root/drivers/gpu/drm/sun4i/sun4i_lvds.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2017 Free Electrons
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 */

#include <linux/clk.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>

#include "sun4i_crtc.h"
#include "sun4i_tcon.h"
#include "sun4i_lvds.h"

struct sun4i_lvds {
        struct drm_connector    connector;
        struct drm_encoder      encoder;

        struct drm_panel        *panel;
};

static inline struct sun4i_lvds *
drm_connector_to_sun4i_lvds(struct drm_connector *connector)
{
        return container_of(connector, struct sun4i_lvds,
                            connector);
}

static inline struct sun4i_lvds *
drm_encoder_to_sun4i_lvds(struct drm_encoder *encoder)
{
        return container_of(encoder, struct sun4i_lvds,
                            encoder);
}

static int sun4i_lvds_get_modes(struct drm_connector *connector)
{
        struct sun4i_lvds *lvds =
                drm_connector_to_sun4i_lvds(connector);

        return drm_panel_get_modes(lvds->panel, connector);
}

static const struct drm_connector_helper_funcs sun4i_lvds_con_helper_funcs = {
        .get_modes      = sun4i_lvds_get_modes,
};

static void
sun4i_lvds_connector_destroy(struct drm_connector *connector)
{
        drm_connector_cleanup(connector);
}

static const struct drm_connector_funcs sun4i_lvds_con_funcs = {
        .fill_modes             = drm_helper_probe_single_connector_modes,
        .destroy                = sun4i_lvds_connector_destroy,
        .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 sun4i_lvds_encoder_enable(struct drm_encoder *encoder)
{
        struct sun4i_lvds *lvds = drm_encoder_to_sun4i_lvds(encoder);

        DRM_DEBUG_DRIVER("Enabling LVDS output\n");

        if (lvds->panel) {
                drm_panel_prepare(lvds->panel);
                drm_panel_enable(lvds->panel);
        }
}

static void sun4i_lvds_encoder_disable(struct drm_encoder *encoder)
{
        struct sun4i_lvds *lvds = drm_encoder_to_sun4i_lvds(encoder);

        DRM_DEBUG_DRIVER("Disabling LVDS output\n");

        if (lvds->panel) {
                drm_panel_disable(lvds->panel);
                drm_panel_unprepare(lvds->panel);
        }
}

static const struct drm_encoder_helper_funcs sun4i_lvds_enc_helper_funcs = {
        .disable        = sun4i_lvds_encoder_disable,
        .enable         = sun4i_lvds_encoder_enable,
};

int sun4i_lvds_init(struct drm_device *drm, struct sun4i_tcon *tcon)
{
        struct drm_encoder *encoder;
        struct drm_bridge *bridge;
        struct sun4i_lvds *lvds;
        int ret;

        lvds = devm_kzalloc(drm->dev, sizeof(*lvds), GFP_KERNEL);
        if (!lvds)
                return -ENOMEM;
        encoder = &lvds->encoder;

        ret = drm_of_find_panel_or_bridge(tcon->dev->of_node, 1, 0,
                                          &lvds->panel, &bridge);
        if (ret) {
                dev_info(drm->dev, "No panel or bridge found... LVDS output disabled\n");
                return 0;
        }

        drm_encoder_helper_add(&lvds->encoder,
                               &sun4i_lvds_enc_helper_funcs);
        ret = drm_simple_encoder_init(drm, &lvds->encoder,
                                      DRM_MODE_ENCODER_LVDS);
        if (ret) {
                dev_err(drm->dev, "Couldn't initialise the lvds encoder\n");
                goto err_out;
        }

        /* The LVDS encoder can only work with the TCON channel 0 */
        lvds->encoder.possible_crtcs = drm_crtc_mask(&tcon->crtc->crtc);

        if (lvds->panel) {
                drm_connector_helper_add(&lvds->connector,
                                         &sun4i_lvds_con_helper_funcs);
                ret = drm_connector_init(drm, &lvds->connector,
                                         &sun4i_lvds_con_funcs,
                                         DRM_MODE_CONNECTOR_LVDS);
                if (ret) {
                        dev_err(drm->dev, "Couldn't initialise the lvds connector\n");
                        goto err_cleanup_connector;
                }

                drm_connector_attach_encoder(&lvds->connector,
                                                  &lvds->encoder);
        }

        if (bridge) {
                ret = drm_bridge_attach(encoder, bridge, NULL, 0);
                if (ret)
                        goto err_cleanup_connector;
        }

        return 0;

err_cleanup_connector:
        drm_encoder_cleanup(&lvds->encoder);
err_out:
        return ret;
}
EXPORT_SYMBOL(sun4i_lvds_init);