drm/i915/bxt: add display initialize/uninitialize sequence (PHY)

Add PHY specific display initialization sequence as per BSpec.

Note that the PHY initialization/uninitialization are done
at their current place only for simplicity, in a future patch - when more
of the runtime PM features will be enabled - these will be moved to
power well#1 and modeset encoder enabling/disabling hooks respectively.

The call to uninitialize the PHY during system/runtime suspend will be
added later in this patchset.

v1: Added function definitions in header files
v2: Imre's review comments addressed
- Moved CDCLK related definitions to i915_reg.h
- Removed defintions for CDCLK frequency
- Split uninit_cdclk() by adding a phy_uninit function
- Calculate freq and decimal based on input frequency
- Program SSA precharge based on input frequency
- Use wait_for 1ms instead 200us udelay for DE PLL locking
- Removed initial value for divider, freq, decimal, ratio.
- Replaced polling loops with wait_for
- Parameterized latency optim setting
- Fix the parts where DE PLL has to be disabled.
- Call CDCLK selection from mode set

v3: (imre)
- add note about the plan to move the cdclk/phy init to a better place
- take rps.hw_lock around pcode access
- fix DDI PHY timeout value
- squash in Vandana's "PORT_CL2CM_DW6_A BUN fix",
  "DDI PHY programming register defn", "Do ddi_phy_init always",
- move PHY register macros next to the corresponding CHV/VLV macros
- move DE PLL register macros here from another patch since they are
  used here first
- add BXT_ prefix to CDCLK flags
- s/COMMON_RESET/COMMON_RESET_DIS/ and clarify related code comments
- fix incorrect read value for the RMW of BXT_PHY_CTL_FAMILY_DDI
- fix using GT_DISPLAY_EDP_POWER_ON vs. GT_DISPLAY_DDI_POWER_ON
  when powering on DDI ports
- fix incorrect port when setting BXT_PORT_TX_DW14_LN for DDI ports
- add missing masking when programming CDCLK_FREQ_DECIMAL
- add missing powering on for DDI-C port, rename OCL2_LDOFUSE_PWR_EN
  to OCL2_LDOFUSE_PWR_DIS to reduce confusion
- add note about mismatch with bspec in the PORT_REF_DW6 fields
- factor out PHY init code to a new function, so we can call it for
  PHY1 and PHY0, instead of open-coding the same

v4: (ville)
- split the CDCLK/PHY parts into two patches, update commit message
  accordingly
- use the existing dpio_phy enum instead of adding a new one for the
  same purpose
- flip the meaning of PHYs so that PHY_A is PHY1 and PHY_BC is PHY0 to
  better match CHV
- s/BXT_PHY/_BXT_PHY/
- use _PIPE for _BXT_PHY instead of open-coding it
- drop _0_2_0_GTTMMADR suffix from BXT_P_CR_GT_DISP_PWRON
- define GT_DISPLAY_POWER_ON in a more standard way
- make a note that the CHV ConfigDB also disagrees about GRC_CODE field
  definitions
- fix lane optimization refactoring fumble from v3
- add per PHY uninit functions to match the init counterparts

Signed-off-by: Vandana Kannan <vandana.kannan@intel.com> (v2)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 25d697b..31cadb8 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1864,6 +1864,130 @@
 	}
 }
 
+static void broxton_phy_init(struct drm_i915_private *dev_priv,
+			     enum dpio_phy phy)
+{
+	enum port port;
+	uint32_t val;
+
+	val = I915_READ(BXT_P_CR_GT_DISP_PWRON);
+	val |= GT_DISPLAY_POWER_ON(phy);
+	I915_WRITE(BXT_P_CR_GT_DISP_PWRON, val);
+
+	/* Considering 10ms timeout until BSpec is updated */
+	if (wait_for(I915_READ(BXT_PORT_CL1CM_DW0(phy)) & PHY_POWER_GOOD, 10))
+		DRM_ERROR("timeout during PHY%d power on\n", phy);
+
+	for (port =  (phy == DPIO_PHY0 ? PORT_B : PORT_A);
+	     port <= (phy == DPIO_PHY0 ? PORT_C : PORT_A); port++) {
+		int lane;
+
+		for (lane = 0; lane < 4; lane++) {
+			val = I915_READ(BXT_PORT_TX_DW14_LN(port, lane));
+			/*
+			 * Note that on CHV this flag is called UPAR, but has
+			 * the same function.
+			 */
+			val &= ~LATENCY_OPTIM;
+			if (lane != 1)
+				val |= LATENCY_OPTIM;
+
+			I915_WRITE(BXT_PORT_TX_DW14_LN(port, lane), val);
+		}
+	}
+
+	/* Program PLL Rcomp code offset */
+	val = I915_READ(BXT_PORT_CL1CM_DW9(phy));
+	val &= ~IREF0RC_OFFSET_MASK;
+	val |= 0xE4 << IREF0RC_OFFSET_SHIFT;
+	I915_WRITE(BXT_PORT_CL1CM_DW9(phy), val);
+
+	val = I915_READ(BXT_PORT_CL1CM_DW10(phy));
+	val &= ~IREF1RC_OFFSET_MASK;
+	val |= 0xE4 << IREF1RC_OFFSET_SHIFT;
+	I915_WRITE(BXT_PORT_CL1CM_DW10(phy), val);
+
+	/* Program power gating */
+	val = I915_READ(BXT_PORT_CL1CM_DW28(phy));
+	val |= OCL1_POWER_DOWN_EN | DW28_OLDO_DYN_PWR_DOWN_EN |
+		SUS_CLK_CONFIG;
+	I915_WRITE(BXT_PORT_CL1CM_DW28(phy), val);
+
+	if (phy == DPIO_PHY0) {
+		val = I915_READ(BXT_PORT_CL2CM_DW6_BC);
+		val |= DW6_OLDO_DYN_PWR_DOWN_EN;
+		I915_WRITE(BXT_PORT_CL2CM_DW6_BC, val);
+	}
+
+	val = I915_READ(BXT_PORT_CL1CM_DW30(phy));
+	val &= ~OCL2_LDOFUSE_PWR_DIS;
+	/*
+	 * On PHY1 disable power on the second channel, since no port is
+	 * connected there. On PHY0 both channels have a port, so leave it
+	 * enabled.
+	 * TODO: port C is only connected on BXT-P, so on BXT0/1 we should
+	 * power down the second channel on PHY0 as well.
+	 */
+	if (phy == DPIO_PHY1)
+		val |= OCL2_LDOFUSE_PWR_DIS;
+	I915_WRITE(BXT_PORT_CL1CM_DW30(phy), val);
+
+	if (phy == DPIO_PHY0) {
+		uint32_t grc_code;
+		/*
+		 * PHY0 isn't connected to an RCOMP resistor so copy over
+		 * the corresponding calibrated value from PHY1, and disable
+		 * the automatic calibration on PHY0.
+		 */
+		if (wait_for(I915_READ(BXT_PORT_REF_DW3(DPIO_PHY1)) & GRC_DONE,
+			     10))
+			DRM_ERROR("timeout waiting for PHY1 GRC\n");
+
+		val = I915_READ(BXT_PORT_REF_DW6(DPIO_PHY1));
+		val = (val & GRC_CODE_MASK) >> GRC_CODE_SHIFT;
+		grc_code = val << GRC_CODE_FAST_SHIFT |
+			   val << GRC_CODE_SLOW_SHIFT |
+			   val;
+		I915_WRITE(BXT_PORT_REF_DW6(DPIO_PHY0), grc_code);
+
+		val = I915_READ(BXT_PORT_REF_DW8(DPIO_PHY0));
+		val |= GRC_DIS | GRC_RDY_OVRD;
+		I915_WRITE(BXT_PORT_REF_DW8(DPIO_PHY0), val);
+	}
+
+	val = I915_READ(BXT_PHY_CTL_FAMILY(phy));
+	val |= COMMON_RESET_DIS;
+	I915_WRITE(BXT_PHY_CTL_FAMILY(phy), val);
+}
+
+void broxton_ddi_phy_init(struct drm_device *dev)
+{
+	/* Enable PHY1 first since it provides Rcomp for PHY0 */
+	broxton_phy_init(dev->dev_private, DPIO_PHY1);
+	broxton_phy_init(dev->dev_private, DPIO_PHY0);
+}
+
+static void broxton_phy_uninit(struct drm_i915_private *dev_priv,
+			       enum dpio_phy phy)
+{
+	uint32_t val;
+
+	val = I915_READ(BXT_PHY_CTL_FAMILY(phy));
+	val &= ~COMMON_RESET_DIS;
+	I915_WRITE(BXT_PHY_CTL_FAMILY(phy), val);
+}
+
+void broxton_ddi_phy_uninit(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	broxton_phy_uninit(dev_priv, DPIO_PHY1);
+	broxton_phy_uninit(dev_priv, DPIO_PHY0);
+
+	/* FIXME: do this in broxton_phy_uninit per phy */
+	I915_WRITE(BXT_P_CR_GT_DISP_PWRON, 0);
+}
+
 void intel_ddi_pll_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1882,6 +2006,7 @@
 			DRM_ERROR("LCPLL1 is disabled\n");
 	} else if (IS_BROXTON(dev)) {
 		broxton_init_cdclk(dev);
+		broxton_ddi_phy_init(dev);
 	} else {
 		/*
 		 * The LCPLL register should be turned on by the BIOS. For now