// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
 */

#include <linux/export.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_bridge_connector.h>
#include <drm/drm_crtc.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_panel.h>
#include <drm/drm_of.h>
#include <drm/drm_simple_kms_helper.h>

#include "tidss_crtc.h"
#include "tidss_drv.h"
#include "tidss_encoder.h"

struct tidss_encoder {
 struct drm_bridge bridge;
 struct drm_encoder encoder;
 struct drm_connector *connector;
 struct drm_bridge *next_bridge;
 struct tidss_device *tidss;
};

static inline struct tidss_encoder
*bridge_to_tidss_encoder(struct drm_bridge *b)
{
 return container_of(b, struct tidss_encoder, bridge);
}

static int tidss_bridge_attach(struct drm_bridge *bridge,
          struct drm_encoder *encoder,
          enum drm_bridge_attach_flags flags)
{
 struct tidss_encoder *t_enc = bridge_to_tidss_encoder(bridge);

 return drm_bridge_attach(encoder, t_enc->next_bridge,
     bridge, flags);
}

static int tidss_bridge_atomic_check(struct drm_bridge *bridge,
         struct drm_bridge_state *bridge_state,
         struct drm_crtc_state *crtc_state,
         struct drm_connector_state *conn_state)
{
 struct tidss_encoder *t_enc = bridge_to_tidss_encoder(bridge);
 struct tidss_device *tidss = t_enc->tidss;
 struct tidss_crtc_state *tcrtc_state = to_tidss_crtc_state(crtc_state);
 struct drm_display_info *di = &conn_state->connector->display_info;
 struct drm_bridge_state *next_bridge_state = NULL;

 if (t_enc->next_bridge)
  next_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
            t_enc->next_bridge);

 if (next_bridge_state) {
  tcrtc_state->bus_flags = next_bridge_state->input_bus_cfg.flags;
  tcrtc_state->bus_format = next_bridge_state->input_bus_cfg.format;
 } else if (di->num_bus_formats) {
  tcrtc_state->bus_format = di->bus_formats[0];
  tcrtc_state->bus_flags = di->bus_flags;
 } else {
  dev_err(tidss->dev, "%s: No bus_formats in connected display\n",
   __func__);
  return -EINVAL;
 }

 return 0;
}

static const struct drm_bridge_funcs tidss_bridge_funcs = {
 .attach    = tidss_bridge_attach,
 .atomic_check   = tidss_bridge_atomic_check,
 .atomic_reset   = drm_atomic_helper_bridge_reset,
 .atomic_duplicate_state  = drm_atomic_helper_bridge_duplicate_state,
 .atomic_destroy_state  = drm_atomic_helper_bridge_destroy_state,
};

int tidss_encoder_create(struct tidss_device *tidss,
    struct drm_bridge *next_bridge,
    u32 encoder_type, u32 possible_crtcs)
{
 struct tidss_encoder *t_enc;
 struct drm_encoder *enc;
 struct drm_connector *connector;
 int ret;

 t_enc = devm_drm_bridge_alloc(tidss->dev, struct tidss_encoder,
          bridge, &tidss_bridge_funcs);
 if (IS_ERR(t_enc))
  return PTR_ERR(t_enc);

 ret = drm_simple_encoder_init(&tidss->ddev, &t_enc->encoder,
          encoder_type);
 if (ret)
  return ret;

 t_enc->tidss = tidss;
 t_enc->next_bridge = next_bridge;

 enc = &t_enc->encoder;
 enc->possible_crtcs = possible_crtcs;

 /* Attaching first bridge to the encoder */
 ret = drm_bridge_attach(enc, &t_enc->bridge, NULL,
    DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 if (ret) {
  dev_err(tidss->dev, "bridge attach failed: %d\n", ret);
  return ret;
 }

 /* Initializing the connector at the end of bridge-chain */
 connector = drm_bridge_connector_init(&tidss->ddev, enc);
 if (IS_ERR(connector)) {
  dev_err(tidss->dev, "bridge_connector create failed\n");
  return PTR_ERR(connector);
 }

 ret = drm_connector_attach_encoder(connector, enc);
 if (ret) {
  dev_err(tidss->dev, "attaching encoder to connector failed\n");
  return ret;
 }

 t_enc->connector = connector;

 dev_dbg(tidss->dev, "Encoder create done\n");

 return ret;
}