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Commit e4a5d54f authored by Ma Ling's avatar Ma Ling Committed by Eric Anholt
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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
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+147 −2
Original line number Original line Diff line number Diff line
@@ -198,9 +198,142 @@ static bool intel_crt_detect_ddc(struct drm_connector *connector)
	return intel_ddc_probe(intel_output);
	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)
static enum drm_connector_status intel_crt_detect(struct drm_connector *connector)
{
{
	struct drm_device *dev = connector->dev;
	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 (IS_I9XX(dev) && !IS_I915G(dev) && !IS_I915GM(dev)) {
		if (intel_crt_detect_hotplug(connector))
		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))
	if (intel_crt_detect_ddc(connector))
		return connector_status_connected;
		return connector_status_connected;


	/* TODO use load detect */
	/* for pre-945g platforms use load detect */
	return connector_status_unknown;
	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)
static void intel_crt_destroy(struct drm_connector *connector)