drm/i915: Add support for VGA load detection (pre-945).
Two approaches for VGA detections: hot plug detection for 945G onwards
and load pipe detection for Pre-945G. Load pipe detection will get one free
pipe, set border color as red and blue, then check CRT status by
swf register. This is a sync-up with the 2D driver.
Signed-off-by: Ma Ling <ling.ma@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 19148c3..640f515 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -198,9 +198,142 @@
return intel_ddc_probe(intel_output);
}
+static enum drm_connector_status
+intel_crt_load_detect(struct drm_crtc *crtc, struct intel_output *intel_output)
+{
+ struct drm_encoder *encoder = &intel_output->enc;
+ struct drm_device *dev = encoder->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+ uint32_t pipe = intel_crtc->pipe;
+ uint32_t save_bclrpat;
+ uint32_t save_vtotal;
+ uint32_t vtotal, vactive;
+ uint32_t vsample;
+ uint32_t vblank, vblank_start, vblank_end;
+ uint32_t dsl;
+ uint32_t bclrpat_reg;
+ uint32_t vtotal_reg;
+ uint32_t vblank_reg;
+ uint32_t vsync_reg;
+ uint32_t pipeconf_reg;
+ uint32_t pipe_dsl_reg;
+ uint8_t st00;
+ enum drm_connector_status status;
+
+ if (pipe == 0) {
+ bclrpat_reg = BCLRPAT_A;
+ vtotal_reg = VTOTAL_A;
+ vblank_reg = VBLANK_A;
+ vsync_reg = VSYNC_A;
+ pipeconf_reg = PIPEACONF;
+ pipe_dsl_reg = PIPEADSL;
+ } else {
+ bclrpat_reg = BCLRPAT_B;
+ vtotal_reg = VTOTAL_B;
+ vblank_reg = VBLANK_B;
+ vsync_reg = VSYNC_B;
+ pipeconf_reg = PIPEBCONF;
+ pipe_dsl_reg = PIPEBDSL;
+ }
+
+ save_bclrpat = I915_READ(bclrpat_reg);
+ save_vtotal = I915_READ(vtotal_reg);
+ vblank = I915_READ(vblank_reg);
+
+ vtotal = ((save_vtotal >> 16) & 0xfff) + 1;
+ vactive = (save_vtotal & 0x7ff) + 1;
+
+ vblank_start = (vblank & 0xfff) + 1;
+ vblank_end = ((vblank >> 16) & 0xfff) + 1;
+
+ /* Set the border color to purple. */
+ I915_WRITE(bclrpat_reg, 0x500050);
+
+ if (IS_I9XX(dev)) {
+ uint32_t pipeconf = I915_READ(pipeconf_reg);
+ I915_WRITE(pipeconf_reg, pipeconf | PIPECONF_FORCE_BORDER);
+ /* Wait for next Vblank to substitue
+ * border color for Color info */
+ intel_wait_for_vblank(dev);
+ st00 = I915_READ8(VGA_MSR_WRITE);
+ status = ((st00 & (1 << 4)) != 0) ?
+ connector_status_connected :
+ connector_status_disconnected;
+
+ I915_WRITE(pipeconf_reg, pipeconf);
+ } else {
+ bool restore_vblank = false;
+ int count, detect;
+
+ /*
+ * If there isn't any border, add some.
+ * Yes, this will flicker
+ */
+ if (vblank_start <= vactive && vblank_end >= vtotal) {
+ uint32_t vsync = I915_READ(vsync_reg);
+ uint32_t vsync_start = (vsync & 0xffff) + 1;
+
+ vblank_start = vsync_start;
+ I915_WRITE(vblank_reg,
+ (vblank_start - 1) |
+ ((vblank_end - 1) << 16));
+ restore_vblank = true;
+ }
+ /* sample in the vertical border, selecting the larger one */
+ if (vblank_start - vactive >= vtotal - vblank_end)
+ vsample = (vblank_start + vactive) >> 1;
+ else
+ vsample = (vtotal + vblank_end) >> 1;
+
+ /*
+ * Wait for the border to be displayed
+ */
+ while (I915_READ(pipe_dsl_reg) >= vactive)
+ ;
+ while ((dsl = I915_READ(pipe_dsl_reg)) <= vsample)
+ ;
+ /*
+ * Watch ST00 for an entire scanline
+ */
+ detect = 0;
+ count = 0;
+ do {
+ count++;
+ /* Read the ST00 VGA status register */
+ st00 = I915_READ8(VGA_MSR_WRITE);
+ if (st00 & (1 << 4))
+ detect++;
+ } while ((I915_READ(pipe_dsl_reg) == dsl));
+
+ /* restore vblank if necessary */
+ if (restore_vblank)
+ I915_WRITE(vblank_reg, vblank);
+ /*
+ * If more than 3/4 of the scanline detected a monitor,
+ * then it is assumed to be present. This works even on i830,
+ * where there isn't any way to force the border color across
+ * the screen
+ */
+ status = detect * 4 > count * 3 ?
+ connector_status_connected :
+ connector_status_disconnected;
+ }
+
+ /* Restore previous settings */
+ I915_WRITE(bclrpat_reg, save_bclrpat);
+
+ return status;
+}
+
static enum drm_connector_status intel_crt_detect(struct drm_connector *connector)
{
struct drm_device *dev = connector->dev;
+ struct intel_output *intel_output = to_intel_output(connector);
+ struct drm_encoder *encoder = &intel_output->enc;
+ struct drm_crtc *crtc;
+ int dpms_mode;
+ enum drm_connector_status status;
if (IS_I9XX(dev) && !IS_I915G(dev) && !IS_I915GM(dev)) {
if (intel_crt_detect_hotplug(connector))
@@ -212,8 +345,20 @@
if (intel_crt_detect_ddc(connector))
return connector_status_connected;
- /* TODO use load detect */
- return connector_status_unknown;
+ /* for pre-945g platforms use load detect */
+ if (encoder->crtc && encoder->crtc->enabled) {
+ status = intel_crt_load_detect(encoder->crtc, intel_output);
+ } else {
+ crtc = intel_get_load_detect_pipe(intel_output,
+ NULL, &dpms_mode);
+ if (crtc) {
+ status = intel_crt_load_detect(crtc, intel_output);
+ intel_release_load_detect_pipe(intel_output, dpms_mode);
+ } else
+ status = connector_status_unknown;
+ }
+
+ return status;
}
static void intel_crt_destroy(struct drm_connector *connector)