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("$FreeBSD$");
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
53#include <arm/broadcom/bcm2835/bcm2835_mbox.h>
54
55#include "mbox_if.h"
56
57#define	REG_READ	0x00
58#define	REG_POL		0x10
59#define	REG_SENDER	0x14
60#define	REG_STATUS	0x18
61#define		STATUS_FULL	0x80000000
62#define		STATUS_EMPTY	0x40000000
63#define	REG_CONFIG	0x1C
64#define		CONFIG_DATA_IRQ	0x00000001
65#define	REG_WRITE	0x20 /* This is Mailbox 1 address */
66
67#define	MBOX_MSG(chan, data)	(((data) & ~0xf) | ((chan) & 0xf))
68#define	MBOX_CHAN(msg)		((msg) & 0xf)
69#define	MBOX_DATA(msg)		((msg) & ~0xf)
70
71#define	MBOX_LOCK(sc)	do {	\
72	mtx_lock(&(sc)->lock);	\
73} while(0)
74
75#define	MBOX_UNLOCK(sc)	do {		\
76	mtx_unlock(&(sc)->lock);	\
77} while(0)
78
79#ifdef  DEBUG
80#define dprintf(fmt, args...) printf(fmt, ##args)
81#else
82#define dprintf(fmt, args...)
83#endif
84
85struct bcm_mbox_softc {
86	struct mtx		lock;
87	struct resource *	mem_res;
88	struct resource *	irq_res;
89	void*			intr_hl;
90	bus_space_tag_t		bst;
91	bus_space_handle_t	bsh;
92	int			valid[BCM2835_MBOX_CHANS];
93	int			msg[BCM2835_MBOX_CHANS];
94};
95
96#define	mbox_read_4(sc, reg)		\
97    bus_space_read_4((sc)->bst, (sc)->bsh, reg)
98#define	mbox_write_4(sc, reg, val)		\
99    bus_space_write_4((sc)->bst, (sc)->bsh, reg, val)
100
101static void
102bcm_mbox_intr(void *arg)
103{
104	struct bcm_mbox_softc *sc = arg;
105	int chan;
106	uint32_t data;
107	uint32_t msg;
108
109	MBOX_LOCK(sc);
110	while (!(mbox_read_4(sc, REG_STATUS) & STATUS_EMPTY)) {
111		msg = mbox_read_4(sc, REG_READ);
112		dprintf("bcm_mbox_intr: raw data %08x\n", msg);
113		chan = MBOX_CHAN(msg);
114		data = MBOX_DATA(msg);
115		if (sc->valid[chan]) {
116			printf("bcm_mbox_intr: channel %d oveflow\n", chan);
117			continue;
118		}
119		dprintf("bcm_mbox_intr: chan %d, data %08x\n", chan, data);
120		sc->msg[chan] = data;
121		sc->valid[chan] = 1;
122		wakeup(&sc->msg[chan]);
123
124	}
125	MBOX_UNLOCK(sc);
126}
127
128static int
129bcm_mbox_probe(device_t dev)
130{
131
132	if (ofw_bus_is_compatible(dev, "broadcom,bcm2835-mbox")) {
133		device_set_desc(dev, "BCM2835 VideoCore Mailbox");
134		return(BUS_PROBE_DEFAULT);
135	}
136
137	return (ENXIO);
138}
139
140static int
141bcm_mbox_attach(device_t dev)
142{
143	struct bcm_mbox_softc *sc = device_get_softc(dev);
144	int i;
145	int rid = 0;
146
147	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
148	if (sc->mem_res == NULL) {
149		device_printf(dev, "could not allocate memory resource\n");
150		return (ENXIO);
151	}
152
153	sc->bst = rman_get_bustag(sc->mem_res);
154	sc->bsh = rman_get_bushandle(sc->mem_res);
155
156	rid = 0;
157	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
158	if (sc->irq_res == NULL) {
159		device_printf(dev, "could not allocate interrupt resource\n");
160		return (ENXIO);
161	}
162
163	/* Setup and enable the timer */
164	if (bus_setup_intr(dev, sc->irq_res, INTR_MPSAFE | INTR_TYPE_MISC,
165	    NULL, bcm_mbox_intr, sc, &sc->intr_hl) != 0) {
166		bus_release_resource(dev, SYS_RES_IRQ, rid, sc->irq_res);
167		device_printf(dev, "Unable to setup the clock irq handler.\n");
168		return (ENXIO);
169	}
170
171	mtx_init(&sc->lock, "vcio mbox", MTX_DEF, 0);
172	for (i = 0; i < BCM2835_MBOX_CHANS; i++) {
173		sc->valid[0] = 0;
174		sc->msg[0] = 0;
175	}
176
177	/* Read all pending messages */
178	bcm_mbox_intr(sc);
179
180	mbox_write_4(sc, REG_CONFIG, CONFIG_DATA_IRQ);
181
182	return (0);
183}
184
185/*
186 * Mailbox API
187 */
188static int
189bcm_mbox_write(device_t dev, int chan, uint32_t data)
190{
191	int limit = 20000;
192	struct bcm_mbox_softc *sc = device_get_softc(dev);
193
194	dprintf("bcm_mbox_write: chan %d, data %08x\n", chan, data);
195	MBOX_LOCK(sc);
196
197	while ((mbox_read_4(sc, REG_STATUS) & STATUS_FULL) && limit--) {
198		DELAY(2);
199	}
200
201	if (limit == 0) {
202		printf("bcm_mbox_write: STATUS_FULL stuck");
203		MBOX_UNLOCK(sc);
204		return (EAGAIN);
205	}
206
207	mbox_write_4(sc, REG_WRITE, MBOX_MSG(chan, data));
208
209	MBOX_UNLOCK(sc);
210	return (0);
211}
212
213static int
214bcm_mbox_read(device_t dev, int chan, uint32_t *data)
215{
216	struct bcm_mbox_softc *sc = device_get_softc(dev);
217
218	dprintf("bcm_mbox_read: chan %d\n", chan);
219	MBOX_LOCK(sc);
220	while (!sc->valid[chan])
221		msleep(&sc->msg[chan], &sc->lock, PZERO, "vcio mbox read", 0);
222	*data = sc->msg[chan];
223	sc->valid[chan] = 0;
224	MBOX_UNLOCK(sc);
225	dprintf("bcm_mbox_read: chan %d, data %08x\n", chan, *data);
226
227	return (0);
228}
229
230static device_method_t bcm_mbox_methods[] = {
231	DEVMETHOD(device_probe,		bcm_mbox_probe),
232	DEVMETHOD(device_attach,	bcm_mbox_attach),
233
234	DEVMETHOD(mbox_read,		bcm_mbox_read),
235	DEVMETHOD(mbox_write,		bcm_mbox_write),
236
237	DEVMETHOD_END
238};
239
240static driver_t bcm_mbox_driver = {
241	"mbox",
242	bcm_mbox_methods,
243	sizeof(struct bcm_mbox_softc),
244};
245
246static devclass_t bcm_mbox_devclass;
247
248DRIVER_MODULE(mbox, simplebus, bcm_mbox_driver, bcm_mbox_devclass, 0, 0);
249
250