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

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

drivers/gpu/drm/i915/intel_crt.c

+147 −2
Original line number 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);

}



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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