drm/i915: change VLV IOSF sideband accessors to not return error code

We never check the return values, and there's not much we could do on
errors anyway. Just simplify the signatures. No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c
index d150972..9a0e6c5 100644
--- a/drivers/gpu/drm/i915/intel_sideband.c
+++ b/drivers/gpu/drm/i915/intel_sideband.c
@@ -63,46 +63,42 @@
 	return 0;
 }
 
-int vlv_punit_read(struct drm_i915_private *dev_priv, u8 addr, u32 *val)
+u32 vlv_punit_read(struct drm_i915_private *dev_priv, u8 addr)
 {
-	int ret;
+	u32 val = 0;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
 	mutex_lock(&dev_priv->dpio_lock);
-	ret = vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_PUNIT,
-			      PUNIT_OPCODE_REG_READ, addr, val);
+	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_PUNIT,
+			PUNIT_OPCODE_REG_READ, addr, &val);
 	mutex_unlock(&dev_priv->dpio_lock);
 
-	return ret;
+	return val;
 }
 
-int vlv_punit_write(struct drm_i915_private *dev_priv, u8 addr, u32 val)
+void vlv_punit_write(struct drm_i915_private *dev_priv, u8 addr, u32 val)
 {
-	int ret;
-
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
 	mutex_lock(&dev_priv->dpio_lock);
-	ret = vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_PUNIT,
-			      PUNIT_OPCODE_REG_WRITE, addr, &val);
+	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_PUNIT,
+			PUNIT_OPCODE_REG_WRITE, addr, &val);
 	mutex_unlock(&dev_priv->dpio_lock);
-
-	return ret;
 }
 
-int vlv_nc_read(struct drm_i915_private *dev_priv, u8 addr, u32 *val)
+u32 vlv_nc_read(struct drm_i915_private *dev_priv, u8 addr)
 {
-	int ret;
+	u32 val = 0;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
 	mutex_lock(&dev_priv->dpio_lock);
-	ret = vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_NC,
-			      PUNIT_OPCODE_REG_READ, addr, val);
+	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_NC,
+			PUNIT_OPCODE_REG_READ, addr, &val);
 	mutex_unlock(&dev_priv->dpio_lock);
 
-	return ret;
+	return val;
 }
 
 u32 vlv_dpio_read(struct drm_i915_private *dev_priv, int reg)