Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

6 files changed, 2290 insertions, 0 deletions

diff --git a/drivers/gpu/drm/gud/Kconfig b/drivers/gpu/drm/gud/Kconfig
new file mode 100644
index 000000000..b4d213694
--- /dev/null
+++ b/drivers/gpu/drm/gud/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config DRM_GUD
+	tristate "GUD USB Display"
+	depends on DRM && USB && MMU
+	select LZ4_COMPRESS
+	select DRM_CLIENT_SELECTION
+	select DRM_KMS_HELPER
+	select DRM_GEM_SHMEM_HELPER
+	select BACKLIGHT_CLASS_DEVICE
+	help
+	  This is a DRM display driver for GUD USB Displays or display
+	  adapters.
+
+	  If M is selected the module will be called gud.
diff --git a/drivers/gpu/drm/gud/Makefile b/drivers/gpu/drm/gud/Makefile
new file mode 100644
index 000000000..68a1c622c
--- /dev/null
+++ b/drivers/gpu/drm/gud/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+gud-y				:= gud_drv.o gud_pipe.o gud_connector.o
+obj-$(CONFIG_DRM_GUD)		+= gud.o
diff --git a/drivers/gpu/drm/gud/gud_connector.c b/drivers/gpu/drm/gud/gud_connector.c
new file mode 100644
index 000000000..8141c3a1e
--- /dev/null
+++ b/drivers/gpu/drm/gud/gud_connector.c
@@ -0,0 +1,733 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2020 Noralf Trønnes
+ */
+
+#include <linux/backlight.h>
+#include <linux/workqueue.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_file.h>
+#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/gud.h>
+
+#include "gud_internal.h"
+
+struct gud_connector {
+	struct drm_connector connector;
+	struct drm_encoder encoder;
+	struct backlight_device *backlight;
+	struct work_struct backlight_work;
+
+	/* Supported properties */
+	u16 *properties;
+	unsigned int num_properties;
+
+	/* Initial gadget tv state if applicable, applied on state reset */
+	struct drm_tv_connector_state initial_tv_state;
+
+	/*
+	 * Initial gadget backlight brightness if applicable, applied on state reset.
+	 * The value -ENODEV is used to signal no backlight.
+	 */
+	int initial_brightness;
+};
+
+static inline struct gud_connector *to_gud_connector(struct drm_connector *connector)
+{
+	return container_of(connector, struct gud_connector, connector);
+}
+
+static void gud_conn_err(struct drm_connector *connector, const char *msg, int ret)
+{
+	dev_err(connector->dev->dev, "%s: %s (ret=%d)\n", connector->name, msg, ret);
+}
+
+/*
+ * Use a worker to avoid taking kms locks inside the backlight lock.
+ * Other display drivers use backlight within their kms locks.
+ * This avoids inconsistent locking rules, which would upset lockdep.
+ */
+static void gud_connector_backlight_update_status_work(struct work_struct *work)
+{
+	struct gud_connector *gconn = container_of(work, struct gud_connector, backlight_work);
+	struct drm_connector *connector = &gconn->connector;
+	struct drm_connector_state *connector_state;
+	struct drm_device *drm = connector->dev;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_commit *state;
+	int idx, ret;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	state = drm_atomic_commit_alloc(drm);
+	if (!state) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	drm_modeset_acquire_init(&ctx, 0);
+	state->acquire_ctx = &ctx;
+retry:
+	connector_state = drm_atomic_get_connector_state(state, connector);
+	if (IS_ERR(connector_state)) {
+		ret = PTR_ERR(connector_state);
+		goto out;
+	}
+
+	/* Reuse tv.brightness to avoid having to subclass */
+	connector_state->tv.brightness = gconn->backlight->props.brightness;
+
+	ret = drm_atomic_commit(state);
+out:
+	if (ret == -EDEADLK) {
+		drm_atomic_commit_clear(state);
+		drm_modeset_backoff(&ctx);
+		goto retry;
+	}
+
+	drm_atomic_commit_put(state);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+exit:
+	drm_dev_exit(idx);
+
+	if (ret)
+		dev_err(drm->dev, "Failed to update backlight, err=%d\n", ret);
+}
+
+static int gud_connector_backlight_update_status(struct backlight_device *bd)
+{
+	struct drm_connector *connector = bl_get_data(bd);
+	struct gud_connector *gconn = to_gud_connector(connector);
+
+	/* The USB timeout is 5 seconds so use system_long_wq for worst case scenario */
+	queue_work(system_long_wq, &gconn->backlight_work);
+
+	return 0;
+}
+
+static const struct backlight_ops gud_connector_backlight_ops = {
+	.update_status	= gud_connector_backlight_update_status,
+};
+
+static int gud_connector_backlight_register(struct gud_connector *gconn)
+{
+	struct drm_connector *connector = &gconn->connector;
+	struct backlight_device *bd;
+	const char *name;
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.scale = BACKLIGHT_SCALE_NON_LINEAR,
+		.max_brightness = 100,
+		.brightness = gconn->initial_brightness,
+	};
+
+	name = kasprintf(GFP_KERNEL, "card%d-%s-backlight",
+			 connector->dev->primary->index, connector->name);
+	if (!name)
+		return -ENOMEM;
+
+	bd = backlight_device_register(name, connector->kdev, connector,
+				       &gud_connector_backlight_ops, &props);
+	kfree(name);
+	if (IS_ERR(bd))
+		return PTR_ERR(bd);
+
+	gconn->backlight = bd;
+
+	return 0;
+}
+
+static int gud_connector_detect(struct drm_connector *connector,
+				struct drm_modeset_acquire_ctx *ctx, bool force)
+{
+	struct gud_device *gdrm = to_gud_device(connector->dev);
+	int idx, ret;
+	u8 status;
+
+	if (!drm_dev_enter(connector->dev, &idx))
+		return connector_status_disconnected;
+
+	if (force) {
+		ret = gud_usb_set(gdrm, GUD_REQ_SET_CONNECTOR_FORCE_DETECT,
+				  connector->index, NULL, 0);
+		if (ret) {
+			ret = connector_status_unknown;
+			goto exit;
+		}
+	}
+
+	ret = gud_usb_get_u8(gdrm, GUD_REQ_GET_CONNECTOR_STATUS, connector->index, &status);
+	if (ret) {
+		ret = connector_status_unknown;
+		goto exit;
+	}
+
+	switch (status & GUD_CONNECTOR_STATUS_CONNECTED_MASK) {
+	case GUD_CONNECTOR_STATUS_DISCONNECTED:
+		ret = connector_status_disconnected;
+		break;
+	case GUD_CONNECTOR_STATUS_CONNECTED:
+		ret = connector_status_connected;
+		break;
+	default:
+		ret = connector_status_unknown;
+		break;
+	}
+
+	if (status & GUD_CONNECTOR_STATUS_CHANGED)
+		connector->epoch_counter += 1;
+exit:
+	drm_dev_exit(idx);
+
+	return ret;
+}
+
+struct gud_connector_get_edid_ctx {
+	void *buf;
+	size_t len;
+	bool edid_override;
+};
+
+static int gud_connector_get_edid_block(void *data, u8 *buf, unsigned int block, size_t len)
+{
+	struct gud_connector_get_edid_ctx *ctx = data;
+	size_t start = block * EDID_LENGTH;
+
+	ctx->edid_override = false;
+
+	if (start + len > ctx->len)
+		return -1;
+
+	memcpy(buf, ctx->buf + start, len);
+
+	return 0;
+}
+
+static int gud_connector_get_modes(struct drm_connector *connector)
+{
+	struct gud_device *gdrm = to_gud_device(connector->dev);
+	struct gud_display_mode_req *reqmodes = NULL;
+	struct gud_connector_get_edid_ctx edid_ctx;
+	unsigned int i, num_modes = 0;
+	const struct drm_edid *drm_edid = NULL;
+	int idx, ret;
+
+	if (!drm_dev_enter(connector->dev, &idx))
+		return 0;
+
+	edid_ctx.edid_override = true;
+	edid_ctx.buf = kmalloc(GUD_CONNECTOR_MAX_EDID_LEN, GFP_KERNEL);
+	if (!edid_ctx.buf)
+		goto out;
+
+	ret = gud_usb_get(gdrm, GUD_REQ_GET_CONNECTOR_EDID, connector->index,
+			  edid_ctx.buf, GUD_CONNECTOR_MAX_EDID_LEN);
+	if (ret > 0 && ret % EDID_LENGTH) {
+		gud_conn_err(connector, "Invalid EDID size", ret);
+	} else if (ret > 0) {
+		edid_ctx.len = ret;
+		drm_edid = drm_edid_read_custom(connector, gud_connector_get_edid_block, &edid_ctx);
+	}
+
+	kfree(edid_ctx.buf);
+	drm_edid_connector_update(connector, drm_edid);
+
+	if (drm_edid && edid_ctx.edid_override)
+		goto out;
+
+	reqmodes = kmalloc_objs(*reqmodes, GUD_CONNECTOR_MAX_NUM_MODES);
+	if (!reqmodes)
+		goto out;
+
+	ret = gud_usb_get(gdrm, GUD_REQ_GET_CONNECTOR_MODES, connector->index,
+			  reqmodes, GUD_CONNECTOR_MAX_NUM_MODES * sizeof(*reqmodes));
+	if (ret <= 0)
+		goto out;
+	if (ret % sizeof(*reqmodes)) {
+		gud_conn_err(connector, "Invalid display mode array size", ret);
+		goto out;
+	}
+
+	num_modes = ret / sizeof(*reqmodes);
+
+	for (i = 0; i < num_modes; i++) {
+		struct drm_display_mode *mode;
+
+		mode = drm_mode_create(connector->dev);
+		if (!mode) {
+			num_modes = i;
+			goto out;
+		}
+
+		gud_to_display_mode(mode, &reqmodes[i]);
+		drm_mode_probed_add(connector, mode);
+	}
+out:
+	if (!num_modes)
+		num_modes = drm_edid_connector_add_modes(connector);
+
+	kfree(reqmodes);
+	drm_edid_free(drm_edid);
+	drm_dev_exit(idx);
+
+	return num_modes;
+}
+
+static int gud_connector_atomic_check(struct drm_connector *connector,
+				      struct drm_atomic_commit *state)
+{
+	struct drm_connector_state *new_state;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_connector_state *old_state;
+
+	new_state = drm_atomic_get_new_connector_state(state, connector);
+	if (!new_state->crtc)
+		return 0;
+
+	old_state = drm_atomic_get_old_connector_state(state, connector);
+	new_crtc_state = drm_atomic_get_new_crtc_state(state, new_state->crtc);
+
+	if (old_state->tv.margins.left != new_state->tv.margins.left ||
+	    old_state->tv.margins.right != new_state->tv.margins.right ||
+	    old_state->tv.margins.top != new_state->tv.margins.top ||
+	    old_state->tv.margins.bottom != new_state->tv.margins.bottom ||
+	    old_state->tv.legacy_mode != new_state->tv.legacy_mode ||
+	    old_state->tv.brightness != new_state->tv.brightness ||
+	    old_state->tv.contrast != new_state->tv.contrast ||
+	    old_state->tv.flicker_reduction != new_state->tv.flicker_reduction ||
+	    old_state->tv.overscan != new_state->tv.overscan ||
+	    old_state->tv.saturation != new_state->tv.saturation ||
+	    old_state->tv.hue != new_state->tv.hue)
+		new_crtc_state->connectors_changed = true;
+
+	return 0;
+}
+
+static const struct drm_connector_helper_funcs gud_connector_helper_funcs = {
+	.detect_ctx = gud_connector_detect,
+	.get_modes = gud_connector_get_modes,
+	.atomic_check = gud_connector_atomic_check,
+};
+
+static int gud_connector_late_register(struct drm_connector *connector)
+{
+	struct gud_connector *gconn = to_gud_connector(connector);
+
+	if (gconn->initial_brightness < 0)
+		return 0;
+
+	return gud_connector_backlight_register(gconn);
+}
+
+static void gud_connector_early_unregister(struct drm_connector *connector)
+{
+	struct gud_connector *gconn = to_gud_connector(connector);
+
+	backlight_device_unregister(gconn->backlight);
+	cancel_work_sync(&gconn->backlight_work);
+}
+
+static void gud_connector_destroy(struct drm_connector *connector)
+{
+	struct gud_connector *gconn = to_gud_connector(connector);
+
+	drm_connector_cleanup(connector);
+	kfree(gconn->properties);
+	kfree(gconn);
+}
+
+static void gud_connector_reset(struct drm_connector *connector)
+{
+	struct gud_connector *gconn = to_gud_connector(connector);
+
+	drm_atomic_helper_connector_reset(connector);
+	connector->state->tv = gconn->initial_tv_state;
+	/* Set margins from command line */
+	drm_atomic_helper_connector_tv_margins_reset(connector);
+	if (gconn->initial_brightness >= 0)
+		connector->state->tv.brightness = gconn->initial_brightness;
+}
+
+static const struct drm_connector_funcs gud_connector_funcs = {
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.late_register = gud_connector_late_register,
+	.early_unregister = gud_connector_early_unregister,
+	.destroy = gud_connector_destroy,
+	.reset = gud_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+/*
+ * The tv.mode property is shared among the connectors and its enum names are
+ * driver specific. This means that if more than one connector uses tv.mode,
+ * the enum names has to be the same.
+ */
+static int gud_connector_add_tv_mode(struct gud_device *gdrm, struct drm_connector *connector)
+{
+	size_t buf_len = GUD_CONNECTOR_TV_MODE_MAX_NUM * GUD_CONNECTOR_TV_MODE_NAME_LEN;
+	const char *modes[GUD_CONNECTOR_TV_MODE_MAX_NUM];
+	unsigned int i, num_modes;
+	char *buf;
+	int ret;
+
+	buf = kmalloc(buf_len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = gud_usb_get(gdrm, GUD_REQ_GET_CONNECTOR_TV_MODE_VALUES,
+			  connector->index, buf, buf_len);
+	if (ret < 0)
+		goto free;
+	if (!ret || ret % GUD_CONNECTOR_TV_MODE_NAME_LEN) {
+		ret = -EIO;
+		goto free;
+	}
+
+	num_modes = ret / GUD_CONNECTOR_TV_MODE_NAME_LEN;
+	for (i = 0; i < num_modes; i++) {
+		char *mode = &buf[i * GUD_CONNECTOR_TV_MODE_NAME_LEN];
+
+		if (!memchr(mode, '\0', GUD_CONNECTOR_TV_MODE_NAME_LEN)) {
+			ret = -EIO;
+			goto free;
+		}
+
+		modes[i] = mode;
+	}
+
+	ret = drm_mode_create_tv_properties_legacy(connector->dev, num_modes, modes);
+free:
+	kfree(buf);
+	if (ret < 0)
+		gud_conn_err(connector, "Failed to add TV modes", ret);
+
+	return ret;
+}
+
+static struct drm_property *
+gud_connector_property_lookup(struct drm_connector *connector, u16 prop)
+{
+	struct drm_mode_config *config = &connector->dev->mode_config;
+
+	switch (prop) {
+	case GUD_PROPERTY_TV_LEFT_MARGIN:
+		return config->tv_left_margin_property;
+	case GUD_PROPERTY_TV_RIGHT_MARGIN:
+		return config->tv_right_margin_property;
+	case GUD_PROPERTY_TV_TOP_MARGIN:
+		return config->tv_top_margin_property;
+	case GUD_PROPERTY_TV_BOTTOM_MARGIN:
+		return config->tv_bottom_margin_property;
+	case GUD_PROPERTY_TV_MODE:
+		return config->legacy_tv_mode_property;
+	case GUD_PROPERTY_TV_BRIGHTNESS:
+		return config->tv_brightness_property;
+	case GUD_PROPERTY_TV_CONTRAST:
+		return config->tv_contrast_property;
+	case GUD_PROPERTY_TV_FLICKER_REDUCTION:
+		return config->tv_flicker_reduction_property;
+	case GUD_PROPERTY_TV_OVERSCAN:
+		return config->tv_overscan_property;
+	case GUD_PROPERTY_TV_SATURATION:
+		return config->tv_saturation_property;
+	case GUD_PROPERTY_TV_HUE:
+		return config->tv_hue_property;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+}
+
+static unsigned int *gud_connector_tv_state_val(u16 prop, struct drm_tv_connector_state *state)
+{
+	switch (prop) {
+	case GUD_PROPERTY_TV_LEFT_MARGIN:
+		return &state->margins.left;
+	case GUD_PROPERTY_TV_RIGHT_MARGIN:
+		return &state->margins.right;
+	case GUD_PROPERTY_TV_TOP_MARGIN:
+		return &state->margins.top;
+	case GUD_PROPERTY_TV_BOTTOM_MARGIN:
+		return &state->margins.bottom;
+	case GUD_PROPERTY_TV_MODE:
+		return &state->legacy_mode;
+	case GUD_PROPERTY_TV_BRIGHTNESS:
+		return &state->brightness;
+	case GUD_PROPERTY_TV_CONTRAST:
+		return &state->contrast;
+	case GUD_PROPERTY_TV_FLICKER_REDUCTION:
+		return &state->flicker_reduction;
+	case GUD_PROPERTY_TV_OVERSCAN:
+		return &state->overscan;
+	case GUD_PROPERTY_TV_SATURATION:
+		return &state->saturation;
+	case GUD_PROPERTY_TV_HUE:
+		return &state->hue;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+}
+
+static int gud_connector_add_properties(struct gud_device *gdrm, struct gud_connector *gconn)
+{
+	struct drm_connector *connector = &gconn->connector;
+	struct drm_device *drm = &gdrm->drm;
+	struct gud_property_req *properties;
+	unsigned int i, num_properties;
+	int ret;
+
+	properties = kzalloc_objs(*properties, GUD_CONNECTOR_PROPERTIES_MAX_NUM);
+	if (!properties)
+		return -ENOMEM;
+
+	ret = gud_usb_get(gdrm, GUD_REQ_GET_CONNECTOR_PROPERTIES, connector->index,
+			  properties, GUD_CONNECTOR_PROPERTIES_MAX_NUM * sizeof(*properties));
+	if (ret <= 0)
+		goto out;
+	if (ret % sizeof(*properties)) {
+		ret = -EIO;
+		goto out;
+	}
+
+	num_properties = ret / sizeof(*properties);
+	ret = 0;
+
+	gconn->properties = kcalloc(num_properties, sizeof(*gconn->properties), GFP_KERNEL);
+	if (!gconn->properties) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	for (i = 0; i < num_properties; i++) {
+		u16 prop = le16_to_cpu(properties[i].prop);
+		u64 val = le64_to_cpu(properties[i].val);
+		struct drm_property *property;
+		unsigned int *state_val;
+
+		drm_dbg(drm, "property: %u = %llu(0x%llx)\n", prop, val, val);
+
+		switch (prop) {
+		case GUD_PROPERTY_TV_LEFT_MARGIN:
+			fallthrough;
+		case GUD_PROPERTY_TV_RIGHT_MARGIN:
+			fallthrough;
+		case GUD_PROPERTY_TV_TOP_MARGIN:
+			fallthrough;
+		case GUD_PROPERTY_TV_BOTTOM_MARGIN:
+			ret = drm_mode_create_tv_margin_properties(drm);
+			if (ret)
+				goto out;
+			break;
+		case GUD_PROPERTY_TV_MODE:
+			ret = gud_connector_add_tv_mode(gdrm, connector);
+			if (ret)
+				goto out;
+			break;
+		case GUD_PROPERTY_TV_BRIGHTNESS:
+			fallthrough;
+		case GUD_PROPERTY_TV_CONTRAST:
+			fallthrough;
+		case GUD_PROPERTY_TV_FLICKER_REDUCTION:
+			fallthrough;
+		case GUD_PROPERTY_TV_OVERSCAN:
+			fallthrough;
+		case GUD_PROPERTY_TV_SATURATION:
+			fallthrough;
+		case GUD_PROPERTY_TV_HUE:
+			/* This is a no-op if already added. */
+			ret = drm_mode_create_tv_properties_legacy(drm, 0, NULL);
+			if (ret)
+				goto out;
+			break;
+		case GUD_PROPERTY_BACKLIGHT_BRIGHTNESS:
+			if (val > 100) {
+				ret = -EINVAL;
+				goto out;
+			}
+			gconn->initial_brightness = val;
+			break;
+		default:
+			/* New ones might show up in future devices, skip those we don't know. */
+			drm_dbg(drm, "Ignoring unknown property: %u\n", prop);
+			continue;
+		}
+
+		gconn->properties[gconn->num_properties++] = prop;
+
+		if (prop == GUD_PROPERTY_BACKLIGHT_BRIGHTNESS)
+			continue; /* not a DRM property */
+
+		property = gud_connector_property_lookup(connector, prop);
+		if (drm_WARN_ON(drm, IS_ERR(property)))
+			continue;
+
+		state_val = gud_connector_tv_state_val(prop, &gconn->initial_tv_state);
+		if (drm_WARN_ON(drm, IS_ERR(state_val)))
+			continue;
+
+		*state_val = val;
+		drm_object_attach_property(&connector->base, property, 0);
+	}
+out:
+	kfree(properties);
+
+	return ret;
+}
+
+int gud_connector_fill_properties(struct drm_connector_state *connector_state,
+				  struct gud_property_req *properties)
+{
+	struct gud_connector *gconn = to_gud_connector(connector_state->connector);
+	unsigned int i;
+
+	for (i = 0; i < gconn->num_properties; i++) {
+		u16 prop = gconn->properties[i];
+		u64 val;
+
+		if (prop == GUD_PROPERTY_BACKLIGHT_BRIGHTNESS) {
+			val = connector_state->tv.brightness;
+		} else {
+			unsigned int *state_val;
+
+			state_val = gud_connector_tv_state_val(prop, &connector_state->tv);
+			if (drm_WARN_ON_ONCE(connector_state->connector->dev, IS_ERR(state_val)))
+				return PTR_ERR(state_val);
+
+			val = *state_val;
+		}
+
+		properties[i].prop = cpu_to_le16(prop);
+		properties[i].val = cpu_to_le64(val);
+	}
+
+	return gconn->num_properties;
+}
+
+static const struct drm_encoder_funcs gud_drm_simple_encoder_funcs_cleanup = {
+	.destroy = drm_encoder_cleanup,
+};
+
+static int gud_connector_create(struct gud_device *gdrm, unsigned int index,
+				struct gud_connector_descriptor_req *desc)
+{
+	struct drm_device *drm = &gdrm->drm;
+	struct gud_connector *gconn;
+	struct drm_connector *connector;
+	int ret, connector_type;
+	u32 flags;
+
+	gconn = kzalloc_obj(*gconn);
+	if (!gconn)
+		return -ENOMEM;
+
+	INIT_WORK(&gconn->backlight_work, gud_connector_backlight_update_status_work);
+	gconn->initial_brightness = -ENODEV;
+	flags = le32_to_cpu(desc->flags);
+	connector = &gconn->connector;
+
+	drm_dbg(drm, "Connector: index=%u type=%u flags=0x%x\n", index, desc->connector_type, flags);
+
+	switch (desc->connector_type) {
+	case GUD_CONNECTOR_TYPE_PANEL:
+		connector_type = DRM_MODE_CONNECTOR_USB;
+		break;
+	case GUD_CONNECTOR_TYPE_VGA:
+		connector_type = DRM_MODE_CONNECTOR_VGA;
+		break;
+	case GUD_CONNECTOR_TYPE_DVI:
+		connector_type = DRM_MODE_CONNECTOR_DVID;
+		break;
+	case GUD_CONNECTOR_TYPE_COMPOSITE:
+		connector_type = DRM_MODE_CONNECTOR_Composite;
+		break;
+	case GUD_CONNECTOR_TYPE_SVIDEO:
+		connector_type = DRM_MODE_CONNECTOR_SVIDEO;
+		break;
+	case GUD_CONNECTOR_TYPE_COMPONENT:
+		connector_type = DRM_MODE_CONNECTOR_Component;
+		break;
+	case GUD_CONNECTOR_TYPE_DISPLAYPORT:
+		connector_type = DRM_MODE_CONNECTOR_DisplayPort;
+		break;
+	case GUD_CONNECTOR_TYPE_HDMI:
+		connector_type = DRM_MODE_CONNECTOR_HDMIA;
+		break;
+	default: /* future types */
+		connector_type = DRM_MODE_CONNECTOR_USB;
+		break;
+	}
+
+	drm_connector_helper_add(connector, &gud_connector_helper_funcs);
+	ret = drm_connector_init(drm, connector, &gud_connector_funcs, connector_type);
+	if (ret) {
+		kfree(connector);
+		return ret;
+	}
+
+	if (drm_WARN_ON(drm, connector->index != index))
+		return -EINVAL;
+
+	if (flags & GUD_CONNECTOR_FLAGS_POLL_STATUS)
+		connector->polled = (DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT);
+	if (flags & GUD_CONNECTOR_FLAGS_INTERLACE)
+		connector->interlace_allowed = true;
+	if (flags & GUD_CONNECTOR_FLAGS_DOUBLESCAN)
+		connector->doublescan_allowed = true;
+
+	ret = gud_connector_add_properties(gdrm, gconn);
+	if (ret) {
+		gud_conn_err(connector, "Failed to add properties", ret);
+		return ret;
+	}
+
+	gconn->encoder.possible_crtcs = drm_crtc_mask(&gdrm->crtc);
+	ret = drm_encoder_init(drm, &gconn->encoder, &gud_drm_simple_encoder_funcs_cleanup,
+			       DRM_MODE_ENCODER_NONE, NULL);
+	if (ret)
+		return ret;
+
+	return drm_connector_attach_encoder(connector, &gconn->encoder);
+}
+
+int gud_get_connectors(struct gud_device *gdrm)
+{
+	struct gud_connector_descriptor_req *descs;
+	unsigned int i, num_connectors;
+	int ret;
+
+	descs = kmalloc_objs(*descs, GUD_CONNECTORS_MAX_NUM);
+	if (!descs)
+		return -ENOMEM;
+
+	ret = gud_usb_get(gdrm, GUD_REQ_GET_CONNECTORS, 0,
+			  descs, GUD_CONNECTORS_MAX_NUM * sizeof(*descs));
+	if (ret < 0)
+		goto free;
+	if (!ret || ret % sizeof(*descs)) {
+		ret = -EIO;
+		goto free;
+	}
+
+	num_connectors = ret / sizeof(*descs);
+
+	for (i = 0; i < num_connectors; i++) {
+		ret = gud_connector_create(gdrm, i, &descs[i]);
+		if (ret)
+			goto free;
+	}
+free:
+	kfree(descs);
+
+	return ret;
+}
diff --git a/drivers/gpu/drm/gud/gud_drv.c b/drivers/gpu/drm/gud/gud_drv.c
new file mode 100644
index 000000000..3a1b9e2a2
--- /dev/null
+++ b/drivers/gpu/drm/gud/gud_drv.c
@@ -0,0 +1,709 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2020 Noralf Trønnes
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+#include <linux/lz4.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/string_helpers.h>
+#include <linux/usb.h>
+#include <linux/vmalloc.h>
+#include <linux/workqueue.h>
+
+#include <drm/clients/drm_client_setup.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_blend.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_debugfs.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fbdev_shmem.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_managed.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/gud.h>
+
+#include "gud_internal.h"
+
+/* Only used internally */
+static const struct drm_format_info gud_drm_format_r1 = {
+	.format = GUD_DRM_FORMAT_R1,
+	.num_planes = 1,
+	.char_per_block = { 1, 0, 0 },
+	.block_w = { 8, 0, 0 },
+	.block_h = { 1, 0, 0 },
+	.hsub = 1,
+	.vsub = 1,
+};
+
+static const struct drm_format_info gud_drm_format_xrgb1111 = {
+	.format = GUD_DRM_FORMAT_XRGB1111,
+	.num_planes = 1,
+	.char_per_block = { 1, 0, 0 },
+	.block_w = { 2, 0, 0 },
+	.block_h = { 1, 0, 0 },
+	.hsub = 1,
+	.vsub = 1,
+};
+
+static int gud_usb_control_msg(struct usb_interface *intf, bool in,
+			       u8 request, u16 value, void *buf, size_t len)
+{
+	u8 requesttype = USB_TYPE_VENDOR | USB_RECIP_INTERFACE;
+	u8 ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
+	struct usb_device *usb = interface_to_usbdev(intf);
+	unsigned int pipe;
+
+	if (len && !buf)
+		return -EINVAL;
+
+	if (in) {
+		pipe = usb_rcvctrlpipe(usb, 0);
+		requesttype |= USB_DIR_IN;
+	} else {
+		pipe = usb_sndctrlpipe(usb, 0);
+		requesttype |= USB_DIR_OUT;
+	}
+
+	return usb_control_msg(usb, pipe, request, requesttype, value,
+			       ifnum, buf, len, USB_CTRL_GET_TIMEOUT);
+}
+
+static int gud_get_display_descriptor(struct usb_interface *intf,
+				      struct gud_display_descriptor_req *desc)
+{
+	void *buf;
+	int ret;
+
+	buf = kmalloc_obj(*desc);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = gud_usb_control_msg(intf, true, GUD_REQ_GET_DESCRIPTOR, 0, buf, sizeof(*desc));
+	memcpy(desc, buf, sizeof(*desc));
+	kfree(buf);
+	if (ret < 0)
+		return ret;
+	if (ret != sizeof(*desc))
+		return -EIO;
+
+	if (desc->magic != le32_to_cpu(GUD_DISPLAY_MAGIC))
+		return -ENODATA;
+
+	DRM_DEV_DEBUG_DRIVER(&intf->dev,
+			     "version=%u flags=0x%x compression=0x%x max_buffer_size=%u\n",
+			     desc->version, le32_to_cpu(desc->flags), desc->compression,
+			     le32_to_cpu(desc->max_buffer_size));
+
+	if (!desc->version || !desc->max_width || !desc->max_height ||
+	    le32_to_cpu(desc->min_width) > le32_to_cpu(desc->max_width) ||
+	    le32_to_cpu(desc->min_height) > le32_to_cpu(desc->max_height))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int gud_status_to_errno(u8 status)
+{
+	switch (status) {
+	case GUD_STATUS_OK:
+		return 0;
+	case GUD_STATUS_BUSY:
+		return -EBUSY;
+	case GUD_STATUS_REQUEST_NOT_SUPPORTED:
+		return -EOPNOTSUPP;
+	case GUD_STATUS_PROTOCOL_ERROR:
+		return -EPROTO;
+	case GUD_STATUS_INVALID_PARAMETER:
+		return -EINVAL;
+	case GUD_STATUS_ERROR:
+		return -EREMOTEIO;
+	default:
+		return -EREMOTEIO;
+	}
+}
+
+static int gud_usb_get_status(struct usb_interface *intf)
+{
+	int ret, status = -EIO;
+	u8 *buf;
+
+	buf = kmalloc_obj(*buf);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = gud_usb_control_msg(intf, true, GUD_REQ_GET_STATUS, 0, buf, sizeof(*buf));
+	if (ret == sizeof(*buf))
+		status = gud_status_to_errno(*buf);
+	kfree(buf);
+
+	if (ret < 0)
+		return ret;
+
+	return status;
+}
+
+static int gud_usb_transfer(struct gud_device *gdrm, bool in, u8 request, u16 index,
+			    void *buf, size_t len)
+{
+	struct usb_interface *intf = to_usb_interface(gdrm->drm.dev);
+	int idx, ret;
+
+	drm_dbg(&gdrm->drm, "%s: request=0x%x index=%u len=%zu\n",
+		in ? "get" : "set", request, index, len);
+
+	if (!drm_dev_enter(&gdrm->drm, &idx))
+		return -ENODEV;
+
+	mutex_lock(&gdrm->ctrl_lock);
+
+	ret = gud_usb_control_msg(intf, in, request, index, buf, len);
+	if (ret == -EPIPE || ((gdrm->flags & GUD_DISPLAY_FLAG_STATUS_ON_SET) && !in && ret >= 0)) {
+		int status;
+
+		status = gud_usb_get_status(intf);
+		if (status < 0) {
+			ret = status;
+		} else if (ret < 0) {
+			dev_err_once(gdrm->drm.dev,
+				     "Unexpected status OK for failed transfer\n");
+			ret = -EPIPE;
+		}
+	}
+
+	if (ret < 0) {
+		drm_dbg(&gdrm->drm, "ret=%d\n", ret);
+		gdrm->stats_num_errors++;
+	}
+
+	mutex_unlock(&gdrm->ctrl_lock);
+	drm_dev_exit(idx);
+
+	return ret;
+}
+
+/*
+ * @buf cannot be allocated on the stack.
+ * Returns number of bytes received or negative error code on failure.
+ */
+int gud_usb_get(struct gud_device *gdrm, u8 request, u16 index, void *buf, size_t max_len)
+{
+	return gud_usb_transfer(gdrm, true, request, index, buf, max_len);
+}
+
+/*
+ * @buf can be allocated on the stack or NULL.
+ * Returns zero on success or negative error code on failure.
+ */
+int gud_usb_set(struct gud_device *gdrm, u8 request, u16 index, void *buf, size_t len)
+{
+	void *trbuf = NULL;
+	int ret;
+
+	if (buf && len) {
+		trbuf = kmemdup(buf, len, GFP_KERNEL);
+		if (!trbuf)
+			return -ENOMEM;
+	}
+
+	ret = gud_usb_transfer(gdrm, false, request, index, trbuf, len);
+	kfree(trbuf);
+	if (ret < 0)
+		return ret;
+
+	return ret != len ? -EIO : 0;
+}
+
+/*
+ * @val can be allocated on the stack.
+ * Returns zero on success or negative error code on failure.
+ */
+int gud_usb_get_u8(struct gud_device *gdrm, u8 request, u16 index, u8 *val)
+{
+	u8 *buf;
+	int ret;
+
+	buf = kmalloc(sizeof(*val), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = gud_usb_get(gdrm, request, index, buf, sizeof(*val));
+	*val = *buf;
+	kfree(buf);
+	if (ret < 0)
+		return ret;
+
+	return ret != sizeof(*val) ? -EIO : 0;
+}
+
+/* Returns zero on success or negative error code on failure. */
+int gud_usb_set_u8(struct gud_device *gdrm, u8 request, u8 val)
+{
+	return gud_usb_set(gdrm, request, 0, &val, sizeof(val));
+}
+
+static int gud_plane_add_properties(struct gud_device *gdrm)
+{
+	struct gud_property_req *properties;
+	unsigned int i, num_properties;
+	int ret;
+
+	properties = kzalloc_objs(*properties, GUD_PROPERTIES_MAX_NUM);
+	if (!properties)
+		return -ENOMEM;
+
+	ret = gud_usb_get(gdrm, GUD_REQ_GET_PROPERTIES, 0,
+			  properties, GUD_PROPERTIES_MAX_NUM * sizeof(*properties));
+	if (ret <= 0)
+		goto out;
+	if (ret % sizeof(*properties)) {
+		ret = -EIO;
+		goto out;
+	}
+
+	num_properties = ret / sizeof(*properties);
+	ret = 0;
+
+	gdrm->properties = drmm_kcalloc(&gdrm->drm, num_properties, sizeof(*gdrm->properties),
+					GFP_KERNEL);
+	if (!gdrm->properties) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	for (i = 0; i < num_properties; i++) {
+		u16 prop = le16_to_cpu(properties[i].prop);
+		u64 val = le64_to_cpu(properties[i].val);
+
+		switch (prop) {
+		case GUD_PROPERTY_ROTATION:
+			/*
+			 * DRM UAPI matches the protocol so use the value directly,
+			 * but mask out any additions on future devices.
+			 */
+			val &= GUD_ROTATION_MASK;
+			if (!(val & GUD_ROTATION_0))
+				continue;
+			ret = drm_plane_create_rotation_property(&gdrm->plane,
+								 DRM_MODE_ROTATE_0, val);
+			break;
+		default:
+			/* New ones might show up in future devices, skip those we don't know. */
+			drm_dbg(&gdrm->drm, "Ignoring unknown property: %u\n", prop);
+			continue;
+		}
+
+		if (ret)
+			goto out;
+
+		gdrm->properties[gdrm->num_properties++] = prop;
+	}
+out:
+	kfree(properties);
+
+	return ret;
+}
+
+static int gud_stats_debugfs(struct seq_file *m, void *data)
+{
+	struct drm_debugfs_entry *entry = m->private;
+	struct gud_device *gdrm = to_gud_device(entry->dev);
+	char buf[10];
+
+	string_get_size(gdrm->bulk_len, 1, STRING_UNITS_2, buf, sizeof(buf));
+	seq_printf(m, "Max buffer size: %s\n", buf);
+	seq_printf(m, "Number of errors:  %u\n", gdrm->stats_num_errors);
+
+	seq_puts(m, "Compression:      ");
+	if (gdrm->compression & GUD_COMPRESSION_LZ4)
+		seq_puts(m, " lz4");
+	if (!gdrm->compression)
+		seq_puts(m, " none");
+	seq_puts(m, "\n");
+
+	if (gdrm->compression) {
+		u64 remainder;
+		u64 ratio = div64_u64_rem(gdrm->stats_length, gdrm->stats_actual_length,
+					  &remainder);
+		u64 ratio_frac = div64_u64(remainder * 10, gdrm->stats_actual_length);
+
+		seq_printf(m, "Compression ratio: %llu.%llu\n", ratio, ratio_frac);
+	}
+
+	return 0;
+}
+
+static const struct drm_crtc_helper_funcs gud_crtc_helper_funcs = {
+	.atomic_check = drm_crtc_helper_atomic_check,
+	.atomic_enable = gud_crtc_atomic_enable,
+	.atomic_disable = gud_crtc_atomic_disable,
+};
+
+static const struct drm_crtc_funcs gud_crtc_funcs = {
+	.reset = drm_atomic_helper_crtc_reset,
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+static const struct drm_plane_helper_funcs gud_plane_helper_funcs = {
+	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
+	.atomic_check = gud_plane_atomic_check,
+	.atomic_update = gud_plane_atomic_update,
+};
+
+static const struct drm_plane_funcs gud_plane_funcs = {
+	.update_plane = drm_atomic_helper_update_plane,
+	.disable_plane = drm_atomic_helper_disable_plane,
+	.destroy = drm_plane_cleanup,
+	DRM_GEM_SHADOW_PLANE_FUNCS,
+};
+
+static const struct drm_mode_config_helper_funcs gud_mode_config_helpers = {
+	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
+static const struct drm_mode_config_funcs gud_mode_config_funcs = {
+	.fb_create = drm_gem_fb_create_with_dirty,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static const u64 gud_plane_modifiers[] = {
+	DRM_FORMAT_MOD_LINEAR,
+	DRM_FORMAT_MOD_INVALID
+};
+
+DEFINE_DRM_GEM_FOPS(gud_fops);
+
+static const struct drm_driver gud_drm_driver = {
+	.driver_features	= DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
+	.fops			= &gud_fops,
+	DRM_GEM_SHMEM_DRIVER_OPS,
+	DRM_FBDEV_SHMEM_DRIVER_OPS,
+
+	.name			= "gud",
+	.desc			= "Generic USB Display",
+	.major			= 1,
+	.minor			= 0,
+};
+
+static int gud_alloc_bulk_buffer(struct gud_device *gdrm)
+{
+	unsigned int i, num_pages;
+	struct page **pages;
+	void *ptr;
+	int ret;
+
+	gdrm->bulk_buf = vmalloc_32(gdrm->bulk_len);
+	if (!gdrm->bulk_buf)
+		return -ENOMEM;
+
+	num_pages = DIV_ROUND_UP(gdrm->bulk_len, PAGE_SIZE);
+	pages = kmalloc_objs(struct page *, num_pages);
+	if (!pages)
+		return -ENOMEM;
+
+	for (i = 0, ptr = gdrm->bulk_buf; i < num_pages; i++, ptr += PAGE_SIZE)
+		pages[i] = vmalloc_to_page(ptr);
+
+	ret = sg_alloc_table_from_pages(&gdrm->bulk_sgt, pages, num_pages,
+					0, gdrm->bulk_len, GFP_KERNEL);
+	kfree(pages);
+
+	return ret;
+}
+
+static void gud_free_buffers_and_mutex(void *data)
+{
+	struct gud_device *gdrm = data;
+
+	vfree(gdrm->compress_buf);
+	gdrm->compress_buf = NULL;
+	sg_free_table(&gdrm->bulk_sgt);
+	vfree(gdrm->bulk_buf);
+	gdrm->bulk_buf = NULL;
+	mutex_destroy(&gdrm->ctrl_lock);
+}
+
+static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	const struct drm_format_info *xrgb8888_emulation_format = NULL;
+	bool rgb565_supported = false, xrgb8888_supported = false;
+	unsigned int num_formats_dev, num_formats = 0;
+	struct usb_endpoint_descriptor *bulk_out;
+	struct gud_display_descriptor_req desc;
+	struct device *dev = &intf->dev;
+	size_t max_buffer_size = 0;
+	struct gud_device *gdrm;
+	struct drm_device *drm;
+	struct device *dma_dev;
+	u8 *formats_dev;
+	u32 *formats;
+	int ret, i;
+
+	ret = usb_find_bulk_out_endpoint(intf->cur_altsetting, &bulk_out);
+	if (ret)
+		return ret;
+
+	ret = gud_get_display_descriptor(intf, &desc);
+	if (ret) {
+		DRM_DEV_DEBUG_DRIVER(dev, "Not a display interface: ret=%d\n", ret);
+		return -ENODEV;
+	}
+
+	if (desc.version > 1) {
+		dev_err(dev, "Protocol version %u is not supported\n", desc.version);
+		return -ENODEV;
+	}
+
+	gdrm = devm_drm_dev_alloc(dev, &gud_drm_driver, struct gud_device, drm);
+	if (IS_ERR(gdrm))
+		return PTR_ERR(gdrm);
+
+	drm = &gdrm->drm;
+
+	gdrm->flags = le32_to_cpu(desc.flags);
+	gdrm->compression = desc.compression & GUD_COMPRESSION_LZ4;
+
+	if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE && gdrm->compression)
+		return -EINVAL;
+
+	mutex_init(&gdrm->ctrl_lock);
+	mutex_init(&gdrm->damage_lock);
+	INIT_WORK(&gdrm->work, gud_flush_work);
+	gud_clear_damage(gdrm);
+
+	ret = devm_add_action(dev, gud_free_buffers_and_mutex, gdrm);
+	if (ret)
+		return ret;
+
+	usb_set_intfdata(intf, gdrm);
+
+	dma_dev = usb_intf_get_dma_device(intf);
+	if (dma_dev) {
+		drm_dev_set_dma_dev(drm, dma_dev);
+		put_device(dma_dev);
+	} else {
+		dev_warn(dev, "buffer sharing not supported"); /* not an error */
+	}
+
+	/* Mode config init */
+	ret = drmm_mode_config_init(drm);
+	if (ret)
+		return ret;
+
+	drm->mode_config.min_width = le32_to_cpu(desc.min_width);
+	drm->mode_config.max_width = le32_to_cpu(desc.max_width);
+	drm->mode_config.min_height = le32_to_cpu(desc.min_height);
+	drm->mode_config.max_height = le32_to_cpu(desc.max_height);
+	drm->mode_config.funcs = &gud_mode_config_funcs;
+	drm->mode_config.helper_private = &gud_mode_config_helpers;
+
+	/* Format init */
+	formats_dev = devm_kmalloc(dev, GUD_FORMATS_MAX_NUM, GFP_KERNEL);
+	/* Add room for emulated XRGB8888 */
+	formats = devm_kmalloc_array(dev, GUD_FORMATS_MAX_NUM + 1, sizeof(*formats), GFP_KERNEL);
+	if (!formats_dev || !formats)
+		return -ENOMEM;
+
+	ret = gud_usb_get(gdrm, GUD_REQ_GET_FORMATS, 0, formats_dev, GUD_FORMATS_MAX_NUM);
+	if (ret < 0)
+		return ret;
+
+	num_formats_dev = ret;
+	for (i = 0; i < num_formats_dev; i++) {
+		const struct drm_format_info *info;
+		size_t fmt_buf_size;
+		u32 format;
+
+		format = gud_to_fourcc(formats_dev[i]);
+		if (!format) {
+			drm_dbg(drm, "Unsupported format: 0x%02x\n", formats_dev[i]);
+			continue;
+		}
+
+		if (format == GUD_DRM_FORMAT_R1)
+			info = &gud_drm_format_r1;
+		else if (format == GUD_DRM_FORMAT_XRGB1111)
+			info = &gud_drm_format_xrgb1111;
+		else
+			info = drm_format_info(format);
+
+		switch (format) {
+		case GUD_DRM_FORMAT_R1:
+			fallthrough;
+		case DRM_FORMAT_R8:
+			fallthrough;
+		case GUD_DRM_FORMAT_XRGB1111:
+			fallthrough;
+		case DRM_FORMAT_RGB332:
+			fallthrough;
+		case DRM_FORMAT_RGB888:
+			if (!xrgb8888_emulation_format)
+				xrgb8888_emulation_format = info;
+			break;
+		case DRM_FORMAT_RGB565:
+			rgb565_supported = true;
+			if (!xrgb8888_emulation_format)
+				xrgb8888_emulation_format = info;
+			break;
+		case DRM_FORMAT_XRGB8888:
+			xrgb8888_supported = true;
+			break;
+		}
+
+		fmt_buf_size = drm_format_info_min_pitch(info, 0, drm->mode_config.max_width) *
+			       drm->mode_config.max_height;
+		max_buffer_size = max(max_buffer_size, fmt_buf_size);
+
+		if (format == GUD_DRM_FORMAT_R1 || format == GUD_DRM_FORMAT_XRGB1111)
+			continue; /* Internal not for userspace */
+
+		formats[num_formats++] = format;
+	}
+
+	if (!num_formats && !xrgb8888_emulation_format) {
+		dev_err(dev, "No supported pixel formats found\n");
+		return -EINVAL;
+	}
+
+	/* Prefer speed over color depth */
+	if (rgb565_supported)
+		drm->mode_config.preferred_depth = 16;
+
+	if (!xrgb8888_supported && xrgb8888_emulation_format) {
+		gdrm->xrgb8888_emulation_format = xrgb8888_emulation_format;
+		formats[num_formats++] = DRM_FORMAT_XRGB8888;
+	}
+
+	if (desc.max_buffer_size)
+		max_buffer_size = le32_to_cpu(desc.max_buffer_size);
+	/* Prevent a misbehaving device from allocating loads of RAM. 4096x4096@XRGB8888 = 64 MB */
+	if (max_buffer_size > SZ_64M)
+		max_buffer_size = SZ_64M;
+
+	gdrm->bulk_pipe = usb_sndbulkpipe(interface_to_usbdev(intf), usb_endpoint_num(bulk_out));
+	gdrm->bulk_len = max_buffer_size;
+
+	ret = gud_alloc_bulk_buffer(gdrm);
+	if (ret)
+		return ret;
+
+	if (gdrm->compression & GUD_COMPRESSION_LZ4) {
+		gdrm->lz4_comp_mem = devm_kmalloc(dev, LZ4_MEM_COMPRESS, GFP_KERNEL);
+		if (!gdrm->lz4_comp_mem)
+			return -ENOMEM;
+
+		gdrm->compress_buf = vmalloc(gdrm->bulk_len);
+		if (!gdrm->compress_buf)
+			return -ENOMEM;
+	}
+
+	/* Pipeline init */
+	ret = drm_universal_plane_init(drm, &gdrm->plane, 0,
+				       &gud_plane_funcs,
+				       formats, num_formats,
+				       gud_plane_modifiers,
+				       DRM_PLANE_TYPE_PRIMARY, NULL);
+	if (ret)
+		return ret;
+
+	drm_plane_helper_add(&gdrm->plane, &gud_plane_helper_funcs);
+	drm_plane_enable_fb_damage_clips(&gdrm->plane);
+
+	ret = gud_plane_add_properties(gdrm);
+	if (ret) {
+		dev_err(dev, "Failed to add properties (error=%d)\n", ret);
+		return ret;
+	}
+
+	ret = drm_crtc_init_with_planes(drm, &gdrm->crtc, &gdrm->plane, NULL,
+					&gud_crtc_funcs, NULL);
+	if (ret)
+		return ret;
+
+	drm_crtc_helper_add(&gdrm->crtc, &gud_crtc_helper_funcs);
+
+	ret = gud_get_connectors(gdrm);
+	if (ret) {
+		dev_err(dev, "Failed to get connectors (error=%d)\n", ret);
+		return ret;
+	}
+
+	drm_mode_config_reset(drm);
+	drm_kms_helper_poll_init(drm);
+
+	drm_debugfs_add_file(drm, "stats", gud_stats_debugfs, NULL);
+
+	ret = drm_dev_register(drm, 0);
+	if (ret)
+		return ret;
+
+	devm_kfree(dev, formats);
+	devm_kfree(dev, formats_dev);
+
+	drm_client_setup(drm, NULL);
+
+	return 0;
+}
+
+static void gud_disconnect(struct usb_interface *interface)
+{
+	struct gud_device *gdrm = usb_get_intfdata(interface);
+	struct drm_device *drm = &gdrm->drm;
+
+	drm_kms_helper_poll_fini(drm);
+	drm_dev_unplug(drm);
+	drm_atomic_helper_shutdown(drm);
+}
+
+static int gud_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct gud_device *gdrm = usb_get_intfdata(intf);
+
+	return drm_mode_config_helper_suspend(&gdrm->drm);
+}
+
+static int gud_resume(struct usb_interface *intf)
+{
+	struct gud_device *gdrm = usb_get_intfdata(intf);
+
+	drm_mode_config_helper_resume(&gdrm->drm);
+
+	return 0;
+}
+
+static const struct usb_device_id gud_id_table[] = {
+	{ USB_DEVICE_INTERFACE_CLASS(0x1d50, 0x614d, USB_CLASS_VENDOR_SPEC) },
+	{ USB_DEVICE_INTERFACE_CLASS(0x16d0, 0x10a9, USB_CLASS_VENDOR_SPEC) },
+	{ USB_DEVICE_INTERFACE_CLASS(0x1209, 0x4fb3, USB_CLASS_VENDOR_SPEC) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(usb, gud_id_table);
+
+static struct usb_driver gud_usb_driver = {
+	.name		= "gud",
+	.probe		= gud_probe,
+	.disconnect	= gud_disconnect,
+	.id_table	= gud_id_table,
+	.suspend	= gud_suspend,
+	.resume		= gud_resume,
+	.reset_resume	= gud_resume,
+};
+
+module_usb_driver(gud_usb_driver);
+
+MODULE_AUTHOR("Noralf Trønnes");
+MODULE_DESCRIPTION("GUD USB Display driver");
+MODULE_LICENSE("Dual MIT/GPL");
diff --git a/drivers/gpu/drm/gud/gud_internal.h b/drivers/gpu/drm/gud/gud_internal.h
new file mode 100644
index 000000000..95744b0b6
--- /dev/null
+++ b/drivers/gpu/drm/gud/gud_internal.h
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef __LINUX_GUD_INTERNAL_H
+#define __LINUX_GUD_INTERNAL_H
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/scatterlist.h>
+#include <linux/usb.h>
+#include <linux/workqueue.h>
+#include <uapi/drm/drm_fourcc.h>
+
+#include <drm/drm_modes.h>
+
+struct gud_device {
+	struct drm_device drm;
+	struct drm_plane plane;
+	struct drm_crtc crtc;
+	struct work_struct work;
+	u32 flags;
+	const struct drm_format_info *xrgb8888_emulation_format;
+
+	u16 *properties;
+	unsigned int num_properties;
+
+	unsigned int bulk_pipe;
+	void *bulk_buf;
+	size_t bulk_len;
+	struct sg_table bulk_sgt;
+
+	u8 compression;
+	void *lz4_comp_mem;
+	void *compress_buf;
+
+	u64 stats_length;
+	u64 stats_actual_length;
+	unsigned int stats_num_errors;
+
+	struct mutex ctrl_lock; /* Serialize get/set and status transfers */
+
+	struct mutex damage_lock; /* Protects the following members: */
+	struct drm_framebuffer *fb;
+	struct drm_rect damage;
+	bool prev_flush_failed;
+	void *shadow_buf;
+};
+
+static inline struct gud_device *to_gud_device(struct drm_device *drm)
+{
+	return container_of(drm, struct gud_device, drm);
+}
+
+static inline struct usb_device *gud_to_usb_device(struct gud_device *gdrm)
+{
+	return interface_to_usbdev(to_usb_interface(gdrm->drm.dev));
+}
+
+int gud_usb_get(struct gud_device *gdrm, u8 request, u16 index, void *buf, size_t len);
+int gud_usb_set(struct gud_device *gdrm, u8 request, u16 index, void *buf, size_t len);
+int gud_usb_get_u8(struct gud_device *gdrm, u8 request, u16 index, u8 *val);
+int gud_usb_set_u8(struct gud_device *gdrm, u8 request, u8 val);
+
+void gud_clear_damage(struct gud_device *gdrm);
+void gud_flush_work(struct work_struct *work);
+void gud_crtc_atomic_enable(struct drm_crtc *crtc,
+			    struct drm_atomic_commit *state);
+void gud_crtc_atomic_disable(struct drm_crtc *crtc,
+			     struct drm_atomic_commit *state);
+int gud_plane_atomic_check(struct drm_plane *plane,
+			   struct drm_atomic_commit *state);
+void gud_plane_atomic_update(struct drm_plane *plane,
+			     struct drm_atomic_commit *atomic_state);
+int gud_connector_fill_properties(struct drm_connector_state *connector_state,
+				  struct gud_property_req *properties);
+int gud_get_connectors(struct gud_device *gdrm);
+
+/* Driver internal fourcc transfer formats */
+#define GUD_DRM_FORMAT_R1		0x00000122
+#define GUD_DRM_FORMAT_XRGB1111		0x03121722
+
+static inline u8 gud_from_fourcc(u32 fourcc)
+{
+	switch (fourcc) {
+	case GUD_DRM_FORMAT_R1:
+		return GUD_PIXEL_FORMAT_R1;
+	case DRM_FORMAT_R8:
+		return GUD_PIXEL_FORMAT_R8;
+	case GUD_DRM_FORMAT_XRGB1111:
+		return GUD_PIXEL_FORMAT_XRGB1111;
+	case DRM_FORMAT_RGB332:
+		return GUD_PIXEL_FORMAT_RGB332;
+	case DRM_FORMAT_RGB565:
+		return GUD_PIXEL_FORMAT_RGB565;
+	case DRM_FORMAT_RGB888:
+		return GUD_PIXEL_FORMAT_RGB888;
+	case DRM_FORMAT_XRGB8888:
+		return GUD_PIXEL_FORMAT_XRGB8888;
+	case DRM_FORMAT_ARGB8888:
+		return GUD_PIXEL_FORMAT_ARGB8888;
+	}
+
+	return 0;
+}
+
+static inline u32 gud_to_fourcc(u8 format)
+{
+	switch (format) {
+	case GUD_PIXEL_FORMAT_R1:
+		return GUD_DRM_FORMAT_R1;
+	case GUD_PIXEL_FORMAT_R8:
+		return DRM_FORMAT_R8;
+	case GUD_PIXEL_FORMAT_XRGB1111:
+		return GUD_DRM_FORMAT_XRGB1111;
+	case GUD_PIXEL_FORMAT_RGB332:
+		return DRM_FORMAT_RGB332;
+	case GUD_PIXEL_FORMAT_RGB565:
+		return DRM_FORMAT_RGB565;
+	case GUD_PIXEL_FORMAT_RGB888:
+		return DRM_FORMAT_RGB888;
+	case GUD_PIXEL_FORMAT_XRGB8888:
+		return DRM_FORMAT_XRGB8888;
+	case GUD_PIXEL_FORMAT_ARGB8888:
+		return DRM_FORMAT_ARGB8888;
+	}
+
+	return 0;
+}
+
+static inline void gud_from_display_mode(struct gud_display_mode_req *dst,
+					 const struct drm_display_mode *src)
+{
+	u32 flags = src->flags & GUD_DISPLAY_MODE_FLAG_USER_MASK;
+
+	if (src->type & DRM_MODE_TYPE_PREFERRED)
+		flags |= GUD_DISPLAY_MODE_FLAG_PREFERRED;
+
+	dst->clock = cpu_to_le32(src->clock);
+	dst->hdisplay = cpu_to_le16(src->hdisplay);
+	dst->hsync_start = cpu_to_le16(src->hsync_start);
+	dst->hsync_end = cpu_to_le16(src->hsync_end);
+	dst->htotal = cpu_to_le16(src->htotal);
+	dst->vdisplay = cpu_to_le16(src->vdisplay);
+	dst->vsync_start = cpu_to_le16(src->vsync_start);
+	dst->vsync_end = cpu_to_le16(src->vsync_end);
+	dst->vtotal = cpu_to_le16(src->vtotal);
+	dst->flags = cpu_to_le32(flags);
+}
+
+static inline void gud_to_display_mode(struct drm_display_mode *dst,
+				       const struct gud_display_mode_req *src)
+{
+	u32 flags = le32_to_cpu(src->flags);
+
+	memset(dst, 0, sizeof(*dst));
+	dst->clock = le32_to_cpu(src->clock);
+	dst->hdisplay = le16_to_cpu(src->hdisplay);
+	dst->hsync_start = le16_to_cpu(src->hsync_start);
+	dst->hsync_end = le16_to_cpu(src->hsync_end);
+	dst->htotal = le16_to_cpu(src->htotal);
+	dst->vdisplay = le16_to_cpu(src->vdisplay);
+	dst->vsync_start = le16_to_cpu(src->vsync_start);
+	dst->vsync_end = le16_to_cpu(src->vsync_end);
+	dst->vtotal = le16_to_cpu(src->vtotal);
+	dst->flags = flags & GUD_DISPLAY_MODE_FLAG_USER_MASK;
+	dst->type = DRM_MODE_TYPE_DRIVER;
+	if (flags & GUD_DISPLAY_MODE_FLAG_PREFERRED)
+		dst->type |= DRM_MODE_TYPE_PREFERRED;
+	drm_mode_set_name(dst);
+}
+
+#endif
diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
new file mode 100644
index 000000000..5ef887d84
--- /dev/null
+++ b/drivers/gpu/drm/gud/gud_pipe.c
@@ -0,0 +1,658 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright 2020 Noralf Trønnes
+ */
+
+#include <linux/lz4.h>
+#include <linux/usb.h>
+#include <linux/vmalloc.h>
+#include <linux/workqueue.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_format_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_print.h>
+#include <drm/drm_rect.h>
+#include <drm/gud.h>
+
+#include "gud_internal.h"
+
+/*
+ * Some userspace rendering loops run all displays in the same loop.
+ * This means that a fast display will have to wait for a slow one.
+ * Such users might want to enable this module parameter.
+ */
+static bool gud_async_flush;
+module_param_named(async_flush, gud_async_flush, bool, 0644);
+MODULE_PARM_DESC(async_flush, "Enable asynchronous flushing [default=0]");
+
+/*
+ * FIXME: The driver is probably broken on Big Endian machines.
+ * See discussion:
+ * https://lore.kernel.org/dri-devel/CAKb7UvihLX0hgBOP3VBG7O+atwZcUVCPVuBdfmDMpg0NjXe-cQ@mail.gmail.com/
+ */
+
+static bool gud_is_big_endian(void)
+{
+#if defined(__BIG_ENDIAN)
+	return true;
+#else
+	return false;
+#endif
+}
+
+static size_t gud_xrgb8888_to_r124(u8 *dst, const struct drm_format_info *format,
+				   void *src, struct drm_framebuffer *fb,
+				   struct drm_rect *rect,
+				   struct drm_format_conv_state *fmtcnv_state)
+{
+	unsigned int block_width = drm_format_info_block_width(format, 0);
+	unsigned int bits_per_pixel = 8 / block_width;
+	unsigned int x, y, width, height;
+	u8 pix, *pix8, *block = dst; /* Assign to silence compiler warning */
+	struct iosys_map dst_map, vmap;
+	size_t len;
+	void *buf;
+
+	drm_WARN_ON_ONCE(fb->dev, format->char_per_block[0] != 1);
+
+	/* Start on a byte boundary */
+	rect->x1 = ALIGN_DOWN(rect->x1, block_width);
+	width = drm_rect_width(rect);
+	height = drm_rect_height(rect);
+	len = drm_format_info_min_pitch(format, 0, width) * height;
+
+	buf = kmalloc_array(height, width, GFP_KERNEL);
+	if (!buf)
+		return 0;
+
+	iosys_map_set_vaddr(&dst_map, buf);
+	iosys_map_set_vaddr(&vmap, src);
+	drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, rect, fmtcnv_state);
+	pix8 = buf;
+
+	for (y = 0; y < height; y++) {
+		for (x = 0; x < width; x++) {
+			unsigned int pixpos = x % block_width; /* within byte from the left */
+			unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
+
+			if (!pixpos) {
+				block = dst++;
+				*block = 0;
+			}
+
+			pix = (*pix8++) >> (8 - bits_per_pixel);
+			*block |= pix << pixshift;
+		}
+	}
+
+	kfree(buf);
+
+	return len;
+}
+
+static size_t gud_xrgb8888_to_color(u8 *dst, const struct drm_format_info *format,
+				    void *src, struct drm_framebuffer *fb,
+				    struct drm_rect *rect)
+{
+	unsigned int block_width = drm_format_info_block_width(format, 0);
+	unsigned int bits_per_pixel = 8 / block_width;
+	u8 r, g, b, pix, *block = dst; /* Assign to silence compiler warning */
+	unsigned int x, y, width;
+	__le32 *sbuf32;
+	u32 pix32;
+	size_t len;
+
+	/* Start on a byte boundary */
+	rect->x1 = ALIGN_DOWN(rect->x1, block_width);
+	width = drm_rect_width(rect);
+	len = drm_format_info_min_pitch(format, 0, width) * drm_rect_height(rect);
+
+	for (y = rect->y1; y < rect->y2; y++) {
+		sbuf32 = src + (y * fb->pitches[0]);
+		sbuf32 += rect->x1;
+
+		for (x = 0; x < width; x++) {
+			unsigned int pixpos = x % block_width; /* within byte from the left */
+			unsigned int pixshift = (block_width - pixpos - 1) * bits_per_pixel;
+
+			if (!pixpos) {
+				block = dst++;
+				*block = 0;
+			}
+
+			pix32 = le32_to_cpu(*sbuf32++);
+			r = pix32 >> 16;
+			g = pix32 >> 8;
+			b = pix32;
+
+			switch (format->format) {
+			case GUD_DRM_FORMAT_XRGB1111:
+				pix = ((r >> 7) << 2) | ((g >> 7) << 1) | (b >> 7);
+				break;
+			default:
+				drm_WARN_ON_ONCE(fb->dev, 1);
+				return len;
+			}
+
+			*block |= pix << pixshift;
+		}
+	}
+
+	return len;
+}
+
+static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
+			  const struct iosys_map *src, bool cached_reads,
+			  const struct drm_format_info *format, struct drm_rect *rect,
+			  struct gud_set_buffer_req *req,
+			  struct drm_format_conv_state *fmtcnv_state)
+{
+	u8 compression = gdrm->compression;
+	struct iosys_map dst;
+	void *vaddr, *buf;
+	size_t pitch, len;
+
+	pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(rect));
+	len = pitch * drm_rect_height(rect);
+	if (len > gdrm->bulk_len)
+		return -E2BIG;
+
+	vaddr = src[0].vaddr;
+retry:
+	if (compression)
+		buf = gdrm->compress_buf;
+	else
+		buf = gdrm->bulk_buf;
+	iosys_map_set_vaddr(&dst, buf);
+
+	/*
+	 * Imported buffers are assumed to be write-combined and thus uncached
+	 * with slow reads (at least on ARM).
+	 */
+	if (format != fb->format) {
+		if (format->format == GUD_DRM_FORMAT_R1) {
+			len = gud_xrgb8888_to_r124(buf, format, vaddr, fb, rect, fmtcnv_state);
+			if (!len)
+				return -ENOMEM;
+		} else if (format->format == DRM_FORMAT_R8) {
+			drm_fb_xrgb8888_to_gray8(&dst, NULL, src, fb, rect, fmtcnv_state);
+		} else if (format->format == DRM_FORMAT_RGB332) {
+			drm_fb_xrgb8888_to_rgb332(&dst, NULL, src, fb, rect, fmtcnv_state);
+		} else if (format->format == DRM_FORMAT_RGB565) {
+			if (gud_is_big_endian()) {
+				drm_fb_xrgb8888_to_rgb565be(&dst, NULL, src, fb, rect,
+							    fmtcnv_state);
+			} else {
+				drm_fb_xrgb8888_to_rgb565(&dst, NULL, src, fb, rect,
+							  fmtcnv_state);
+			}
+		} else if (format->format == DRM_FORMAT_RGB888) {
+			drm_fb_xrgb8888_to_rgb888(&dst, NULL, src, fb, rect, fmtcnv_state);
+		} else {
+			len = gud_xrgb8888_to_color(buf, format, vaddr, fb, rect);
+		}
+	} else if (gud_is_big_endian() && format->cpp[0] > 1) {
+		drm_fb_swab(&dst, NULL, src, fb, rect, cached_reads, fmtcnv_state);
+	} else if (compression && cached_reads && pitch == fb->pitches[0]) {
+		/* can compress directly from the framebuffer */
+		buf = vaddr + rect->y1 * pitch;
+	} else {
+		drm_fb_memcpy(&dst, NULL, src, fb, rect);
+	}
+
+	memset(req, 0, sizeof(*req));
+	req->x = cpu_to_le32(rect->x1);
+	req->y = cpu_to_le32(rect->y1);
+	req->width = cpu_to_le32(drm_rect_width(rect));
+	req->height = cpu_to_le32(drm_rect_height(rect));
+	req->length = cpu_to_le32(len);
+
+	if (compression & GUD_COMPRESSION_LZ4) {
+		int complen;
+
+		complen = LZ4_compress_default(buf, gdrm->bulk_buf, len, len, gdrm->lz4_comp_mem);
+		if (complen <= 0) {
+			compression = 0;
+			goto retry;
+		}
+
+		req->compression = GUD_COMPRESSION_LZ4;
+		req->compressed_length = cpu_to_le32(complen);
+	}
+
+	return 0;
+}
+
+struct gud_usb_bulk_context {
+	struct timer_list timer;
+	struct usb_sg_request sgr;
+};
+
+static void gud_usb_bulk_timeout(struct timer_list *t)
+{
+	struct gud_usb_bulk_context *ctx = timer_container_of(ctx, t, timer);
+
+	usb_sg_cancel(&ctx->sgr);
+}
+
+static int gud_usb_bulk(struct gud_device *gdrm, size_t len)
+{
+	struct gud_usb_bulk_context ctx;
+	int ret;
+
+	ret = usb_sg_init(&ctx.sgr, gud_to_usb_device(gdrm), gdrm->bulk_pipe, 0,
+			  gdrm->bulk_sgt.sgl, gdrm->bulk_sgt.nents, len, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	timer_setup_on_stack(&ctx.timer, gud_usb_bulk_timeout, 0);
+	mod_timer(&ctx.timer, jiffies + msecs_to_jiffies(3000));
+
+	usb_sg_wait(&ctx.sgr);
+
+	if (!timer_delete_sync(&ctx.timer))
+		ret = -ETIMEDOUT;
+	else if (ctx.sgr.status < 0)
+		ret = ctx.sgr.status;
+	else if (ctx.sgr.bytes != len)
+		ret = -EIO;
+
+	timer_destroy_on_stack(&ctx.timer);
+
+	return ret;
+}
+
+static int gud_flush_rect(struct gud_device *gdrm, struct drm_framebuffer *fb,
+			  const struct iosys_map *src, bool cached_reads,
+			  const struct drm_format_info *format, struct drm_rect *rect,
+			  struct drm_format_conv_state *fmtcnv_state)
+{
+	struct gud_set_buffer_req req;
+	size_t len, trlen;
+	int ret;
+
+	drm_dbg(&gdrm->drm, "Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
+
+	ret = gud_prep_flush(gdrm, fb, src, cached_reads, format, rect, &req, fmtcnv_state);
+	if (ret)
+		return ret;
+
+	len = le32_to_cpu(req.length);
+
+	if (req.compression)
+		trlen = le32_to_cpu(req.compressed_length);
+	else
+		trlen = len;
+
+	gdrm->stats_length += len;
+	/* Did it wrap around? */
+	if (gdrm->stats_length <= len && gdrm->stats_actual_length) {
+		gdrm->stats_length = len;
+		gdrm->stats_actual_length = 0;
+	}
+	gdrm->stats_actual_length += trlen;
+
+	if (!(gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE) || gdrm->prev_flush_failed) {
+		ret = gud_usb_set(gdrm, GUD_REQ_SET_BUFFER, 0, &req, sizeof(req));
+		if (ret)
+			return ret;
+	}
+
+	ret = gud_usb_bulk(gdrm, trlen);
+	if (ret)
+		gdrm->stats_num_errors++;
+
+	return ret;
+}
+
+void gud_clear_damage(struct gud_device *gdrm)
+{
+	gdrm->damage.x1 = INT_MAX;
+	gdrm->damage.y1 = INT_MAX;
+	gdrm->damage.x2 = 0;
+	gdrm->damage.y2 = 0;
+}
+
+static void gud_flush_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
+			     const struct iosys_map *src, bool cached_reads,
+			     struct drm_rect *damage)
+{
+	struct drm_format_conv_state fmtcnv_state = DRM_FORMAT_CONV_STATE_INIT;
+	const struct drm_format_info *format;
+	unsigned int i, lines;
+	size_t pitch;
+	int ret;
+
+	format = fb->format;
+	if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
+		format = gdrm->xrgb8888_emulation_format;
+
+	/* Split update if it's too big */
+	pitch = drm_format_info_min_pitch(format, 0, drm_rect_width(damage));
+	lines = drm_rect_height(damage);
+
+	if (gdrm->bulk_len < lines * pitch)
+		lines = gdrm->bulk_len / pitch;
+
+	for (i = 0; i < DIV_ROUND_UP(drm_rect_height(damage), lines); i++) {
+		struct drm_rect rect = *damage;
+
+		rect.y1 += i * lines;
+		rect.y2 = min_t(u32, rect.y1 + lines, damage->y2);
+
+		ret = gud_flush_rect(gdrm, fb, src, cached_reads, format, &rect, &fmtcnv_state);
+		if (ret) {
+			if (ret != -ENODEV && ret != -ECONNRESET &&
+			    ret != -ESHUTDOWN && ret != -EPROTO)
+				dev_err_ratelimited(fb->dev->dev,
+						    "Failed to flush framebuffer: error=%d\n", ret);
+			gdrm->prev_flush_failed = true;
+			break;
+		}
+	}
+
+	drm_format_conv_state_release(&fmtcnv_state);
+}
+
+void gud_flush_work(struct work_struct *work)
+{
+	struct gud_device *gdrm = container_of(work, struct gud_device, work);
+	struct iosys_map shadow_map;
+	struct drm_framebuffer *fb;
+	struct drm_rect damage;
+	int idx;
+
+	if (!drm_dev_enter(&gdrm->drm, &idx))
+		return;
+
+	mutex_lock(&gdrm->damage_lock);
+	fb = gdrm->fb;
+	gdrm->fb = NULL;
+	iosys_map_set_vaddr(&shadow_map, gdrm->shadow_buf);
+	damage = gdrm->damage;
+	gud_clear_damage(gdrm);
+	mutex_unlock(&gdrm->damage_lock);
+
+	if (!fb)
+		goto out;
+
+	gud_flush_damage(gdrm, fb, &shadow_map, true, &damage);
+
+	drm_framebuffer_put(fb);
+out:
+	drm_dev_exit(idx);
+}
+
+static int gud_fb_queue_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
+			       const struct iosys_map *src, struct drm_rect *damage)
+{
+	struct drm_framebuffer *old_fb = NULL;
+	struct iosys_map shadow_map;
+
+	mutex_lock(&gdrm->damage_lock);
+
+	if (!gdrm->shadow_buf) {
+		gdrm->shadow_buf = vcalloc(fb->pitches[0], fb->height);
+		if (!gdrm->shadow_buf) {
+			mutex_unlock(&gdrm->damage_lock);
+			return -ENOMEM;
+		}
+	}
+
+	iosys_map_set_vaddr(&shadow_map, gdrm->shadow_buf);
+	iosys_map_incr(&shadow_map, drm_fb_clip_offset(fb->pitches[0], fb->format, damage));
+	drm_fb_memcpy(&shadow_map, fb->pitches, src, fb, damage);
+
+	if (fb != gdrm->fb) {
+		old_fb = gdrm->fb;
+		drm_framebuffer_get(fb);
+		gdrm->fb = fb;
+	}
+
+	gdrm->damage.x1 = min(gdrm->damage.x1, damage->x1);
+	gdrm->damage.y1 = min(gdrm->damage.y1, damage->y1);
+	gdrm->damage.x2 = max(gdrm->damage.x2, damage->x2);
+	gdrm->damage.y2 = max(gdrm->damage.y2, damage->y2);
+
+	mutex_unlock(&gdrm->damage_lock);
+
+	queue_work(system_long_wq, &gdrm->work);
+
+	if (old_fb)
+		drm_framebuffer_put(old_fb);
+
+	return 0;
+}
+
+static void gud_fb_handle_damage(struct gud_device *gdrm, struct drm_framebuffer *fb,
+				 const struct iosys_map *src, struct drm_rect *damage)
+{
+	int ret;
+
+	if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE)
+		drm_rect_init(damage, 0, 0, fb->width, fb->height);
+
+	if (gud_async_flush) {
+		ret = gud_fb_queue_damage(gdrm, fb, src, damage);
+		if (ret != -ENOMEM)
+			return;
+	}
+
+	/* Imported buffers are assumed to be WriteCombined with uncached reads */
+	gud_flush_damage(gdrm, fb, src, !drm_gem_is_imported(fb->obj[0]), damage);
+}
+
+int gud_plane_atomic_check(struct drm_plane *plane,
+			   struct drm_atomic_commit *state)
+{
+	struct gud_device *gdrm = to_gud_device(plane->dev);
+	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
+	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
+	struct drm_crtc *crtc = new_plane_state->crtc;
+	struct drm_crtc_state *crtc_state = NULL;
+	const struct drm_display_mode *mode;
+	struct drm_framebuffer *old_fb = old_plane_state->fb;
+	struct drm_connector_state *connector_state = NULL;
+	struct drm_framebuffer *fb = new_plane_state->fb;
+	const struct drm_format_info *format;
+	struct drm_connector *connector;
+	unsigned int i, num_properties;
+	struct gud_state_req *req;
+	int idx, ret;
+	size_t len;
+
+	if (crtc)
+		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+
+	ret = drm_atomic_helper_check_plane_state(new_plane_state, crtc_state,
+						  DRM_PLANE_NO_SCALING,
+						  DRM_PLANE_NO_SCALING,
+						  false, false);
+	if (ret)
+		return ret;
+
+	if (!new_plane_state->visible)
+		return 0;
+
+	if (old_plane_state->rotation != new_plane_state->rotation)
+		crtc_state->mode_changed = true;
+
+	mode = &crtc_state->mode;
+	format = fb->format;
+
+	if (old_fb && old_fb->format != format)
+		crtc_state->mode_changed = true;
+
+	if (!crtc_state->mode_changed && !crtc_state->connectors_changed)
+		return 0;
+
+	/* Only one connector is supported */
+	if (hweight32(crtc_state->connector_mask) != 1)
+		return -EINVAL;
+
+	if (format->format == DRM_FORMAT_XRGB8888 && gdrm->xrgb8888_emulation_format)
+		format = gdrm->xrgb8888_emulation_format;
+
+	for_each_new_connector_in_state(state, connector, connector_state, i) {
+		if (connector_state->crtc)
+			break;
+	}
+
+	/*
+	 * DRM_IOCTL_MODE_OBJ_SETPROPERTY on the rotation property will not have
+	 * the connector included in the state.
+	 */
+	if (!connector_state) {
+		struct drm_connector_list_iter conn_iter;
+
+		drm_connector_list_iter_begin(plane->dev, &conn_iter);
+		drm_for_each_connector_iter(connector, &conn_iter) {
+			if (connector->state->crtc) {
+				connector_state = connector->state;
+				break;
+			}
+		}
+		drm_connector_list_iter_end(&conn_iter);
+	}
+
+	if (drm_WARN_ON_ONCE(plane->dev, !connector_state))
+		return -ENOENT;
+
+	len = struct_size(req, properties,
+			  size_add(GUD_PROPERTIES_MAX_NUM, GUD_CONNECTOR_PROPERTIES_MAX_NUM));
+	req = kzalloc(len, GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	gud_from_display_mode(&req->mode, mode);
+
+	req->format = gud_from_fourcc(format->format);
+	if (drm_WARN_ON_ONCE(plane->dev, !req->format)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	req->connector = drm_connector_index(connector_state->connector);
+
+	ret = gud_connector_fill_properties(connector_state, req->properties);
+	if (ret < 0)
+		goto out;
+
+	num_properties = ret;
+	for (i = 0; i < gdrm->num_properties; i++) {
+		u16 prop = gdrm->properties[i];
+		u64 val;
+
+		switch (prop) {
+		case GUD_PROPERTY_ROTATION:
+			/* DRM UAPI matches the protocol so use value directly */
+			val = new_plane_state->rotation;
+			break;
+		default:
+			drm_WARN_ON_ONCE(plane->dev, 1);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		req->properties[num_properties + i].prop = cpu_to_le16(prop);
+		req->properties[num_properties + i].val = cpu_to_le64(val);
+		num_properties++;
+	}
+
+	if (drm_dev_enter(fb->dev, &idx)) {
+		len = struct_size(req, properties, num_properties);
+		ret = gud_usb_set(gdrm, GUD_REQ_SET_STATE_CHECK, 0, req, len);
+		drm_dev_exit(idx);
+	}  else {
+		ret = -ENODEV;
+	}
+out:
+	kfree(req);
+
+	return ret;
+}
+
+void gud_crtc_atomic_enable(struct drm_crtc *crtc,
+			    struct drm_atomic_commit *state)
+{
+	struct drm_device *drm = crtc->dev;
+	struct gud_device *gdrm = to_gud_device(drm);
+	int idx;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
+	gud_usb_set(gdrm, GUD_REQ_SET_STATE_COMMIT, 0, NULL, 0);
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, 1);
+
+	drm_dev_exit(idx);
+}
+
+void gud_crtc_atomic_disable(struct drm_crtc *crtc,
+			     struct drm_atomic_commit *state)
+{
+	struct drm_device *drm = crtc->dev;
+	struct gud_device *gdrm = to_gud_device(drm);
+	int idx;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_DISPLAY_ENABLE, 0);
+	gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 0);
+
+	drm_dev_exit(idx);
+}
+
+void gud_plane_atomic_update(struct drm_plane *plane,
+			     struct drm_atomic_commit *atomic_state)
+{
+	struct drm_device *drm = plane->dev;
+	struct gud_device *gdrm = to_gud_device(drm);
+	struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(atomic_state, plane);
+	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(atomic_state, plane);
+	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(new_state);
+	struct drm_framebuffer *fb = new_state->fb;
+	struct drm_crtc *crtc = new_state->crtc;
+	struct drm_rect damage;
+	struct drm_atomic_helper_damage_iter iter;
+	int ret, idx;
+
+	if (!crtc || crtc->state->mode_changed || !crtc->state->enable) {
+		cancel_work_sync(&gdrm->work);
+		mutex_lock(&gdrm->damage_lock);
+		if (gdrm->fb) {
+			drm_framebuffer_put(gdrm->fb);
+			gdrm->fb = NULL;
+		}
+		gud_clear_damage(gdrm);
+		vfree(gdrm->shadow_buf);
+		gdrm->shadow_buf = NULL;
+		mutex_unlock(&gdrm->damage_lock);
+	}
+
+	if (!crtc || !drm_dev_enter(drm, &idx))
+		return;
+
+	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
+	if (ret)
+		goto out;
+
+	drm_atomic_helper_damage_iter_init(&iter, old_state, new_state);
+	drm_atomic_for_each_plane_damage(&iter, &damage)
+		gud_fb_handle_damage(gdrm, fb, &shadow_plane_state->data[0], &damage);
+
+	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+
+out:
+	drm_dev_exit(idx);
+}