[PATCH 09/11] drm/fbdevdrm: Add primary plane
Mathieu Malaterre
malat at debian.org
Tue Mar 26 13:33:59 UTC 2019
On Tue, Mar 26, 2019 at 10:18 AM Thomas Zimmermann <tzimmermann at suse.de> wrote:
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
> 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);
A simple compile/test here leads to:
...
../drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.c:174:2: note: in expansion
of macro 'do_div'
do_div(width, cpp);
^~~~~~
In file included from ./arch/powerpc/include/generated/asm/div64.h:1,
from ../include/linux/kernel.h:18,
from ../include/linux/list.h:9,
from ../include/linux/rculist.h:10,
from ../include/linux/pid.h:5,
from ../include/linux/sched.h:14,
from ../drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.c:15:
../include/asm-generic/div64.h:239:22: error: passing argument 1 of
'__div64_32' from incompatible pointer type
[-Werror=incompatible-pointer-types]
__rem = __div64_32(&(n), __base); \
^~~~
../drivers/gpu/drm/fbdevdrm/fbdevdrm_modes.c:174:2: note: in expansion
of macro 'do_div'
do_div(width, cpp);
^~~~~~
../include/asm-generic/div64.h:213:38: note: expected 'uint64_t *'
{aka 'long long unsigned int *'} but argument is of type 'unsigned int
*'
extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
...
> +
> + 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
>
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