linux/include/drm/i915_powerwell.h
Jani Nikula c149dcb5c6 drm/i915: provide interface for audio driver to query cdclk
For Haswell and Broadwell, if the display power well has been disabled,
the display audio controller divider values EM4 M VALUE and EM5 N VALUE
will have been lost. The CDCLK frequency is required for reprogramming them
to generate 24MHz HD-A link BCLK. So provide a private interface for the
audio driver to query CDCLK.

This is a stopgap solution until a more generic interface between audio
and display drivers has been implemented.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Mengdong Lin <mengdong.lin@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-07-04 07:46:09 +02:00

38 lines
1.6 KiB
C

/**************************************************************************
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#ifndef _I915_POWERWELL_H_
#define _I915_POWERWELL_H_
/* For use by hda_i915 driver */
extern int i915_request_power_well(void);
extern int i915_release_power_well(void);
extern int i915_get_cdclk_freq(void);
#endif /* _I915_POWERWELL_H_ */