1 /* $NetBSD: bcm2835_mbox.c,v 1.17 2021/08/07 16:18:43 thorpej Exp $ */
2
3 /*-
4 * Copyright (c) 2012 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Nick Hudson
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: bcm2835_mbox.c,v 1.17 2021/08/07 16:18:43 thorpej Exp $");
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/device.h>
38 #include <sys/kernel.h>
39 #include <sys/timetc.h>
40 #include <sys/bus.h>
41 #include <sys/mutex.h>
42
43 #include <arm/broadcom/bcm2835_mbox.h>
44 #include <arm/broadcom/bcm2835_mboxreg.h>
45 #include <arm/broadcom/bcm2835reg.h>
46 #include <arm/broadcom/bcm2835var.h>
47
48 static struct bcm2835mbox_softc *bcm2835mbox_sc;
49
50 static int
bcmmbox_intr1(struct bcm2835mbox_softc * sc,int cv)51 bcmmbox_intr1(struct bcm2835mbox_softc *sc, int cv)
52 {
53 uint32_t mbox, chan, data;
54 int ret = 0;
55
56 KASSERT(mutex_owned(&sc->sc_intr_lock));
57
58 bus_space_barrier(sc->sc_iot, sc->sc_ioh, 0, BCM2835_MBOX_SIZE,
59 BUS_SPACE_BARRIER_READ);
60
61 while ((bus_space_read_4(sc->sc_iot, sc->sc_ioh,
62 BCM2835_MBOX0_STATUS) & BCM2835_MBOX_STATUS_EMPTY) == 0) {
63
64 mbox = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
65 BCM2835_MBOX0_READ);
66
67 chan = BCM2835_MBOX_CHAN(mbox);
68 data = BCM2835_MBOX_DATA(mbox);
69 ret = 1;
70
71 if (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) != 0) {
72 aprint_error("bcmmbox_intr: chan %d overflow\n",chan);
73 continue;
74 }
75
76 sc->sc_mbox[chan] = data | BCM2835_MBOX_CHANMASK;
77
78 if (cv)
79 cv_broadcast(&sc->sc_chan[chan]);
80 }
81
82 return ret;
83 }
84
85 void
bcmmbox_attach(struct bcm2835mbox_softc * sc)86 bcmmbox_attach(struct bcm2835mbox_softc *sc)
87 {
88 struct bcmmbox_attach_args baa;
89 int i;
90
91 if (bcm2835mbox_sc == NULL)
92 bcm2835mbox_sc = sc;
93
94 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE);
95 mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_VM);
96 for (i = 0; i < BCM2835_MBOX_NUMCHANNELS; ++i)
97 cv_init(&sc->sc_chan[i], "bcmmbox");
98
99 /* enable mbox interrupt */
100 if (sc->sc_intrh != NULL)
101 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BCM2835_MBOX_CFG,
102 BCM2835_MBOX_CFG_DATAIRQEN);
103
104 baa.baa_dmat = sc->sc_dmat;
105 sc->sc_platdev = config_found(sc->sc_dev, &baa, NULL, CFARGS_NONE);
106 }
107
108 int
bcmmbox_intr(void * cookie)109 bcmmbox_intr(void *cookie)
110 {
111 struct bcm2835mbox_softc *sc = cookie;
112 int ret;
113
114 mutex_enter(&sc->sc_intr_lock);
115
116 ret = bcmmbox_intr1(sc, 1);
117
118 mutex_exit(&sc->sc_intr_lock);
119
120 return ret;
121 }
122
123 void
bcmmbox_read(uint8_t chan,uint32_t * data)124 bcmmbox_read(uint8_t chan, uint32_t *data)
125 {
126 struct bcm2835mbox_softc *sc = bcm2835mbox_sc;
127
128 KASSERT(sc != NULL);
129
130 mutex_enter(&sc->sc_lock);
131
132 mutex_enter(&sc->sc_intr_lock);
133 while (BCM2835_MBOX_CHAN(sc->sc_mbox[chan]) == 0) {
134 if (cold || sc->sc_intrh == NULL)
135 bcmmbox_intr1(sc, 0);
136 else
137 cv_wait(&sc->sc_chan[chan], &sc->sc_intr_lock);
138 }
139 *data = BCM2835_MBOX_DATA(sc->sc_mbox[chan]);
140 sc->sc_mbox[chan] = 0;
141 mutex_exit(&sc->sc_intr_lock);
142
143 mutex_exit(&sc->sc_lock);
144 }
145
146 void
bcmmbox_write(uint8_t chan,uint32_t data)147 bcmmbox_write(uint8_t chan, uint32_t data)
148 {
149 struct bcm2835mbox_softc *sc = bcm2835mbox_sc;
150
151 KASSERT(sc != NULL);
152 KASSERT(BCM2835_MBOX_CHAN(chan) == chan);
153 KASSERT(BCM2835_MBOX_CHAN(data) == 0);
154
155 mutex_enter(&sc->sc_lock);
156
157 bcm2835_mbox_write(sc->sc_iot, sc->sc_ioh, chan, data);
158
159 mutex_exit(&sc->sc_lock);
160 }
161
162 int
bcmmbox_request(uint8_t chan,void * buf,size_t buflen,uint32_t * pres)163 bcmmbox_request(uint8_t chan, void *buf, size_t buflen, uint32_t *pres)
164 {
165 struct bcm2835mbox_softc *sc = bcm2835mbox_sc;
166 void *dma_buf;
167 bus_dmamap_t map;
168 bus_dma_segment_t segs[1];
169 int nsegs;
170 int error;
171
172 KASSERT(sc != NULL);
173
174 error = bus_dmamem_alloc(sc->sc_dmat, buflen, 16, 0, segs, 1,
175 &nsegs, BUS_DMA_WAITOK);
176 if (error)
177 return error;
178 error = bus_dmamem_map(sc->sc_dmat, segs, nsegs, buflen, &dma_buf,
179 BUS_DMA_WAITOK);
180 if (error)
181 goto map_failed;
182 error = bus_dmamap_create(sc->sc_dmat, buflen, 1, buflen, 0,
183 BUS_DMA_WAITOK, &map);
184 if (error)
185 goto create_failed;
186 error = bus_dmamap_load(sc->sc_dmat, map, dma_buf, buflen, NULL,
187 BUS_DMA_WAITOK);
188 if (error)
189 goto load_failed;
190
191 memcpy(dma_buf, buf, buflen);
192
193 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen,
194 BUS_DMASYNC_PREWRITE|BUS_DMASYNC_PREREAD);
195 bcmmbox_write(chan, map->dm_segs[0].ds_addr);
196 bcmmbox_read(chan, pres);
197 bus_dmamap_sync(sc->sc_dmat, map, 0, buflen,
198 BUS_DMASYNC_POSTWRITE|BUS_DMASYNC_POSTREAD);
199
200 memcpy(buf, dma_buf, buflen);
201
202 bus_dmamap_unload(sc->sc_dmat, map);
203 load_failed:
204 bus_dmamap_destroy(sc->sc_dmat, map);
205 create_failed:
206 bus_dmamem_unmap(sc->sc_dmat, dma_buf, buflen);
207 map_failed:
208 bus_dmamem_free(sc->sc_dmat, segs, nsegs);
209
210 return error;
211 }
212