bcm2835_mbox.c revision 262586 
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: stable/10/sys/arm/broadcom/bcm2835/bcm2835_mbox.c 262586 2014-02-28 00:39:35Z brueffer $");
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/intr.h>
43
44#include <dev/fdt/fdt_common.h>
45#include <dev/ofw/openfirm.h>
46#include <dev/ofw/ofw_bus.h>
47#include <dev/ofw/ofw_bus_subr.h>
48
49#include <machine/bus.h>
50#include <machine/fdt.h>
51
52#include <arm/broadcom/bcm2835/bcm2835_mbox.h>
53
54#include "mbox_if.h"
55
56#define	REG_READ	0x00
57#define	REG_POL		0x10
58#define	REG_SENDER	0x14
59#define	REG_STATUS	0x18
60#define		STATUS_FULL	0x80000000
61#define		STATUS_EMPTY	0x40000000
62#define	REG_CONFIG	0x1C
63#define		CONFIG_DATA_IRQ	0x00000001
64#define	REG_WRITE	0x20 /* This is Mailbox 1 address */
65
66#define	MBOX_MSG(chan, data)	(((data) & ~0xf) | ((chan) & 0xf))
67#define	MBOX_CHAN(msg)		((msg) & 0xf)
68#define	MBOX_DATA(msg)		((msg) & ~0xf)
69
70#define	MBOX_LOCK(sc)	do {	\
71	mtx_lock(&(sc)->lock);	\
72} while(0)
73
74#define	MBOX_UNLOCK(sc)	do {		\
75	mtx_unlock(&(sc)->lock);	\
76} while(0)
77
78#ifdef  DEBUG
79#define dprintf(fmt, args...) printf(fmt, ##args)
80#else
81#define dprintf(fmt, args...)
82#endif
83
84struct bcm_mbox_softc {
85	struct mtx		lock;
86	struct resource *	mem_res;
87	struct resource *	irq_res;
88	void*			intr_hl;
89	bus_space_tag_t		bst;
90	bus_space_handle_t	bsh;
91	int			valid[BCM2835_MBOX_CHANS];
92	int			msg[BCM2835_MBOX_CHANS];
93};
94
95#define	mbox_read_4(sc, reg)		\
96    bus_space_read_4((sc)->bst, (sc)->bsh, reg)
97#define	mbox_write_4(sc, reg, val)		\
98    bus_space_write_4((sc)->bst, (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(sc);
109	while (!(mbox_read_4(sc, REG_STATUS) & STATUS_EMPTY)) {
110		msg = mbox_read_4(sc, 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(sc);
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	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
147	if (sc->mem_res == NULL) {
148		device_printf(dev, "could not allocate memory resource\n");
149		return (ENXIO);
150	}
151
152	sc->bst = rman_get_bustag(sc->mem_res);
153	sc->bsh = rman_get_bushandle(sc->mem_res);
154
155	rid = 0;
156	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
157	if (sc->irq_res == NULL) {
158		device_printf(dev, "could not allocate interrupt resource\n");
159		return (ENXIO);
160	}
161
162	/* Setup and enable the timer */
163	if (bus_setup_intr(dev, sc->irq_res, INTR_MPSAFE | INTR_TYPE_MISC,
164	    NULL, bcm_mbox_intr, sc, &sc->intr_hl) != 0) {
165		bus_release_resource(dev, SYS_RES_IRQ, rid, sc->irq_res);
166		device_printf(dev, "Unable to setup the clock irq handler.\n");
167		return (ENXIO);
168	}
169
170	mtx_init(&sc->lock, "vcio mbox", NULL, MTX_DEF);
171	for (i = 0; i < BCM2835_MBOX_CHANS; i++) {
172		sc->valid[0] = 0;
173		sc->msg[0] = 0;
174	}
175
176	/* Read all pending messages */
177	bcm_mbox_intr(sc);
178
179	mbox_write_4(sc, REG_CONFIG, CONFIG_DATA_IRQ);
180
181	return (0);
182}
183
184/*
185 * Mailbox API
186 */
187static int
188bcm_mbox_write(device_t dev, int chan, uint32_t data)
189{
190	int limit = 20000;
191	struct bcm_mbox_softc *sc = device_get_softc(dev);
192
193	dprintf("bcm_mbox_write: chan %d, data %08x\n", chan, data);
194	MBOX_LOCK(sc);
195
196	while ((mbox_read_4(sc, REG_STATUS) & STATUS_FULL) && limit--) {
197		DELAY(2);
198	}
199
200	if (limit == 0) {
201		printf("bcm_mbox_write: STATUS_FULL stuck");
202		MBOX_UNLOCK(sc);
203		return (EAGAIN);
204	}
205
206	mbox_write_4(sc, REG_WRITE, MBOX_MSG(chan, data));
207
208	MBOX_UNLOCK(sc);
209	return (0);
210}
211
212static int
213bcm_mbox_read(device_t dev, int chan, uint32_t *data)
214{
215	struct bcm_mbox_softc *sc = device_get_softc(dev);
216
217	dprintf("bcm_mbox_read: chan %d\n", chan);
218	MBOX_LOCK(sc);
219	while (!sc->valid[chan])
220		msleep(&sc->msg[chan], &sc->lock, PZERO, "vcio mbox read", 0);
221	*data = sc->msg[chan];
222	sc->valid[chan] = 0;
223	MBOX_UNLOCK(sc);
224	dprintf("bcm_mbox_read: chan %d, data %08x\n", chan, *data);
225
226	return (0);
227}
228
229static device_method_t bcm_mbox_methods[] = {
230	DEVMETHOD(device_probe,		bcm_mbox_probe),
231	DEVMETHOD(device_attach,	bcm_mbox_attach),
232
233	DEVMETHOD(mbox_read,		bcm_mbox_read),
234	DEVMETHOD(mbox_write,		bcm_mbox_write),
235
236	DEVMETHOD_END
237};
238
239static driver_t bcm_mbox_driver = {
240	"mbox",
241	bcm_mbox_methods,
242	sizeof(struct bcm_mbox_softc),
243};
244
245static devclass_t bcm_mbox_devclass;
246
247DRIVER_MODULE(mbox, simplebus, bcm_mbox_driver, bcm_mbox_devclass, 0, 0);
248
249