[PATCH 10/18] drm/i915: split some conversion functions out into separate functions.

[Dariusz Gadomski]

From: Dave Airlie <airlied at redhat.com>

BugLink: https://bugs.launchpad.net/bugs/1104230

for MST I need to reuse these, so split them out early.

Signed-off-by: Dave Airlie <airlied at redhat.com>

Conflicts:
	drivers/gpu/drm/i915/intel_display.c

(cherry picked from commit a8445dd9e2bc9d369198755a079b905273bceef7 upstream)
Signed-off-by: Dariusz Gadomski <dariusz.gadomski at canonical.com>
---
 drivers/gpu/drm/i915/intel_ddi.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 7a9186f..b791379 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -751,6 +751,20 @@ intel_ddi_calculate_wrpll(int clock /* in Hz */,
 	*r2_out = best.r2;
 }
 
+static int link_bw_to_pll_sel(int link_bw)
+{
+	switch (link_bw) {
+	case DP_LINK_BW_1_62:
+		return PORT_CLK_SEL_LCPLL_810;
+	case DP_LINK_BW_2_7:
+		return PORT_CLK_SEL_LCPLL_1350;
+	case DP_LINK_BW_5_4:
+		return PORT_CLK_SEL_LCPLL_2700;
+	default:
+		return -1;
+	}
+}
+
 /*
  * Tries to find a PLL for the CRTC. If it finds, it increases the refcount and
  * stores it in intel_crtc->ddi_pll_sel, so other mode sets won't be able to
@@ -773,17 +787,8 @@ bool intel_ddi_pll_select(struct intel_crtc *intel_crtc)
 	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
-		switch (intel_dp->link_bw) {
-		case DP_LINK_BW_1_62:
-			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_810;
-			break;
-		case DP_LINK_BW_2_7:
-			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_1350;
-			break;
-		case DP_LINK_BW_5_4:
-			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_2700;
-			break;
-		default:
+		intel_crtc->ddi_pll_sel = link_bw_to_pll_sel(intel_dp->link_bw);
+		if (intel_crtc->ddi_pll_sel == -1) {
 			DRM_ERROR("Link bandwidth %d unsupported\n",
 				  intel_dp->link_bw);
 			return false;
-- 
1.9.1