/*	$OpenBSD: ccp.c,v 1.3 2020/05/29 04:42:25 deraadt Exp $ */

/*
 * Copyright (c) 2018 David Gwynne <dlg@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/timeout.h>

#include <machine/bus.h>

#include <dev/ic/ccpvar.h>

#define CCP_REG_TRNG		0xc

static void	ccp_rng(void *);

struct cfdriver ccp_cd = {
	NULL,
	"ccp",
	DV_DULL
};

void
ccp_attach(struct ccp_softc *sc)
{
	timeout_set(&sc->sc_tick, ccp_rng, sc);
	ccp_rng(sc);

	printf("\n");
}

static void
ccp_rng(void *arg)
{
	struct ccp_softc *sc = arg;
	uint32_t trng;

	trng = bus_space_read_4(sc->sc_iot, sc->sc_ioh, CCP_REG_TRNG);
	if (trng != 0)
		enqueue_randomness(trng);

	timeout_add_msec(&sc->sc_tick, 100);
}