root/drivers/gpu/drm/logicvc/logicvc_interface.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2019-2022 Bootlin
 * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
 */

#include <linux/types.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_connector.h>
#include <drm/drm_drv.h>
#include <drm/drm_encoder.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

#include "logicvc_crtc.h"
#include "logicvc_drm.h"
#include "logicvc_interface.h"
#include "logicvc_regs.h"

#define logicvc_interface_from_drm_encoder(c) \
        container_of(c, struct logicvc_interface, drm_encoder)
#define logicvc_interface_from_drm_connector(c) \
        container_of(c, struct logicvc_interface, drm_connector)

static void logicvc_encoder_enable(struct drm_encoder *drm_encoder)
{
        struct logicvc_drm *logicvc = logicvc_drm(drm_encoder->dev);
        struct logicvc_interface *interface =
                logicvc_interface_from_drm_encoder(drm_encoder);

        regmap_update_bits(logicvc->regmap, LOGICVC_POWER_CTRL_REG,
                           LOGICVC_POWER_CTRL_VIDEO_ENABLE,
                           LOGICVC_POWER_CTRL_VIDEO_ENABLE);

        if (interface->drm_panel) {
                drm_panel_prepare(interface->drm_panel);
                drm_panel_enable(interface->drm_panel);
        }
}

static void logicvc_encoder_disable(struct drm_encoder *drm_encoder)
{
        struct logicvc_interface *interface =
                logicvc_interface_from_drm_encoder(drm_encoder);

        if (interface->drm_panel) {
                drm_panel_disable(interface->drm_panel);
                drm_panel_unprepare(interface->drm_panel);
        }
}

static const struct drm_encoder_helper_funcs logicvc_encoder_helper_funcs = {
        .enable                 = logicvc_encoder_enable,
        .disable                = logicvc_encoder_disable,
};

static const struct drm_encoder_funcs logicvc_encoder_funcs = {
        .destroy                = drm_encoder_cleanup,
};

static int logicvc_connector_get_modes(struct drm_connector *drm_connector)
{
        struct logicvc_interface *interface =
                logicvc_interface_from_drm_connector(drm_connector);

        if (interface->drm_panel)
                return drm_panel_get_modes(interface->drm_panel, drm_connector);

        WARN_ONCE(1, "Retrieving modes from a native connector is not implemented.");

        return 0;
}

static const struct drm_connector_helper_funcs logicvc_connector_helper_funcs = {
        .get_modes              = logicvc_connector_get_modes,
};

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

static int logicvc_interface_encoder_type(struct logicvc_drm *logicvc)
{
        switch (logicvc->config.display_interface) {
        case LOGICVC_DISPLAY_INTERFACE_LVDS_4BITS:
        case LOGICVC_DISPLAY_INTERFACE_LVDS_4BITS_CAMERA:
        case LOGICVC_DISPLAY_INTERFACE_LVDS_3BITS:
                return DRM_MODE_ENCODER_LVDS;
        case LOGICVC_DISPLAY_INTERFACE_DVI:
                return DRM_MODE_ENCODER_TMDS;
        case LOGICVC_DISPLAY_INTERFACE_RGB:
                return DRM_MODE_ENCODER_DPI;
        default:
                return DRM_MODE_ENCODER_NONE;
        }
}

static int logicvc_interface_connector_type(struct logicvc_drm *logicvc)
{
        switch (logicvc->config.display_interface) {
        case LOGICVC_DISPLAY_INTERFACE_LVDS_4BITS:
        case LOGICVC_DISPLAY_INTERFACE_LVDS_4BITS_CAMERA:
        case LOGICVC_DISPLAY_INTERFACE_LVDS_3BITS:
                return DRM_MODE_CONNECTOR_LVDS;
        case LOGICVC_DISPLAY_INTERFACE_DVI:
                return DRM_MODE_CONNECTOR_DVID;
        case LOGICVC_DISPLAY_INTERFACE_RGB:
                return DRM_MODE_CONNECTOR_DPI;
        default:
                return DRM_MODE_CONNECTOR_Unknown;
        }
}

static bool logicvc_interface_native_connector(struct logicvc_drm *logicvc)
{
        switch (logicvc->config.display_interface) {
        case LOGICVC_DISPLAY_INTERFACE_DVI:
                return true;
        default:
                return false;
        }
}

void logicvc_interface_attach_crtc(struct logicvc_drm *logicvc)
{
        uint32_t possible_crtcs = drm_crtc_mask(&logicvc->crtc->drm_crtc);

        logicvc->interface->drm_encoder.possible_crtcs = possible_crtcs;
}

int logicvc_interface_init(struct logicvc_drm *logicvc)
{
        struct logicvc_interface *interface;
        struct drm_device *drm_dev = &logicvc->drm_dev;
        struct device *dev = drm_dev->dev;
        struct device_node *of_node = dev->of_node;
        int encoder_type = logicvc_interface_encoder_type(logicvc);
        int connector_type = logicvc_interface_connector_type(logicvc);
        bool native_connector = logicvc_interface_native_connector(logicvc);
        int ret;

        interface = devm_kzalloc(dev, sizeof(*interface), GFP_KERNEL);
        if (!interface) {
                ret = -ENOMEM;
                goto error_early;
        }

        ret = drm_of_find_panel_or_bridge(of_node, 0, 0, &interface->drm_panel,
                                          &interface->drm_bridge);
        if (ret == -EPROBE_DEFER)
                goto error_early;

        ret = drm_encoder_init(drm_dev, &interface->drm_encoder,
                               &logicvc_encoder_funcs, encoder_type, NULL);
        if (ret) {
                drm_err(drm_dev, "Failed to initialize encoder\n");
                goto error_early;
        }

        drm_encoder_helper_add(&interface->drm_encoder,
                               &logicvc_encoder_helper_funcs);

        if (native_connector || interface->drm_panel) {
                ret = drm_connector_init(drm_dev, &interface->drm_connector,
                                         &logicvc_connector_funcs,
                                         connector_type);
                if (ret) {
                        drm_err(drm_dev, "Failed to initialize connector\n");
                        goto error_encoder;
                }

                drm_connector_helper_add(&interface->drm_connector,
                                         &logicvc_connector_helper_funcs);

                ret = drm_connector_attach_encoder(&interface->drm_connector,
                                                   &interface->drm_encoder);
                if (ret) {
                        drm_err(drm_dev,
                                "Failed to attach connector to encoder\n");
                        goto error_encoder;
                }
        }

        if (interface->drm_bridge) {
                ret = drm_bridge_attach(&interface->drm_encoder,
                                        interface->drm_bridge, NULL, 0);
                if (ret) {
                        drm_err(drm_dev,
                                "Failed to attach bridge to encoder\n");
                        goto error_encoder;
                }
        }

        logicvc->interface = interface;

        return 0;

error_encoder:
        drm_encoder_cleanup(&interface->drm_encoder);

error_early:
        return ret;
}