLL1 enabled\n");
+	I915_STATE_WARN(I915_READ(WRPLL_CTL(1)) & WRPLL_PLL_ENABLE,
+			"WRPLL2 enabled\n");
+	I915_STATE_WARN(I915_READ(PP_STATUS(0)) & PP_ON,
+			"Panel power on\n");
+	I915_STATE_WARN(I915_READ(BLC_PWM_CPU_CTL2) & BLM_PWM_ENABLE,
+			"CPU PWM1 enabled\n");
+	if (IS_HASWELL(dev_priv))
+		I915_STATE_WARN(I915_READ(HSW_BLC_PWM2_CTL) & BLM_PWM_ENABLE,
+				"CPU PWM2 enabled\n");
+	I915_STATE_WARN(I915_READ(BLC_PWM_PCH_CTL1) & BLM_PCH_PWM_ENABLE,
+			"PCH PWM1 enabled\n");
+	I915_STATE_WARN(I915_READ(UTIL_PIN_CTL) & UTIL_PIN_ENABLE,
+			"Utility pin enabled\n");
+	I915_STATE_WARN(I915_READ(PCH_GTC_CTL) & PCH_GTC_ENABLE,
+			"PCH GTC enabled\n");
+
+	/*
+	 * In theory we can still leave IRQs enabled, as long as only the HPD
+	 * interrupts remain enabled. We used to check for that, but since it's
+	 * gen-specific and since we only disable LCPLL after we fully disable
+	 * the interrupts, the check below should be enough.
+	 */
+	I915_STATE_WARN(intel_irqs_enabled(dev_priv), "IRQs enabled\n");
+}
+
+static u32 hsw_read_dcomp(struct drm_i915_private *dev_priv)
+{
+	if (IS_HASWELL(dev_priv))
+		return I915_READ(D_COMP_HSW);
+	else
+		return I915_READ(D_COMP_BDW);
+}
+
+static void hsw_write_dcomp(struct drm_i915_private *dev_priv, u32 val)
+{
+	if (IS_HASWELL(dev_priv)) {
+		if (sandybridge_pcode_write(dev_priv,
+					    GEN6_PCODE_WRITE_D_COMP, val))
+			DRM_DEBUG_KMS("Failed to write to D_COMP\n");
+	} else {
+		I915_WRITE(D_COMP_BDW, val);
+		POSTING_READ(D_COMP_BDW);
+	}
+}
+
+/*
+ * This function implements pieces of two sequences from BSpec:
+ * - Sequence for display software to disable LCPLL
+ * - Sequence for display software to allow package C8+
+ * The steps implemented here are just the steps that actually touch the LCPLL
+ * register. Callers should take care of disabling all the display engine
+ * functions, doing the mode unset, fixing interrupts, etc.
+ */
+static void hsw_disable_lcpll(struct drm_i915_private *dev_priv,
+			      bool switch_to_fclk, bool allow_power_down)
+{
+	u32 val;
+
+	assert_can_disable_lcpll(dev_priv);
+
+	val = I915_READ(LCPLL_CTL);
+
+	if (switch_to_fclk) {
+		val |= LCPLL_CD_SOURCE_FCLK;
+		I915_WRITE(LCPLL_CTL, val);
+
+		if (wait_for_us(I915_READ(LCPLL_CTL) &
+				LCPLL_CD_SOURCE_FCLK_DONE, 1))
+			DRM_ERROR("Switching to FCLK failed\n");
+
+		val = I915_READ(LCPLL_CTL);
+	}
+
+	val |= LCPLL_PLL_DISABLE;
+	I915_WRITE(LCPLL_CTL, val);
+	POSTING_READ(LCPLL_CTL);
+
+	if (intel_wait_for_register(&dev_priv->uncore, LCPLL_CTL,
+				    LCPLL_PLL_LOCK, 0, 1))
+		DRM_ERROR("LCPLL still locked\n");
+
+	val = hsw_read_dcomp(dev_priv);
+	val |= D_COMP_COMP_DISABLE;
+	hsw_write_dcomp(dev_priv, val);
+	ndelay(100);
+
+	if (wait_for((hsw_read_dcomp(dev_priv) &
+		      D_COMP_RCOMP_IN_PROGRESS) == 0, 1))
+		DRM_ERROR("D_COMP RCOMP still in progress\n");
+
+	if (allow_power_down) {
+		val = I915_READ(LCPLL_CTL);
+		val |= LCPLL_POWER_DOWN_ALLOW;
+		I915_WRITE(LCPLL_CTL, val);
+		POSTING_READ(LCPLL_CTL);
+	}
+}
+
+/*
+ * Fully restores LCPLL, disallowing power down and switching back to LCPLL
+ * source.
+ */
+static void hsw_restore_lcpll(struct drm_i915_private *dev_priv)
+{
+	u32 val;
+
+	val = I915_READ(LCPLL_CTL);
+
+	if ((val & (LCPLL_PLL_LOCK | LCPLL_PLL_DISABLE | LCPLL_CD_SOURCE_FCLK |
+		    LCPLL_POWER_DOWN_ALLOW)) == LCPLL_PLL_LOCK)
+		return;
+
+	/*
+	 * Make sure we're not on PC8 state before disabling PC8, otherwise
+	 * we'll hang the machine. To prevent PC8 state, just enable force_wake.
+	 */
+	intel_uncore_forcewake_get(&dev_priv->uncore, FORCEWAKE_ALL);
+
+	if (val & LCPLL_POWER_DOWN_ALLOW) {
+		val &= ~LCPLL_POWER_DOWN_ALLOW;
+		I915_WRITE(LCPLL_CTL, val);
+		POSTING_READ(LCPLL_CTL);
+	}
+
+	val = hsw_read_dcomp(dev_priv);
+	val |= D_COMP_COMP_FORCE;
+	val &= ~D_COMP_COMP_DISABLE;
+	hsw_write_dcomp(dev_priv, val);
+
+	val = I915_READ(LCPLL_CTL);
+	val &= ~LCPLL_PLL_DISABLE;
+	I915_WRITE(LCPLL_CTL, val);
+
+	if (intel_wait_for_register(&dev_priv->uncore, LCPLL_CTL,
+				    LCPLL_PLL_LOCK, LCPLL_PLL_LOCK, 5))
+		DRM_ERROR("LCPLL not locked yet\n");
+
+	if (val & LCPLL_CD_SOURCE_FCLK) {
+		val = I915_READ(LCPLL_CTL);
+		val &= ~LCPLL_CD_SOURCE_FCLK;
+		I915_WRITE(LCPLL_CTL, val);
+
+		if (wait_for_us((I915_READ(LCPLL_CTL) &
+				 LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1))
+			DRM_ERROR("Switching back to LCPLL failed\n");
+	}
+
+	intel_uncore_forcewake_put(&dev_priv->uncore, FORCEWAKE_ALL);
+
+	intel_update_cdclk(dev_priv);
+	intel_dump_cdclk_state(&dev_priv->cdclk.hw, "Current CDCLK");
+}
+
+/*
+ * Package states C8 and deeper are really deep PC states that can only be
+ * reached when all the devices on the system allow it, so even if the graphics
+ * device allows PC8+, it doesn't mean the system will actually get to these
+ * states. Our driver only allows PC8+ when going into runtime PM.
+ *
+ * The requirements for PC8+ are that all the outputs are disabled, the power
+ * well is disabled and most interrupts are disabled, and these are also
+ * requirements for runtime PM. When these conditions are met, we manually do
+ * the other conditions: disable the interrupts, clocks and switch LCPLL refclk
+ * to Fclk. If we're in PC8+ and we get an non-hotplug interrupt, we can hard
+ * hang the machine.
+ *
+ * When we really reach PC8 or deeper states (not just when we allow it) we lose
+ * the state of some registers, so when we come back from PC8+ we need to
+ * restore this state. We don't get into PC8+ if we're not in RC6, so we don't
+ * need to take care of the registers kept by RC6. Notice that this happens even
+ * if we don't put the device in PCI D3 state (which is what currently happens
+ * because of the runtime PM support).
+ *
+ * For more, read "Display Sequences for Package C8" on the hardware
+ * documentation.
+ */
+void hsw_enable_pc8(struct drm_i915_private *dev_priv)
+{
+	u32 val;
+
+	DRM_DEBUG_KMS("Enabling package C8+\n");
+
+	if (HAS_PCH_LPT_LP(dev_priv)) {
+		val = I915_READ(SOUTH_DSPCLK_GATE_D);
+		val &= ~PCH_LP_PARTITION_LEVEL_DISABLE;
+		I915_WRITE(SOUTH_DSPCLK_GATE_D, val);
+	}
+
+	lpt_disable_clkout_dp(dev_priv);
+	hsw_disable_lcpll(dev_priv, true, true);
+}
+
+void hsw_disable_pc8(struct drm_i915_private *dev_priv)
+{
+	u32 val;
+
+	DRM_DEBUG_KMS("Disabling package C8+\n");
+
+	hsw_restore_lcpll(dev_priv);
+	intel_init_pch_refclk(dev_priv);
+
+	if (HAS_PCH_LPT_LP(dev_priv)) {
+		val = I915_READ(SOUTH_DSPCLK_GATE_D);
+		val |= PCH_LP_PARTITION_LEVEL_DISABLE;
+		I915_WRITE(SOUTH_DSPCLK_GATE_D, val);
+	}
+}
+
 static void intel_pch_reset_handshake(struct drm_i915_private *dev_priv,
 				      bool enable)
 {