bcm2835_mbox.c revision 1.14
1/* $NetBSD: bcm2835_mbox.c,v 1.14 2019/12/30 18:43:38 jmcneill 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 1.14 2019/12/30 18:43:38 jmcneill 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 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_MBOX_CFG, 101 BCM2835_MBOX_CFG_DATAIRQEN); 102 103 baa.baa_dmat = sc->sc_dmat; 104 sc->sc_platdev = config_found_ia(sc->sc_dev, "bcmmboxbus", &baa, NULL); 105} 106 107int 108bcmmbox_intr(void *cookie) 109{ 110 struct bcm2835mbox_softc *sc = cookie; 111 int ret; 112 113 mutex_enter(&sc->sc_intr_lock); 114 115 ret = bcmmbox_intr1(sc, 1); 116 117 mutex_exit(&sc->sc_intr_lock); 118 119 return ret; 120} 121 122void 123bcmmbox_read(uint8_t chan, uint32_t *data) 124{ 125 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 126 127 KASSERT(sc != NULL); 128 129 mutex_enter(&sc->sc_lock); 130 131 mutex_enter(&sc->sc_intr_lock); 132 while (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) == 0) { 133 if (cold) 134 bcmmbox_intr1(sc, 0); 135 else 136 cv_wait(&sc->sc_chan[chan], &sc->sc_intr_lock); 137 } 138 *data = BCM2835_MBOX_DATA(sc->sc_mbox[chan]); 139 sc->sc_mbox[chan] = 0; 140 mutex_exit(&sc->sc_intr_lock); 141 142 mutex_exit(&sc->sc_lock); 143} 144 145void 146bcmmbox_write(uint8_t chan, uint32_t data) 147{ 148 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 149 150 KASSERT(sc != NULL); 151 KASSERT(BCM2835_MBOX_CHAN(chan) == chan); 152 KASSERT(BCM2835_MBOX_CHAN(data) == 0); 153 154 mutex_enter(&sc->sc_lock); 155 156 bcm2835_mbox_write(sc->sc_iot, sc->sc_ioh, chan, data); 157 158 mutex_exit(&sc->sc_lock); 159} 160 161int 162bcmmbox_request(uint8_t chan, void *buf, size_t buflen, uint32_t *pres) 163{ 164 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 165 void *dma_buf; 166 bus_dmamap_t map; 167 bus_dma_segment_t segs[1]; 168 int nsegs; 169 int error; 170 171 KASSERT(sc != NULL); 172 173 error = bus_dmamem_alloc(sc->sc_dmat, buflen, 16, 0, segs, 1, 174 &nsegs, BUS_DMA_WAITOK); 175 if (error) 176 return error; 177 error = bus_dmamem_map(sc->sc_dmat, segs, nsegs, buflen, &dma_buf, 178 BUS_DMA_WAITOK); 179 if (error) 180 goto map_failed; 181 error = bus_dmamap_create(sc->sc_dmat, buflen, 1, buflen, 0, 182 BUS_DMA_WAITOK, &map); 183 if (error) 184 goto create_failed; 185 error = bus_dmamap_load(sc->sc_dmat, map, dma_buf, buflen, NULL, 186 BUS_DMA_WAITOK); 187 if (error) 188 goto load_failed; 189 190 memcpy(dma_buf, buf, buflen); 191 192 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, 193 BUS_DMASYNC_PREWRITE|BUS_DMASYNC_PREREAD); 194 bcmmbox_write(chan, map->dm_segs[0].ds_addr); 195 bcmmbox_read(chan, pres); 196 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, 197 BUS_DMASYNC_POSTWRITE|BUS_DMASYNC_POSTREAD); 198 199 memcpy(buf, dma_buf, buflen); 200 201 bus_dmamap_unload(sc->sc_dmat, map); 202load_failed: 203 bus_dmamap_destroy(sc->sc_dmat, map); 204create_failed: 205 bus_dmamem_unmap(sc->sc_dmat, dma_buf, buflen); 206map_failed: 207 bus_dmamem_free(sc->sc_dmat, segs, nsegs); 208 209 return error; 210} 211