drm/i915: Clean up TV pipe select bits

Parametrize the TV pipe select bits.

For consistency with the new way of doing things, let's read out the
pipe select bits even when the port is disable, even though we don't
need that behaviour for asserts in this case.

v2: Order the defines shift,mask,value (Jani)
    Clear the stale pipe select bit in load detection (Jani)
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180514172423.9302-4-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -4696,7 +4696,9 @@ enum {
 /* Enables the TV encoder */
 # define TV_ENC_ENABLE			(1 << 31)
 /* Sources the TV encoder input from pipe B instead of A. */
-# define TV_ENC_PIPEB_SELECT		(1 << 30)
+# define TV_ENC_PIPE_SEL_SHIFT		30
+# define TV_ENC_PIPE_SEL_MASK		(1 << 30)
+# define TV_ENC_PIPE_SEL(pipe)		((pipe) << 30)
 /* Outputs composite video (DAC A only) */
 # define TV_ENC_OUTPUT_COMPOSITE	(0 << 28)
 /* Outputs SVideo video (DAC B/C) */

drivers/gpu/drm/i915/intel_tv.c

@@ -798,16 +798,12 @@ static struct intel_tv *intel_attached_tv(struct drm_connector *connector)
 static bool
 intel_tv_get_hw_state(struct intel_encoder *encoder, enum pipe *pipe)
 {
-	struct drm_device *dev = encoder->base.dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	u32 tmp = I915_READ(TV_CTL);
 
-	if (!(tmp & TV_ENC_ENABLE))
-		return false;
+	*pipe = (tmp & TV_ENC_PIPE_SEL_MASK) >> TV_ENC_PIPE_SEL_SHIFT;
 
-	*pipe = PORT_TO_PIPE(tmp);
-
-	return true;
+	return tmp & TV_ENC_ENABLE;
 }
 
 static void
@@ -1024,8 +1020,7 @@ static void intel_tv_pre_enable(struct intel_encoder *encoder,
 		break;
 	}
 
-	if (intel_crtc->pipe == 1)
-		tv_ctl |= TV_ENC_PIPEB_SELECT;
+	tv_ctl |= TV_ENC_PIPE_SEL(intel_crtc->pipe);
 	tv_ctl |= tv_mode->oversample;
 
 	if (tv_mode->progressive)
@@ -1149,12 +1144,9 @@ intel_tv_detect_type(struct intel_tv *intel_tv,
 	save_tv_ctl = tv_ctl = I915_READ(TV_CTL);
 
 	/* Poll for TV detection */
-	tv_ctl &= ~(TV_ENC_ENABLE | TV_TEST_MODE_MASK);
+	tv_ctl &= ~(TV_ENC_ENABLE | TV_ENC_PIPE_SEL_MASK | TV_TEST_MODE_MASK);
 	tv_ctl |= TV_TEST_MODE_MONITOR_DETECT;
-	if (intel_crtc->pipe == 1)
-		tv_ctl |= TV_ENC_PIPEB_SELECT;
-	else
-		tv_ctl &= ~TV_ENC_PIPEB_SELECT;
+	tv_ctl |= TV_ENC_PIPE_SEL(intel_crtc->pipe);
 
 	tv_dac &= ~(TVDAC_SENSE_MASK | DAC_A_MASK | DAC_B_MASK | DAC_C_MASK);
 	tv_dac |= (TVDAC_STATE_CHG_EN |