// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2011 Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
 */
/*
 * generic EDID driver
 */

#include <linux/slab.h>
#include <linux/fb.h>
#include "via_aux.h"
#include "../edid.h"


static const char *name = "EDID";


static void query_edid(struct via_aux_drv *drv)
{
        struct fb_monspecs *spec = drv->data;
        unsigned char edid[EDID_LENGTH];
        bool valid = false;

        if (spec) {
                fb_destroy_modedb(spec->modedb);
        } else {
                spec = kmalloc_obj(*spec);
                if (!spec)
                        return;
        }

        spec->version = spec->revision = 0;
        if (via_aux_read(drv, 0x00, edid, EDID_LENGTH)) {
                fb_edid_to_monspecs(edid, spec);
                valid = spec->version || spec->revision;
        }

        if (!valid) {
                kfree(spec);
                spec = NULL;
        } else
                printk(KERN_DEBUG "EDID: %s %s\n", spec->manufacturer, spec->monitor);

        drv->data = spec;
}

static const struct fb_videomode *get_preferred_mode(struct via_aux_drv *drv)
{
        struct fb_monspecs *spec = drv->data;
        int i;

        if (!spec || !spec->modedb || !(spec->misc & FB_MISC_1ST_DETAIL))
                return NULL;

        for (i = 0; i < spec->modedb_len; i++) {
                if (spec->modedb[i].flag & FB_MODE_IS_FIRST &&
                        spec->modedb[i].flag & FB_MODE_IS_DETAILED)
                        return &spec->modedb[i];
        }

        return NULL;
}

static void cleanup(struct via_aux_drv *drv)
{
        struct fb_monspecs *spec = drv->data;

        if (spec)
                fb_destroy_modedb(spec->modedb);
}

void via_aux_edid_probe(struct via_aux_bus *bus)
{
        struct via_aux_drv drv = {
                .bus    =       bus,
                .addr   =       0x50,
                .name   =       name,
                .cleanup        =       cleanup,
                .get_preferred_mode     =       get_preferred_mode};

        query_edid(&drv);

        /* as EDID devices can be connected/disconnected just add the driver */
        via_aux_add(&drv);
}