1 /* $OpenBSD: rkrng.c,v 1.5 2023/04/14 01:11:32 dlg Exp $ */ 2 /* 3 * Copyright (c) 2020 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/ofw_clock.h> 28 #include <dev/ofw/fdt.h> 29 30 /* Registers */ 31 32 /* V1 */ 33 #define RNG_CTRL 0x0008 34 #define RNG_CTRL_START (1 << 8) 35 #define RNG_TRNG_CTRL 0x0200 36 #define RNG_TRNG_CTRL_OSC_ENABLE (1 << 16) 37 #define RNG_TRNG_CTRL_SAMPLE_PERIOD(x) (x) 38 #define RNG_DATA0 0x0204 39 40 /* True Random Number Generator (TRNG) */ 41 #define TRNG_RST_CTL 0x0004 42 #define TRNG_RST_CTL_SW_RNG_RESET (0x1U << 1) 43 #define TRNG_CTL 0x0400 44 #define TRNG_CTL_RNG_START (0x1U << 0) 45 #define TRNG_CTL_RNG_ENABLE (0x1U << 1) 46 #define TRNG_CTL_RING_SEL_MASK (0x3U << 2) 47 #define TRNG_CTL_RING_SEL_SLOWEST (0x0U << 2) 48 #define TRNG_CTL_RING_SEL_SLOW (0x1U << 2) 49 #define TRNG_CTL_RING_SEL_FAST (0x2U << 2) 50 #define TRNG_CTL_RING_SEL_FASTEST (0x3U << 2) 51 #define TRNG_CTL_RNG_LEN_MASK (0x3U << 4) 52 #define TRNG_CTL_RNG_LEN_64BIT (0x0U << 4) 53 #define TRNG_CTL_RNG_LEN_128BIT (0x1U << 4) 54 #define TRNG_CTL_RNG_LEN_192BIT (0x2U << 4) 55 #define TRNG_CTL_RNG_LEN_256BIT (0x3U << 4) 56 #define TRNG_SAMPLE_CNT 0x0404 57 #define TRNG_DOUT_BASE 0x0410 58 59 #define HREAD4(sc, reg) \ 60 (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg))) 61 #define HWRITE4(sc, reg, val) \ 62 bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val)) 63 64 struct rkrng_v; 65 66 struct rkrng_softc { 67 struct device sc_dev; 68 const struct rkrng_v *sc_v; 69 bus_space_tag_t sc_iot; 70 bus_space_handle_t sc_ioh; 71 72 struct timeout sc_to; 73 int sc_started; 74 }; 75 76 struct rkrng_v { 77 unsigned int version; 78 void (*start)(struct rkrng_softc *sc); 79 int (*starting)(struct rkrng_softc *sc); 80 void (*stop)(struct rkrng_softc *sc); 81 bus_size_t dout; 82 }; 83 84 int rkrng_match(struct device *, void *, void *); 85 void rkrng_attach(struct device *, struct device *, void *); 86 87 const struct cfattach rkrng_ca = { 88 sizeof (struct rkrng_softc), rkrng_match, rkrng_attach 89 }; 90 91 struct cfdriver rkrng_cd = { 92 NULL, "rkrng", DV_DULL 93 }; 94 95 void rkrng_rnd(void *); 96 97 void rkrng_v1_start(struct rkrng_softc *); 98 int rkrng_v1_starting(struct rkrng_softc *); 99 void rkrng_v1_stop(struct rkrng_softc *); 100 101 static const struct rkrng_v rkrnv_v1 = { 102 .version = 1, 103 .start = rkrng_v1_start, 104 .starting = rkrng_v1_starting, 105 .stop = rkrng_v1_stop, 106 .dout = RNG_DATA0, 107 }; 108 109 void rkrng_v2_start(struct rkrng_softc *); 110 int rkrng_v2_starting(struct rkrng_softc *); 111 void rkrng_v2_stop(struct rkrng_softc *); 112 113 static const struct rkrng_v rkrnv_v2 = { 114 .version = 2, 115 .start = rkrng_v2_start, 116 .starting = rkrng_v2_starting, 117 .stop = rkrng_v2_stop, 118 .dout = TRNG_DOUT_BASE, 119 }; 120 121 int 122 rkrng_match(struct device *parent, void *match, void *aux) 123 { 124 struct fdt_attach_args *faa = aux; 125 126 return OF_is_compatible(faa->fa_node, "rockchip,cryptov1-rng") || 127 OF_is_compatible(faa->fa_node, "rockchip,cryptov2-rng"); 128 } 129 130 void 131 rkrng_attach(struct device *parent, struct device *self, void *aux) 132 { 133 struct rkrng_softc *sc = (struct rkrng_softc *)self; 134 struct fdt_attach_args *faa = aux; 135 136 if (OF_is_compatible(faa->fa_node, "rockchip,cryptov1-rng")) 137 sc->sc_v = &rkrnv_v1; 138 else if (OF_is_compatible(faa->fa_node, "rockchip,cryptov2-rng")) 139 sc->sc_v = &rkrnv_v2; 140 else { 141 printf(": unhandled version\n"); 142 return; 143 } 144 145 if (faa->fa_nreg < 1) { 146 printf(": no registers\n"); 147 return; 148 } 149 150 sc->sc_iot = faa->fa_iot; 151 if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr, 152 faa->fa_reg[0].size, 0, &sc->sc_ioh)) { 153 printf(": can't map registers\n"); 154 return; 155 } 156 157 printf(": ver %u\n", sc->sc_v->version); 158 159 clock_set_assigned(faa->fa_node); 160 clock_enable_all(faa->fa_node); 161 162 timeout_set(&sc->sc_to, rkrng_rnd, sc); 163 rkrng_rnd(sc); 164 } 165 166 void 167 rkrng_v1_start(struct rkrng_softc *sc) 168 { 169 HWRITE4(sc, RNG_TRNG_CTRL, RNG_TRNG_CTRL_OSC_ENABLE | 170 RNG_TRNG_CTRL_SAMPLE_PERIOD(100)); 171 HWRITE4(sc, RNG_CTRL, (RNG_CTRL_START << 16) | RNG_CTRL_START); 172 } 173 174 int 175 rkrng_v1_starting(struct rkrng_softc *sc) 176 { 177 return (HREAD4(sc, RNG_CTRL) & RNG_CTRL_START); 178 } 179 180 void 181 rkrng_v1_stop(struct rkrng_softc *sc) 182 { 183 HWRITE4(sc, RNG_CTRL, (RNG_CTRL_START << 16) | 0); 184 } 185 186 void 187 rkrng_v2_start(struct rkrng_softc *sc) 188 { 189 uint32_t ctl_m = TRNG_CTL_RNG_START | TRNG_CTL_RNG_ENABLE | 190 TRNG_CTL_RING_SEL_MASK | TRNG_CTL_RNG_LEN_MASK; 191 uint32_t ctl_v = TRNG_CTL_RNG_START | TRNG_CTL_RNG_ENABLE | 192 TRNG_CTL_RING_SEL_SLOW | TRNG_CTL_RNG_LEN_256BIT; 193 194 HWRITE4(sc, TRNG_SAMPLE_CNT, 100); 195 HWRITE4(sc, TRNG_CTL, (ctl_m << 16) | ctl_v); 196 } 197 198 int 199 rkrng_v2_starting(struct rkrng_softc *sc) 200 { 201 return (HREAD4(sc, TRNG_CTL) & TRNG_CTL_RNG_START); 202 } 203 204 void 205 rkrng_v2_stop(struct rkrng_softc *sc) 206 { 207 uint32_t ctl_m = TRNG_CTL_RNG_START | TRNG_CTL_RNG_ENABLE; 208 209 HWRITE4(sc, TRNG_CTL, (ctl_m << 16) | 0); 210 } 211 212 void 213 rkrng_rnd(void *arg) 214 { 215 struct rkrng_softc *sc = arg; 216 bus_size_t off; 217 218 if (!sc->sc_started) { 219 sc->sc_v->start(sc); 220 sc->sc_started = 1; 221 timeout_add_usec(&sc->sc_to, 100); 222 return; 223 } 224 225 if (sc->sc_v->starting(sc)) { 226 timeout_add_usec(&sc->sc_to, 100); 227 return; 228 } 229 230 for (off = 0; off < 32; off += 4) 231 enqueue_randomness(HREAD4(sc, sc->sc_v->dout + off)); 232 233 sc->sc_v->stop(sc); 234 sc->sc_started = 0; 235 236 timeout_add_sec(&sc->sc_to, 1); 237 } 238