Quelle  lsdc_output_7a1000.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2023 Loongson Technology Corporation Limited
 */

#include <drm/drm_atomic_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_probe_helper.h>

#include "lsdc_drv.h"
#include "lsdc_output.h"

/*
 * The display controller in the LS7A1000 exports two DVO interfaces, thus
 * external encoder is required, except connected to the DPI panel directly.
 *
 *       ___________________                                     _________
 *      |            -------|                                   |         |
 *      |  CRTC0 --> | DVO0 ----> Encoder0 ---> Connector0 ---> | Display |
 *      |  _   _     -------|        ^             ^            |_________|
 *      | | | | |  +------+ |        |             |
 *      | |_| |_|  | i2c6 | <--------+-------------+
 *      |          +------+ |
 *      |                   |
 *      |  DC in LS7A1000   |
 *      |                   |
 *      |  _   _   +------+ |
 *      | | | | |  | i2c7 | <--------+-------------+
 *      | |_| |_|  +------+ |        |             |             _________
 *      |            -------|        |             |            |         |
 *      |  CRTC1 --> | DVO1 ----> Encoder1 ---> Connector1 ---> |  Panel  |
 *      |            -------|                                   |_________|
 *      |___________________|
 *
 * Currently, we assume the external encoders connected to the DVO are
 * transparent. Loongson's DVO interface can directly drive RGB888 panels.
 *
 *  TODO: Add support for non-transparent encoders
 */

static int ls7a1000_dpi_connector_get_modes(struct drm_connector *conn)
{
 int num;

 if (conn->ddc) {
  const struct drm_edid *drm_edid;

  drm_edid = drm_edid_read(conn);
  drm_edid_connector_update(conn, drm_edid);
  num = drm_edid_connector_add_modes(conn);
  drm_edid_free(drm_edid);

  return num;
 }

 num = drm_add_modes_noedid(conn, 1920, 1200);

 drm_set_preferred_mode(conn, 1024, 768);

 return num;
}

static struct drm_encoder *
ls7a1000_dpi_connector_get_best_encoder(struct drm_connector *connector,
     struct drm_atomic_state *state)
{
 struct lsdc_output *output = connector_to_lsdc_output(connector);

 return &output->encoder;
}

static const struct drm_connector_helper_funcs
ls7a1000_dpi_connector_helpers = {
 .atomic_best_encoder = ls7a1000_dpi_connector_get_best_encoder,
 .get_modes = ls7a1000_dpi_connector_get_modes,
};

static enum drm_connector_status
ls7a1000_dpi_connector_detect(struct drm_connector *connector, bool force)
{
 struct i2c_adapter *ddc = connector->ddc;

 if (ddc) {
  if (drm_probe_ddc(ddc))
   return connector_status_connected;

  return connector_status_disconnected;
 }

 return connector_status_unknown;
}

static const struct drm_connector_funcs ls7a1000_dpi_connector_funcs = {
 .detect = ls7a1000_dpi_connector_detect,
 .fill_modes = drm_helper_probe_single_connector_modes,
 .destroy = drm_connector_cleanup,
 .reset = drm_atomic_helper_connector_reset,
 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state
};

static void ls7a1000_pipe0_encoder_reset(struct drm_encoder *encoder)
{
 struct drm_device *ddev = encoder->dev;
 struct lsdc_device *ldev = to_lsdc(ddev);

 /*
 * We need this for S3 support, screen will not lightup if don't set
 * this register correctly.
 */
 lsdc_wreg32(ldev, LSDC_CRTC0_DVO_CONF_REG,
      PHY_CLOCK_POL | PHY_CLOCK_EN | PHY_DATA_EN);
}

static void ls7a1000_pipe1_encoder_reset(struct drm_encoder *encoder)
{
 struct drm_device *ddev = encoder->dev;
 struct lsdc_device *ldev = to_lsdc(ddev);

 /*
 * We need this for S3 support, screen will not lightup if don't set
 * this register correctly.
 */

 /* DVO */
 lsdc_wreg32(ldev, LSDC_CRTC1_DVO_CONF_REG,
      BIT(31) | PHY_CLOCK_POL | PHY_CLOCK_EN | PHY_DATA_EN);
}

static const struct drm_encoder_funcs ls7a1000_encoder_funcs[2] = {
 {
  .reset = ls7a1000_pipe0_encoder_reset,
  .destroy = drm_encoder_cleanup,
 },
 {
  .reset = ls7a1000_pipe1_encoder_reset,
  .destroy = drm_encoder_cleanup,
 },
};

int ls7a1000_output_init(struct drm_device *ddev,
    struct lsdc_display_pipe *dispipe,
    struct i2c_adapter *ddc,
    unsigned int index)
{
 struct lsdc_output *output = &dispipe->output;
 struct drm_encoder *encoder = &output->encoder;
 struct drm_connector *connector = &output->connector;
 int ret;

 ret = drm_encoder_init(ddev, encoder, &ls7a1000_encoder_funcs[index],
          DRM_MODE_ENCODER_TMDS, "encoder-%u", index);
 if (ret)
  return ret;

 encoder->possible_crtcs = BIT(index);

 ret = drm_connector_init_with_ddc(ddev, connector,
       &ls7a1000_dpi_connector_funcs,
       DRM_MODE_CONNECTOR_DPI, ddc);
 if (ret)
  return ret;

 drm_info(ddev, "display pipe-%u has a DVO\n", index);

 drm_connector_helper_add(connector, &ls7a1000_dpi_connector_helpers);

 drm_connector_attach_encoder(connector, encoder);

 connector->polled = DRM_CONNECTOR_POLL_CONNECT |
       DRM_CONNECTOR_POLL_DISCONNECT;

 connector->interlace_allowed = 0;
 connector->doublescan_allowed = 0;

 return 0;
}