1 /*- 2 * Copyright (c) 2012 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to The NetBSD Foundation 6 * by Matt Thomas of 3am Software Foundry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #define RNG_PRIVATE 31 32 #include "locators.h" 33 34 #include <sys/cdefs.h> 35 36 __KERNEL_RCSID(1, "$NetBSD: bcm53xx_rng.c,v 1.10 2017/01/08 05:05:27 christos Exp $"); 37 38 #include <sys/param.h> 39 #include <sys/bus.h> 40 #include <sys/callout.h> 41 #include <sys/device.h> 42 #include <sys/intr.h> 43 #include <sys/rndsource.h> 44 #include <sys/systm.h> 45 46 #include <arm/broadcom/bcm53xx_reg.h> 47 #include <arm/broadcom/bcm53xx_var.h> 48 49 static int bcmrng_ccb_match(device_t, cfdata_t, void *); 50 static void bcmrng_ccb_attach(device_t, device_t, void *); 51 52 struct bcmrng_softc { 53 device_t sc_dev; 54 bus_space_tag_t sc_bst; 55 bus_space_handle_t sc_bsh; 56 krndsource_t sc_rnd_source; 57 struct callout sc_rnd_callout; 58 kmutex_t *sc_lock; 59 #ifdef RNG_USE_INTR 60 size_t sc_intr_amount; 61 void *sc_ih; 62 #endif 63 }; 64 65 static void bcmrng_callout(void *arg); 66 static size_t bcmrng_empty(struct bcmrng_softc *); 67 #ifdef RNG_USE_INTR 68 static int bcmrng_intr(void *); 69 #endif 70 71 CFATTACH_DECL_NEW(bcmrng_ccb, sizeof(struct bcmrng_softc), 72 bcmrng_ccb_match, bcmrng_ccb_attach, NULL, NULL); 73 74 static int 75 bcmrng_ccb_match(device_t parent, cfdata_t cf, void *aux) 76 { 77 struct bcmccb_attach_args * const ccbaa = aux; 78 const struct bcm_locators * const loc = &ccbaa->ccbaa_loc; 79 80 if (strcmp(cf->cf_name, loc->loc_name)) 81 return 0; 82 83 KASSERT(cf->cf_loc[BCMCCBCF_PORT] == BCMCCBCF_PORT_DEFAULT); 84 85 return 1; 86 } 87 88 static inline uint32_t 89 bcmrng_read_4(struct bcmrng_softc *sc, bus_size_t o) 90 { 91 return bus_space_read_4(sc->sc_bst, sc->sc_bsh, o); 92 } 93 94 static inline void 95 bcmrng_read_multi_4(struct bcmrng_softc *sc, bus_size_t o, uint32_t *p, 96 size_t c) 97 { 98 return bus_space_read_multi_4(sc->sc_bst, sc->sc_bsh, o, p, c); 99 } 100 101 __unused static inline void 102 bcmrng_write_4(struct bcmrng_softc *sc, bus_size_t o, uint32_t v) 103 { 104 bus_space_write_4(sc->sc_bst, sc->sc_bsh, o, v); 105 } 106 107 /* 108 * To be called from initarm for an early start. 109 */ 110 void 111 bcm53xx_rng_start(bus_space_tag_t bst, bus_space_handle_t bsh) 112 { 113 /* 114 * Disable the interrupt and enable the RNG. 115 */ 116 bus_space_write_4(bst, bsh, CCB_BASE + RNG_BASE + RNG_INT_MASK, RNG_INT_OFF); 117 bus_space_write_4(bst, bsh, CCB_BASE + RNG_BASE + RNG_CTRL, 118 bus_space_read_4(bst, bsh, CCB_BASE + RNG_BASE + RNG_CTRL) | RNG_RBGEN); 119 } 120 121 static void 122 bcmrng_ccb_attach(device_t parent, device_t self, void *aux) 123 { 124 struct bcmrng_softc * const sc = device_private(self); 125 struct bcmccb_attach_args * const ccbaa = aux; 126 const struct bcm_locators * const loc = &ccbaa->ccbaa_loc; 127 128 sc->sc_dev = self; 129 130 /* make sure it's running */ 131 bcm53xx_rng_start(ccbaa->ccbaa_ccb_bst, ccbaa->ccbaa_ccb_bsh); 132 133 sc->sc_bst = ccbaa->ccbaa_ccb_bst; 134 bus_space_subregion(sc->sc_bst, ccbaa->ccbaa_ccb_bsh, 135 loc->loc_offset, loc->loc_size, &sc->sc_bsh); 136 137 aprint_naive("\n"); 138 aprint_normal(": Random Number Generator (%u bit FIFO)\n", 139 32 * bcmrng_read_4(sc, RNG_FF_THRESHOLD)); 140 141 sc->sc_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SOFTCLOCK); 142 143 callout_init(&sc->sc_rnd_callout, CALLOUT_MPSAFE); 144 145 rnd_attach_source(&sc->sc_rnd_source, device_xname(self), RND_TYPE_RNG, 146 RND_FLAG_COLLECT_VALUE); 147 148 #ifdef RNG_USE_INTR 149 sc->sc_ih = intr_establish(loc->loc_intrs[0], IPL_VM, IST_LEVEL, 150 bcmrng_intr, sc); 151 if (sc->sc_ih == NULL) { 152 aprint_error_dev(self, "failed to establish interrupt %d\n", 153 loc->loc_intrs[0]); 154 } else { 155 aprint_normal_dev(self, "interrupting on irq %d\n", loc->loc_intrs[0]); 156 } 157 #else 158 bcmrng_callout(sc); 159 #endif 160 } 161 162 size_t 163 bcmrng_empty(struct bcmrng_softc *sc) 164 { 165 mutex_enter(sc->sc_lock); 166 uint32_t data[128]; 167 size_t nwords = __SHIFTOUT(bcmrng_read_4(sc, RNG_STATUS), RNG_VAL); 168 if (nwords == 0) { 169 mutex_exit(sc->sc_lock); 170 return 0; 171 } 172 if (nwords > __arraycount(data)) 173 nwords = __arraycount(data); 174 175 bcmrng_read_multi_4(sc, RNG_DATA, data, nwords); 176 177 rnd_add_data(&sc->sc_rnd_source, data, sizeof(data), sizeof(data) * 8); 178 mutex_exit(sc->sc_lock); 179 //aprint_debug_dev(sc->sc_dev, "added %zu words\n", nwords); 180 return nwords; 181 } 182 183 void 184 bcmrng_callout(void *arg) 185 { 186 struct bcmrng_softc * const sc = arg; 187 188 bcmrng_empty(sc); 189 190 callout_reset(&sc->sc_rnd_callout, 1, bcmrng_callout, sc); 191 } 192 193 #ifdef RNG_USE_INTR 194 int 195 bcmrng_intr(void *arg) 196 { 197 struct bcmrng_softc * const sc = arg; 198 199 sc->sc_intr_amount += bcmrng_empty(sc); 200 if (sc->sc_intr_amount >= 0x10000) { 201 bcmrng_callout(sc); 202 bcmrng_write_4(sc, RNG_INT_MASK, RNG_INT_OFF); 203 } 204 return 1; 205 } 206 #endif 207
Indexes created Sat Sep 20 22:09:52 GMT 2025