xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_mbox.c (revision 87c1627502a5dde91e5284118eec8682b60f27a2)
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 #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 
82 struct 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 
93 static 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 
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;
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 
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 	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 
191 static 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 
197 static driver_t bcm_mbox_driver = {
198 	"mbox",
199 	bcm_mbox_methods,
200 	sizeof(struct bcm_mbox_softc),
201 };
202 
203 static devclass_t bcm_mbox_devclass;
204 
205 DRIVER_MODULE(mbox, simplebus, bcm_mbox_driver, bcm_mbox_devclass, 0, 0);
206 
207 /*
208  * Mailbox API
209  */
210 int
211 bcm_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 
234 int
235 bcm_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