drm/nouveau/volt: Parse the max voltage map entries

There are at least three "max" entries, which specify the max voltage.
Because they are actually normal voltage map entries, they can also be
affected by the temperature.

Nvidia respects those entries and if they get changed, nvidia uses the
lower voltage from all three.

We shouldn't exceed those voltages at any given time.

v2: State what those entries do in the source.
v3: Add the third max entry.
v5: Better describe the entries.

Signed-off-by: Karol Herbst <karolherbst@gmail.com>
Reviewed-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/include/nvkm/subdev/volt.h b/drivers/gpu/drm/nouveau/include/nvkm/subdev/volt.h
index fc68825ffcbb..2612a04c49bb 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/volt.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/volt.h
@@ -15,6 +15,16 @@ struct nvkm_volt {
 
 	u32 max_uv;
 	u32 min_uv;
+
+	/*
+	 * These are fully functional map entries creating a sw ceiling for
+	 * the voltage. These all can describe different kind of curves, so
+	 * that for any given temperature a different one can return the lowest
+	 * value of all three.
+	 */
+	u8 max0_id;
+	u8 max1_id;
+	u8 max2_id;
 };
 
 int nvkm_volt_map_min(struct nvkm_volt *volt, u8 id);