[Nouveau] [PATCH v4 04/37] volt: add nvkm_volt_map_min function

[Karol Herbst]

this is a copy of nvkm_volt_map, which always returns the lowest possible
voltage for a cstate.

nvkm_volt_map will get a temperature parameter there later and also fix the
voltage calculation, so that this functions will be completly different later.

Signed-off-by: Karol Herbst <nouveau at karolherbst.de>
Reviewed-by: Martin Peres <martin.peres at free.fr>
Tested-by: Pierre Moreau <pierre.morrow at free.fr>
---
 drm/nouveau/include/nvkm/subdev/volt.h |  1 +
 drm/nouveau/nvkm/subdev/volt/base.c    | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drm/nouveau/include/nvkm/subdev/volt.h b/drm/nouveau/include/nvkm/subdev/volt.h
index b765f4f..fc68825 100644
--- a/drm/nouveau/include/nvkm/subdev/volt.h
+++ b/drm/nouveau/include/nvkm/subdev/volt.h
@@ -17,6 +17,7 @@ struct nvkm_volt {
 	u32 min_uv;
 };
 
+int nvkm_volt_map_min(struct nvkm_volt *volt, u8 id);
 int nvkm_volt_get(struct nvkm_volt *);
 int nvkm_volt_set_id(struct nvkm_volt *, u8 id, int condition);
 
diff --git a/drm/nouveau/nvkm/subdev/volt/base.c b/drm/nouveau/nvkm/subdev/volt/base.c
index b7dd3ac..ecf4cb4 100644
--- a/drm/nouveau/nvkm/subdev/volt/base.c
+++ b/drm/nouveau/nvkm/subdev/volt/base.c
@@ -65,6 +65,28 @@ nvkm_volt_set(struct nvkm_volt *volt, u32 uv)
 	return ret;
 }
 
+int
+nvkm_volt_map_min(struct nvkm_volt *volt, u8 id)
+{
+	struct nvkm_bios *bios = volt->subdev.device->bios;
+	struct nvbios_vmap_entry info;
+	u8  ver, len;
+	u16 vmap;
+
+	vmap = nvbios_vmap_entry_parse(bios, id, &ver, &len, &info);
+	if (vmap) {
+		if (info.link != 0xff) {
+			int ret = nvkm_volt_map_min(volt, info.link);
+			if (ret < 0)
+				return ret;
+			info.min += ret;
+		}
+		return info.min;
+	}
+
+	return id ? id * 10000 : -ENODEV;
+}
+
 static int
 nvkm_volt_map(struct nvkm_volt *volt, u8 id)
 {
-- 
2.8.1