1 /* $OpenBSD: ccp.c,v 1.2 2018/04/28 15:44:59 jasper Exp $ */ 2 3 /* 4 * Copyright (c) 2018 David Gwynne <dlg@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/param.h> 20 #include <sys/systm.h> 21 #include <sys/buf.h> 22 #include <sys/device.h> 23 #include <sys/malloc.h> 24 #include <sys/kernel.h> 25 #include <sys/timeout.h> 26 27 #include <machine/bus.h> 28 29 #include <dev/rndvar.h> 30 31 #include <dev/ic/ccpvar.h> 32 33 #define CCP_REG_TRNG 0xc 34 35 static void ccp_rng(void *); 36 37 struct cfdriver ccp_cd = { 38 NULL, 39 "ccp", 40 DV_DULL 41 }; 42 43 void 44 ccp_attach(struct ccp_softc *sc) 45 { 46 timeout_set(&sc->sc_tick, ccp_rng, sc); 47 ccp_rng(sc); 48 49 printf("\n"); 50 } 51 52 static void 53 ccp_rng(void *arg) 54 { 55 struct ccp_softc *sc = arg; 56 uint32_t trng; 57 58 trng = bus_space_read_4(sc->sc_iot, sc->sc_ioh, CCP_REG_TRNG); 59 if (trng != 0) 60 enqueue_randomness(trng); 61 62 timeout_add_msec(&sc->sc_tick, 100); 63 } 64