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: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 413877d..f802368 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4620,3 +4620,59 @@
 {
 	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;
+}
+