drm/i915: Extract PCU communication

There is a special mechanism for communicating with the PCU already
being used for the ring frequency stuff. As we'll be needing this for
other commands, extract it now to make future code less error prone and
the current code more reusable.

I'm not entirely sure if this code matches 1:1 with the previous code
behaviorally. Functionally however, it should be the same.

CC: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Fixup compile fail reported by Wu Fengguang.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 9e446b62164..32814340f76 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1630,6 +1630,9 @@ void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv);
 void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv);
 int __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv);
 
+int sandybridge_pcode_read(struct drm_i915_private *dev_priv, u8 mbox, u32 *val);
+int sandybridge_pcode_write(struct drm_i915_private *dev_priv, u8 mbox, u32 val);
+
 #define __i915_read(x, y) \
 	u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg);