1 /**
2 * \file control/cards.c
3 * \brief Basic Soundcard Operations
4 * \author Jaroslav Kysela <perex@perex.cz>
5 * \date 1998-2001
6 */
7 /*
8 * Soundcard Operations - main file
9 * Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>
10 *
11 *
12 * This library is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Lesser General Public License as
14 * published by the Free Software Foundation; either version 2.1 of
15 * the License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Lesser General Public License for more details.
21 *
22 * You should have received a copy of the GNU Lesser General Public
23 * License along with this library; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 *
26 */
27
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <unistd.h>
31 #include <string.h>
32 #include <ctype.h>
33 #include <fcntl.h>
34 #include <sys/ioctl.h>
35 #include "control_local.h"
36
37 #ifndef DOC_HIDDEN
38 #define SND_FILE_CONTROL ALSA_DEVICE_DIRECTORY "controlC%i"
39 #define SND_FILE_LOAD ALOAD_DEVICE_DIRECTORY "aloadC%i"
40 #endif
41
snd_card_load2(const char * control)42 static int snd_card_load2(const char *control)
43 {
44 int open_dev;
45 snd_ctl_card_info_t info;
46
47 open_dev = snd_open_device(control, O_RDONLY);
48 if (open_dev >= 0) {
49 if (ioctl(open_dev, SNDRV_CTL_IOCTL_CARD_INFO, &info) < 0) {
50 int err = -errno;
51 close(open_dev);
52 return err;
53 }
54 close(open_dev);
55 return info.card;
56 } else {
57 return -errno;
58 }
59 }
60
snd_card_load1(int card)61 static int snd_card_load1(int card)
62 {
63 int res;
64 char control[sizeof(SND_FILE_CONTROL) + 10];
65
66 sprintf(control, SND_FILE_CONTROL, card);
67 res = snd_card_load2(control);
68 #ifdef SUPPORT_ALOAD
69 if (res < 0) {
70 char aload[sizeof(SND_FILE_LOAD) + 10];
71 sprintf(aload, SND_FILE_LOAD, card);
72 res = snd_card_load2(aload);
73 }
74 #endif
75 return res;
76 }
77
78 /**
79 * \brief Try to load the driver for a card.
80 * \param card Card number.
81 * \return 1 if driver is present, zero if driver is not present
82 */
snd_card_load(int card)83 int snd_card_load(int card)
84 {
85 return !!(snd_card_load1(card) >= 0);
86 }
87
88 /**
89 * \brief Try to determine the next card.
90 * \param rcard pointer to card number
91 * \result zero if success, otherwise a negative error code
92 *
93 * Tries to determine the next card from given card number.
94 * If card number is -1, then the first available card is
95 * returned. If the result card number is -1, no more cards
96 * are available.
97 */
snd_card_next(int * rcard)98 int snd_card_next(int *rcard)
99 {
100 int card;
101
102 if (rcard == NULL)
103 return -EINVAL;
104 card = *rcard;
105 card = card < 0 ? 0 : card + 1;
106 for (; card < SND_MAX_CARDS; card++) {
107 if (snd_card_load(card)) {
108 *rcard = card;
109 return 0;
110 }
111 }
112 *rcard = -1;
113 return 0;
114 }
115
116 /**
117 * \brief Convert card string to an integer value.
118 * \param string String containing card identifier
119 * \return zero if success, otherwise a negative error code
120 *
121 * The accepted format is an integer value in ASCII representation
122 * or the card identifier (the id parameter for sound-card drivers).
123 * The control device name like /dev/snd/controlC0 is accepted, too.
124 */
snd_card_get_index(const char * string)125 int snd_card_get_index(const char *string)
126 {
127 int card, err;
128 snd_ctl_t *handle;
129 snd_ctl_card_info_t info;
130
131 if (!string || *string == '\0')
132 return -EINVAL;
133 if ((isdigit(*string) && *(string + 1) == 0) ||
134 (isdigit(*string) && isdigit(*(string + 1)) && *(string + 2) == 0)) {
135 if (sscanf(string, "%i", &card) != 1)
136 return -EINVAL;
137 if (card < 0 || card >= SND_MAX_CARDS)
138 return -EINVAL;
139 err = snd_card_load1(card);
140 if (err >= 0)
141 return card;
142 return err;
143 }
144 if (string[0] == '/') /* device name */
145 return snd_card_load2(string);
146 for (card = 0; card < SND_MAX_CARDS; card++) {
147 #ifdef SUPPORT_ALOAD
148 if (! snd_card_load(card))
149 continue;
150 #endif
151 if (snd_ctl_hw_open(&handle, NULL, card, 0) < 0)
152 continue;
153 if (snd_ctl_card_info(handle, &info) < 0) {
154 snd_ctl_close(handle);
155 continue;
156 }
157 snd_ctl_close(handle);
158 if (!strcmp((const char *)info.id, string))
159 return card;
160 }
161 return -ENODEV;
162 }
163
164 /**
165 * \brief Obtain the card name.
166 * \param card Card number
167 * \param name Result - card name corresponding to card number
168 * \result zero if success, otherwise a negative error code
169 *
170 * The value returned in name is allocated with strdup and should be
171 * freed when no longer used.
172 */
snd_card_get_name(int card,char ** name)173 int snd_card_get_name(int card, char **name)
174 {
175 snd_ctl_t *handle;
176 snd_ctl_card_info_t info;
177 int err;
178
179 if (name == NULL)
180 return -EINVAL;
181 if ((err = snd_ctl_hw_open(&handle, NULL, card, 0)) < 0)
182 return err;
183 if ((err = snd_ctl_card_info(handle, &info)) < 0) {
184 snd_ctl_close(handle);
185 return err;
186 }
187 snd_ctl_close(handle);
188 *name = strdup((const char *)info.name);
189 if (*name == NULL)
190 return -ENOMEM;
191 return 0;
192 }
193
194 /**
195 * \brief Obtain the card long name.
196 * \param card Card number
197 * \param name Result - card long name corresponding to card number
198 * \result zero if success, otherwise a negative error code
199 *
200 * The value returned in name is allocated with strdup and should be
201 * freed when no longer used.
202 */
snd_card_get_longname(int card,char ** name)203 int snd_card_get_longname(int card, char **name)
204 {
205 snd_ctl_t *handle;
206 snd_ctl_card_info_t info;
207 int err;
208
209 if (name == NULL)
210 return -EINVAL;
211 if ((err = snd_ctl_hw_open(&handle, NULL, card, 0)) < 0)
212 return err;
213 if ((err = snd_ctl_card_info(handle, &info)) < 0) {
214 snd_ctl_close(handle);
215 return err;
216 }
217 snd_ctl_close(handle);
218 *name = strdup((const char *)info.longname);
219 if (*name == NULL)
220 return -ENOMEM;
221 return 0;
222 }
223