1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
new file mode 100644
index 000000000..273e1c59c
--- /dev/null
+++ b/drivers/gpu/drm/drm_encoder.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#include <linux/export.h>
+#include <drm/drmP.h>
+#include <drm/drm_encoder.h>
+
+#include "drm_crtc_internal.h"
+
+/**
+ * DOC: overview
+ *
+ * Encoders represent the connecting element between the CRTC (as the overall
+ * pixel pipeline, represented by &struct drm_crtc) and the connectors (as the
+ * generic sink entity, represented by &struct drm_connector). An encoder takes
+ * pixel data from a CRTC and converts it to a format suitable for any attached
+ * connector. Encoders are objects exposed to userspace, originally to allow
+ * userspace to infer cloning and connector/CRTC restrictions. Unfortunately
+ * almost all drivers get this wrong, making the uabi pretty much useless. On
+ * top of that the exposed restrictions are too simple for today's hardware, and
+ * the recommended way to infer restrictions is by using the
+ * DRM_MODE_ATOMIC_TEST_ONLY flag for the atomic IOCTL.
+ *
+ * Otherwise encoders aren't used in the uapi at all (any modeset request from
+ * userspace directly connects a connector with a CRTC), drivers are therefore
+ * free to use them however they wish. Modeset helper libraries make strong use
+ * of encoders to facilitate code sharing. But for more complex settings it is
+ * usually better to move shared code into a separate &drm_bridge. Compared to
+ * encoders, bridges also have the benefit of being purely an internal
+ * abstraction since they are not exposed to userspace at all.
+ *
+ * Encoders are initialized with drm_encoder_init() and cleaned up using
+ * drm_encoder_cleanup().
+ */
+static const struct drm_prop_enum_list drm_encoder_enum_list[] = {
+	{ DRM_MODE_ENCODER_NONE, "None" },
+	{ DRM_MODE_ENCODER_DAC, "DAC" },
+	{ DRM_MODE_ENCODER_TMDS, "TMDS" },
+	{ DRM_MODE_ENCODER_LVDS, "LVDS" },
+	{ DRM_MODE_ENCODER_TVDAC, "TV" },
+	{ DRM_MODE_ENCODER_VIRTUAL, "Virtual" },
+	{ DRM_MODE_ENCODER_DSI, "DSI" },
+	{ DRM_MODE_ENCODER_DPMST, "DP MST" },
+	{ DRM_MODE_ENCODER_DPI, "DPI" },
+};
+
+int drm_encoder_register_all(struct drm_device *dev)
+{
+	struct drm_encoder *encoder;
+	int ret = 0;
+
+	drm_for_each_encoder(encoder, dev) {
+		if (encoder->funcs->late_register)
+			ret = encoder->funcs->late_register(encoder);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+void drm_encoder_unregister_all(struct drm_device *dev)
+{
+	struct drm_encoder *encoder;
+
+	drm_for_each_encoder(encoder, dev) {
+		if (encoder->funcs->early_unregister)
+			encoder->funcs->early_unregister(encoder);
+	}
+}
+
+/**
+ * drm_encoder_init - Init a preallocated encoder
+ * @dev: drm device
+ * @encoder: the encoder to init
+ * @funcs: callbacks for this encoder
+ * @encoder_type: user visible type of the encoder
+ * @name: printf style format string for the encoder name, or NULL for default name
+ *
+ * Initialises a preallocated encoder. Encoder should be subclassed as part of
+ * driver encoder objects. At driver unload time drm_encoder_cleanup() should be
+ * called from the driver's &drm_encoder_funcs.destroy hook.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int drm_encoder_init(struct drm_device *dev,
+		     struct drm_encoder *encoder,
+		     const struct drm_encoder_funcs *funcs,
+		     int encoder_type, const char *name, ...)
+{
+	int ret;
+
+	/* encoder index is used with 32bit bitmasks */
+	if (WARN_ON(dev->mode_config.num_encoder >= 32))
+		return -EINVAL;
+
+	ret = drm_mode_object_add(dev, &encoder->base, DRM_MODE_OBJECT_ENCODER);
+	if (ret)
+		return ret;
+
+	encoder->dev = dev;
+	encoder->encoder_type = encoder_type;
+	encoder->funcs = funcs;
+	if (name) {
+		va_list ap;
+
+		va_start(ap, name);
+		encoder->name = kvasprintf(GFP_KERNEL, name, ap);
+		va_end(ap);
+	} else {
+		encoder->name = kasprintf(GFP_KERNEL, "%s-%d",
+					  drm_encoder_enum_list[encoder_type].name,
+					  encoder->base.id);
+	}
+	if (!encoder->name) {
+		ret = -ENOMEM;
+		goto out_put;
+	}
+
+	list_add_tail(&encoder->head, &dev->mode_config.encoder_list);
+	encoder->index = dev->mode_config.num_encoder++;
+
+out_put:
+	if (ret)
+		drm_mode_object_unregister(dev, &encoder->base);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_encoder_init);
+
+/**
+ * drm_encoder_cleanup - cleans up an initialised encoder
+ * @encoder: encoder to cleanup
+ *
+ * Cleans up the encoder but doesn't free the object.
+ */
+void drm_encoder_cleanup(struct drm_encoder *encoder)
+{
+	struct drm_device *dev = encoder->dev;
+
+	/* Note that the encoder_list is considered to be static; should we
+	 * remove the drm_encoder at runtime we would have to decrement all
+	 * the indices on the drm_encoder after us in the encoder_list.
+	 */
+
+	if (encoder->bridge) {
+		struct drm_bridge *bridge = encoder->bridge;
+		struct drm_bridge *next;
+
+		while (bridge) {
+			next = bridge->next;
+			drm_bridge_detach(bridge);
+			bridge = next;
+		}
+	}
+
+	drm_mode_object_unregister(dev, &encoder->base);
+	kfree(encoder->name);
+	list_del(&encoder->head);
+	dev->mode_config.num_encoder--;
+
+	memset(encoder, 0, sizeof(*encoder));
+}
+EXPORT_SYMBOL(drm_encoder_cleanup);
+
+static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder)
+{
+	struct drm_connector *connector;
+	struct drm_device *dev = encoder->dev;
+	bool uses_atomic = false;
+	struct drm_connector_list_iter conn_iter;
+
+	/* For atomic drivers only state objects are synchronously updated and
+	 * protected by modeset locks, so check those first. */
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
+		if (!connector->state)
+			continue;
+
+		uses_atomic = true;
+
+		if (connector->state->best_encoder != encoder)
+			continue;
+
+		drm_connector_list_iter_end(&conn_iter);
+		return connector->state->crtc;
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	/* Don't return stale data (e.g. pending async disable). */
+	if (uses_atomic)
+		return NULL;
+
+	return encoder->crtc;
+}
+
+int drm_mode_getencoder(struct drm_device *dev, void *data,
+			struct drm_file *file_priv)
+{
+	struct drm_mode_get_encoder *enc_resp = data;
+	struct drm_encoder *encoder;
+	struct drm_crtc *crtc;
+
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
+	encoder = drm_encoder_find(dev, file_priv, enc_resp->encoder_id);
+	if (!encoder)
+		return -ENOENT;
+
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+	crtc = drm_encoder_get_crtc(encoder);
+	if (crtc && drm_lease_held(file_priv, crtc->base.id))
+		enc_resp->crtc_id = crtc->base.id;
+	else
+		enc_resp->crtc_id = 0;
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+	enc_resp->encoder_type = encoder->encoder_type;
+	enc_resp->encoder_id = encoder->base.id;
+	enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
+							  encoder->possible_crtcs);
+	enc_resp->possible_clones = encoder->possible_clones;
+
+	return 0;
+}