1 /* $OpenBSD: amlrng.c,v 1.3 2021/10/24 17:52:26 mpi 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 32 #define HREAD4(sc, reg) \ 33 (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg))) 34 35 struct amlrng_softc { 36 struct device sc_dev; 37 bus_space_tag_t sc_iot; 38 bus_space_handle_t sc_ioh; 39 40 struct timeout sc_to; 41 }; 42 43 int amlrng_match(struct device *, void *, void *); 44 void amlrng_attach(struct device *, struct device *, void *); 45 46 const struct cfattach amlrng_ca = { 47 sizeof (struct amlrng_softc), amlrng_match, amlrng_attach 48 }; 49 50 struct cfdriver amlrng_cd = { 51 NULL, "amlrng", DV_DULL 52 }; 53 54 void amlrng_rnd(void *); 55 56 int 57 amlrng_match(struct device *parent, void *match, void *aux) 58 { 59 struct fdt_attach_args *faa = aux; 60 61 return OF_is_compatible(faa->fa_node, "amlogic,meson-rng"); 62 } 63 64 void 65 amlrng_attach(struct device *parent, struct device *self, void *aux) 66 { 67 struct amlrng_softc *sc = (struct amlrng_softc *)self; 68 struct fdt_attach_args *faa = aux; 69 70 if (faa->fa_nreg < 1) { 71 printf(": no registers\n"); 72 return; 73 } 74 75 sc->sc_iot = faa->fa_iot; 76 if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr, 77 faa->fa_reg[0].size, 0, &sc->sc_ioh)) { 78 printf(": can't map registers\n"); 79 return; 80 } 81 82 printf("\n"); 83 84 timeout_set(&sc->sc_to, amlrng_rnd, sc); 85 amlrng_rnd(sc); 86 } 87 88 void 89 amlrng_rnd(void *arg) 90 { 91 struct amlrng_softc *sc = arg; 92 93 enqueue_randomness(HREAD4(sc, RNG_DATA)); 94 timeout_add_sec(&sc->sc_to, 1); 95 } 96