[Nouveau] [PATCH v4 36/37] WIP volt/gk104: readout speedo

[Karol Herbst]

this gk104 volt implementation has to be reworked a little, because the speedo
readout in maxwell doesn't need those strange 0 and 41 writes into 0x122634,
but it needs this PWM thing.

Maybe Maxwell is PWM only and we could just simplify it there, but without
proper knowledge there has some refactoring to be made.

Signed-off-by: Karol Herbst <nouveau at karolherbst.de>
---
 drm/nouveau/nvkm/subdev/volt/gk104.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drm/nouveau/nvkm/subdev/volt/gk104.c b/drm/nouveau/nvkm/subdev/volt/gk104.c
index b735173..81788c2 100644
--- a/drm/nouveau/nvkm/subdev/volt/gk104.c
+++ b/drm/nouveau/nvkm/subdev/volt/gk104.c
@@ -27,6 +27,7 @@
 #include <subdev/gpio.h>
 #include <subdev/bios.h>
 #include <subdev/bios/volt.h>
+#include <subdev/fuse.h>
 
 #define gk104_volt(p) container_of((p), struct gk104_volt, base)
 struct gk104_volt {
@@ -64,13 +65,31 @@ gk104_volt_set(struct nvkm_volt *base, u32 uv)
 	return 0;
 }
 
+static int
+gk104_volt_speedo_read(struct nvkm_volt *volt)
+{
+	struct nvkm_device *device = volt->subdev.device;
+	struct nvkm_fuse *fuse = device->fuse;
+	int ret;
+
+	if (!fuse)
+		return -EINVAL;
+
+	nvkm_wr32(device, 0x122634, 0x0);
+	ret = nvkm_fuse_read(fuse, 0x3a8);
+	nvkm_wr32(device, 0x122634, 0x41);
+	return ret;
+}
+
 static const struct nvkm_volt_func
 gk104_volt_pwm = {
 	.volt_get = gk104_volt_get,
 	.volt_set = gk104_volt_set,
+	.speedo_read = gk104_volt_speedo_read,
 }, gk104_volt_gpio = {
 	.vid_get = nvkm_voltgpio_get,
 	.vid_set = nvkm_voltgpio_set,
+	.speedo_read = gk104_volt_speedo_read,
 };
 
 int
-- 
2.8.1