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 1.5 2013/12/17 13:13:26 joerg Exp $"); 37 38 #include <sys/bus.h> 39 #include <sys/callout.h> 40 #include <sys/device.h> 41 #include <sys/intr.h> 42 #include <sys/rnd.h> 43 #include <sys/systm.h> 44 45 #include <arm/broadcom/bcm53xx_reg.h> 46 #include <arm/broadcom/bcm53xx_var.h> 47 48 static int bcmrng_ccb_match(device_t, cfdata_t, void *); 49 static void bcmrng_ccb_attach(device_t, device_t, void *); 50 51 struct bcmrng_softc { 52 device_t sc_dev; 53 bus_space_tag_t sc_bst; 54 bus_space_handle_t sc_bsh; 55 krndsource_t sc_rnd_source; 56 struct callout sc_rnd_callout; 57 kmutex_t *sc_lock; 58 #ifdef RNG_USE_INTR 59 size_t sc_intr_amount; 60 void *sc_ih; 61 #endif 62 }; 63 64 static void bcmrng_callout(void *arg); 65 static size_t bcmrng_empty(struct bcmrng_softc *); 66 #ifdef RNG_USE_INTR 67 static int bcmrng_intr(void *); 68 #endif 69 70 CFATTACH_DECL_NEW(bcmrng_ccb, sizeof(struct bcmrng_softc), 71 bcmrng_ccb_match, bcmrng_ccb_attach, NULL, NULL); 72 73 static int 74 bcmrng_ccb_match(device_t parent, cfdata_t cf, void *aux) 75 { 76 struct bcmccb_attach_args * const ccbaa = aux; 77 const struct bcm_locators * const loc = &ccbaa->ccbaa_loc; 78 79 if (strcmp(cf->cf_name, loc->loc_name)) 80 return 0; 81 82 KASSERT(cf->cf_loc[BCMCCBCF_PORT] == BCMCCBCF_PORT_DEFAULT); 83 84 return 1; 85 } 86 87 static inline uint32_t 88 bcmrng_read_4(struct bcmrng_softc *sc, bus_size_t o) 89 { 90 return bus_space_read_4(sc->sc_bst, sc->sc_bsh, o); 91 } 92 93 static inline void 94 bcmrng_read_multi_4(struct bcmrng_softc *sc, bus_size_t o, uint32_t *p, 95 size_t c) 96 { 97 return bus_space_read_multi_4(sc->sc_bst, sc->sc_bsh, o, p, c); 98 } 99 100 __unused static inline void 101 bcmrng_write_4(struct bcmrng_softc *sc, bus_size_t o, uint32_t v) 102 { 103 bus_space_write_4(sc->sc_bst, sc->sc_bsh, o, v); 104 } 105 106 /* 107 * To be called from initarm for an early start. 108 */ 109 void 110 bcm53xx_rng_start(bus_space_tag_t bst, bus_space_handle_t bsh) 111 { 112 /* 113 * Disable the interrupt and enable the RNG. 114 */ 115 bus_space_write_4(bst, bsh, CCB_BASE + RNG_BASE + RNG_INT_MASK, RNG_INT_OFF); 116 bus_space_write_4(bst, bsh, CCB_BASE + RNG_BASE + RNG_CTRL, 117 bus_space_read_4(bst, bsh, CCB_BASE + RNG_BASE + RNG_CTRL) | RNG_RBGEN); 118 } 119 120 static void 121 bcmrng_ccb_attach(device_t parent, device_t self, void *aux) 122 { 123 struct bcmrng_softc * const sc = device_private(self); 124 struct bcmccb_attach_args * const ccbaa = aux; 125 const struct bcm_locators * const loc = &ccbaa->ccbaa_loc; 126 127 sc->sc_dev = self; 128 129 /* make sure it's running */ 130 bcm53xx_rng_start(ccbaa->ccbaa_ccb_bst, ccbaa->ccbaa_ccb_bsh); 131 132 sc->sc_bst = ccbaa->ccbaa_ccb_bst; 133 bus_space_subregion(sc->sc_bst, ccbaa->ccbaa_ccb_bsh, 134 loc->loc_offset, loc->loc_size, &sc->sc_bsh); 135 136 aprint_naive("\n"); 137 aprint_normal(": Random Number Generator (%u bit FIFO)\n", 138 32 * bcmrng_read_4(sc, RNG_FF_THRESHOLD)); 139 140 sc->sc_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SOFTCLOCK); 141 142 callout_init(&sc->sc_rnd_callout, CALLOUT_MPSAFE); 143 144 rnd_attach_source(&sc->sc_rnd_source, device_xname(self), RND_TYPE_RNG, 145 RND_FLAG_NO_ESTIMATE); 146 147 #ifdef RNG_USE_INTR 148 sc->sc_ih = intr_establish(loc->loc_intrs[0], IPL_VM, IST_LEVEL, 149 bcmrng_intr, sc); 150 if (sc->sc_ih == NULL) { 151 aprint_error_dev(self, "failed to establish interrupt %d\n", 152 loc->loc_intrs[0]); 153 } else { 154 aprint_normal_dev(self, "interrupting on irq %d\n", loc->loc_intrs[0]); 155 } 156 #else 157 bcmrng_callout(sc); 158 #endif 159 } 160 161 size_t 162 bcmrng_empty(struct bcmrng_softc *sc) 163 { 164 mutex_enter(sc->sc_lock); 165 size_t nwords = __SHIFTOUT(bcmrng_read_4(sc, RNG_STATUS), RNG_VAL); 166 if (nwords == 0) { 167 mutex_exit(sc->sc_lock); 168 return 0; 169 } 170 171 uint32_t data[nwords]; 172 173 bcmrng_read_multi_4(sc, RNG_DATA, data, nwords); 174 175 rnd_add_data(&sc->sc_rnd_source, data, sizeof(data), sizeof(data) * 8); 176 mutex_exit(sc->sc_lock); 177 //aprint_debug_dev(sc->sc_dev, "added %zu words\n", nwords); 178 return nwords; 179 } 180 181 void 182 bcmrng_callout(void *arg) 183 { 184 struct bcmrng_softc * const sc = arg; 185 186 bcmrng_empty(sc); 187 188 callout_reset(&sc->sc_rnd_callout, 1, bcmrng_callout, sc); 189 } 190 191 #ifdef RNG_USE_INTR 192 int 193 bcmrng_intr(void *arg) 194 { 195 struct bcmrng_softc * const sc = arg; 196 197 sc->sc_intr_amount += bcmrng_empty(sc); 198 if (sc->sc_intr_amount >= 0x10000) { 199 bcmrng_callout(sc); 200 bcmrng_write_4(sc, RNG_INT_MASK, RNG_INT_OFF); 201 } 202 return 1; 203 } 204 #endif 205