drm/i915/gen11: add support for reading the timestamp frequency

The only thing that differs here is that the crystal clock freq now
has four possible values.

This patch gets rid of the "Unknown gen, unable to compute..." message
at boot for gen11.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180109232835.11478-18-paulo.r.zanoni@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -861,6 +861,12 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK	(1 << GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT)
 #define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ	0
 #define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ	1
+#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT	3
+#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK	(0x7 << GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT)
+#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ	0
+#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ	1
+#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_38_4_MHZ	2
+#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_25_MHZ	3
 #define  GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT	1
 #define  GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK	(0x3 << GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT)
 

drivers/gpu/drm/i915/intel_device_info.c

@@ -596,6 +596,52 @@ static u32 read_reference_ts_freq(struct drm_i915_private *dev_priv)
 	return base_freq + frac_freq;
 }
 
+static u32 gen10_get_crystal_clock_freq(struct drm_i915_private *dev_priv,
+					u32 rpm_config_reg)
+{
+	u32 f19_2_mhz = 19200;
+	u32 f24_mhz = 24000;
+	u32 crystal_clock = (rpm_config_reg &
+			     GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
+			    GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
+
+	switch (crystal_clock) {
+	case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
+		return f19_2_mhz;
+	case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
+		return f24_mhz;
+	default:
+		MISSING_CASE(crystal_clock);
+		return 0;
+	}
+}
+
+static u32 gen11_get_crystal_clock_freq(struct drm_i915_private *dev_priv,
+					u32 rpm_config_reg)
+{
+	u32 f19_2_mhz = 19200;
+	u32 f24_mhz = 24000;
+	u32 f25_mhz = 25000;
+	u32 f38_4_mhz = 38400;
+	u32 crystal_clock = (rpm_config_reg &
+			     GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
+			    GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
+
+	switch (crystal_clock) {
+	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
+		return f24_mhz;
+	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
+		return f19_2_mhz;
+	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_38_4_MHZ:
+		return f38_4_mhz;
+	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_25_MHZ:
+		return f25_mhz;
+	default:
+		MISSING_CASE(crystal_clock);
+		return 0;
+	}
+}
+
 static u32 read_timestamp_frequency(struct drm_i915_private *dev_priv)
 {
 	u32 f12_5_mhz = 12500;
@@ -636,10 +682,9 @@ static u32 read_timestamp_frequency(struct drm_i915_private *dev_priv)
 		}
 
 		return freq;
-	} else if (INTEL_GEN(dev_priv) <= 10) {
+	} else if (INTEL_GEN(dev_priv) <= 11) {
 		u32 ctc_reg = I915_READ(CTC_MODE);
 		u32 freq = 0;
-		u32 rpm_config_reg = 0;
 
 		/* First figure out the reference frequency. There are 2 ways
 		 * we can compute the frequency, either through the
@@ -649,20 +694,14 @@ static u32 read_timestamp_frequency(struct drm_i915_private *dev_priv)
 		if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) {
 			freq = read_reference_ts_freq(dev_priv);
 		} else {
-			u32 crystal_clock;
-
-			rpm_config_reg = I915_READ(RPM_CONFIG0);
-			crystal_clock = (rpm_config_reg &
-					 GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
-				GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
-			switch (crystal_clock) {
-			case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
-				freq = f19_2_mhz;
-				break;
-			case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
-				freq = f24_mhz;
-				break;
-			}
+			u32 rpm_config_reg = I915_READ(RPM_CONFIG0);
+
+			if (INTEL_GEN(dev_priv) <= 10)
+				freq = gen10_get_crystal_clock_freq(dev_priv,
+								rpm_config_reg);
+			else
+				freq = gen11_get_crystal_clock_freq(dev_priv,
+								rpm_config_reg);
 
 			/* Now figure out how the command stream's timestamp
 			 * register increments from this frequency (it might