/* $OpenBSD: bcm2835_dmac.c,v 1.5 2024/10/17 05:10:53 jsg Exp $ */ /* * Copyright (c) 2020 Tobias Heider * Copyright (c) 2019 Neil Ashford * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /*- * Copyright (c) 2014 Jared D. McNeill * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #define BCMDMAC_CHANNELMASK ((1 << 12) - 1) #define DEVNAME(sc) ((sc)->sc_dev.dv_xname) struct bcmdmac_softc { struct device sc_dev; bus_space_tag_t sc_iot; bus_space_handle_t sc_ioh; int sc_fa_node; struct mutex sc_lock; struct bcmdmac_channel *sc_channels; int sc_nchannels; uint32_t sc_channelmask; }; static struct bcmdmac_softc *bcmdmac_sc = NULL; struct bcmdmac_channel { struct bcmdmac_softc *ch_sc; void *ch_ih; uint8_t ch_index; void (*ch_callback)(uint32_t, uint32_t, void *); void *ch_callbackarg; uint32_t ch_debug; }; int bcmdmac_match(struct device *, void *, void *); void bcmdmac_attach(struct device *, struct device *, void *); const struct cfattach bcmdmac_ca = { sizeof(struct bcmdmac_softc), bcmdmac_match, bcmdmac_attach, }; struct cfdriver bcmdmac_cd = { NULL, "bcmdmac", DV_DULL }; /* utilities */ enum bcmdmac_type bcmdmac_channel_type(struct bcmdmac_channel *ch) { if (ISSET(ch->ch_debug, DMAC_DEBUG_LITE)) return BCMDMAC_TYPE_LITE; else return BCMDMAC_TYPE_NORMAL; } int bcmdmac_channel_used(struct bcmdmac_channel *ch) { return ch->ch_callback != NULL; } void bcmdmac_write(struct bcmdmac_softc *sc, bus_size_t offset, uint32_t value) { bus_space_write_4(sc->sc_iot, sc->sc_ioh, offset, value); } uint32_t bcmdmac_read(struct bcmdmac_softc *sc, bus_size_t offset) { return bus_space_read_4(sc->sc_iot, sc->sc_ioh, offset); } /* driver handles */ int bcmdmac_match(struct device *parent, void *match, void *aux) { struct fdt_attach_args *faa = aux; return OF_is_compatible(faa->fa_node, "brcm,bcm2835-dma"); } void bcmdmac_attach(struct device *parent, struct device *self, void *aux) { struct bcmdmac_softc *sc = (struct bcmdmac_softc *)self; struct fdt_attach_args *faa = aux; struct bcmdmac_channel *ch; uint32_t val; int index; bus_addr_t addr; bus_size_t size; if (bcmdmac_sc) { printf(": already attached\n"); return; } bcmdmac_sc = sc; sc->sc_iot = faa->fa_iot; sc->sc_fa_node = faa->fa_node; if (faa->fa_nreg < 1) { printf(": no registers\n"); return; } addr = faa->fa_reg[0].addr; size = faa->fa_reg[0].size; if (bus_space_map(sc->sc_iot, addr, size, 0, &sc->sc_ioh)) { printf(": can't map registers\n"); return; } sc->sc_channelmask = OF_getpropint(faa->fa_node, "brcm,dma-channel-mask", -1); sc->sc_channelmask &= BCMDMAC_CHANNELMASK; mtx_init(&sc->sc_lock, IPL_SCHED); sc->sc_nchannels = 32 - __builtin_clz(sc->sc_channelmask); sc->sc_channels = malloc(sizeof(*sc->sc_channels) * sc->sc_nchannels, M_DEVBUF, M_WAITOK); printf(":"); for (index = 0; index < sc->sc_nchannels; index++) { ch = &sc->sc_channels[index]; ch->ch_sc = sc; ch->ch_index = index; ch->ch_callback = NULL; ch->ch_callbackarg = NULL; ch->ch_ih = NULL; if (!ISSET(sc->sc_channelmask, (1 << index))) continue; printf(" DMA%d", index); ch->ch_debug = bcmdmac_read(sc, DMAC_DEBUG(index)); val = bcmdmac_read(sc, DMAC_CS(index)); val |= DMAC_CS_RESET; bcmdmac_write(sc, DMAC_CS(index), val); } printf("\n"); } int bcmdmac_intr(void *arg) { struct bcmdmac_channel *ch = arg; struct bcmdmac_softc *sc = ch->ch_sc; uint32_t cs, ce; cs = bcmdmac_read(sc, DMAC_CS(ch->ch_index)); bcmdmac_write(sc, DMAC_CS(ch->ch_index), cs); cs &= DMAC_CS_INT | DMAC_CS_END | DMAC_CS_ERROR; ce = bcmdmac_read(sc, DMAC_DEBUG(ch->ch_index)); ce &= DMAC_DEBUG_READ_ERROR | DMAC_DEBUG_FIFO_ERROR | DMAC_DEBUG_READ_LAST_NOT_SET_ERROR; bcmdmac_write(sc, DMAC_DEBUG(ch->ch_index), ce); if (ch->ch_callback) ch->ch_callback(cs, ce, ch->ch_callbackarg); return 1; } struct bcmdmac_channel * bcmdmac_alloc(enum bcmdmac_type type, int ipl, void (*cb)(uint32_t, uint32_t, void *), void *cbarg) { struct bcmdmac_softc *sc = bcmdmac_sc; struct bcmdmac_channel *ch = NULL; int index; if (sc == NULL) return NULL; mtx_enter(&sc->sc_lock); for (index = 0; index < sc->sc_nchannels; index++) { if (!ISSET(sc->sc_channelmask, (1 << index))) continue; if (bcmdmac_channel_type(&sc->sc_channels[index]) != type) continue; if (bcmdmac_channel_used(&sc->sc_channels[index])) continue; ch = &sc->sc_channels[index]; ch->ch_callback = cb; ch->ch_callbackarg = cbarg; break; } mtx_leave(&sc->sc_lock); if (ch == NULL) return NULL; KASSERT(ch->ch_ih == NULL); ch->ch_ih = fdt_intr_establish_idx(sc->sc_fa_node, ch->ch_index, ipl, bcmdmac_intr, ch, sc->sc_dev.dv_xname); if (ch->ch_ih == NULL) { printf("%s: failed to establish interrupt for DMA%d\n", DEVNAME(sc), ch->ch_index); ch->ch_callback = NULL; ch->ch_callbackarg = NULL; ch = NULL; } return ch; } void bcmdmac_free(struct bcmdmac_channel *ch) { struct bcmdmac_softc *sc = ch->ch_sc; uint32_t val; bcmdmac_halt(ch); /* reset chip */ val = bcmdmac_read(sc, DMAC_CS(ch->ch_index)); val |= DMAC_CS_RESET; val &= ~DMAC_CS_ACTIVE; bcmdmac_write(sc, DMAC_CS(ch->ch_index), val); mtx_enter(&sc->sc_lock); fdt_intr_disestablish(ch->ch_ih); ch->ch_ih = NULL; ch->ch_callback = NULL; ch->ch_callbackarg = NULL; mtx_leave(&sc->sc_lock); } void bcmdmac_set_conblk_addr(struct bcmdmac_channel *ch, bus_addr_t addr) { struct bcmdmac_softc *sc = ch->ch_sc; bcmdmac_write(sc, DMAC_CONBLK_AD(ch->ch_index), addr); } int bcmdmac_transfer(struct bcmdmac_channel *ch) { struct bcmdmac_softc *sc = ch->ch_sc; uint32_t val; val = bcmdmac_read(sc, DMAC_CS(ch->ch_index)); if (ISSET(val, DMAC_CS_ACTIVE)) return EBUSY; val |= DMAC_CS_ACTIVE; bcmdmac_write(sc, DMAC_CS(ch->ch_index), val); return 0; } void bcmdmac_halt(struct bcmdmac_channel *ch) { struct bcmdmac_softc *sc = ch->ch_sc; uint32_t val; /* pause DMA */ val = bcmdmac_read(sc, DMAC_CS(ch->ch_index)); val &= ~DMAC_CS_ACTIVE; bcmdmac_write(sc, DMAC_CS(ch->ch_index), val); /* XXX wait for paused state */ /* end descriptor chain */ bcmdmac_write(sc, DMAC_NEXTCONBK(ch->ch_index), 0); /* resume DMA, which then stops */ val |= DMAC_CS_ACTIVE | DMAC_CS_ABORT; bcmdmac_write(sc, DMAC_CS(ch->ch_index), val); }