xref: /openbmc/qemu/hw/sd/core.c (revision a9ded601)
1 /*
2  * SD card bus interface code.
3  *
4  * Copyright (c) 2015 Linaro Limited
5  *
6  * Author:
7  *  Peter Maydell <peter.maydell@linaro.org>
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms and conditions of the GNU General Public License,
11  * version 2 or later, as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  * more details.
17  *
18  * You should have received a copy of the GNU General Public License along with
19  * this program.  If not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include "qemu/osdep.h"
23 #include "hw/qdev-core.h"
24 #include "sysemu/block-backend.h"
25 #include "hw/sd/sd.h"
26 
27 static SDState *get_card(SDBus *sdbus)
28 {
29     /* We only ever have one child on the bus so just return it */
30     BusChild *kid = QTAILQ_FIRST(&sdbus->qbus.children);
31 
32     if (!kid) {
33         return NULL;
34     }
35     return SD_CARD(kid->child);
36 }
37 
38 int sdbus_do_command(SDBus *sdbus, SDRequest *req, uint8_t *response)
39 {
40     SDState *card = get_card(sdbus);
41 
42     if (card) {
43         SDCardClass *sc = SD_CARD_GET_CLASS(card);
44 
45         return sc->do_command(card, req, response);
46     }
47 
48     return 0;
49 }
50 
51 void sdbus_write_data(SDBus *sdbus, uint8_t value)
52 {
53     SDState *card = get_card(sdbus);
54 
55     if (card) {
56         SDCardClass *sc = SD_CARD_GET_CLASS(card);
57 
58         sc->write_data(card, value);
59     }
60 }
61 
62 uint8_t sdbus_read_data(SDBus *sdbus)
63 {
64     SDState *card = get_card(sdbus);
65 
66     if (card) {
67         SDCardClass *sc = SD_CARD_GET_CLASS(card);
68 
69         return sc->read_data(card);
70     }
71 
72     return 0;
73 }
74 
75 bool sdbus_data_ready(SDBus *sdbus)
76 {
77     SDState *card = get_card(sdbus);
78 
79     if (card) {
80         SDCardClass *sc = SD_CARD_GET_CLASS(card);
81 
82         return sc->data_ready(card);
83     }
84 
85     return false;
86 }
87 
88 bool sdbus_get_inserted(SDBus *sdbus)
89 {
90     SDState *card = get_card(sdbus);
91 
92     if (card) {
93         SDCardClass *sc = SD_CARD_GET_CLASS(card);
94 
95         return sc->get_inserted(card);
96     }
97 
98     return false;
99 }
100 
101 bool sdbus_get_readonly(SDBus *sdbus)
102 {
103     SDState *card = get_card(sdbus);
104 
105     if (card) {
106         SDCardClass *sc = SD_CARD_GET_CLASS(card);
107 
108         return sc->get_readonly(card);
109     }
110 
111     return false;
112 }
113 
114 void sdbus_set_inserted(SDBus *sdbus, bool inserted)
115 {
116     SDBusClass *sbc = SD_BUS_GET_CLASS(sdbus);
117     BusState *qbus = BUS(sdbus);
118 
119     if (sbc->set_inserted) {
120         sbc->set_inserted(qbus->parent, inserted);
121     }
122 }
123 
124 void sdbus_set_readonly(SDBus *sdbus, bool readonly)
125 {
126     SDBusClass *sbc = SD_BUS_GET_CLASS(sdbus);
127     BusState *qbus = BUS(sdbus);
128 
129     if (sbc->set_readonly) {
130         sbc->set_readonly(qbus->parent, readonly);
131     }
132 }
133 
134 void sdbus_reparent_card(SDBus *from, SDBus *to)
135 {
136     SDState *card = get_card(from);
137     SDCardClass *sc;
138     bool readonly;
139 
140     /* We directly reparent the card object rather than implementing this
141      * as a hotpluggable connection because we don't want to expose SD cards
142      * to users as being hotpluggable, and we can get away with it in this
143      * limited use case. This could perhaps be implemented more cleanly in
144      * future by adding support to the hotplug infrastructure for "device
145      * can be hotplugged only via code, not by user".
146      */
147 
148     if (!card) {
149         return;
150     }
151 
152     sc = SD_CARD_GET_CLASS(card);
153     readonly = sc->get_readonly(card);
154 
155     sdbus_set_inserted(from, false);
156     qdev_set_parent_bus(DEVICE(card), &to->qbus);
157     sdbus_set_inserted(to, true);
158     sdbus_set_readonly(to, readonly);
159 }
160 
161 static const TypeInfo sd_bus_info = {
162     .name = TYPE_SD_BUS,
163     .parent = TYPE_BUS,
164     .instance_size = sizeof(SDBus),
165     .class_size = sizeof(SDBusClass),
166 };
167 
168 static void sd_bus_register_types(void)
169 {
170     type_register_static(&sd_bus_info);
171 }
172 
173 type_init(sd_bus_register_types)
174