xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_mbox.c (revision d0bd1251350a0564fb20f0044f061f1c6b6079c2)
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/sema.h>
38 #include <sys/timeet.h>
39 #include <sys/timetc.h>
40 #include <sys/watchdog.h>
41 #include <machine/bus.h>
42 #include <machine/cpu.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 
85 struct 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			msg[BCM2835_MBOX_CHANS];
93 	struct sema		sema[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 
101 static void
102 bcm_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 	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->msg[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] = MBOX_MSG(data, 0xf);
120 		sema_post(&sc->sema[chan]);
121 	}
122 }
123 
124 static int
125 bcm_mbox_probe(device_t dev)
126 {
127 
128 	if (!ofw_bus_status_okay(dev))
129 		return (ENXIO);
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 
139 static int
140 bcm_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->msg[i] = 0;
173 		sema_init(&sc->sema[i], 0, "mbox");
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  */
187 static int
188 bcm_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 
212 static int
213 bcm_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 (sema_trywait(&sc->sema[chan]) == 0) {
220 		/* do not unlock sc while waiting for the mbox */
221 		if (sema_timedwait(&sc->sema[chan], 10*hz) == 0)
222 			break;
223 		printf("timeout sema for chan %d\n", chan);
224 	}
225 	/*
226 	 *  get data from intr handler, the same channel is never coming
227 	 *  because of holding sc lock.
228 	 */
229 	*data = MBOX_DATA(sc->msg[chan]);
230 	sc->msg[chan] = 0;
231 	MBOX_UNLOCK(sc);
232 	dprintf("bcm_mbox_read: chan %d, data %08x\n", chan, *data);
233 
234 	return (0);
235 }
236 
237 static device_method_t bcm_mbox_methods[] = {
238 	DEVMETHOD(device_probe,		bcm_mbox_probe),
239 	DEVMETHOD(device_attach,	bcm_mbox_attach),
240 
241 	DEVMETHOD(mbox_read,		bcm_mbox_read),
242 	DEVMETHOD(mbox_write,		bcm_mbox_write),
243 
244 	DEVMETHOD_END
245 };
246 
247 static driver_t bcm_mbox_driver = {
248 	"mbox",
249 	bcm_mbox_methods,
250 	sizeof(struct bcm_mbox_softc),
251 };
252 
253 static devclass_t bcm_mbox_devclass;
254 
255 DRIVER_MODULE(mbox, simplebus, bcm_mbox_driver, bcm_mbox_devclass, 0, 0);
256 
257