1/* $OpenBSD: qcrng.c,v 1.1 2023/04/28 05:13:37 phessler Exp $ */ 2/* 3 * Copyright (c) 2019 Mark Kettenis <kettenis@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18#include <sys/param.h> 19#include <sys/systm.h> 20#include <sys/device.h> 21#include <sys/timeout.h> 22 23#include <machine/bus.h> 24#include <machine/fdt.h> 25 26#include <dev/ofw/openfirm.h> 27#include <dev/ofw/fdt.h> 28 29/* Registers */ 30#define RNG_DATA 0x0000 31#define RNG_STATUS 0x0004 32 33#define HREAD4(sc, reg) \ 34 (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg))) 35 36struct qcrng_softc { 37 struct device sc_dev; 38 bus_space_tag_t sc_iot; 39 bus_space_handle_t sc_ioh; 40 41 struct timeout sc_to; 42}; 43 44int qcrng_match(struct device *, void *, void *); 45void qcrng_attach(struct device *, struct device *, void *); 46 47const struct cfattach qcrng_ca = { 48 sizeof (struct qcrng_softc), qcrng_match, qcrng_attach 49}; 50 51struct cfdriver qcrng_cd = { 52 NULL, "qcrng", DV_DULL 53}; 54 55void qcrng_rnd(void *); 56 57int 58qcrng_match(struct device *parent, void *match, void *aux) 59{ 60 struct fdt_attach_args *faa = aux; 61 62 return OF_is_compatible(faa->fa_node, "qcom,prng-ee"); 63} 64 65void 66qcrng_attach(struct device *parent, struct device *self, void *aux) 67{ 68 struct qcrng_softc *sc = (struct qcrng_softc *)self; 69 struct fdt_attach_args *faa = aux; 70 71 if (faa->fa_nreg < 1) { 72 printf(": no registers\n"); 73 return; 74 } 75 76 sc->sc_iot = faa->fa_iot; 77 if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr, 78 faa->fa_reg[0].size, 0, &sc->sc_ioh)) { 79 printf(": can't map registers\n"); 80 return; 81 } 82 83 printf("\n"); 84 85 timeout_set(&sc->sc_to, qcrng_rnd, sc); 86 qcrng_rnd(sc); 87} 88 89void 90qcrng_rnd(void *arg) 91{ 92 struct qcrng_softc *sc = arg; 93 94 if (HREAD4(sc, RNG_STATUS) & 0x1) 95 enqueue_randomness(HREAD4(sc, RNG_DATA)); 96 97 timeout_add_sec(&sc->sc_to, 1); 98} 99