bcm2835_mbox.c revision 1.12
1 /* $NetBSD: bcm2835_mbox.c,v 1.12 2017/12/10 21:38:26 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 1.12 2017/12/10 21:38:26 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/bcm2835_mbox.h> 44 #include <arm/broadcom/bcm2835_mboxreg.h> 45 #include <arm/broadcom/bcm2835reg.h> 46 47 #include <dev/fdt/fdtvar.h> 48 49 struct bcm2835mbox_softc { 50 device_t sc_dev; 51 device_t sc_platdev; 52 53 bus_space_tag_t sc_iot; 54 bus_space_handle_t sc_ioh; 55 bus_dma_tag_t sc_dmat; 56 void *sc_intrh; 57 58 kmutex_t sc_lock; 59 kmutex_t sc_intr_lock; 60 kcondvar_t sc_chan[BCM2835_MBOX_NUMCHANNELS]; 61 uint32_t sc_mbox[BCM2835_MBOX_NUMCHANNELS]; 62 }; 63 64 static struct bcm2835mbox_softc *bcm2835mbox_sc; 65 66 static int bcmmbox_match(device_t, cfdata_t, void *); 67 static void bcmmbox_attach(device_t, device_t, void *); 68 static int bcmmbox_intr1(struct bcm2835mbox_softc *, int); 69 static int bcmmbox_intr(void *); 70 71 CFATTACH_DECL_NEW(bcmmbox, sizeof(struct bcm2835mbox_softc), 72 bcmmbox_match, bcmmbox_attach, NULL, NULL); 73 74 /* ARGSUSED */ 75 static int 76 bcmmbox_match(device_t parent, cfdata_t match, void *aux) 77 { 78 const char * const compatible[] = { "brcm,bcm2835-mbox", NULL }; 79 struct fdt_attach_args * const faa = aux; 80 81 return of_match_compatible(faa->faa_phandle, compatible); 82 } 83 84 static void 85 bcmmbox_attach(device_t parent, device_t self, void *aux) 86 { 87 struct bcm2835mbox_softc *sc = device_private(self); 88 struct fdt_attach_args * const faa = aux; 89 struct bcmmbox_attach_args baa; 90 const int phandle = faa->faa_phandle; 91 int i; 92 93 aprint_naive("\n"); 94 aprint_normal(": VC mailbox\n"); 95 96 sc->sc_dev = self; 97 sc->sc_iot = faa->faa_bst; 98 sc->sc_dmat = faa->faa_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 bus_addr_t addr; 105 bus_size_t size; 106 107 if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) { 108 aprint_error(": couldn't get register address\n"); 109 return; 110 } 111 112 if (bus_space_map(faa->faa_bst, addr, size, 0, &sc->sc_ioh) != 0) { 113 aprint_error_dev(sc->sc_dev, "unable to map device\n"); 114 return; 115 } 116 117 char intrstr[128]; 118 if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) { 119 aprint_error(": failed to decode interrupt\n"); 120 return; 121 } 122 123 sc->sc_intrh = fdtbus_intr_establish(phandle, 0, IPL_VM, IST_LEVEL, 124 bcmmbox_intr, sc); 125 if (sc->sc_intrh == NULL) { 126 aprint_error_dev(self, "failed to establish interrupt %s\n", 127 intrstr); 128 return; 129 } 130 aprint_normal_dev(self, "interrupting on %s\n", intrstr); 131 132 /* enable mbox interrupt */ 133 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_MBOX_CFG, 134 BCM2835_MBOX_CFG_DATAIRQEN); 135 136 if (bcm2835mbox_sc == NULL) 137 bcm2835mbox_sc = sc; 138 139 baa.baa_dmat = sc->sc_dmat; 140 sc->sc_platdev = config_found_ia(self, "bcmmboxbus", &baa, NULL); 141 } 142 143 static int 144 bcmmbox_intr1(struct bcm2835mbox_softc *sc, int cv) 145 { 146 uint32_t mbox, chan, data; 147 int ret = 0; 148 149 KASSERT(mutex_owned(&sc->sc_intr_lock)); 150 151 bus_space_barrier(sc->sc_iot, sc->sc_ioh, 0, BCM2835_MBOX_SIZE, 152 BUS_SPACE_BARRIER_READ); 153 154 while ((bus_space_read_4(sc->sc_iot, sc->sc_ioh, 155 BCM2835_MBOX0_STATUS) & BCM2835_MBOX_STATUS_EMPTY) == 0) { 156 157 mbox = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 158 BCM2835_MBOX0_READ); 159 160 chan = BCM2835_MBOX_CHAN(mbox); 161 data = BCM2835_MBOX_DATA(mbox); 162 ret = 1; 163 164 if (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) != 0) { 165 aprint_error("bcmmbox_intr: chan %d overflow\n",chan); 166 continue; 167 } 168 169 sc->sc_mbox[chan] = data | BCM2835_MBOX_CHANMASK; 170 171 if (cv) 172 cv_broadcast(&sc->sc_chan[chan]); 173 } 174 175 return ret; 176 } 177 178 static int 179 bcmmbox_intr(void *cookie) 180 { 181 struct bcm2835mbox_softc *sc = cookie; 182 int ret; 183 184 mutex_enter(&sc->sc_intr_lock); 185 186 ret = bcmmbox_intr1(sc, 1); 187 188 mutex_exit(&sc->sc_intr_lock); 189 190 return ret; 191 } 192 193 void 194 bcmmbox_read(uint8_t chan, uint32_t *data) 195 { 196 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 197 198 KASSERT(sc != NULL); 199 200 mutex_enter(&sc->sc_lock); 201 202 mutex_enter(&sc->sc_intr_lock); 203 while (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) == 0) { 204 if (cold) 205 bcmmbox_intr1(sc, 0); 206 else 207 cv_wait(&sc->sc_chan[chan], &sc->sc_intr_lock); 208 } 209 *data = BCM2835_MBOX_DATA(sc->sc_mbox[chan]); 210 sc->sc_mbox[chan] = 0; 211 mutex_exit(&sc->sc_intr_lock); 212 213 mutex_exit(&sc->sc_lock); 214 } 215 216 void 217 bcmmbox_write(uint8_t chan, uint32_t data) 218 { 219 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 220 221 KASSERT(sc != NULL); 222 KASSERT(BCM2835_MBOX_CHAN(chan) == chan); 223 KASSERT(BCM2835_MBOX_CHAN(data) == 0); 224 225 mutex_enter(&sc->sc_lock); 226 227 bcm2835_mbox_write(sc->sc_iot, sc->sc_ioh, chan, data); 228 229 mutex_exit(&sc->sc_lock); 230 } 231 232 int 233 bcmmbox_request(uint8_t chan, void *buf, size_t buflen, uint32_t *pres) 234 { 235 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 236 void *dma_buf; 237 bus_dmamap_t map; 238 bus_dma_segment_t segs[1]; 239 int nsegs; 240 int error; 241 242 KASSERT(sc != NULL); 243 244 error = bus_dmamem_alloc(sc->sc_dmat, buflen, 16, 0, segs, 1, 245 &nsegs, BUS_DMA_WAITOK); 246 if (error) 247 return error; 248 error = bus_dmamem_map(sc->sc_dmat, segs, nsegs, buflen, &dma_buf, 249 BUS_DMA_WAITOK); 250 if (error) 251 goto map_failed; 252 error = bus_dmamap_create(sc->sc_dmat, buflen, 1, buflen, 0, 253 BUS_DMA_WAITOK, &map); 254 if (error) 255 goto create_failed; 256 error = bus_dmamap_load(sc->sc_dmat, map, dma_buf, buflen, NULL, 257 BUS_DMA_WAITOK); 258 if (error) 259 goto load_failed; 260 261 memcpy(dma_buf, buf, buflen); 262 263 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, 264 BUS_DMASYNC_PREWRITE|BUS_DMASYNC_PREREAD); 265 bcmmbox_write(chan, map->dm_segs[0].ds_addr); 266 bcmmbox_read(chan, pres); 267 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, 268 BUS_DMASYNC_POSTWRITE|BUS_DMASYNC_POSTREAD); 269 270 memcpy(buf, dma_buf, buflen); 271 272 bus_dmamap_unload(sc->sc_dmat, map); 273 load_failed: 274 bus_dmamap_destroy(sc->sc_dmat, map); 275 create_failed: 276 bus_dmamem_unmap(sc->sc_dmat, dma_buf, buflen); 277 map_failed: 278 bus_dmamem_free(sc->sc_dmat, segs, nsegs); 279 280 return error; 281 } 282
Indexes created Wed Oct 15 16:09:53 GMT 2025