drm/i915: VLV GPU frequency to opcode functions

When requesting frequency changes or querying status from the Punit, we
need to use an opcode that corresponds to the frequency, taking into
account the memory frequency.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1887,6 +1887,8 @@ int sandybridge_pcode_read(struct drm_i915_private *dev_priv, u8 mbox, u32 *val)
 int sandybridge_pcode_write(struct drm_i915_private *dev_priv, u8 mbox, u32 val);
 int valleyview_punit_read(struct drm_i915_private *dev_priv, u8 addr, u32 *val);
 int valleyview_punit_write(struct drm_i915_private *dev_priv, u8 addr, u32 val);
+int vlv_gpu_freq(int ddr_freq, int val);
+int vlv_freq_opcode(int ddr_freq, int val);
 
 #define __i915_read(x, y) \
 	u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg);

drivers/gpu/drm/i915/intel_pm.c

@@ -4620,3 +4620,59 @@ int valleyview_punit_write(struct drm_i915_private *dev_priv, u8 addr, u32 val)
 {
 	return vlv_punit_rw(dev_priv, PUNIT_OPCODE_REG_WRITE, addr, &val);
 }
+
+int vlv_gpu_freq(int ddr_freq, int val)
+{
+	int mult, base;
+
+	switch (ddr_freq) {
+	case 800:
+		mult = 20;
+		base = 120;
+		break;
+	case 1066:
+		mult = 22;
+		base = 133;
+		break;
+	case 1333:
+		mult = 21;
+		base = 125;
+		break;
+	default:
+		return -1;
+	}
+
+	return ((val - 0xbd) * mult) + base;
+}
+
+int vlv_freq_opcode(int ddr_freq, int val)
+{
+	int mult, base;
+
+	switch (ddr_freq) {
+	case 800:
+		mult = 20;
+		base = 120;
+		break;
+	case 1066:
+		mult = 22;
+		base = 133;
+		break;
+	case 1333:
+		mult = 21;
+		base = 125;
+		break;
+	default:
+		return -1;
+	}
+
+	val /= mult;
+	val -= base / mult;
+	val += 0xbd;
+
+	if (val > 0xea)
+		val = 0xea;
+
+	return val;
+}
+