Initialize writeback connector initialising the virtual encoder
and intel connector. We also allocate memory for drm_writeback_connector
but not the drm_connector within it due to a constraint
we need all connectors to be an intel_connector.
The writeback_format arrays is used to tell the user which
drm formats are supported by us.
Bspec: 49275
Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
---
drivers/gpu/drm/i915/Makefile | 1 +
.../gpu/drm/i915/display/intel_writeback.c | 129 ++++++++++++++++++
.../gpu/drm/i915/display/intel_writeback.h | 17 +++
3 files changed, 147 insertions(+)
create mode 100644 drivers/gpu/drm/i915/display/intel_writeback.c
create mode 100644 drivers/gpu/drm/i915/display/intel_writeback.h
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 853543443072..c9201f6111c3 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -295,6 +295,7 @@ i915-y += \
display/intel_vblank.o \
display/intel_vga.o \
display/intel_wm.o \
+ display/intel_writeback.o \
display/skl_scaler.o \
display/skl_universal_plane.o \
display/skl_watermark.o \
diff --git a/drivers/gpu/drm/i915/display/intel_writeback.c
b/drivers/gpu/drm/i915/display/intel_writeback.c
new file mode 100644
index 000000000000..f3843ac9b026
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_writeback.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#include <linux/slab.h>
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_writeback.h>
+#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_encoder.h>
+
+#include "i915_drv.h"
+#include "intel_atomic.h"
+#include "intel_de.h"
+#include "intel_display_types.h"
+#include "intel_display_driver.h"
+#include "intel_connector.h"
+#include "intel_writeback.h"
+
+struct intel_writeback_connector {
+ struct drm_writeback_connector base;
+ struct intel_encoder encoder;
+ struct intel_connector connector;
+ enum transcoder trans;
+ int frame_num;
+};
+
+static const u32 writeback_formats[] = {
+ DRM_FORMAT_XYUV8888,
+ DRM_FORMAT_YUYV,
+ DRM_FORMAT_XBGR8888,
+ DRM_FORMAT_XVYU2101010,
+ DRM_FORMAT_VYUY,
+ DRM_FORMAT_XBGR2101010,
+};
+
+static int intel_writeback_connector_init(struct intel_connector *connector)
+{
+ struct intel_digital_connector_state *conn_state;
+
+ conn_state = kzalloc(sizeof(*conn_state), GFP_KERNEL);
+ if (!conn_state)
+ return -ENOMEM;
+
+ __drm_atomic_helper_connector_reset(&connector->base,
+ &conn_state->base);
+ return 0;
+}
+
+static int
+intel_writeback_connector_alloc(struct intel_connector *connector)
+{
+ if (intel_writeback_connector_init(connector) < 0) {
+ kfree(connector);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static const struct drm_encoder_funcs drm_writeback_encoder_funcs = {
+ .destroy = drm_encoder_cleanup,
+};
+
+const struct drm_connector_funcs conn_funcs = {
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .atomic_duplicate_state = intel_digital_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_connector_helper_funcs conn_helper_funcs = {
+};
+
+static const struct drm_writeback_connector_helper_funcs
writeback_conn_helper_funcs = {
+};
+
+int intel_writeback_init(struct intel_display *display)
+{
+ struct intel_encoder *encoder;
+ struct intel_writeback_connector *writeback_conn;
+ struct intel_connector *connector;
+ int ret;
+
+ writeback_conn = kzalloc(sizeof(*writeback_conn), GFP_KERNEL);
+ if (!writeback_conn)
+ return -ENOSPC;
+
+ encoder = &writeback_conn->encoder;
+ encoder->base.possible_crtcs = 0xf;
+ ret = drm_encoder_init(display->drm, &encoder->base,
+ &drm_writeback_encoder_funcs,
+ DRM_MODE_ENCODER_VIRTUAL, NULL);
+ if (ret) {
+ kfree(writeback_conn);
+ return ret;
+ }
+
+ encoder->type = INTEL_OUTPUT_WRITEBACK;
+ encoder->pipe_mask = ~0;
+ encoder->cloneable = 0;
+
+ connector = &writeback_conn->connector;
+ intel_writeback_connector_alloc(connector);
+
+ connector->base.interlace_allowed = 0;
+ drm_connector_helper_add(&connector->base, &conn_helper_funcs);
+ ret = drm_writeback_connector_init_with_conn(display->drm,
&connector->base,
+ &writeback_conn->base,
+ &encoder->base,
&conn_funcs,
+
&writeback_conn_helper_funcs,
+ writeback_formats,
+
ARRAY_SIZE(writeback_formats));
+ if (ret) {
+ intel_connector_free(connector);
+ drm_encoder_cleanup(&encoder->base);
+ kfree(&writeback_conn->encoder);
+ kfree(writeback_conn);
+ return ret;
+ }
+
+ intel_connector_attach_encoder(connector, encoder);
+ connector->get_hw_state = intel_connector_get_hw_state;
+ connector->base.status = connector_status_disconnected;
+ writeback_conn->frame_num = 1;
+
+ return 0;
+}
diff --git a/drivers/gpu/drm/i915/display/intel_writeback.h
b/drivers/gpu/drm/i915/display/intel_writeback.h
new file mode 100644
index 000000000000..5911684cb81a
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_writeback.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#ifndef __INTEL_WRITEBACK_H__
+#define __INTEL_WRITEBACK_H__
+
+#include <linux/types.h>
+
+struct intel_display;
+struct intel_writeback_connector;
+
+int intel_writeback_init(struct intel_display *display);
+
+#endif /* __INTEL_WRITEBACK_H__ */
+
--
2.34.1
