bcm2835_mbox.c revision 1.10
1/* $NetBSD: bcm2835_mbox.c,v 1.10 2015/07/29 10:47:58 skrll Exp $ */ 2 3/*- 4 * Copyright (c) 2012 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Nick Hudson 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33__KERNEL_RCSID(0, "$NetBSD: bcm2835_mbox.c,v 1.10 2015/07/29 10:47:58 skrll Exp $"); 34 35#include <sys/param.h> 36#include <sys/systm.h> 37#include <sys/device.h> 38#include <sys/kernel.h> 39#include <sys/timetc.h> 40#include <sys/bus.h> 41#include <sys/mutex.h> 42 43#include <arm/broadcom/bcm_amba.h> 44#include <arm/broadcom/bcm2835_mbox.h> 45#include <arm/broadcom/bcm2835_mboxreg.h> 46#include <arm/broadcom/bcm2835reg.h> 47 48struct bcm2835mbox_softc { 49 device_t sc_dev; 50 device_t sc_platdev; 51 52 bus_space_tag_t sc_iot; 53 bus_space_handle_t sc_ioh; 54 bus_dma_tag_t sc_dmat; 55 void *sc_intrh; 56 57 kmutex_t sc_lock; 58 kmutex_t sc_intr_lock; 59 kcondvar_t sc_chan[BCM2835_MBOX_NUMCHANNELS]; 60 uint32_t sc_mbox[BCM2835_MBOX_NUMCHANNELS]; 61}; 62 63static struct bcm2835mbox_softc *bcm2835mbox_sc; 64 65static int bcmmbox_match(device_t, cfdata_t, void *); 66static void bcmmbox_attach(device_t, device_t, void *); 67static int bcmmbox_intr1(struct bcm2835mbox_softc *, int); 68static int bcmmbox_intr(void *); 69 70CFATTACH_DECL_NEW(bcmmbox, sizeof(struct bcm2835mbox_softc), 71 bcmmbox_match, bcmmbox_attach, NULL, NULL); 72 73/* ARGSUSED */ 74static int 75bcmmbox_match(device_t parent, cfdata_t match, void *aux) 76{ 77 struct amba_attach_args *aaa = aux; 78 79 if (strcmp(aaa->aaa_name, "bcmmbox") != 0) 80 return 0; 81 82 return 1; 83} 84 85static void 86bcmmbox_attach(device_t parent, device_t self, void *aux) 87{ 88 struct bcm2835mbox_softc *sc = device_private(self); 89 struct amba_attach_args *aaa = aux; 90 struct bcmmbox_attach_args baa; 91 int i; 92 93 aprint_naive("\n"); 94 aprint_normal(": VC mailbox\n"); 95 96 sc->sc_dev = self; 97 sc->sc_iot = aaa->aaa_iot; 98 sc->sc_dmat = aaa->aaa_dmat; 99 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); 100 mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_VM); 101 for (i = 0; i < BCM2835_MBOX_NUMCHANNELS; ++i) 102 cv_init(&sc->sc_chan[i], "bcmmbox"); 103 104 if (bus_space_map(aaa->aaa_iot, aaa->aaa_addr, BCM2835_MBOX_SIZE, 0, 105 &sc->sc_ioh)) { 106 aprint_error_dev(sc->sc_dev, "unable to map device\n"); 107 return; 108 } 109 110 sc->sc_intrh = intr_establish(aaa->aaa_intr, IST_LEVEL, IPL_VM, 111 bcmmbox_intr, sc); 112 if (sc->sc_intrh == NULL) { 113 aprint_error_dev(sc->sc_dev, "unable to establish interrupt\n"); 114 return; 115 } 116 117 /* enable mbox interrupt */ 118 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_MBOX_CFG, 119 BCM2835_MBOX_CFG_DATAIRQEN); 120 121 if (bcm2835mbox_sc == NULL) 122 bcm2835mbox_sc = sc; 123 124 baa.baa_dmat = aaa->aaa_dmat; 125 sc->sc_platdev = config_found_ia(self, "bcmmboxbus", &baa, NULL); 126} 127 128static int 129bcmmbox_intr1(struct bcm2835mbox_softc *sc, int cv) 130{ 131 uint32_t mbox, chan, data; 132 int ret = 0; 133 134 KASSERT(mutex_owned(&sc->sc_intr_lock)); 135 136 bus_space_barrier(sc->sc_iot, sc->sc_ioh, 0, BCM2835_MBOX_SIZE, 137 BUS_SPACE_BARRIER_READ); 138 139 while ((bus_space_read_4(sc->sc_iot, sc->sc_ioh, 140 BCM2835_MBOX0_STATUS) & BCM2835_MBOX_STATUS_EMPTY) == 0) { 141 142 mbox = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 143 BCM2835_MBOX0_READ); 144 145 chan = BCM2835_MBOX_CHAN(mbox); 146 data = BCM2835_MBOX_DATA(mbox); 147 ret = 1; 148 149 if (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) != 0) { 150 aprint_error("bcmmbox_intr: chan %d overflow\n",chan); 151 continue; 152 } 153 154 sc->sc_mbox[chan] = data | BCM2835_MBOX_CHANMASK; 155 156 if (cv) 157 cv_broadcast(&sc->sc_chan[chan]); 158 } 159 160 return ret; 161} 162 163static int 164bcmmbox_intr(void *cookie) 165{ 166 struct bcm2835mbox_softc *sc = cookie; 167 int ret; 168 169 mutex_enter(&sc->sc_intr_lock); 170 171 ret = bcmmbox_intr1(sc, 1); 172 173 mutex_exit(&sc->sc_intr_lock); 174 175 return ret; 176} 177 178void 179bcmmbox_read(uint8_t chan, uint32_t *data) 180{ 181 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 182 183 KASSERT(sc != NULL); 184 185 mutex_enter(&sc->sc_lock); 186 187 mutex_enter(&sc->sc_intr_lock); 188 while (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) == 0) { 189 if (cold) 190 bcmmbox_intr1(sc, 0); 191 else 192 cv_wait(&sc->sc_chan[chan], &sc->sc_intr_lock); 193 } 194 *data = BCM2835_MBOX_DATA(sc->sc_mbox[chan]); 195 sc->sc_mbox[chan] = 0; 196 mutex_exit(&sc->sc_intr_lock); 197 198 mutex_exit(&sc->sc_lock); 199} 200 201void 202bcmmbox_write(uint8_t chan, uint32_t data) 203{ 204 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 205 206 KASSERT(sc != NULL); 207 KASSERT(BCM2835_MBOX_CHAN(chan) == chan); 208 KASSERT(BCM2835_MBOX_CHAN(data) == 0); 209 210 mutex_enter(&sc->sc_lock); 211 212 bcm2835_mbox_write(sc->sc_iot, sc->sc_ioh, chan, data); 213 214 mutex_exit(&sc->sc_lock); 215} 216 217int 218bcmmbox_request(uint8_t chan, void *buf, size_t buflen, uint32_t *pres) 219{ 220 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 221 void *dma_buf; 222 bus_dmamap_t map; 223 bus_dma_segment_t segs[1]; 224 int nsegs; 225 int error; 226 227 KASSERT(sc != NULL); 228 229 error = bus_dmamem_alloc(sc->sc_dmat, buflen, 16, 0, segs, 1, 230 &nsegs, BUS_DMA_WAITOK); 231 if (error) 232 return error; 233 error = bus_dmamem_map(sc->sc_dmat, segs, nsegs, buflen, &dma_buf, 234 BUS_DMA_WAITOK); 235 if (error) 236 goto map_failed; 237 error = bus_dmamap_create(sc->sc_dmat, buflen, 1, buflen, 0, 238 BUS_DMA_WAITOK, &map); 239 if (error) 240 goto create_failed; 241 error = bus_dmamap_load(sc->sc_dmat, map, dma_buf, buflen, NULL, 242 BUS_DMA_WAITOK); 243 if (error) 244 goto load_failed; 245 246 memcpy(dma_buf, buf, buflen); 247 248 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, 249 BUS_DMASYNC_PREWRITE|BUS_DMASYNC_PREREAD); 250 bcmmbox_write(chan, map->dm_segs[0].ds_addr); 251 bcmmbox_read(chan, pres); 252 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, 253 BUS_DMASYNC_POSTWRITE|BUS_DMASYNC_POSTREAD); 254 255 memcpy(buf, dma_buf, buflen); 256 257 bus_dmamap_unload(sc->sc_dmat, map); 258load_failed: 259 bus_dmamap_destroy(sc->sc_dmat, map); 260create_failed: 261 bus_dmamem_unmap(sc->sc_dmat, dma_buf, buflen); 262map_failed: 263 bus_dmamem_free(sc->sc_dmat, segs, nsegs); 264 265 return error; 266} 267