drm_hwcomposer: Initial implementation

This adds a very basic hwcomposer implementation on top of
libdrm.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Change-Id: I472feb9bc08a4c4cd9849370c849d266ea58da9c

Android.mk

@@ -0,0 +1,38 @@
+# Copyright (C) 2015 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_SHARED_LIBRARIES := \
+	libdrm \
+	libhardware \
+	liblog \
+	libutils \
+
+LOCAL_C_INCLUDES := \
+	external/drm_gralloc \
+	external/libdrm \
+	external/libdrm/include/drm \
+	system/core/include/utils \
+
+LOCAL_CFLAGS :=
+LOCAL_SRC_FILES := hwcomposer.cpp
+LOCAL_MODULE := hwcomposer.drm
+LOCAL_MODULE_TAGS := optional
+LOCAL_MODULE_RELATIVE_PATH := hw
+LOCAL_MODULE_CLASS := SHARED_LIBRARIES
+LOCAL_MODULE_SUFFIX := $(TARGET_SHLIB_SUFFIX)
+include $(BUILD_SHARED_LIBRARY)

hwcomposer.cpp

@@ -0,0 +1,903 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "hwcomposer-drm"
+
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/param.h>
+
+#include <cutils/log.h>
+
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <drm/drm_fourcc.h>
+
+#include <hardware/hardware.h>
+#include <hardware/hwcomposer.h>
+
+#include <gralloc_drm.h>
+#include <gralloc_drm_priv.h>
+#include <gralloc_drm_handle.h>
+
+#define ARRAY_SIZE(arr) (int)(sizeof(arr) / sizeof((arr)[0]))
+
+#define HWCOMPOSER_DRM_DEVICE "/dev/dri/card0"
+#define MAX_NUM_DISPLAYS 3
+#define UM_PER_INCH 25400
+
+static const uint32_t panel_types[] = {
+	DRM_MODE_CONNECTOR_LVDS,
+	DRM_MODE_CONNECTOR_eDP,
+	DRM_MODE_CONNECTOR_DSI,
+};
+
+struct hwc_drm_display {
+	uint32_t connector_id;
+
+	drmModeModeInfoPtr configs;
+	uint32_t num_configs;
+
+	int active_config;
+	uint32_t active_crtc;
+};
+
+struct hwc_context_t {
+	hwc_composer_device_1_t device;
+
+	int fd;
+	struct drm_module_t *gralloc_module; /* TODO: NUKE THIS */
+
+	hwc_procs_t const *procs;
+
+	struct hwc_drm_display displays[MAX_NUM_DISPLAYS];
+	int num_displays;
+};
+
+static int hwc_get_drm_display(struct hwc_context_t *ctx, int display,
+			struct hwc_drm_display **hd)
+{
+	if (display >= MAX_NUM_DISPLAYS) {
+		ALOGE("Requested display is out-of-bounds %d %d", display,
+			MAX_NUM_DISPLAYS);
+		return -EINVAL;
+	}
+	*hd = &ctx->displays[display];
+	return 0;
+}
+
+static int hwc_prepare_layer(hwc_layer_1_t *layer)
+{
+	/* TODO: We can't handle background right now, defer to sufaceFlinger */
+	if (layer->compositionType == HWC_BACKGROUND) {
+		layer->compositionType = HWC_FRAMEBUFFER;
+		ALOGV("Can't handle background layers yet");
+
+	/* TODO: Support sideband compositions */
+	} else if (layer->compositionType == HWC_SIDEBAND) {
+		layer->compositionType = HWC_FRAMEBUFFER;
+		ALOGV("Can't handle sideband content yet");
+	}
+
+	layer->hints = 0;
+
+	/* TODO: Handle cursor by setting compositionType=HWC_CURSOR_OVERLAY */
+	if (layer->flags & HWC_IS_CURSOR_LAYER) {
+		ALOGV("Can't handle async cursors yet");
+	}
+
+	/* TODO: Handle transformations */
+	if (layer->transform) {
+		ALOGV("Can't handle transformations yet");
+	}
+
+	/* TODO: Handle blending & plane alpha*/
+	if (layer->blending == HWC_BLENDING_PREMULT ||
+	    layer->blending == HWC_BLENDING_COVERAGE) {
+		ALOGV("Can't handle blending yet");
+	}
+
+	/* TODO: Handle cropping & scaling */
+
+	return 0;
+}
+
+static int hwc_prepare(hwc_composer_device_1_t */* dev */, size_t num_displays,
+			hwc_display_contents_1_t** display_contents)
+{
+	int ret = 0, i, j;
+
+	/* TODO: Check flags for HWC_GEOMETRY_CHANGED */
+
+	for (i = 0; i < (int)num_displays && i < MAX_NUM_DISPLAYS; i++) {
+		for (j = 0; j < (int)display_contents[i]->numHwLayers; j++) {
+			ret = hwc_prepare_layer(
+					&display_contents[i]->hwLayers[j]);
+			if (ret) {
+				ALOGE("Failed to prepare layer %d:%d", j, i);
+				return ret;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static int hwc_bo_add_fb(hwc_context_t */* ctx */, struct gralloc_drm_bo_t *bo)
+{
+	uint32_t pitches[4] = { 0, 0, 0, 0 };
+	uint32_t handles[4] = { 0, 0, 0, 0 };
+	uint32_t offsets[4] = { 0, 0, 0, 0 };
+	int drm_format;
+
+	pitches[0] = bo->handle->stride;
+	handles[0] = bo->fb_handle;
+
+	switch(bo->handle->format) {
+		case HAL_PIXEL_FORMAT_RGB_888:
+			drm_format = DRM_FORMAT_BGR888;
+			break;
+		case HAL_PIXEL_FORMAT_BGRA_8888:
+			drm_format = DRM_FORMAT_ARGB8888;
+			break;
+		case HAL_PIXEL_FORMAT_RGBX_8888:
+			drm_format = DRM_FORMAT_XBGR8888;
+			break;
+		case HAL_PIXEL_FORMAT_RGBA_8888:
+			drm_format = DRM_FORMAT_ABGR8888;
+			break;
+		case HAL_PIXEL_FORMAT_RGB_565:
+			drm_format = DRM_FORMAT_BGR565;
+			break;
+		case HAL_PIXEL_FORMAT_YV12:
+			drm_format = DRM_FORMAT_YVU420;
+			break;
+		default:
+			ALOGE("error resolving drm format");
+			return -EINVAL;
+	}
+
+	return drmModeAddFB2(bo->drm->fd, bo->handle->width, bo->handle->height,
+		drm_format, handles, pitches, offsets, (uint32_t *) &bo->fb_id,
+		0);
+}
+
+static bool hwc_mode_is_equal(drmModeModeInfoPtr a, drmModeModeInfoPtr b)
+{
+	return a->clock == b->clock &&
+		a->hdisplay == b->hdisplay &&
+		a->hsync_start == b->hsync_start &&
+		a->hsync_end == b->hsync_end &&
+		a->htotal == b->htotal &&
+		a->hskew == b->hskew &&
+		a->vdisplay == b->vdisplay &&
+		a->vsync_start == b->vsync_start &&
+		a->vsync_end == b->vsync_end &&
+		a->vtotal == b->vtotal &&
+		a->vscan == b->vscan &&
+		a->vrefresh == b->vrefresh &&
+		a->flags == b->flags &&
+		a->type == b->type &&
+		!strcmp(a->name, b->name);
+}
+
+static int hwc_set_display(hwc_context_t *ctx, int display,
+			hwc_display_contents_1_t* display_contents)
+{
+	struct hwc_drm_display *hd = NULL;
+	drmModeCrtcPtr crtc;
+	drmModeModeInfoPtr m;
+	hwc_layer_1_t *layer = NULL;
+	int ret, i;
+
+	/* TODO: NUKE THIS */
+	gralloc_drm_t *drm = ctx->gralloc_module->drm;
+	gralloc_drm_handle_t *gr_handle;
+	struct gralloc_drm_bo_t *bo;
+
+	ret = hwc_get_drm_display(ctx, display, &hd);
+	if (ret)
+		return ret;
+
+	if (!hd->active_crtc) {
+		ALOGE("There is no active crtc for display %d", display);
+		return -ENOENT;
+	}
+
+	/*
+	 * TODO: We can only support one hw layer atm, so choose either the
+	 * first one or the framebuffer target.
+	 */
+	if (!display_contents->numHwLayers) {
+		return 0;
+	} else if (display_contents->numHwLayers == 1) {
+		layer = &display_contents->hwLayers[0];
+	} else {
+		for (i = 0; i < (int)display_contents->numHwLayers; i++) {
+			layer = &display_contents->hwLayers[i];
+			if (layer->compositionType == HWC_FRAMEBUFFER_TARGET)
+				break;
+		}
+		if (i == (int)display_contents->numHwLayers) {
+			ALOGE("Could not find a suitable layer for display %d",
+				display);
+		}
+	}
+
+	gr_handle = (gralloc_drm_handle_t *)layer->handle;
+
+	bo = gr_handle->data;
+	if (!bo) {
+		ALOGE("Could not get drm bo from handle");
+		return -EINVAL;
+	}
+
+	if (!bo->fb_id) {
+		ret = hwc_bo_add_fb(ctx, bo);
+		if (ret) {
+			ALOGE("could not create drm fb %d", ret);
+			return ret;
+		}
+	}
+
+	crtc = drmModeGetCrtc(ctx->fd, hd->active_crtc);
+	if (!crtc) {
+		ALOGE("Failed to get crtc for display %d", display);
+		return -ENODEV;
+	}
+
+	m = &hd->configs[hd->active_config];
+
+	/* Do a modeset if we haven't done one, or the mode has changed */
+	if (!crtc->mode_valid || !hwc_mode_is_equal(m, &crtc->mode)) {
+		ret = drmModeSetCrtc(ctx->fd, crtc->crtc_id, bo->fb_id, 0, 0,
+			&hd->connector_id, 1, m);
+		if (ret) {
+			ALOGE("Modeset failed for crtc %d", crtc->crtc_id);
+			goto out;
+		}
+		goto out;
+	}
+
+	ret = drmModePageFlip(ctx->fd, crtc->crtc_id, bo->fb_id, 0, 0);
+	if (ret) {
+		ALOGE("Failed to flip buffer for crtc %d", crtc->crtc_id);
+		goto out;
+	}
+
+out:
+	drmModeFreeCrtc(crtc);
+	return ret;
+}
+
+static int hwc_set(hwc_composer_device_1_t *dev, size_t num_displays,
+			hwc_display_contents_1_t** display_contents)
+{
+	struct hwc_context_t *ctx = (struct hwc_context_t *)&dev->common;
+	int ret = 0, i;
+
+	/* TODO: Handle acquire & release fences */
+
+	for (i = 0; i < (int)num_displays && i < MAX_NUM_DISPLAYS; i++) {
+		display_contents[i]->retireFenceFd = -1; /* TODO: sync */
+
+		ret = hwc_set_display(ctx, i, display_contents[i]);
+	}
+
+	return ret;
+}
+
+static int hwc_event_control(struct hwc_composer_device_1 */* dev */,
+			int /* display */, int /* event */, int /* enabled */)
+{
+	int ret;
+
+	/* TODO */
+	return 0;
+}
+
+static int hwc_set_power_mode(struct hwc_composer_device_1* dev, int display,
+			int mode)
+{
+	struct hwc_context_t *ctx = (struct hwc_context_t *)&dev->common;
+	struct hwc_drm_display *hd = NULL;
+	drmModeConnectorPtr c;
+	int ret, i;
+	uint32_t dpms_prop = 0;
+	uint64_t dpms_value = 0;
+
+	ret = hwc_get_drm_display(ctx, display, &hd);
+	if (ret)
+		return ret;
+
+	c = drmModeGetConnector(ctx->fd, hd->connector_id);
+	if (!c) {
+		ALOGE("Failed to get connector %d", display);
+		return -ENODEV;
+	}
+
+	for (i = 0; !dpms_prop && i < c->count_props; i++) {
+		drmModePropertyPtr p;
+
+		p = drmModeGetProperty(ctx->fd, c->props[i]);
+		if (!p)
+			continue;
+
+		if (!strcmp(p->name, "DPMS"))
+			dpms_prop = c->props[i];
+
+		drmModeFreeProperty(p);
+	}
+	if (!dpms_prop) {
+		ALOGE("Failed to get DPMS property from display %d", display);
+		ret = -ENOENT;
+		goto out;
+	}
+
+	switch(mode) {
+	case HWC_POWER_MODE_OFF:
+		dpms_value = DRM_MODE_DPMS_OFF;
+		break;
+
+	/* We can't support dozing right now, so go full on */
+	case HWC_POWER_MODE_DOZE:
+	case HWC_POWER_MODE_DOZE_SUSPEND:
+	case HWC_POWER_MODE_NORMAL:
+		dpms_value = DRM_MODE_DPMS_ON;
+		break;
+	};
+
+	ret = drmModeConnectorSetProperty(ctx->fd, c->connector_id,
+			dpms_prop, dpms_value);
+	if (ret) {
+		ALOGE("Failed to set DPMS property for display %d", display);
+		goto out;
+	}
+
+out:
+	drmModeFreeConnector(c);
+	return ret;
+}
+
+static int hwc_query(struct hwc_composer_device_1 */* dev */, int what,
+			int *value)
+{
+	switch(what) {
+	case HWC_BACKGROUND_LAYER_SUPPORTED:
+		*value = 0; /* TODO: We should do this */
+		break;
+	case HWC_VSYNC_PERIOD:
+		ALOGW("Query for deprecated vsync value, returning 60Hz");
+		*value = 1000 * 1000 * 1000 / 60;
+		break;
+	case HWC_DISPLAY_TYPES_SUPPORTED:
+		*value = HWC_DISPLAY_PRIMARY | HWC_DISPLAY_EXTERNAL;
+		break;
+	}
+	return 0;
+}
+
+static void hwc_register_procs(struct hwc_composer_device_1* dev,
+			hwc_procs_t const* procs)
+{
+	struct hwc_context_t *ctx = (struct hwc_context_t *)&dev->common;
+
+	ctx->procs = procs;
+}
+
+static int hwc_get_display_configs(struct hwc_composer_device_1* dev,
+			int display, uint32_t* configs, size_t* numConfigs)
+{
+	struct hwc_context_t *ctx = (struct hwc_context_t *)&dev->common;
+	struct hwc_drm_display *hd = NULL;
+	drmModeConnectorPtr c;
+	int ret = 0, i;
+
+	if (!*numConfigs)
+		return 0;
+
+	ret = hwc_get_drm_display(ctx, display, &hd);
+	if (ret)
+		return ret;
+
+	c = drmModeGetConnector(ctx->fd, hd->connector_id);
+	if (!c) {
+		ALOGE("Failed to get connector %d", display);
+		return -ENODEV;
+	}
+
+	if (hd->configs)
+		free(hd->configs);
+
+	hd->active_config = -1;
+	hd->configs = (drmModeModeInfoPtr)calloc(c->count_modes,
+					sizeof(*hd->configs));
+	if (!hd->configs) {
+		ALOGE("Failed to allocate config list for display %d", display);
+		ret = -ENOMEM;
+		hd->num_configs = 0;
+		goto out;
+	}
+
+	for (i = 0; i < c->count_modes; i++) {
+		drmModeModeInfoPtr m = &hd->configs[i];
+
+		memcpy(m, &c->modes[i], sizeof(*m));
+
+		if (i < (int)*numConfigs)
+			configs[i] = i;
+	}
+
+	hd->num_configs = c->count_modes;
+	*numConfigs = MIN(c->count_modes, *numConfigs);
+
+out:
+	drmModeFreeConnector(c);
+	return ret;
+}
+
+static int hwc_check_config_valid(struct hwc_context_t *ctx,
+			drmModeConnectorPtr connector, int display,
+			int config_idx)
+{
+	struct hwc_drm_display *hd = NULL;
+	drmModeModeInfoPtr m = NULL;
+	int ret = 0, i;
+
+	ret = hwc_get_drm_display(ctx, display, &hd);
+	if (ret)
+		return ret;
+
+	/* Make sure the requested config is still valid for the display */
+	for (i = 0; i < connector->count_modes; i++) {
+		if (hwc_mode_is_equal(&connector->modes[i],
+				&hd->configs[config_idx])) {
+			m = &hd->configs[config_idx];
+			break;
+		}
+	}
+	if (!m)
+		return -ENOENT;
+
+	return 0;
+}
+
+static int hwc_get_display_attributes(struct hwc_composer_device_1* dev,
+		int display, uint32_t config, const uint32_t* attributes,
+		int32_t* values)
+{
+	struct hwc_context_t *ctx = (struct hwc_context_t *)&dev->common;
+	struct hwc_drm_display *hd = NULL;
+	drmModeConnectorPtr c;
+	drmModeModeInfoPtr m;
+	int ret, i;
+
+	ret = hwc_get_drm_display(ctx, display, &hd);
+	if (ret)
+		return ret;
+
+	if (config >= hd->num_configs) {
+		ALOGE("Requested config is out-of-bounds %d %d", config,
+			hd->num_configs);
+		return -EINVAL;
+	}
+
+	c = drmModeGetConnector(ctx->fd, hd->connector_id);
+	if (!c) {
+		ALOGE("Failed to get connector %d", display);
+		return -ENODEV;
+	}
+
+	ret = hwc_check_config_valid(ctx, c, display, (int)config);
+	if (ret) {
+		ALOGE("Provided config is no longer valid %u", config);
+		goto out;
+	}
+
+	m = &hd->configs[config];
+	for (i = 0; attributes[i] != HWC_DISPLAY_NO_ATTRIBUTE; i++) {
+		switch(attributes[i]) {
+		case HWC_DISPLAY_VSYNC_PERIOD:
+			values[i] = 1000 * 1000 * 1000 / m->vrefresh;
+			break;
+		case HWC_DISPLAY_WIDTH:
+			values[i] = m->hdisplay;
+			break;
+		case HWC_DISPLAY_HEIGHT:
+			values[i] = m->vdisplay;
+			break;
+		case HWC_DISPLAY_DPI_X:
+			/* Dots per 1000 inches */
+			values[i] = c->mmWidth ?
+				(m->hdisplay * UM_PER_INCH) / c->mmWidth : 0;
+			break;
+		case HWC_DISPLAY_DPI_Y:
+			/* Dots per 1000 inches */
+			values[i] = c->mmHeight ?
+				(m->vdisplay * UM_PER_INCH) / c->mmHeight : 0;
+			break;
+		}
+	}
+
+out:
+	drmModeFreeConnector(c);
+	return ret;
+}
+
+static int hwc_get_active_config(struct hwc_composer_device_1* dev, int display)
+{
+	struct hwc_context_t *ctx = (struct hwc_context_t *)&dev->common;
+	struct hwc_drm_display *hd = NULL;
+	drmModeConnectorPtr c;
+	int ret;
+
+	ret = hwc_get_drm_display(ctx, display, &hd);
+	if (ret)
+		return ret;
+
+	if (hd->active_config < 0)
+		return -1;
+
+	c = drmModeGetConnector(ctx->fd, hd->connector_id);
+	if (!c) {
+		ALOGE("Failed to get connector %d", display);
+		return -ENODEV;
+	}
+
+	ret = hwc_check_config_valid(ctx, c, display, hd->active_config);
+	if (ret) {
+		ALOGE("Config is no longer valid %d", hd->active_config);
+		ret = -1;
+		goto out;
+	}
+
+	ret = hd->active_config;
+
+out:
+	drmModeFreeConnector(c);
+	return ret;
+}
+
+static bool hwc_crtc_is_bound(struct hwc_context_t *ctx, uint32_t crtc_id)
+{
+	int i;
+
+	for (i = 0; i < MAX_NUM_DISPLAYS; i++) {
+		if (ctx->displays[i].active_crtc == crtc_id)
+			return true;
+	}
+	return false;
+}
+
+static int hwc_try_encoder(struct hwc_context_t *ctx, drmModeResPtr r,
+			uint32_t encoder_id, uint32_t *crtc_id)
+{
+	drmModeEncoderPtr e;
+	int ret, i;
+
+	e = drmModeGetEncoder(ctx->fd, encoder_id);
+	if (!e) {
+		ALOGE("Failed to get encoder for connector %d", encoder_id);
+		return -ENODEV;
+	}
+
+	/* First try to use the currently-bound crtc */
+	if (e->crtc_id) {
+		if (!hwc_crtc_is_bound(ctx, e->crtc_id)) {
+			*crtc_id = e->crtc_id;
+			ret = 0;
+			goto out;
+		}
+	}
+
+	/* Try to find a possible crtc which will work */
+	for (i = 0; i < r->count_crtcs; i++) {
+		if (!(e->possible_crtcs & (1 << i)))
+			continue;
+
+		/* We've already tried this earlier */
+		if (e->crtc_id == r->crtcs[i])
+			continue;
+
+		if (!hwc_crtc_is_bound(ctx, r->crtcs[i])) {
+			*crtc_id = r->crtcs[i];
+			ret = 0;
+			goto out;
+		}
+	}
+
+	/* We can't use the encoder, but nothing went wrong, try another one */
+	ret = -EAGAIN;
+
+out:
+	drmModeFreeEncoder(e);
+	return ret;
+}
+
+static int hwc_set_active_config(struct hwc_composer_device_1* dev, int display,
+			int index)
+{
+	struct hwc_context_t *ctx = (struct hwc_context_t *)&dev->common;
+	struct hwc_drm_display *hd = NULL;
+	drmModeResPtr r = NULL;
+	drmModeConnectorPtr c;
+	uint32_t crtc_id = 0;
+	int ret, i;
+	bool new_crtc, new_encoder;
+
+	ret = hwc_get_drm_display(ctx, display, &hd);
+	if (ret)
+		return ret;
+
+	c = drmModeGetConnector(ctx->fd, hd->connector_id);
+	if (!c) {
+		ALOGE("Failed to get connector %d", display);
+		return -ENODEV;
+	}
+
+	if (c->connection == DRM_MODE_DISCONNECTED) {
+		ALOGE("Tried to configure a disconnected display %d", display);
+		ret = -ENODEV;
+		goto out;
+	}
+
+	ret = hwc_check_config_valid(ctx, c, display, index);
+	if (ret) {
+		ALOGE("Provided config is no longer valid %u", index);
+		ret = -ENOENT;
+		goto out;
+	}
+
+	r = drmModeGetResources(ctx->fd);
+	if (!r) {
+		ALOGE("Failed to get drm resources");
+		goto out;
+	}
+
+	/* We no longer have an active_crtc */
+	hd->active_crtc = 0;
+
+	/* First, try to use the currently-connected encoder */
+	if (c->encoder_id) {
+		ret = hwc_try_encoder(ctx, r, c->encoder_id, &crtc_id);
+		if (ret && ret != -EAGAIN) {
+			ALOGE("Encoder try failed %d", ret);
+			goto out;
+		}
+	}
+
+	/* We couldn't find a crtc with the attached encoder, try the others */
+	if (!crtc_id) {
+		for (i = 0; i < c->count_encoders; i++) {
+			ret = hwc_try_encoder(ctx, r, c->encoders[i], &crtc_id);
+			if (!ret) {
+				break;
+			} else if (ret != -EAGAIN) {
+				ALOGE("Encoder try failed %d", ret);
+				goto out;
+			}
+		}
+		if (!crtc_id) {
+			ALOGE("Couldn't find valid crtc to modeset");
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
+	hd->active_crtc = crtc_id;
+	hd->active_config = index;
+
+	/* TODO: Once we have atomic, set the crtc timing info here */
+
+out:
+	if (r)
+		drmModeFreeResources(r);
+
+	drmModeFreeConnector(c);
+	return ret;
+}
+
+static int hwc_device_close(struct hw_device_t *dev)
+{
+	struct hwc_context_t *ctx = (struct hwc_context_t *)dev;
+
+	free(ctx);
+
+	return 0;
+}
+
+static int hwc_initialize_display(struct hwc_context_t *ctx, int display,
+			uint32_t connector_id)
+{
+	struct hwc_drm_display *hd = NULL;
+	int ret;
+
+	ret = hwc_get_drm_display(ctx, display, &hd);
+	if (ret)
+		return ret;
+
+	hd->active_config = -1;
+	hd->connector_id = connector_id;
+
+	return 0;
+}
+
+static int hwc_enumerate_displays(struct hwc_context_t *ctx)
+{
+	struct hwc_drm_display *panel_hd;
+	drmModeResPtr res;
+	drmModeConnectorPtr *conn_list;
+	int ret = 0, i, j;
+
+	res = drmModeGetResources(ctx->fd);
+	if (!res) {
+		ALOGE("Failed to get drm resources");
+		return -ENODEV;
+	}
+
+	conn_list = (drmModeConnector **)calloc(res->count_connectors,
+			sizeof(*conn_list));
+	if (!conn_list) {
+		ALOGE("Failed to allocate connector list");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	for (i = 0; i < res->count_connectors; i++) {
+		conn_list[i] = drmModeGetConnector(ctx->fd, res->connectors[i]);
+		if (!conn_list[i]) {
+			ALOGE("Failed to get connector %d", res->connectors[i]);
+			ret = -ENODEV;
+			goto out;
+		}
+	}
+
+	ctx->num_displays = 0;
+
+	/* Find a connected, panel type connector for display 0 */
+	for (i = 0; i < res->count_connectors; i++) {
+		drmModeConnectorPtr c = conn_list[i];
+
+		for (j = 0; j < ARRAY_SIZE(panel_types); j++) {
+			if (c->connector_type == panel_types[j] &&
+			    c->connection == DRM_MODE_CONNECTED)
+				break;
+		}
+		if (j == ARRAY_SIZE(panel_types))
+			continue;
+
+		hwc_initialize_display(ctx, ctx->num_displays, c->connector_id);
+		ctx->num_displays++;
+		break;
+	}
+
+	ret = hwc_get_drm_display(ctx, 0, &panel_hd);
+	if (ret)
+		goto out;
+
+	/* Fill in the other displays */
+	for (i = 0; i < res->count_connectors; i++) {
+		drmModeConnectorPtr c = conn_list[i];
+
+		if (panel_hd->connector_id == c->connector_id)
+			continue;
+
+		hwc_initialize_display(ctx, ctx->num_displays, c->connector_id);
+		ctx->num_displays++;
+	}
+
+out:
+	for (i = 0; i < res->count_connectors; i++) {
+		if (conn_list[i])
+			drmModeFreeConnector(conn_list[i]);
+	}
+	free(conn_list);
+
+	if (res)
+		drmModeFreeResources(res);
+
+	return ret;
+}
+
+static int hwc_device_open(const struct hw_module_t* module, const char* name,
+			struct hw_device_t** dev)
+{
+	int ret = 0;
+	struct hwc_context_t *ctx;
+
+	if (strcmp(name, HWC_HARDWARE_COMPOSER)) {
+		ALOGE("Invalid module name- %s", name);
+		return -EINVAL;
+	}
+
+	ctx = (hwc_context_t *)calloc(1, sizeof(*ctx));
+	if (!ctx) {
+		ALOGE("Failed to allocate hwc context");
+		return -ENOMEM;
+	}
+
+	/* TODO: NUKE THIS */
+	ret = hw_get_module(GRALLOC_HARDWARE_MODULE_ID,
+			(const hw_module_t **)&ctx->gralloc_module);
+	if (ret) {
+		ALOGE("Failed to open gralloc module");
+		goto out;
+	}
+
+	/* TODO: Use drmOpenControl here instead */
+	ctx->fd = open(HWCOMPOSER_DRM_DEVICE, O_RDWR);
+	if (ctx->fd < 0) {
+		ALOGE("Failed to open dri- %s", strerror(-errno));
+		goto out;
+	}
+
+	ret = drmSetMaster(ctx->fd);
+	if (ret) {
+		ALOGE("Failed to set hwcomposer as drm master %d", ret);
+		goto out;
+	}
+
+	ret = hwc_enumerate_displays(ctx);
+	if (ret) {
+		ALOGE("Failed to enumerate displays: %s", strerror(ret));
+		goto out;
+	}
+
+	ctx->device.common.tag = HARDWARE_DEVICE_TAG;
+	ctx->device.common.version = HWC_DEVICE_API_VERSION_1_4;
+	ctx->device.common.module = const_cast<hw_module_t*>(module);
+	ctx->device.common.close = hwc_device_close;
+
+	ctx->device.prepare = hwc_prepare;
+	ctx->device.set = hwc_set;
+	ctx->device.eventControl = hwc_event_control;
+	ctx->device.setPowerMode = hwc_set_power_mode;
+	ctx->device.query = hwc_query;
+	ctx->device.registerProcs = hwc_register_procs;
+	ctx->device.getDisplayConfigs = hwc_get_display_configs;
+	ctx->device.getDisplayAttributes = hwc_get_display_attributes;
+	ctx->device.getActiveConfig = hwc_get_active_config;
+	ctx->device.setActiveConfig = hwc_set_active_config;
+	ctx->device.setCursorPositionAsync = NULL; /* TODO: Add cursor */
+
+	*dev = &ctx->device.common;
+
+	return 0;
+out:
+	if (ctx->fd >= 0)
+		close(ctx->fd);
+
+	free(ctx);
+	return ret;
+}
+
+static struct hw_module_methods_t hwc_module_methods = {
+	open: hwc_device_open
+};
+
+hwc_module_t HAL_MODULE_INFO_SYM = {
+	common: {
+		tag: HARDWARE_MODULE_TAG,
+		version_major: 1,
+		version_minor: 0,
+		id: HWC_HARDWARE_MODULE_ID,
+		name: "DRM hwcomposer module",
+		author: "The Android Open Source Project",
+		methods: &hwc_module_methods,
+		dso: NULL,
+		reserved: { 0 },
+	}
+};