bcm2835_mbox.c revision 1.1
1/* $NetBSD: bcm2835_mbox.c,v 1.1 2012/08/20 07:45:24 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 1.1 2012/08/20 07:45:24 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 42#include <arm/broadcom/bcm_amba.h> 43#include <arm/broadcom/bcm2835_mbox.h> 44#include <arm/broadcom/bcm2835_mboxreg.h> 45#include <arm/broadcom/bcm2835reg.h> 46 47struct bcm2835mbox_softc { 48 device_t sc_dev; 49 50 bus_space_tag_t sc_iot; 51 bus_space_handle_t sc_ioh; 52}; 53 54static struct bcm2835mbox_softc *bcm2835mbox_sc; 55 56static int bcmmbox_match(device_t, cfdata_t, void *); 57static void bcmmbox_attach(device_t, device_t, void *); 58 59CFATTACH_DECL_NEW(bcmmbox, sizeof(struct bcm2835mbox_softc), 60 bcmmbox_match, bcmmbox_attach, NULL, NULL); 61 62/* ARGSUSED */ 63static int 64bcmmbox_match(device_t parent, cfdata_t match, void *aux) 65{ 66 struct amba_attach_args *aaa = aux; 67 68 if (strcmp(aaa->aaa_name, "bcmmbox") != 0) 69 return 0; 70 71 return 1; 72} 73 74static void 75bcmmbox_attach(device_t parent, device_t self, void *aux) 76{ 77 struct bcm2835mbox_softc *sc = device_private(self); 78 struct amba_attach_args *aaa = aux; 79 80 aprint_naive("\n"); 81 aprint_normal(": VC mailbox\n"); 82 83 if (bcm2835mbox_sc == NULL) 84 bcm2835mbox_sc = sc; 85 86 sc->sc_dev = self; 87 sc->sc_iot = aaa->aaa_iot; 88 89 if (bus_space_map(aaa->aaa_iot, aaa->aaa_addr, BCM2835_MBOX_SIZE, 0, 90 &sc->sc_ioh)) { 91 aprint_error_dev(sc->sc_dev, "unable to map device\n"); 92 return; 93 } 94} 95 96void 97bcmmbox_read(uint8_t chan, uint32_t *data) 98{ 99 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 100 uint32_t mbox; 101 102 KASSERT(sc != NULL); 103 104 for (;;) { 105 uint8_t rchan; 106 uint32_t rdata; 107 108 bus_space_barrier(sc->sc_iot, sc->sc_ioh, 0, 109 BCM2835_MBOX_SIZE, BUS_SPACE_BARRIER_READ); 110 111 if ((bus_space_read_4(sc->sc_iot, sc->sc_ioh, 112 BCM2835_MBOX0_STATUS) & BCM2835_MBOX_STATUS_EMPTY) != 0) 113 continue; 114 115 mbox = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 116 BCM2835_MBOX0_READ); 117 118 rchan = BCM2835_MBOX_CHAN(mbox); 119 rdata = BCM2835_MBOX_DATA(mbox); 120 121 if (rchan == chan) { 122 *data = rdata; 123 return; 124 } 125 } 126} 127 128void 129bcmmbox_write(uint8_t chan, uint32_t data) 130{ 131 struct bcm2835mbox_softc *sc = bcm2835mbox_sc; 132 133 KASSERT(sc != NULL); 134 uint32_t rdata; 135 136 for (;;) { 137 138 bus_space_barrier(sc->sc_iot, sc->sc_ioh, 0, 139 BCM2835_MBOX_SIZE, BUS_SPACE_BARRIER_READ); 140 141 if ((rdata = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 142 BCM2835_MBOX0_STATUS) & BCM2835_MBOX_STATUS_FULL) == 0) 143 break; 144 } 145 146 bus_space_write_4(sc->sc_iot, sc->sc_ioh, 147 BCM2835_MBOX1_WRITE, BCM2835_MBOX_MSG(chan, data)); 148 149 bus_space_barrier(sc->sc_iot, sc->sc_ioh, 0, 150 BCM2835_MBOX_SIZE, BUS_SPACE_BARRIER_WRITE); 151} 152