From: Jani Nikula <jani.nikula@xxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
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@xxxxxxxxx>
Reviewed-by: Damien Lespiau <damien.lespiau@xxxxxxxxx>
Signed-off-by: Mengdong Lin <mengdong.lin@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
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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