drm/i915: add functions to disable and restore LCPLL

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For now there are no callers, but these functions are going to be
needed for the code that allows Package C8+. Other future features may
also require this code.

Also merge the commit which introduced assert_can_disable_lcpll and
had the following commit message:

Most of the hardware needs to be disabled before LCPLL is disabled, so
let's add a function to assert some of items listed in the "Display
Sequences for LCPLL disabling" documentation.

The idea is that hsw_disable_lcpll should not disable the hardware,
the callers need to take care of calling hsw_disable_lcpll only once
everything is already disabled.

v2: - Rebase.
    - Fix D_COMP wait timeout.
v3: - Use wait_for_atomic_use (Ben)
    - Remove/add a useless/needed POSTING_READ (Ben)
    - Early return in case LCPLL is already restored (Ben)
    - Add ndelay(100) (Ben)
v4: - Merge the commit that added assert_can_disable_lcpll (Ben)
    - Add interrupt assertions (Ben)

Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Fix compile fail since there's no HAS_LP_PCH yet.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

...

This commit is contained in:

Paulo Zanoni 2013-07-23 11:19:26 -03:00 • committed by Daniel Vetter

parent 47701c3ba2

commit be256dc702

3 changed files with 154 additions and 0 deletions

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15

drivers/gpu/drm/i915/i915_reg.h

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136

drivers/gpu/drm/i915/intel_display.c

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3

drivers/gpu/drm/i915/intel_drv.h

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