You can override the widget used in any admin form with formfield_overrides.
ModelAdmin.formfield_overrides
This provides a quick-and-dirty way to override some of the Field options for use in the admin. formfield_overrides is a dictionary mapping a field class to a dict of arguments to pass to the field at construction time.
So in your case, you'd want to override the lovely open layers map with a plain old text field. The following would replace the maps with a text input for any PointField in the GeoModel model.
from app.models import GeoModel
from django.forms.widgets import TextInput
from django.contrib.gis.db import models
from django.contrib import admin
class DirectAdmin(admin.ModelAdmin):
formfield_overrides = {
models.PointField: {'widget': TextInput }
}
admin.site.register(GeoModel, DirectAdmin)
You might find a Textarea makes reading the WKT a lot easier, so change the second import to:
from django.forms.widgets import Textarea
And use that in the override instead of the TextInput:
models.PointField: {'widget': Textarea }