Commit e4a5d54f authored by Ma Ling's avatar Ma Ling Committed by Eric Anholt

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: default avatarMa Ling <ling.ma@intel.com>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
parent 619ac3b7
......@@ -198,9 +198,142 @@ static bool intel_crt_detect_ddc(struct drm_connector *connector)
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 @@ static enum drm_connector_status intel_crt_detect(struct drm_connector *connecto
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)
......
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