bcm2835_mbox.c revision 1.3 
1/*	$NetBSD: bcm2835_mbox.c,v 1.3 2013/01/07 20:15:32 jmcneill 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 1.3 2013/01/07 20:15:32 jmcneill 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
42#include <arm/broadcom/bcm_amba.h>
43#include <arm/broadcom/bcm2835_mbox.h>
44#include <arm/broadcom/bcm2835_mboxreg.h>
45#include <arm/broadcom/bcm2835reg.h>
46
47struct bcm2835mbox_softc {
48	device_t sc_dev;
49	device_t sc_platdev;
50
51	bus_space_tag_t sc_iot;
52	bus_space_handle_t sc_ioh;
53	bus_dma_tag_t sc_dmat;
54};
55
56static struct bcm2835mbox_softc *bcm2835mbox_sc;
57
58static int bcmmbox_match(device_t, cfdata_t, void *);
59static void bcmmbox_attach(device_t, device_t, void *);
60
61CFATTACH_DECL_NEW(bcmmbox, sizeof(struct bcm2835mbox_softc),
62    bcmmbox_match, bcmmbox_attach, NULL, NULL);
63
64/* ARGSUSED */
65static int
66bcmmbox_match(device_t parent, cfdata_t match, void *aux)
67{
68	struct amba_attach_args *aaa = aux;
69
70	if (strcmp(aaa->aaa_name, "bcmmbox") != 0)
71		return 0;
72
73	return 1;
74}
75
76static void
77bcmmbox_attach(device_t parent, device_t self, void *aux)
78{
79        struct bcm2835mbox_softc *sc = device_private(self);
80 	struct amba_attach_args *aaa = aux;
81	struct bcmmbox_attach_args baa;
82
83	aprint_naive("\n");
84	aprint_normal(": VC mailbox\n");
85
86	if (bcm2835mbox_sc == NULL)
87		bcm2835mbox_sc = sc;
88
89	sc->sc_dev = self;
90	sc->sc_iot = aaa->aaa_iot;
91	sc->sc_dmat = aaa->aaa_dmat;
92
93	if (bus_space_map(aaa->aaa_iot, aaa->aaa_addr, BCM2835_MBOX_SIZE, 0,
94	    &sc->sc_ioh)) {
95		aprint_error_dev(sc->sc_dev, "unable to map device\n");
96		return;
97	}
98
99	baa.baa_dmat = aaa->aaa_dmat;
100	sc->sc_platdev = config_found_ia(self, "bcmmboxbus", &baa, NULL);
101}
102
103void
104bcmmbox_read(uint8_t chan, uint32_t *data)
105{
106	struct bcm2835mbox_softc *sc = bcm2835mbox_sc;
107
108	KASSERT(sc != NULL);
109
110	return bcm2835_mbox_read(sc->sc_iot, sc->sc_ioh, chan, data);
111}
112
113void
114bcmmbox_write(uint8_t chan, uint32_t data)
115{
116	struct bcm2835mbox_softc *sc = bcm2835mbox_sc;
117
118	KASSERT(sc != NULL);
119
120	return bcm2835_mbox_write(sc->sc_iot, sc->sc_ioh, chan, data);
121}
122
123int
124bcmmbox_request(uint8_t chan, void *buf, size_t buflen, uint32_t *pres)
125{
126	struct bcm2835mbox_softc *sc = bcm2835mbox_sc;
127	void *dma_buf;
128	bus_dmamap_t map;
129	bus_dma_segment_t segs[1];
130	int nsegs;
131	int error;
132
133	KASSERT(sc != NULL);
134
135	error = bus_dmamem_alloc(sc->sc_dmat, buflen, 16, 0, segs, 1,
136	    &nsegs, BUS_DMA_WAITOK);
137	if (error)
138		return error;
139	error = bus_dmamem_map(sc->sc_dmat, segs, nsegs, buflen, &dma_buf,
140	    BUS_DMA_WAITOK);
141	if (error)
142		goto map_failed;
143	error = bus_dmamap_create(sc->sc_dmat, buflen, 1, buflen, 0,
144	    BUS_DMA_WAITOK, &map);
145	if (error)
146		goto create_failed;
147	error = bus_dmamap_load(sc->sc_dmat, map, dma_buf, buflen, NULL,
148	    BUS_DMA_WAITOK);
149	if (error)
150		goto load_failed;
151
152	memcpy(dma_buf, buf, buflen);
153
154	bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, BUS_DMASYNC_PREWRITE);
155	bcmmbox_write(chan, map->dm_segs[0].ds_addr);
156	bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, BUS_DMASYNC_POSTWRITE);
157	bus_dmamap_sync(sc->sc_dmat, map, 0, buflen, BUS_DMASYNC_PREREAD);
158	bcmmbox_read(chan, pres);
159
160	memcpy(buf, dma_buf, buflen);
161
162	bus_dmamap_unload(sc->sc_dmat, map);
163load_failed:
164	bus_dmamap_destroy(sc->sc_dmat, map);
165create_failed:
166	bus_dmamem_unmap(sc->sc_dmat, dma_buf, buflen);
167map_failed:
168	bus_dmamem_free(sc->sc_dmat, segs, nsegs);
169	return error;
170}
171