bcm2835_mbox.c revision 1.17
1/* $NetBSD: bcm2835_mbox.c,v 1.17 2021/08/07 16:18:43 thorpej 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 1.17 2021/08/07 16:18:43 thorpej 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/bcm2835_mbox.h> 44#include <arm/broadcom/bcm2835_mboxreg.h> 45#include <arm/broadcom/bcm2835reg.h> 46#include <arm/broadcom/bcm2835var.h> 47 48static struct bcm2835mbox_softc *bcm2835mbox_sc; 49 50static int 51bcmmbox_intr1(struct bcm2835mbox_softc *sc, int cv) 52{ 53 uint32_t mbox, chan, data; 54 int ret = 0; 55 56 KASSERT(mutex_owned(&sc->sc_intr_lock)); 57 58 bus_space_barrier(sc->sc_iot, sc->sc_ioh, 0, BCM2835_MBOX_SIZE, 59 BUS_SPACE_BARRIER_READ); 60 61 while ((bus_space_read_4(sc->sc_iot, sc->sc_ioh, 62 BCM2835_MBOX0_STATUS) & BCM2835_MBOX_STATUS_EMPTY) == 0) { 63 64 mbox = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 65 BCM2835_MBOX0_READ); 66 67 chan = BCM2835_MBOX_CHAN(mbox); 68 data = BCM2835_MBOX_DATA(mbox); 69 ret = 1; 70 71 if (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) != 0) { 72 aprint_error("bcmmbox_intr: chan %d overflow\n",chan); 73 continue; 74 } 75 76 sc->sc_mbox[chan] = data | BCM2835_MBOX_CHANMASK; 77 78 if (cv) 79 cv_broadcast(&sc->sc_chan[chan]); 80 } 81 82 return ret; 83} 84 85void 86bcmmbox_attach(struct bcm2835mbox_softc *sc) 87{ 88 struct bcmmbox_attach_args baa; 89 int i; 90 91 if (bcm2835mbox_sc == NULL) 92 bcm2835mbox_sc = sc; 93 94 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); 95 mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_VM); 96 for (i = 0; i < BCM2835_MBOX_NUMCHANNELS; ++i) 97 cv_init(&sc->sc_chan[i], "bcmmbox"); 98 99 /* enable mbox interrupt */ 100 if (sc->sc_intrh != NULL) 101 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_MBOX_CFG, 102 BCM2835_MBOX_CFG_DATAIRQEN); 103 104 baa.baa_dmat = sc->sc_dmat; 105 sc->sc_platdev = config_found(sc->sc_dev, &baa, NULL, CFARGS_NONE); 106} 107 108int 109bcmmbox_intr(void *cookie) 110{ 111 struct bcm2835mbox_softc *sc = cookie; 112 int ret; 113 114 mutex_enter(&sc->sc_intr_lock); 115 116 ret = bcmmbox_intr1(sc, 1); 117 118 mutex_exit(&sc->sc_intr_lock); 119 120 return ret; 121} 122 123void 124bcmmbox_read(uint8_t chan, uint32_t *data) 125{ 126 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 127 128 KASSERT(sc != NULL); 129 130 mutex_enter(&sc->sc_lock); 131 132 mutex_enter(&sc->sc_intr_lock); 133 while (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) == 0) { 134 if (cold || sc->sc_intrh == NULL) 135 bcmmbox_intr1(sc, 0); 136 else 137 cv_wait(&sc->sc_chan[chan], &sc->sc_intr_lock); 138 } 139 *data = BCM2835_MBOX_DATA(sc->sc_mbox[chan]); 140 sc->sc_mbox[chan] = 0; 141 mutex_exit(&sc->sc_intr_lock); 142 143 mutex_exit(&sc->sc_lock); 144} 145 146void 147bcmmbox_write(uint8_t chan, uint32_t data) 148{ 149 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 150 151 KASSERT(sc != NULL); 152 KASSERT(BCM2835_MBOX_CHAN(chan) == chan); 153 KASSERT(BCM2835_MBOX_CHAN(data) == 0); 154 155 mutex_enter(&sc->sc_lock); 156 157 bcm2835_mbox_write(sc->sc_iot, sc->sc_ioh, chan, data); 158 159 mutex_exit(&sc->sc_lock); 160} 161 162int 163bcmmbox_request(uint8_t chan, void *buf, size_t buflen, uint32_t *pres) 164{ 165 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 166 void *dma_buf; 167 bus_dmamap_t map; 168 bus_dma_segment_t segs[1]; 169 int nsegs; 170 int error; 171 172 KASSERT(sc != NULL); 173 174 error = bus_dmamem_alloc(sc->sc_dmat, buflen, 16, 0, segs, 1, 175 &nsegs, BUS_DMA_WAITOK); 176 if (error) 177 return error; 178 error = bus_dmamem_map(sc->sc_dmat, segs, nsegs, buflen, &dma_buf, 179 BUS_DMA_WAITOK); 180 if (error) 181 goto map_failed; 182 error = bus_dmamap_create(sc->sc_dmat, buflen, 1, buflen, 0, 183 BUS_DMA_WAITOK, &map); 184 if (error) 185 goto create_failed; 186 error = bus_dmamap_load(sc->sc_dmat, map, dma_buf, buflen, NULL, 187 BUS_DMA_WAITOK); 188 if (error) 189 goto load_failed; 190 191 memcpy(dma_buf, buf, buflen); 192 193 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, 194 BUS_DMASYNC_PREWRITE|BUS_DMASYNC_PREREAD); 195 bcmmbox_write(chan, map->dm_segs[0].ds_addr); 196 bcmmbox_read(chan, pres); 197 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, 198 BUS_DMASYNC_POSTWRITE|BUS_DMASYNC_POSTREAD); 199 200 memcpy(buf, dma_buf, buflen); 201 202 bus_dmamap_unload(sc->sc_dmat, map); 203load_failed: 204 bus_dmamap_destroy(sc->sc_dmat, map); 205create_failed: 206 bus_dmamem_unmap(sc->sc_dmat, dma_buf, buflen); 207map_failed: 208 bus_dmamem_free(sc->sc_dmat, segs, nsegs); 209 210 return error; 211} 212