drm/nouveau/volt/gk20a: don't misuse kernel-doc comments

Change kernel-doc "/**" comments to common "/*" comments to prevent
kernel-doc warnings:

gk20a.c:49: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* cvb_mv = ((c2 * speedo / s_scale + c1) * speedo / s_scale + c0)
gk20a.c:49: warning: missing initial short description on line:
* cvb_mv = ((c2 * speedo / s_scale + c1) * speedo / s_scale + c0)
gk20a.c:62: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* cvb_t_mv =
gk20a.c:62: warning: missing initial short description on line:
* cvb_t_mv =

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: nouveau@lists.freedesktop.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231231233633.6596-4-rdunlap@infradead.org

drm/nouveau/volt: switch to instanced constructor

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/nouveau/volt/gm20b: add support for vmin parameter

Chips may be characterized for a minimum voltage. Support this extra
parameter and select the appropriate minimum voltage for the detected
GPU speedo.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt/gk20a: rename constructor

Strip the _ prefix off the gk20a volt constructor.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt/gk20a: constify and name v_scale

Give a name to this constant so we at least get an idea of what it is
for.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt/gk20a: make unused public functions static

Nobody else is using these, so make them private.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt/gk20a: split constructor

Split the constructor function so we can reuse the same logic in other
chips.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt/gk20a: share reusable members & functions

The CVB calculation and voltage setting functions can be reused for the
future chips. So move the declaration to gk20a.h.

Signed-off-by: Vince Hsu <vinceh@nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/tegra: merge platform setup from nouveau drm

The copyright header in nvkm/engine/device/platform.c has been replaced
with the NVIDIA one from drm/nouveau_platform.c, as most of the actual
code is now theirs.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt: convert to new-style nvkm_subdev

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/platform: remove subclassing of nvkm_device

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt: switch to subdev printk macros

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt: cosmetic changes

This is purely preparation for upcoming commits, there should be no
code changes here.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau/volt: namespace + nvidia gpu names (no binary change)

The namespace of NVKM is being changed to nvkm_ instead of nouveau_,
which will be used for the DRM part of the driver. This is being
done in order to make it very clear as to what part of the driver a
given symbol belongs to, and as a minor step towards splitting the
DRM driver out to be able to stand on its own (for virt).

Because there's already a large amount of churn here anyway, this is
as good a time as any to also switch to NVIDIA's device and chipset
naming to ease collaboration with them.

A comparison of objdump disassemblies proves no code changes.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drm/nouveau: remove symlinks, move core/ to nvkm/ (no code changes)

The symlinks were annoying some people, and they're not used anywhere
else in the kernel tree. The include directory structure has been
changed so that symlinks aren't needed anymore.

NVKM has been moved from core/ to nvkm/ to make it more obvious as to
what the directory is for, and as some minor prep for when NVKM gets
split out into its own module (virt) at a later date.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>