linux/drivers/video/fbdev/via/via_aux_edid.c

86 lines
1.7 KiB
C

// 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(sizeof(*spec), GFP_KERNEL);
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);
}