xref: /openbmc/qemu/hw/sd/core.c (revision d1fd31f8)
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 "hw/sd/sd.h"
25 #include "trace.h"
26 
27 static inline const char *sdbus_name(SDBus *sdbus)
28 {
29     return sdbus->qbus.name;
30 }
31 
32 static SDState *get_card(SDBus *sdbus)
33 {
34     /* We only ever have one child on the bus so just return it */
35     BusChild *kid = QTAILQ_FIRST(&sdbus->qbus.children);
36 
37     if (!kid) {
38         return NULL;
39     }
40     return SD_CARD(kid->child);
41 }
42 
43 uint8_t sdbus_get_dat_lines(SDBus *sdbus)
44 {
45     SDState *slave = get_card(sdbus);
46     uint8_t dat_lines = 0b1111; /* 4 bit bus width */
47 
48     if (slave) {
49         SDCardClass *sc = SD_CARD_GET_CLASS(slave);
50 
51         if (sc->get_dat_lines) {
52             dat_lines = sc->get_dat_lines(slave);
53         }
54     }
55     trace_sdbus_get_dat_lines(sdbus_name(sdbus), dat_lines);
56 
57     return dat_lines;
58 }
59 
60 bool sdbus_get_cmd_line(SDBus *sdbus)
61 {
62     SDState *slave = get_card(sdbus);
63     bool cmd_line = true;
64 
65     if (slave) {
66         SDCardClass *sc = SD_CARD_GET_CLASS(slave);
67 
68         if (sc->get_cmd_line) {
69             cmd_line = sc->get_cmd_line(slave);
70         }
71     }
72     trace_sdbus_get_cmd_line(sdbus_name(sdbus), cmd_line);
73 
74     return cmd_line;
75 }
76 
77 void sdbus_set_voltage(SDBus *sdbus, uint16_t millivolts)
78 {
79     SDState *card = get_card(sdbus);
80 
81     trace_sdbus_set_voltage(sdbus_name(sdbus), millivolts);
82     if (card) {
83         SDCardClass *sc = SD_CARD_GET_CLASS(card);
84 
85         assert(sc->set_voltage);
86         sc->set_voltage(card, millivolts);
87     }
88 }
89 
90 int sdbus_do_command(SDBus *sdbus, SDRequest *req, uint8_t *response)
91 {
92     SDState *card = get_card(sdbus);
93 
94     trace_sdbus_command(sdbus_name(sdbus), req->cmd, req->arg, req->crc);
95     if (card) {
96         SDCardClass *sc = SD_CARD_GET_CLASS(card);
97 
98         return sc->do_command(card, req, response);
99     }
100 
101     return 0;
102 }
103 
104 void sdbus_write_data(SDBus *sdbus, uint8_t value)
105 {
106     SDState *card = get_card(sdbus);
107 
108     trace_sdbus_write(sdbus_name(sdbus), value);
109     if (card) {
110         SDCardClass *sc = SD_CARD_GET_CLASS(card);
111 
112         sc->write_data(card, value);
113     }
114 }
115 
116 uint8_t sdbus_read_data(SDBus *sdbus)
117 {
118     SDState *card = get_card(sdbus);
119     uint8_t value = 0;
120 
121     if (card) {
122         SDCardClass *sc = SD_CARD_GET_CLASS(card);
123 
124         value = sc->read_data(card);
125     }
126     trace_sdbus_read(sdbus_name(sdbus), value);
127 
128     return value;
129 }
130 
131 bool sdbus_data_ready(SDBus *sdbus)
132 {
133     SDState *card = get_card(sdbus);
134 
135     if (card) {
136         SDCardClass *sc = SD_CARD_GET_CLASS(card);
137 
138         return sc->data_ready(card);
139     }
140 
141     return false;
142 }
143 
144 bool sdbus_get_inserted(SDBus *sdbus)
145 {
146     SDState *card = get_card(sdbus);
147 
148     if (card) {
149         SDCardClass *sc = SD_CARD_GET_CLASS(card);
150 
151         return sc->get_inserted(card);
152     }
153 
154     return false;
155 }
156 
157 bool sdbus_get_readonly(SDBus *sdbus)
158 {
159     SDState *card = get_card(sdbus);
160 
161     if (card) {
162         SDCardClass *sc = SD_CARD_GET_CLASS(card);
163 
164         return sc->get_readonly(card);
165     }
166 
167     return false;
168 }
169 
170 void sdbus_set_inserted(SDBus *sdbus, bool inserted)
171 {
172     SDBusClass *sbc = SD_BUS_GET_CLASS(sdbus);
173     BusState *qbus = BUS(sdbus);
174 
175     if (sbc->set_inserted) {
176         sbc->set_inserted(qbus->parent, inserted);
177     }
178 }
179 
180 void sdbus_set_readonly(SDBus *sdbus, bool readonly)
181 {
182     SDBusClass *sbc = SD_BUS_GET_CLASS(sdbus);
183     BusState *qbus = BUS(sdbus);
184 
185     if (sbc->set_readonly) {
186         sbc->set_readonly(qbus->parent, readonly);
187     }
188 }
189 
190 void sdbus_reparent_card(SDBus *from, SDBus *to)
191 {
192     SDState *card = get_card(from);
193     SDCardClass *sc;
194     bool readonly;
195 
196     /* We directly reparent the card object rather than implementing this
197      * as a hotpluggable connection because we don't want to expose SD cards
198      * to users as being hotpluggable, and we can get away with it in this
199      * limited use case. This could perhaps be implemented more cleanly in
200      * future by adding support to the hotplug infrastructure for "device
201      * can be hotplugged only via code, not by user".
202      */
203 
204     if (!card) {
205         return;
206     }
207 
208     sc = SD_CARD_GET_CLASS(card);
209     readonly = sc->get_readonly(card);
210 
211     sdbus_set_inserted(from, false);
212     qdev_set_parent_bus(DEVICE(card), &to->qbus);
213     sdbus_set_inserted(to, true);
214     sdbus_set_readonly(to, readonly);
215 }
216 
217 static const TypeInfo sd_bus_info = {
218     .name = TYPE_SD_BUS,
219     .parent = TYPE_BUS,
220     .instance_size = sizeof(SDBus),
221     .class_size = sizeof(SDBusClass),
222 };
223 
224 static void sd_bus_register_types(void)
225 {
226     type_register_static(&sd_bus_info);
227 }
228 
229 type_init(sd_bus_register_types)
230