xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_mbox.c (revision 6ef6ba9950260f42b47499d17874d00ca9290955)
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/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 
84 struct 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 
100 static void
101 bcm_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 
127 static int
128 bcm_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 
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", MTX_DEF, 0);
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  */
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 (!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 
229 static 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 
239 static driver_t bcm_mbox_driver = {
240 	"mbox",
241 	bcm_mbox_methods,
242 	sizeof(struct bcm_mbox_softc),
243 };
244 
245 static devclass_t bcm_mbox_devclass;
246 
247 DRIVER_MODULE(mbox, simplebus, bcm_mbox_driver, bcm_mbox_devclass, 0, 0);
248 
249