Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/gpu/drm/fbdevdrm/Makefile | 1 +
drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.c | 42 ++
drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.h | 7 +
drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c | 9 +-
drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.h | 2 +
drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.c | 498 ++++++++++++++++++++
drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.h | 27 ++
7 files changed, 585 insertions(+), 1 deletion(-)
create mode 100644 drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.c
create mode 100644 drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.h
diff --git a/drivers/gpu/drm/fbdevdrm/Makefile b/drivers/gpu/drm/fbdevdrm/Makefile
index 2ca906a3258b..5507152d8187 100644
--- a/drivers/gpu/drm/fbdevdrm/Makefile
+++ b/drivers/gpu/drm/fbdevdrm/Makefile
@@ -5,6 +5,7 @@ fbdevdrm-y := fbdevdrm_bo.o \
fbdevdrm_format.o \
fbdevdrm_modes.o \
fbdevdrm_modeset.o \
+ fbdevdrm_primary.o \
fbdevdrm_ttm.o
obj-$(CONFIG_DRM_FBDEVDRM) += fbdevdrm.o
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.c b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.c
index bd3ad691e7ce..8dea7ef369dc 100644
--- a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.c
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.c
@@ -11,8 +11,12 @@
*/
#include "fbdevdrm_modes.h"
+#include <drm/drm.h>
+#include <linux/sched.h> /* for TASK_COMM_LEN in <drm/drm_framebuffer.h> */
+#include <drm/drm_framebuffer.h>
#include <drm/drm_modes.h>
#include <linux/fb.h>
+#include "fbdevdrm_format.h"
void drm_mode_update_from_fb_videomode(struct drm_display_mode *mode,
const struct fb_videomode *fb_mode)
@@ -151,3 +155,41 @@ fbdevdrm_init_fb_var_screeninfo_from_mode(struct fb_var_screeninfo *fb_var,
memset(fb_var, 0, sizeof(*fb_var));
fbdevdrm_update_fb_var_screeninfo_from_mode(fb_var, mode);
}
+
+int fbdevdrm_update_fb_var_screeninfo_from_framebuffer(
+ struct fb_var_screeninfo *fb_var, struct drm_framebuffer *fb,
+ size_t vram_size)
+{
+ unsigned int width, pitch;
+ uint64_t cpp, lines;
+ int ret;
+
+ /* Our virtual screen covers all the graphics memory (sans some
+ * trailing bytes). This allows for setting the scanout buffer's
+ * address with fb_pan_display().
+ */
+
+ width = fb->pitches[0];
+ cpp = drm_format_plane_cpp(fb->format[0].format, 0);
+ do_div(width, cpp);
+
+ if (width > (__u32)-1)
+ return -EINVAL; /* would overflow fb_var->xres_virtual */
+
+ pitch = fb->pitches[0];
+ lines = vram_size;
+ do_div(lines, pitch);
+
+ if (lines > (__u32)-1)
+ return -EINVAL; /* would overflow fb_var->yres_virtual */
+
+ fb_var->xres_virtual = width;
+ fb_var->yres_virtual = lines;
+
+ ret = fbdevdrm_update_fb_var_screeninfo_from_format(
+ fb_var, fb->format[0].format);
+ if (ret)
+ return ret;
+
+ return 0;
+}
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.h b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.h
index f88a86a83858..925eea78e3f0 100644
--- a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.h
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.h
@@ -13,8 +13,11 @@
#ifndef FBDEVDRM_MODES_H
#define FBDEVDRM_MODES_H
+#include <linux/types.h>
+
struct drm_device;
struct drm_display_mode;
+struct drm_framebuffer;
struct fb_videomode;
struct fb_var_screeninfo;
@@ -43,4 +46,8 @@ void
fbdevdrm_init_fb_var_screeninfo_from_mode(struct fb_var_screeninfo *var,
const struct drm_display_mode *mode);
+int fbdevdrm_update_fb_var_screeninfo_from_framebuffer(
+ struct fb_var_screeninfo *fb_var, struct drm_framebuffer *fb,
+ size_t vram_size);
+
#endif
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c
index 585f3478f190..3473b85acbf1 100644
--- a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c
@@ -20,6 +20,7 @@
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_probe_helper.h>
#include <linux/fb.h>
+#include "fbdevdrm_primary.h"
/*
* CRTC
@@ -376,7 +377,13 @@ int fbdevdrm_modeset_init(struct fbdevdrm_modeset *modeset,
* connect them with each other.
*/
- ret = drm_crtc_init_with_planes(dev, &modeset->crtc, NULL, NULL,
+ ret = fbdevdrm_init_primary_plane_from_fb_info(
+ &modeset->primary_plane, dev, 0, fb_info);
+ if (ret)
+ goto err_drm_mode_config_cleanup;
+
+ ret = drm_crtc_init_with_planes(dev, &modeset->crtc,
+ &modeset->primary_plane, NULL,
&fbdevdrm_crtc_funcs, NULL);
if (ret)
goto err_drm_mode_config_cleanup;
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.h b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.h
index 21e87caa8196..ec753014aba1 100644
--- a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.h
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.h
@@ -16,11 +16,13 @@
#include <drm/drm_connector.h>
#include <drm/drm_crtc.h>
#include <drm/drm_encoder.h>
+#include <drm/drm_plane.h>
struct drm_device;
struct fb_info;
struct fbdevdrm_modeset {
+ struct drm_plane primary_plane;
struct drm_crtc crtc;
struct drm_encoder encoder;
struct drm_connector connector;
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.c b/drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.c
new file mode 100644
index 000000000000..8ba8e6bd1c14
--- /dev/null
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.c
@@ -0,0 +1,498 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * One purpose of this driver is to allow for easy conversion of framebuffer
+ * drivers to DRM. As a special exception to the GNU GPL, you are allowed to
+ * relicense this file under the terms of a license of your choice if you're
+ * porting a framebuffer driver. In order to do so, update the SPDX license
+ * identifier to the new license and remove this exception.
+ *
+ * If you add code to this file, please ensure that it's compatible with the
+ * stated exception.
+ */
+
+#include "fbdevdrm_primary.h"
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_plane.h>
+#include <linux/fb.h>
+#include "fbdevdrm_bo.h"
+#include "fbdevdrm_format.h"
+#include "fbdevdrm_modes.h"
+#include "fbdevdrm_modeset.h"
+
+static struct fbdevdrm_modeset* fbdevdrm_modeset_of_primary_plane(
+ struct drm_plane *primary_plane)
+{
+ return container_of(primary_plane, struct fbdevdrm_modeset,
+ primary_plane);
+}
+
+/*
+ * Primary plane
+ */
+
+static int primary_plane_helper_prepare_fb(struct drm_plane *plane,
+ struct drm_plane_state *new_state)
+{
+ struct drm_gem_object *gem;
+ struct fbdevdrm_bo *fbo;
+ int ret;
+
+ if (!new_state->fb)
+ return 0;
+
+ gem = new_state->fb->obj[0];
+ fbo = fbdevdrm_bo_of_gem(gem);
+
+ ret = fbdevdrm_bo_pin(fbo, TTM_PL_FLAG_VRAM);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static void primary_plane_helper_cleanup_fb(struct drm_plane *plane,
+ struct drm_plane_state *old_state)
+{
+ struct drm_gem_object *gem;
+ struct fbdevdrm_bo *fbo;
+
+ if (!old_state->fb)
+ return;
+
+ gem = old_state->fb->obj[0];
+ fbo = fbdevdrm_bo_of_gem(gem);
+
+ fbdevdrm_bo_unpin(fbo);
+}
+
+static void fbdevdrm_update_fb_var_screeninfo_from_crtc_state(
+ struct fb_var_screeninfo *fb_var, struct drm_crtc_state* crtc_state)
+{
+ fbdevdrm_update_fb_var_screeninfo_from_mode(fb_var, &crtc_state->adjusted_mode);
+}
+
+static int primary_plane_helper_atomic_check(struct drm_plane *plane,
+ struct drm_plane_state *state)
+{
+ struct drm_crtc_state *new_crtc_state;
+ int ret;
+ struct fbdevdrm_modeset *modeset;
+ struct fb_var_screeninfo fb_var;
+
+ if (!state->crtc)
+ return 0;
+
+ new_crtc_state = drm_atomic_get_new_crtc_state(state->state,
+ state->crtc);
+ if (!new_crtc_state)
+ return 0;
+
+ ret = drm_atomic_helper_check_plane_state(state, new_crtc_state,
+ 1 << 16, 1 << 16,
+ false, true);
+ if (ret < 0) {
+ DRM_ERROR("fbdrmdev: %s:%d ret=%d:\n", __func__, __LINE__, ret);
+ return ret;
+ }
+
+ if (!state->visible || !state->fb)
+ return 0;
+
+ /* Virtual screen sizes are not supported.
+ */
+
+ if (drm_rect_width(&state->dst) != state->fb->width ||
+ drm_rect_height(&state->dst) != state->fb->height) {
+ DRM_ERROR("fbdevdrm: %s:%d: virtual screen sizes not supported\n", __func__, __LINE__);
+ return -EINVAL;
+ }
+ if (state->dst.x1 || state->dst.y1) {
+ DRM_ERROR("fbdevdrm: %s:%d: virtual screen offset not supported\n", __func__, __LINE__);
+ return -EINVAL;
+ }
+
+ /* Pixel formats have to be compatible with fbdev. This is
+ * usually some variation of XRGB.
+ */
+
+ if (!plane->state ||
+ !plane->state->fb ||
+ plane->state->fb->format[0].format != state->fb->format[0].format) {
+
+ modeset = fbdevdrm_modeset_of_primary_plane(plane);
+
+ if (modeset->fb_info->fbops->fb_check_var) {
+ memcpy(&fb_var, &modeset->fb_info->var,
+ sizeof(fb_var));
+ fbdevdrm_update_fb_var_screeninfo_from_crtc_state(
+ &fb_var, new_crtc_state);
+ fbdevdrm_update_fb_var_screeninfo_from_framebuffer(
+ &fb_var, state->fb,
+ modeset->fb_info->fix.smem_len);
+ ret = modeset->fb_info->fbops->fb_check_var(
+ &fb_var, modeset->fb_info);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int set_palette_cmap(struct fb_info* fb_info)
+{
+ __u32 len;
+ const struct fb_cmap* default_cmap;
+ struct fb_cmap cmap;
+ int ret;
+ const __u32 gamma_len[3] = {
+ fb_info->var.red.length,
+ fb_info->var.green.length,
+ fb_info->var.blue.length
+ };
+
+ len = max3(gamma_len[0], gamma_len[1], gamma_len[2]);
+ if (!len || (len > 31)) {
+ DRM_ERROR("fbdevdrm: gamma LUT has invalid bit count"
+ " of %u\n", (unsigned int)len);
+ return -EINVAL;
+ }
+
+ default_cmap = fb_default_cmap(1ul << len);
+ if (!default_cmap)
+ return -EINVAL;
+
+ memset(&cmap, 0, sizeof(cmap));
+ ret = fb_alloc_cmap(&cmap, default_cmap->len, 0);
+ if (ret)
+ return ret;
+ ret = fb_copy_cmap(default_cmap, &cmap);
+ if (ret)
+ goto err_fb_dealloc_cmap;
+ ret = fb_set_cmap(&cmap, fb_info);
+ if (ret)
+ return ret;
+ fb_dealloc_cmap(&cmap);
+
+ return 0;
+
+err_fb_dealloc_cmap:
+ fb_dealloc_cmap(&cmap);
+ return ret;
+}
+
+static int set_linear_cmap(struct fb_info* fb_info)
+{
+ struct fb_cmap cmap;
+ int ret;
+ size_t i;
+ unsigned int j;
+ u16 *lut;
+ u16 incr;
+ u16 *gamma_lut[3];
+ __u32 len;
+ const __u32 gamma_len[3] = {
+ fb_info->var.red.length,
+ fb_info->var.green.length,
+ fb_info->var.blue.length
+ };
+
+ len = max3(gamma_len[0], gamma_len[1], gamma_len[2]);
+ if (!len || (len > 8)) {
+ DRM_ERROR("fbdevdrm: gamma LUT has invalid bit count"
+ " of %u\n", (unsigned int)len);
+ return -EINVAL;
+ }
+
+ memset(&cmap, 0, sizeof(cmap));
+ ret = fb_alloc_cmap(&cmap, 1ul << len, 0);
+ if (ret)
+ return ret;
+
+ gamma_lut[0] = cmap.red;
+ gamma_lut[1] = cmap.green;
+ gamma_lut[2] = cmap.blue;
+
+ for (i = 0; i < ARRAY_SIZE(gamma_lut); ++i) {
+ lut = gamma_lut[i];
+ len = 1ul << gamma_len[i];
+ incr = 0x10000u >> gamma_len[i];
+ for (j = 0; j < len; ++j, ++lut) {
+ *lut = incr * j;
+ }
+ /* In order to have no intensity at index 0 and full
+ * intensity at the final index of the LUT, we fix-up the
+ * table's final entries. The fix-up makes intensity grow
+ * faster near the final entries of the gamma LUT. The human
+ * eye is more sensitive to changes to the lower intensities,
+ * so this is probably not directly perceivable.
+ */
+ for (lut -= gamma_len[i], j = gamma_len[i]; j > 0; ++lut) {
+ --j;
+ *lut += (incr >> j) - 1; /* subtract 1 to not
+ * overflow the LUT's
+ * final entry */
+ }
+ }
+
+ ret = fb_set_cmap(&cmap, fb_info);
+ if (ret)
+ goto err_fb_dealloc_cmap;
+ fb_dealloc_cmap(&cmap);
+
+ return 0;
+
+err_fb_dealloc_cmap:
+ fb_dealloc_cmap(&cmap);
+ return -EINVAL;
+}
+
+static int set_cmap(struct fb_info *fb_info)
+{
+ int ret = 0;
+
+ switch (fb_info->fix.visual) {
+ case FB_VISUAL_PSEUDOCOLOR:
+ ret = set_palette_cmap(fb_info);
+ break;
+ case FB_VISUAL_DIRECTCOLOR:
+ ret = set_linear_cmap(fb_info);
+ break;
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+static void primary_plane_helper_atomic_update(
+ struct drm_plane *plane, struct drm_plane_state *old_state)
+{
+ struct fbdevdrm_modeset *modeset;
+ uint32_t format;
+ struct fb_var_screeninfo fb_var;
+ int ret;
+ struct drm_gem_object *gem;
+ struct fbdevdrm_bo *fbo;
+ __u32 line_length;
+ uint64_t yoffset;
+ uint32_t xoffset;
+
+ modeset = fbdevdrm_modeset_of_primary_plane(plane);
+
+ format = fbdevdrm_format_of_fb_info(modeset->fb_info);
+
+ /* DRM porting notes: Some fbdev drivers report alpha channels for
+ * their framebuffer, even though they don't support transparent
+ * primary planes. For the format test below, we ignore the alpha
+ * channel and use the non-transparent equivalent of the pixel format.
+ * If you're porting an fbdev driver to DRM, remove this switch
+ * statement and report the correct format instead.
+ */
+ switch (format) {
+ case DRM_FORMAT_ARGB8888:
+ format = DRM_FORMAT_XRGB8888;
+ break;
+ case DRM_FORMAT_ABGR8888:
+ format = DRM_FORMAT_XBGR8888;
+ break;
+ case DRM_FORMAT_RGBA8888:
+ format = DRM_FORMAT_RGBX8888;
+ break;
+ case DRM_FORMAT_BGRA8888:
+ format = DRM_FORMAT_BGRX8888;
+ break;
+ default:
+ break;
+ }
+
+ if ((format != plane->state->fb->format[0].format) ||
+ (modeset->fb_info->var.xres_virtual != plane->state->fb->width)) {
+
+ /* Pixel format changed, update fb_info accordingly
+ */
+
+ memcpy(&fb_var, &modeset->fb_info->var, sizeof(fb_var));
+ ret = fbdevdrm_update_fb_var_screeninfo_from_framebuffer(
+ &fb_var, plane->state->fb,
+ modeset->fb_info->fix.smem_len);
+ if (ret)
+ return;
+
+ fb_var.activate = FB_ACTIVATE_NOW;
+
+ ret = fb_set_var(modeset->fb_info, &fb_var);
+ if (ret) {
+ DRM_ERROR("fbdevdrm: fb_set_var() failed: %d\n", ret);
+ return;
+ }
+ }
+
+ if (!old_state->fb || /* first-time update */
+ (format != plane->state->fb->format[0].format)) {
+
+ /* DRM porting notes: Below we set the LUTs for palette and
+ * gamma correction. This is required by some fbdev drivers,
+ * such as nvidiafb and atyfb, which don't initialize the
+ * table to pass-through the framebuffer values unchanged. This
+ * is actually CRTC state, but the respective function
+ * crtc_helper_mode_set_nofb() is only called when a CRTC
+ * property changes, changes in color formats are not handled
+ * there. When you're porting a fbdev driver to DRM, remove
+ * the call. Gamma LUTs are CRTC properties and should be
+ * handled there. Either remove gamma correction or set up
+ * the respective CRTC properties for userspace.
+ */
+ set_cmap(modeset->fb_info);
+ }
+
+ /* With the fb interface, we cannot directly program
+ * the scanout buffer's address. Instead we use the
+ * panning function to point the graphics card to the
+ * buffer's location.
+ */
+
+ gem = plane->state->fb->obj[0];
+ fbo = fbdevdrm_bo_of_gem(gem);
+
+ line_length = plane->state->fb->pitches[0];
+ yoffset = fbo->bo.offset;
+ xoffset = do_div(yoffset, line_length);
+ if (yoffset > (__u32)-1) {
+ /* The value of yoffset doesn't fit into a 32-bit value,
+ * so we cannot use it for display panning. Either the
+ * graphics card has GiBs of VRAM or this is a bug with
+ * memory management. */
+ DRM_ERROR("fbdevdrm: buffer object is not aligned to a "
+ "multiple of the scanline size.\n");
+ return;
+ } else if (xoffset) {
+ /* The buffer starts in the middle of a scanline. The
+ * memory manager should have prevented this. This
+ * problem indicates a bug with the buffer aligning. */
+ DRM_ERROR("fbdevdrm: buffer object is not aligned to a "
+ "multiple of the scanline size.\n");
+ return;
+ }
+
+ memcpy(&fb_var, &modeset->fb_info->var, sizeof(fb_var));
+ fb_var.xoffset = xoffset;
+ fb_var.yoffset = yoffset;
+
+ ret = fb_pan_display(modeset->fb_info, &fb_var);
+ if (ret) {
+ DRM_ERROR("fbdevdrm: fb_pan_display() failed: %d\n", ret);
+ return;
+ }
+}
+
+static void primary_plane_helper_atomic_disable(
+ struct drm_plane *plane, struct drm_plane_state *old_state)
+{ }
+
+static int primary_plane_helper_atomic_async_check(
+ struct drm_plane *plane, struct drm_plane_state *state)
+{
+ return 0;
+}
+
+static void primary_plane_helper_atomic_async_update(
+ struct drm_plane *plane, struct drm_plane_state *new_state)
+{
+ drm_plane_cleanup(plane);
+}
+
+static const struct drm_plane_helper_funcs primary_plane_helper_funcs = {
+ .prepare_fb = primary_plane_helper_prepare_fb,
+ .cleanup_fb = primary_plane_helper_cleanup_fb,
+ .atomic_check = primary_plane_helper_atomic_check,
+ .atomic_update = primary_plane_helper_atomic_update,
+ .atomic_disable = primary_plane_helper_atomic_disable,
+ .atomic_async_check = primary_plane_helper_atomic_async_check,
+ .atomic_async_update = primary_plane_helper_atomic_async_update
+};
+
+static void primary_plane_destroy(struct drm_plane *plane)
+{
+ drm_plane_cleanup(plane);
+}
+
+static const struct drm_plane_funcs primary_plane_funcs = {
+ .update_plane = drm_atomic_helper_update_plane,
+ .disable_plane = drm_atomic_helper_disable_plane,
+ .destroy = primary_plane_destroy,
+ .reset = drm_atomic_helper_plane_reset,
+ .set_property = NULL, /* unused */
+ .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
+ .atomic_set_property = NULL, /* unused */
+ .atomic_get_property = NULL, /* unused */
+ .late_register = NULL, /* unused */
+ .early_unregister = NULL, /* unused */
+ .atomic_print_state = NULL, /* unused */
+ .format_mod_supported = NULL /* unused */
+};
+
+static const uint32_t*
+formats_from_fb_info(const struct fb_info* fb_info, unsigned int* format_count)
+{
+ /* TODO: Detect the actually supported formats or have some
+ * sort of whitelist for known hardware devices.
+ */
+ static const uint32_t formats[] = {
+ DRM_FORMAT_XRGB8888,
+ DRM_FORMAT_RGB565
+ };
+
+ *format_count = ARRAY_SIZE(formats);
+
+ return formats;
+}
+
+int fbdevdrm_init_primary_plane_from_fb_info(struct drm_plane *plane,
+ struct drm_device *dev,
+ uint32_t possible_crtcs,
+ struct fb_info *fb_info)
+{
+ uint32_t cur_format;
+ const uint32_t* format;
+ unsigned int format_count;
+ int ret;
+
+ /* We first try to find the supported pixel formats from the
+ * fb_info's hardware settings. If that fails, we take the
+ * current settings. */
+ format = formats_from_fb_info(fb_info, &format_count);
+ if (!format_count) {
+ cur_format = fbdevdrm_format_of_fb_info(fb_info);
+ format = &cur_format;
+ format_count = 1;
+ }
+ if (!format_count)
+ return -ENODEV;
+
+ ret = drm_universal_plane_init(dev, plane, possible_crtcs,
+ &primary_plane_funcs,
+ format, format_count,
+ NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
+ if (ret < 0)
+ return ret;
+ drm_plane_helper_add(plane, &primary_plane_helper_funcs);
+
+ ret = drm_plane_create_rotation_property(plane, DRM_MODE_ROTATE_0,
+ DRM_MODE_ROTATE_0);
+ if (ret < 0)
+ goto err_drm_plane_cleanup;
+
+ ret = drm_plane_create_zpos_immutable_property(plane, 0);
+ if (ret < 0)
+ goto err_drm_plane_cleanup;
+
+ return 0;
+
+err_drm_plane_cleanup:
+ drm_plane_cleanup(plane);
+ return ret;
+}
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.h b/drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.h
new file mode 100644
index 000000000000..529c272c6e0b
--- /dev/null
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_primary.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * One purpose of this driver is to allow for easy conversion of framebuffer
+ * drivers to DRM. As a special exception to the GNU GPL, you are allowed to
+ * relicense this file under the terms of a license of your choice if you're
+ * porting a framebuffer driver. In order to do so, update the SPDX license
+ * identifier to the new license and remove this exception.
+ *
+ * If you add code to this file, please ensure that it's compatible with the
+ * stated exception.
+ */
+
+#ifndef FBDEVDRM_PRIMARY_H
+#define FBDEVDRM_PRIMARY_H
+
+#include <linux/types.h>
+
+struct drm_device;
+struct drm_plane;
+struct fb_info;
+
+int fbdevdrm_init_primary_plane_from_fb_info(struct drm_plane *plane,
+ struct drm_device *dev,
+ uint32_t possible_crtcs,
+ struct fb_info *fb_info);
+
+#endif
--
2.21.0
