/*
 * Mesa 3-D graphics library
 *
 * Copyright © 2021, Google Inc.
 * SPDX-License-Identifier: MIT
 */

#include <assert.h>
#include <dlfcn.h>
#include <errno.h>
#include <string.h>
#include <hardware/gralloc.h>

#include "util/log.h"
#include "util/u_memory.h"

#include "u_gralloc_internal.h"

/* More recent CrOS gralloc has a perform op that fills out the struct below
 * with canonical information about the buffer and its modifier, planes,
 * offsets and strides.  If we have this, we can skip straight to
 * createImageFromDmaBufs2() and avoid all the guessing and recalculations.
 * This also gives us the modifier and plane offsets/strides for multiplanar
 * compressed buffers (eg Intel CCS buffers) in order to make that work in
 * Android.
 */

struct cros_gralloc {
   struct u_gralloc base;
   gralloc_module_t *gralloc_module;
};

static const char cros_gralloc_module_name[] = "CrOS Gralloc";

#define CROS_GRALLOC_DRM_GET_BUFFER_INFO               4
#define CROS_GRALLOC_DRM_GET_USAGE                     5
#define CROS_GRALLOC_DRM_GET_USAGE_FRONT_RENDERING_BIT 0x1

struct cros_gralloc0_buffer_info {
   uint32_t drm_fourcc;
   int num_fds;
   int fds[4];
   uint64_t modifier;
   int offset[4];
   int stride[4];
};

static int
cros_get_buffer_info(struct u_gralloc *gralloc,
                     struct u_gralloc_buffer_handle *hnd,
                     struct u_gralloc_buffer_basic_info *out)
{
   struct cros_gralloc0_buffer_info info;
   struct cros_gralloc *gr = (struct cros_gralloc *)gralloc;
   gralloc_module_t *gr_mod = gr->gralloc_module;

   if (gr_mod->perform(gr_mod, CROS_GRALLOC_DRM_GET_BUFFER_INFO, hnd->handle,
                       &info) == 0) {
      out->drm_fourcc = info.drm_fourcc;
      out->modifier = info.modifier;
      out->num_planes = info.num_fds;
      for (int i = 0; i < out->num_planes; i++) {
         out->fds[i] = info.fds[i];
         out->offsets[i] = info.offset[i];
         out->strides[i] = info.stride[i];
      }

      return 0;
   }

   return -EINVAL;
}

static int
cros_get_front_rendering_usage(struct u_gralloc *gralloc, uint64_t *out_usage)
{
   struct cros_gralloc *gr = (struct cros_gralloc *)gralloc;
   uint32_t front_rendering_usage = 0;

   if (gr->gralloc_module->perform(
          gr->gralloc_module, CROS_GRALLOC_DRM_GET_USAGE,
          CROS_GRALLOC_DRM_GET_USAGE_FRONT_RENDERING_BIT,
          &front_rendering_usage) == 0) {
      *out_usage = front_rendering_usage;
      return 0;
   }

   return -ENOTSUP;
}

static int
destroy(struct u_gralloc *gralloc)
{
   struct cros_gralloc *gr = (struct cros_gralloc *)gralloc;
   if (gr->gralloc_module)
      dlclose(gr->gralloc_module->common.dso);

   FREE(gr);

   return 0;
}

struct u_gralloc *
u_gralloc_cros_api_create()
{
   struct cros_gralloc *gr = CALLOC_STRUCT(cros_gralloc);
   int err = 0;

   err = hw_get_module(GRALLOC_HARDWARE_MODULE_ID,
                       (const hw_module_t **)&gr->gralloc_module);

   if (err)
      goto fail;

   if (strcmp(gr->gralloc_module->common.name, cros_gralloc_module_name) != 0)
      goto fail;

   if (!gr->gralloc_module->perform) {
      mesa_logw("Oops. CrOS gralloc doesn't have perform callback");
      goto fail;
   }

   gr->base.ops.get_buffer_basic_info = cros_get_buffer_info;
   gr->base.ops.get_front_rendering_usage = cros_get_front_rendering_usage;
   gr->base.ops.destroy = destroy;

   mesa_logi("Using gralloc0 CrOS API");

   return &gr->base;

fail:
   destroy(&gr->base);

   return NULL;
}