bcm2835_mbox.c revision 239922
1/*- 2 * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/arm/broadcom/bcm2835/bcm2835_mbox.c 239922 2012-08-30 20:59:37Z gonzo $"); 29 30#include <sys/param.h> 31#include <sys/systm.h> 32#include <sys/bus.h> 33#include <sys/kernel.h> 34#include <sys/module.h> 35#include <sys/malloc.h> 36#include <sys/rman.h> 37#include <sys/timeet.h> 38#include <sys/timetc.h> 39#include <sys/watchdog.h> 40#include <machine/bus.h> 41#include <machine/cpu.h> 42#include <machine/frame.h> 43#include <machine/intr.h> 44 45#include <dev/fdt/fdt_common.h> 46#include <dev/ofw/openfirm.h> 47#include <dev/ofw/ofw_bus.h> 48#include <dev/ofw/ofw_bus_subr.h> 49 50#include <machine/bus.h> 51#include <machine/fdt.h> 52#include <arm/broadcom/bcm2835/bcm2835_mbox.h> 53 54#define REG_READ 0x00 55#define REG_POL 0x10 56#define REG_SENDER 0x14 57#define REG_STATUS 0x18 58#define STATUS_FULL 0x80000000 59#define STATUS_EMPTY 0x40000000 60#define REG_CONFIG 0x1C 61#define CONFIG_DATA_IRQ 0x00000001 62#define REG_WRITE 0x20 /* This is Mailbox 1 address */ 63 64#define MBOX_MSG(chan, data) (((data) & ~0xf) | ((chan) & 0xf)) 65#define MBOX_CHAN(msg) ((msg) & 0xf) 66#define MBOX_DATA(msg) ((msg) & ~0xf) 67 68#define MBOX_LOCK do { \ 69 mtx_lock(&bcm_mbox_sc->lock); \ 70} while(0) 71 72#define MBOX_UNLOCK do { \ 73 mtx_unlock(&bcm_mbox_sc->lock); \ 74} while(0) 75 76#ifdef DEBUG 77#define dprintf(fmt, args...) printf(fmt, ##args) 78#else 79#define dprintf(fmt, args...) 80#endif 81 82struct bcm_mbox_softc { 83 struct mtx lock; 84 struct resource * mem_res; 85 struct resource * irq_res; 86 void* intr_hl; 87 bus_space_tag_t bst; 88 bus_space_handle_t bsh; 89 int valid[BCM2835_MBOX_CHANS]; 90 int msg[BCM2835_MBOX_CHANS]; 91}; 92 93static struct bcm_mbox_softc *bcm_mbox_sc = NULL; 94 95#define mbox_read_4(reg) \ 96 bus_space_read_4(bcm_mbox_sc->bst, bcm_mbox_sc->bsh, reg) 97#define mbox_write_4(reg, val) \ 98 bus_space_write_4(bcm_mbox_sc->bst, bcm_mbox_sc->bsh, reg, val) 99 100static void 101bcm_mbox_intr(void *arg) 102{ 103 struct bcm_mbox_softc *sc = arg; 104 int chan; 105 uint32_t data; 106 uint32_t msg; 107 108 MBOX_LOCK; 109 while (!(mbox_read_4(REG_STATUS) & STATUS_EMPTY)) { 110 msg = mbox_read_4(REG_READ); 111 dprintf("bcm_mbox_intr: raw data %08x\n", msg); 112 chan = MBOX_CHAN(msg); 113 data = MBOX_DATA(msg); 114 if (sc->valid[chan]) { 115 printf("bcm_mbox_intr: channel %d oveflow\n", chan); 116 continue; 117 } 118 dprintf("bcm_mbox_intr: chan %d, data %08x\n", chan, data); 119 sc->msg[chan] = data; 120 sc->valid[chan] = 1; 121 wakeup(&sc->msg[chan]); 122 123 } 124 MBOX_UNLOCK; 125} 126 127static int 128bcm_mbox_probe(device_t dev) 129{ 130 131 if (ofw_bus_is_compatible(dev, "broadcom,bcm2835-mbox")) { 132 device_set_desc(dev, "BCM2835 VideoCore Mailbox"); 133 return(BUS_PROBE_DEFAULT); 134 } 135 136 return (ENXIO); 137} 138 139static int 140bcm_mbox_attach(device_t dev) 141{ 142 struct bcm_mbox_softc *sc = device_get_softc(dev); 143 int i; 144 int rid = 0; 145 146 if (bcm_mbox_sc != NULL) 147 return (EINVAL); 148 149 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 150 if (sc->mem_res == NULL) { 151 device_printf(dev, "could not allocate memory resource\n"); 152 return (ENXIO); 153 } 154 155 sc->bst = rman_get_bustag(sc->mem_res); 156 sc->bsh = rman_get_bushandle(sc->mem_res); 157 158 rid = 0; 159 sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE); 160 if (sc->irq_res == NULL) { 161 device_printf(dev, "could not allocate interrupt resource\n"); 162 return (ENXIO); 163 } 164 165 /* Setup and enable the timer */ 166 if (bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC, 167 NULL, bcm_mbox_intr, sc, 168 &sc->intr_hl) != 0) { 169 bus_release_resource(dev, SYS_RES_IRQ, rid, 170 sc->irq_res); 171 device_printf(dev, "Unable to setup the clock irq handler.\n"); 172 return (ENXIO); 173 } 174 175 mtx_init(&sc->lock, "vcio mbox", MTX_DEF, 0); 176 for (i = 0; i < BCM2835_MBOX_CHANS; i++) { 177 sc->valid[0] = 0; 178 sc->msg[0] = 0; 179 } 180 181 bcm_mbox_sc = sc; 182 /* Read all pending messages */ 183 bcm_mbox_intr(sc); 184 185 /* Should be called after bcm_mbox_sc initialization */ 186 mbox_write_4(REG_CONFIG, CONFIG_DATA_IRQ); 187 188 return (0); 189} 190 191static device_method_t bcm_mbox_methods[] = { 192 DEVMETHOD(device_probe, bcm_mbox_probe), 193 DEVMETHOD(device_attach, bcm_mbox_attach), 194 { 0, 0 } 195}; 196 197static driver_t bcm_mbox_driver = { 198 "mbox", 199 bcm_mbox_methods, 200 sizeof(struct bcm_mbox_softc), 201}; 202 203static devclass_t bcm_mbox_devclass; 204 205DRIVER_MODULE(mbox, simplebus, bcm_mbox_driver, bcm_mbox_devclass, 0, 0); 206 207/* 208 * Mailbox API 209 */ 210int 211bcm_mbox_write(int chan, uint32_t data) 212{ 213 int limit = 20000; 214 215 dprintf("bcm_mbox_write: chan %d, data %08x\n", chan, data); 216 MBOX_LOCK; 217 218 while ((mbox_read_4(REG_STATUS) & STATUS_FULL) && limit--) { 219 DELAY(2); 220 } 221 222 if (limit == 0) { 223 printf("bcm_mbox_write: STATUS_FULL stuck"); 224 MBOX_UNLOCK; 225 return (EAGAIN); 226 } 227 228 mbox_write_4(REG_WRITE, MBOX_MSG(chan, data)); 229 230 MBOX_UNLOCK; 231 return (0); 232} 233 234int 235bcm_mbox_read(int chan, uint32_t *data) 236{ 237 struct bcm_mbox_softc *sc = bcm_mbox_sc; 238 239 dprintf("bcm_mbox_read: chan %d\n", chan); 240 MBOX_LOCK; 241 while (!sc->valid[chan]) 242 msleep(&sc->msg[chan], &sc->lock, PZERO, "vcio mbox read", 0); 243 *data = bcm_mbox_sc->msg[chan]; 244 bcm_mbox_sc->valid[chan] = 0; 245 MBOX_UNLOCK; 246 dprintf("bcm_mbox_read: chan %d, data %08x\n", chan, *data); 247 248 return (0); 249} 250