drm/i915: Gather the HDMI level shifter logic into one place
The knowledge about the HDMI/DVI DDI translation table was scattered
around.
- info->hdmi_level_shift was initialized with 6, the index of the 800
mV, 0dB translation
- A check on the VBT value was done to ensure it wasn't overflowing
the translation table (< 0xC)
- The actual programming was done in intel_ddi.c
As we need to change that knowledge for Broadwell, let's gather
everything into one place.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ce30bb3..0d7e55f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1232,6 +1232,12 @@
};
struct ddi_vbt_port_info {
+ /*
+ * This is an index in the HDMI/DVI DDI buffer translation table.
+ * The special value HDMI_LEVEL_SHIFT_UNKNOWN means the VBT didn't
+ * populate this field.
+ */
+#define HDMI_LEVEL_SHIFT_UNKNOWN 0xff
uint8_t hdmi_level_shift;
uint8_t supports_dvi:1;
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index a669550..031c565 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -976,12 +976,10 @@
if (bdb->version >= 158) {
/* The VBT HDMI level shift values match the table we have. */
hdmi_level_shift = child->raw[7] & 0xF;
- if (hdmi_level_shift < 0xC) {
- DRM_DEBUG_KMS("VBT HDMI level shift for port %c: %d\n",
- port_name(port),
- hdmi_level_shift);
- info->hdmi_level_shift = hdmi_level_shift;
- }
+ DRM_DEBUG_KMS("VBT HDMI level shift for port %c: %d\n",
+ port_name(port),
+ hdmi_level_shift);
+ info->hdmi_level_shift = hdmi_level_shift;
}
}
@@ -1114,8 +1112,7 @@
struct ddi_vbt_port_info *info =
&dev_priv->vbt.ddi_port_info[port];
- /* Recommended BSpec default: 800mV 0dB. */
- info->hdmi_level_shift = 6;
+ info->hdmi_level_shift = HDMI_LEVEL_SHIFT_UNKNOWN;
info->supports_dvi = (port != PORT_A && port != PORT_E);
info->supports_hdmi = info->supports_dvi;
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 3634575..3af8340 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -145,7 +145,7 @@
{
struct drm_i915_private *dev_priv = dev->dev_private;
u32 reg;
- int i;
+ int i, n_hdmi_entries, hdmi_800mV_0dB;
int hdmi_level = dev_priv->vbt.ddi_port_info[port].hdmi_level_shift;
const u32 *ddi_translations_fdi;
const u32 *ddi_translations_dp;
@@ -156,15 +156,21 @@
ddi_translations_fdi = bdw_ddi_translations_fdi;
ddi_translations_dp = bdw_ddi_translations_dp;
ddi_translations_edp = bdw_ddi_translations_edp;
+ n_hdmi_entries = ARRAY_SIZE(hsw_ddi_translations_hdmi);
+ hdmi_800mV_0dB = 6;
} else if (IS_HASWELL(dev)) {
ddi_translations_fdi = hsw_ddi_translations_fdi;
ddi_translations_dp = hsw_ddi_translations_dp;
ddi_translations_edp = hsw_ddi_translations_dp;
+ n_hdmi_entries = ARRAY_SIZE(hsw_ddi_translations_hdmi);
+ hdmi_800mV_0dB = 6;
} else {
WARN(1, "ddi translation table missing\n");
ddi_translations_edp = bdw_ddi_translations_dp;
ddi_translations_fdi = bdw_ddi_translations_fdi;
ddi_translations_dp = bdw_ddi_translations_dp;
+ n_hdmi_entries = ARRAY_SIZE(hsw_ddi_translations_hdmi);
+ hdmi_800mV_0dB = 6;
}
switch (port) {
@@ -193,6 +199,12 @@
I915_WRITE(reg, ddi_translations[i]);
reg += 4;
}
+
+ /* Choose a good default if VBT is badly populated */
+ if (hdmi_level == HDMI_LEVEL_SHIFT_UNKNOWN ||
+ hdmi_level >= n_hdmi_entries)
+ hdmi_level = hdmi_800mV_0dB;
+
/* Entry 9 is for HDMI: */
for (i = 0; i < 2; i++) {
I915_WRITE(reg, hsw_ddi_translations_hdmi[hdmi_level * 2 + i]);