| From | Jiri Slaby <> | Subject | [PATCH 3.12 005/206] drm/i915: provide interface for audio driver to query cdclk | Date | Tue, 18 Nov 2014 15:06:00 +0100 |
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From: Jani Nikula <jani.nikula@intel.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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commit c149dcb5c60bfea8871f16dfcc0690255eeb825f upstream.
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> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- drivers/gpu/drm/i915/intel_pm.c | 20 ++++++++++++++++++++ include/drm/i915_powerwell.h | 1 + 2 files changed, 21 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index aa99bb61778c..a7daa2a3ac82 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -5378,6 +5378,26 @@ int i915_release_power_well(void) } EXPORT_SYMBOL_GPL(i915_release_power_well); +/* + * Private interface for the audio driver to get CDCLK in kHz. + * + * Caller must request power well using i915_request_power_well() prior to + * making the call. + */ +int i915_get_cdclk_freq(void) +{ + struct drm_i915_private *dev_priv; + + if (!hsw_pwr) + return -ENODEV; + + dev_priv = container_of(hsw_pwr, struct drm_i915_private, + power_well); + + return intel_ddi_get_cdclk_freq(dev_priv); +} +EXPORT_SYMBOL_GPL(i915_get_cdclk_freq); + int i915_init_power_well(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; diff --git a/include/drm/i915_powerwell.h b/include/drm/i915_powerwell.h index 2baba9996094..baa6f11b1837 100644 --- a/include/drm/i915_powerwell.h +++ b/include/drm/i915_powerwell.h @@ -32,5 +32,6 @@ /* 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_ */ -- 2.1.3
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