drm/i915/display: split out load detect to a separate file

Load detect is shared between tv and crt but otherwise isolated in
intel_display.c.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230417153741.1074692-1-jani.nikula@intel.com

1 files changed, 229 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_load_detect.c b/drivers/gpu/drm/i915/display/intel_load_detect.c
new file mode 100644
index 000000000000..5d6bb6d712bc
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_load_detect.c
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_atomic_uapi.h>
+
+#include "i915_drv.h"
+#include "intel_atomic.h"
+#include "intel_crtc.h"
+#include "intel_display_types.h"
+#include "intel_load_detect.h"
+
+/* VESA 640x480x72Hz mode to set on the pipe */
+static const struct drm_display_mode load_detect_mode = {
+	DRM_MODE("640x480", DRM_MODE_TYPE_DEFAULT, 31500, 640, 664,
+		 704, 832, 0, 480, 489, 491, 520, 0, DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC),
+};
+
+static int intel_modeset_disable_planes(struct drm_atomic_state *state,
+					struct drm_crtc *crtc)
+{
+	struct drm_plane *plane;
+	struct drm_plane_state *plane_state;
+	int ret, i;
+
+	ret = drm_atomic_add_affected_planes(state, crtc);
+	if (ret)
+		return ret;
+
+	for_each_new_plane_in_state(state, plane, plane_state, i) {
+		if (plane_state->crtc != crtc)
+			continue;
+
+		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+		if (ret)
+			return ret;
+
+		drm_atomic_set_fb_for_plane(plane_state, NULL);
+	}
+
+	return 0;
+}
+
+int intel_load_detect_get_pipe(struct drm_connector *connector,
+			       struct intel_load_detect_pipe *old,
+			       struct drm_modeset_acquire_ctx *ctx)
+{
+	struct intel_encoder *encoder =
+		intel_attached_encoder(to_intel_connector(connector));
+	struct intel_crtc *possible_crtc;
+	struct intel_crtc *crtc = NULL;
+	struct drm_device *dev = encoder->base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct drm_mode_config *config = &dev->mode_config;
+	struct drm_atomic_state *state = NULL, *restore_state = NULL;
+	struct drm_connector_state *connector_state;
+	struct intel_crtc_state *crtc_state;
+	int ret;
+
+	drm_dbg_kms(&dev_priv->drm, "[CONNECTOR:%d:%s], [ENCODER:%d:%s]\n",
+		    connector->base.id, connector->name,
+		    encoder->base.base.id, encoder->base.name);
+
+	old->restore_state = NULL;
+
+	drm_WARN_ON(dev, !drm_modeset_is_locked(&config->connection_mutex));
+
+	/*
+	 * Algorithm gets a little messy:
+	 *
+	 *   - if the connector already has an assigned crtc, use it (but make
+	 *     sure it's on first)
+	 *
+	 *   - try to find the first unused crtc that can drive this connector,
+	 *     and use that if we find one
+	 */
+
+	/* See if we already have a CRTC for this connector */
+	if (connector->state->crtc) {
+		crtc = to_intel_crtc(connector->state->crtc);
+
+		ret = drm_modeset_lock(&crtc->base.mutex, ctx);
+		if (ret)
+			goto fail;
+
+		/* Make sure the crtc and connector are running */
+		goto found;
+	}
+
+	/* Find an unused one (if possible) */
+	for_each_intel_crtc(dev, possible_crtc) {
+		if (!(encoder->base.possible_crtcs &
+		      drm_crtc_mask(&possible_crtc->base)))
+			continue;
+
+		ret = drm_modeset_lock(&possible_crtc->base.mutex, ctx);
+		if (ret)
+			goto fail;
+
+		if (possible_crtc->base.state->enable) {
+			drm_modeset_unlock(&possible_crtc->base.mutex);
+			continue;
+		}
+
+		crtc = possible_crtc;
+		break;
+	}
+
+	/*
+	 * If we didn't find an unused CRTC, don't use any.
+	 */
+	if (!crtc) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "no pipe available for load-detect\n");
+		ret = -ENODEV;
+		goto fail;
+	}
+
+found:
+	state = drm_atomic_state_alloc(dev);
+	restore_state = drm_atomic_state_alloc(dev);
+	if (!state || !restore_state) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	state->acquire_ctx = ctx;
+	to_intel_atomic_state(state)->internal = true;
+
+	restore_state->acquire_ctx = ctx;
+	to_intel_atomic_state(restore_state)->internal = true;
+
+	connector_state = drm_atomic_get_connector_state(state, connector);
+	if (IS_ERR(connector_state)) {
+		ret = PTR_ERR(connector_state);
+		goto fail;
+	}
+
+	ret = drm_atomic_set_crtc_for_connector(connector_state, &crtc->base);
+	if (ret)
+		goto fail;
+
+	crtc_state = intel_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		goto fail;
+	}
+
+	crtc_state->uapi.active = true;
+
+	ret = drm_atomic_set_mode_for_crtc(&crtc_state->uapi,
+					   &load_detect_mode);
+	if (ret)
+		goto fail;
+
+	ret = intel_modeset_disable_planes(state, &crtc->base);
+	if (ret)
+		goto fail;
+
+	ret = PTR_ERR_OR_ZERO(drm_atomic_get_connector_state(restore_state, connector));
+	if (!ret)
+		ret = PTR_ERR_OR_ZERO(drm_atomic_get_crtc_state(restore_state, &crtc->base));
+	if (!ret)
+		ret = drm_atomic_add_affected_planes(restore_state, &crtc->base);
+	if (ret) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "Failed to create a copy of old state to restore: %i\n",
+			    ret);
+		goto fail;
+	}
+
+	ret = drm_atomic_commit(state);
+	if (ret) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "failed to set mode on load-detect pipe\n");
+		goto fail;
+	}
+
+	old->restore_state = restore_state;
+	drm_atomic_state_put(state);
+
+	/* let the connector get through one full cycle before testing */
+	intel_crtc_wait_for_next_vblank(crtc);
+
+	return true;
+
+fail:
+	if (state) {
+		drm_atomic_state_put(state);
+		state = NULL;
+	}
+	if (restore_state) {
+		drm_atomic_state_put(restore_state);
+		restore_state = NULL;
+	}
+
+	if (ret == -EDEADLK)
+		return ret;
+
+	return false;
+}
+
+void intel_load_detect_release_pipe(struct drm_connector *connector,
+				    struct intel_load_detect_pipe *old,
+				    struct drm_modeset_acquire_ctx *ctx)
+{
+	struct intel_encoder *intel_encoder =
+		intel_attached_encoder(to_intel_connector(connector));
+	struct drm_i915_private *i915 = to_i915(intel_encoder->base.dev);
+	struct drm_encoder *encoder = &intel_encoder->base;
+	struct drm_atomic_state *state = old->restore_state;
+	int ret;
+
+	drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s], [ENCODER:%d:%s]\n",
+		    connector->base.id, connector->name,
+		    encoder->base.id, encoder->name);
+
+	if (!state)
+		return;
+
+	ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
+	if (ret)
+		drm_dbg_kms(&i915->drm,
+			    "Couldn't release load detect pipe: %i\n", ret);
+	drm_atomic_state_put(state);
+}