drm/i915: rename intel_pm.[ch] to intel_clock_gating.[ch]

Observe that intel_pm.[ch] is now purely about clock gating, so rename
them to intel_clock_gating.[ch]. Rename the functions to
intel_clock_gating_*() to follow coding conventions.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230403122428.3526263-1-jani.nikula@intel.com

drm/i915: use proper helper for register updates

There is special helper for register read/modify/write.

Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221006163200.2803722-5-andrzej.hajda@intel.com

drm/i915: Use str_on_off()

Remove the local onoff() implementation and adopt the
str_on_off() from linux/string_helpers.h.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220225234631.3725943-4-lucas.demarchi@intel.com

drm/i915: Move GT registers to their own header file

This is a huge, chaotic mass of registers copied over as-is without any
real cleanup. We'll come back and organize these better, align on
consistent coding style, remove dead code, etc. in separate patches
later that will be easier to review.

v2:
- Add missing include in intel_pxp_irq.c
v3:
- Correct a few indentation errors (Lucas)
- Minor conflict resolution

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220127234334.4016964-6-matthew.d.roper@intel.com

drm/i915: switch vlv_suspend to use intel uncore register accessors

Prefer intel_uncore_* over I915_READ, I915_WRITE, and POSTING_READ.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200212144058.5686-2-jani.nikula@intel.com

drm/i915: split out vlv/chv specific suspend/resume code

i915_drv.c is a fairly big file, and having very specific vlv/chv
suspend/resume code in it is a distraction. Split it out to a new
vlv_suspend.[ch] file.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200212144058.5686-1-jani.nikula@intel.com