drm/i915: Unify power well ID enums

Atm, the power well IDs are defined in separate platform specific enums,
which isn't ideal for the following reasons:
- the IDs are used by helpers like lookup_power_well() in a platform
  independent way
- the always-on power well is used by multiple platforms and so needs
  now separate IDs, although these IDs refer to the same thing

To make things more consistent use a single enum instead of the two
separate ones, listing the IDs per platform (or set of very similar
platforms like all GEN9/10). Replace the separate always-on power
well IDs with a single ID.

While at it also add a note clarifying the distinction between regular
power wells that follow a common programming pattern and custom ones
that are programmed in some other way. The IDs for regular power wells
need to stay fixed, since they also define the request and state HW flag
positions in their corresponding power well control register(s).

v2:
- Add comment about id to req,status bit mapping to the enum. (Rodrigo)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170711204236.5618-1-imre.deak@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1383,7 +1383,7 @@ struct i915_power_well {
 	bool hw_enabled;
 	u64 domains;
 	/* unique identifier for this power well */
-	unsigned long id;
+	enum i915_power_well_id id;
 	/*
 	 * Arbitraty data associated with this power well. Platform and power
 	 * well specific.

drivers/gpu/drm/i915/i915_reg.h

@@ -1063,9 +1063,20 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define   DP_SSS_RESET(pipe)			_DP_SSS(0x2, (pipe))
 #define   DP_SSS_PWR_GATE(pipe)			_DP_SSS(0x3, (pipe))
 
-/* See the PUNIT HAS v0.8 for the below bits */
-enum punit_power_well {
-	/* These numbers are fixed and must match the position of the pw bits */
+/**
+ * i915_power_well_id:
+ *
+ * Platform specific IDs used to look up power wells and - except for custom
+ * power wells - to define request/status register flag bit positions. As such
+ * the set of IDs on a given platform must be unique and except for custom
+ * power wells their value must stay fixed.
+ */
+enum i915_power_well_id {
+	/*
+	 * VLV/CHV
+	 *  - PUNIT_REG_PWRGT_CTRL (bit: id*2),
+	 *    PUNIT_REG_PWRGT_STATUS (bit: id*2) (PUNIT HAS v0.8)
+	 */
 	PUNIT_POWER_WELL_RENDER			= 0,
 	PUNIT_POWER_WELL_MEDIA			= 1,
 	PUNIT_POWER_WELL_DISP2D			= 3,
@@ -1080,13 +1091,11 @@ enum punit_power_well {
 	/*  - custom power well */
 	CHV_DISP_PW_PIPE_A,			/* 13 */
 
-	/* Not actual bit groups. Used as IDs for lookup_power_well() */
-	PUNIT_POWER_WELL_ALWAYS_ON,
-};
-
-enum skl_disp_power_wells {
-	/* These numbers are fixed and must match the position of the pw bits */
-	SKL_DISP_PW_MISC_IO,
+	/*
+	 * GEN9+
+	 *  - HSW_PWR_WELL_DRIVER (status bit: id*2, req bit: id*2+1)
+	 */
+	SKL_DISP_PW_MISC_IO = 0,
 	SKL_DISP_PW_DDI_A_E,
 	GLK_DISP_PW_DDI_A = SKL_DISP_PW_DDI_A_E,
 	CNL_DISP_PW_DDI_A = SKL_DISP_PW_DDI_A_E,
@@ -1105,13 +1114,18 @@ enum skl_disp_power_wells {
 	SKL_DISP_PW_1 = 14,
 	SKL_DISP_PW_2,
 
-	/* Not actual bit groups. Used as IDs for lookup_power_well() */
-	SKL_DISP_PW_ALWAYS_ON,
+	/* - custom power wells */
 	SKL_DISP_PW_DC_OFF,
-
 	BXT_DPIO_CMN_A,
 	BXT_DPIO_CMN_BC,
-	GLK_DPIO_CMN_C,
+	GLK_DPIO_CMN_C,			/* 19 */
+
+	/*
+	 * Multiple platforms.
+	 * Must start following the highest ID of any platform.
+	 * - custom power wells
+	 */
+	I915_DISP_PW_ALWAYS_ON = 20,
 };
 
 #define SKL_POWER_WELL_STATE(pw) (1 << ((pw) * 2))

drivers/gpu/drm/i915/intel_runtime_pm.c

@@ -50,10 +50,11 @@
  */
 
 bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv,
-				    int power_well_id);
+					 enum i915_power_well_id power_well_id);
 
 static struct i915_power_well *
-lookup_power_well(struct drm_i915_private *dev_priv, int power_well_id);
+lookup_power_well(struct drm_i915_private *dev_priv,
+		  enum i915_power_well_id power_well_id);
 
 const char *
 intel_display_power_domain_str(enum intel_display_power_domain domain)
@@ -344,7 +345,7 @@ static void skl_power_well_pre_disable(struct drm_i915_private *dev_priv,
 static void gen9_wait_for_power_well_enable(struct drm_i915_private *dev_priv,
 					    struct i915_power_well *power_well)
 {
-	int id = power_well->id;
+	enum i915_power_well_id id = power_well->id;
 
 	/* Timeout for PW1:10 us, AUX:not specified, other PWs:20 us. */
 	WARN_ON(intel_wait_for_register(dev_priv,
@@ -354,7 +355,8 @@ static void gen9_wait_for_power_well_enable(struct drm_i915_private *dev_priv,
 					1));
 }
 
-static u32 gen9_power_well_requesters(struct drm_i915_private *dev_priv, int id)
+static u32 gen9_power_well_requesters(struct drm_i915_private *dev_priv,
+				      enum i915_power_well_id id)
 {
 	u32 req_mask = SKL_POWER_WELL_REQ(id);
 	u32 ret;
@@ -370,7 +372,7 @@ static u32 gen9_power_well_requesters(struct drm_i915_private *dev_priv, int id)
 static void gen9_wait_for_power_well_disable(struct drm_i915_private *dev_priv,
 					     struct i915_power_well *power_well)
 {
-	int id = power_well->id;
+	enum i915_power_well_id id = power_well->id;
 	bool disabled;
 	u32 reqs;
 
@@ -837,7 +839,7 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
 	case CNL_DISP_PW_AUX_D:
 		break;
 	default:
-		WARN(1, "Unknown power well %lu\n", power_well->id);
+		WARN(1, "Unknown power well %u\n", power_well->id);
 		return;
 	}
 
@@ -1089,7 +1091,7 @@ static void i830_pipes_power_well_sync_hw(struct drm_i915_private *dev_priv,
 static void vlv_set_power_well(struct drm_i915_private *dev_priv,
 			       struct i915_power_well *power_well, bool enable)
 {
-	enum punit_power_well power_well_id = power_well->id;
+	enum i915_power_well_id power_well_id = power_well->id;
 	u32 mask;
 	u32 state;
 	u32 ctrl;
@@ -1137,7 +1139,7 @@ static void vlv_power_well_disable(struct drm_i915_private *dev_priv,
 static bool vlv_power_well_enabled(struct drm_i915_private *dev_priv,
 				   struct i915_power_well *power_well)
 {
-	int power_well_id = power_well->id;
+	enum i915_power_well_id power_well_id = power_well->id;
 	bool enabled = false;
 	u32 mask;
 	u32 state;
@@ -1324,8 +1326,9 @@ static void vlv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv,
 
 #define POWER_DOMAIN_MASK (GENMASK_ULL(POWER_DOMAIN_NUM - 1, 0))
 
-static struct i915_power_well *lookup_power_well(struct drm_i915_private *dev_priv,
-						 int power_well_id)
+static struct i915_power_well *
+lookup_power_well(struct drm_i915_private *dev_priv,
+		  enum i915_power_well_id power_well_id)
 {
 	struct i915_power_domains *power_domains = &dev_priv->power_domains;
 	int i;
@@ -2117,7 +2120,7 @@ static struct i915_power_well vlv_power_wells[] = {
 		.always_on = 1,
 		.domains = POWER_DOMAIN_MASK,
 		.ops = &i9xx_always_on_power_well_ops,
-		.id = PUNIT_POWER_WELL_ALWAYS_ON,
+		.id = I915_DISP_PW_ALWAYS_ON,
 	},
 	{
 		.name = "display",
@@ -2202,7 +2205,7 @@ static struct i915_power_well chv_power_wells[] = {
 };
 
 bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv,
-				    int power_well_id)
+					 enum i915_power_well_id power_well_id)
 {
 	struct i915_power_well *power_well;
 	bool ret;
@@ -2219,7 +2222,7 @@ static struct i915_power_well skl_power_wells[] = {
 		.always_on = 1,
 		.domains = POWER_DOMAIN_MASK,
 		.ops = &i9xx_always_on_power_well_ops,
-		.id = SKL_DISP_PW_ALWAYS_ON,
+		.id = I915_DISP_PW_ALWAYS_ON,
 	},
 	{
 		.name = "power well 1",