drm/i915: Extend pcode mailbox interface

In sandybridge_pcode_read and sandybridge_pcode_write,
extend the mbox parameter from u8 to u32.

On Haswell and Sandybridge, bits 7:0 encode the mailbox
command and bits 28:8 are used for address control for
specific commands.

Based on suggestion from Ville Syrjälä.
Signed-off-by: Tom O'Rourke <Tom.O'Rourke@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -2975,8 +2975,8 @@ void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv, int fw_engine);
 void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine);
 void assert_force_wake_inactive(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);
+int sandybridge_pcode_read(struct drm_i915_private *dev_priv, u32 mbox, u32 *val);
+int sandybridge_pcode_write(struct drm_i915_private *dev_priv, u32 mbox, u32 val);
 
 /* intel_sideband.c */
 u32 vlv_punit_read(struct drm_i915_private *dev_priv, u8 addr);

drivers/gpu/drm/i915/intel_pm.c

@@ -7158,7 +7158,7 @@ void intel_init_pm(struct drm_device *dev)
 	}
 }
 
-int sandybridge_pcode_read(struct drm_i915_private *dev_priv, u8 mbox, u32 *val)
+int sandybridge_pcode_read(struct drm_i915_private *dev_priv, u32 mbox, u32 *val)
 {
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
@@ -7183,7 +7183,7 @@ int sandybridge_pcode_read(struct drm_i915_private *dev_priv, u8 mbox, u32 *val)
 	return 0;
 }
 
-int sandybridge_pcode_write(struct drm_i915_private *dev_priv, u8 mbox, u32 val)
+int sandybridge_pcode_write(struct drm_i915_private *dev_priv, u32 mbox, u32 val)
 {
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));