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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * ALSA sequencer device management | |
4 | * Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de> | |
5 | * | |
1da177e4 LT |
6 | *---------------------------------------------------------------- |
7 | * | |
8 | * This device handler separates the card driver module from sequencer | |
9 | * stuff (sequencer core, synth drivers, etc), so that user can avoid | |
10 | * to spend unnecessary resources e.g. if he needs only listening to | |
11 | * MP3s. | |
12 | * | |
13 | * The card (or lowlevel) driver creates a sequencer device entry | |
14 | * via snd_seq_device_new(). This is an entry pointer to communicate | |
15 | * with the sequencer device "driver", which is involved with the | |
16 | * actual part to communicate with the sequencer core. | |
17 | * Each sequencer device entry has an id string and the corresponding | |
18 | * driver with the same id is loaded when required. For example, | |
19 | * lowlevel codes to access emu8000 chip on sbawe card are included in | |
20 | * emu8000-synth module. To activate this module, the hardware | |
21 | * resources like i/o port are passed via snd_seq_device argument. | |
1da177e4 LT |
22 | */ |
23 | ||
7c37ae5c | 24 | #include <linux/device.h> |
1da177e4 | 25 | #include <linux/init.h> |
da155d5b | 26 | #include <linux/module.h> |
1da177e4 LT |
27 | #include <sound/core.h> |
28 | #include <sound/info.h> | |
29 | #include <sound/seq_device.h> | |
30 | #include <sound/seq_kernel.h> | |
31 | #include <sound/initval.h> | |
32 | #include <linux/kmod.h> | |
33 | #include <linux/slab.h> | |
1a60d4c5 | 34 | #include <linux/mutex.h> |
1da177e4 LT |
35 | |
36 | MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>"); | |
37 | MODULE_DESCRIPTION("ALSA sequencer device management"); | |
38 | MODULE_LICENSE("GPL"); | |
39 | ||
7c37ae5c TI |
40 | /* |
41 | * bus definition | |
42 | */ | |
43 | static int snd_seq_bus_match(struct device *dev, struct device_driver *drv) | |
44 | { | |
45 | struct snd_seq_device *sdev = to_seq_dev(dev); | |
46 | struct snd_seq_driver *sdrv = to_seq_drv(drv); | |
1da177e4 | 47 | |
7c37ae5c TI |
48 | return strcmp(sdrv->id, sdev->id) == 0 && |
49 | sdrv->argsize == sdev->argsize; | |
50 | } | |
1da177e4 | 51 | |
7c37ae5c TI |
52 | static struct bus_type snd_seq_bus_type = { |
53 | .name = "snd_seq", | |
54 | .match = snd_seq_bus_match, | |
1da177e4 LT |
55 | }; |
56 | ||
7c37ae5c TI |
57 | /* |
58 | * proc interface -- just for compatibility | |
59 | */ | |
cd6a6503 | 60 | #ifdef CONFIG_SND_PROC_FS |
6581f4e7 | 61 | static struct snd_info_entry *info_entry; |
1da177e4 | 62 | |
7c37ae5c TI |
63 | static int print_dev_info(struct device *dev, void *data) |
64 | { | |
65 | struct snd_seq_device *sdev = to_seq_dev(dev); | |
66 | struct snd_info_buffer *buffer = data; | |
1da177e4 | 67 | |
7c37ae5c TI |
68 | snd_iprintf(buffer, "snd-%s,%s,%d\n", sdev->id, |
69 | dev->driver ? "loaded" : "empty", | |
70 | dev->driver ? 1 : 0); | |
71 | return 0; | |
72 | } | |
1da177e4 | 73 | |
c7e0b5bf TI |
74 | static void snd_seq_device_info(struct snd_info_entry *entry, |
75 | struct snd_info_buffer *buffer) | |
1da177e4 | 76 | { |
7c37ae5c | 77 | bus_for_each_dev(&snd_seq_bus_type, NULL, buffer, print_dev_info); |
1da177e4 | 78 | } |
04f141a8 | 79 | #endif |
7c37ae5c | 80 | |
1da177e4 LT |
81 | /* |
82 | * load all registered drivers (called from seq_clientmgr.c) | |
83 | */ | |
84 | ||
ee2da997 | 85 | #ifdef CONFIG_MODULES |
54a721ab | 86 | /* flag to block auto-loading */ |
68ab6108 | 87 | static atomic_t snd_seq_in_init = ATOMIC_INIT(1); /* blocked as default */ |
1da177e4 | 88 | |
7c37ae5c | 89 | static int request_seq_drv(struct device *dev, void *data) |
1da177e4 | 90 | { |
7c37ae5c | 91 | struct snd_seq_device *sdev = to_seq_dev(dev); |
1da177e4 | 92 | |
7c37ae5c TI |
93 | if (!dev->driver) |
94 | request_module("snd-%s", sdev->id); | |
95 | return 0; | |
68ab6108 | 96 | } |
1da177e4 | 97 | |
7c37ae5c | 98 | static void autoload_drivers(struct work_struct *work) |
68ab6108 | 99 | { |
7c37ae5c TI |
100 | /* avoid reentrance */ |
101 | if (atomic_inc_return(&snd_seq_in_init) == 1) | |
102 | bus_for_each_dev(&snd_seq_bus_type, NULL, NULL, | |
103 | request_seq_drv); | |
104 | atomic_dec(&snd_seq_in_init); | |
68ab6108 TI |
105 | } |
106 | ||
7c37ae5c TI |
107 | static DECLARE_WORK(autoload_work, autoload_drivers); |
108 | ||
68ab6108 TI |
109 | static void queue_autoload_drivers(void) |
110 | { | |
7c37ae5c | 111 | schedule_work(&autoload_work); |
68ab6108 TI |
112 | } |
113 | ||
114 | void snd_seq_autoload_init(void) | |
115 | { | |
116 | atomic_dec(&snd_seq_in_init); | |
117 | #ifdef CONFIG_SND_SEQUENCER_MODULE | |
118 | /* initial autoload only when snd-seq is a module */ | |
119 | queue_autoload_drivers(); | |
120 | #endif | |
121 | } | |
b6a42670 | 122 | EXPORT_SYMBOL(snd_seq_autoload_init); |
b6a42670 | 123 | |
54a721ab TI |
124 | void snd_seq_autoload_exit(void) |
125 | { | |
126 | atomic_inc(&snd_seq_in_init); | |
127 | } | |
128 | EXPORT_SYMBOL(snd_seq_autoload_exit); | |
129 | ||
68ab6108 TI |
130 | void snd_seq_device_load_drivers(void) |
131 | { | |
68ab6108 TI |
132 | queue_autoload_drivers(); |
133 | flush_work(&autoload_work); | |
1da177e4 | 134 | } |
b6a42670 | 135 | EXPORT_SYMBOL(snd_seq_device_load_drivers); |
940ba1f5 AB |
136 | |
137 | static inline void cancel_autoload_drivers(void) | |
138 | { | |
139 | cancel_work_sync(&autoload_work); | |
140 | } | |
72496edc | 141 | #else |
940ba1f5 AB |
142 | static inline void queue_autoload_drivers(void) |
143 | { | |
144 | } | |
145 | ||
146 | static inline void cancel_autoload_drivers(void) | |
147 | { | |
148 | } | |
72496edc | 149 | #endif |
1da177e4 | 150 | |
7c37ae5c TI |
151 | /* |
152 | * device management | |
153 | */ | |
154 | static int snd_seq_device_dev_free(struct snd_device *device) | |
155 | { | |
156 | struct snd_seq_device *dev = device->device_data; | |
157 | ||
fc27fe7e | 158 | cancel_autoload_drivers(); |
7c37ae5c TI |
159 | put_device(&dev->dev); |
160 | return 0; | |
161 | } | |
162 | ||
163 | static int snd_seq_device_dev_register(struct snd_device *device) | |
164 | { | |
165 | struct snd_seq_device *dev = device->device_data; | |
166 | int err; | |
167 | ||
168 | err = device_add(&dev->dev); | |
169 | if (err < 0) | |
170 | return err; | |
171 | if (!dev->dev.driver) | |
172 | queue_autoload_drivers(); | |
173 | return 0; | |
174 | } | |
175 | ||
176 | static int snd_seq_device_dev_disconnect(struct snd_device *device) | |
177 | { | |
178 | struct snd_seq_device *dev = device->device_data; | |
179 | ||
180 | device_del(&dev->dev); | |
181 | return 0; | |
182 | } | |
183 | ||
184 | static void snd_seq_dev_release(struct device *dev) | |
185 | { | |
186 | struct snd_seq_device *sdev = to_seq_dev(dev); | |
187 | ||
188 | if (sdev->private_free) | |
189 | sdev->private_free(sdev); | |
190 | kfree(sdev); | |
191 | } | |
192 | ||
1da177e4 LT |
193 | /* |
194 | * register a sequencer device | |
f2f9307a | 195 | * card = card info |
1da177e4 LT |
196 | * device = device number (if any) |
197 | * id = id of driver | |
198 | * result = return pointer (NULL allowed if unnecessary) | |
199 | */ | |
af03c243 TI |
200 | int snd_seq_device_new(struct snd_card *card, int device, const char *id, |
201 | int argsize, struct snd_seq_device **result) | |
1da177e4 | 202 | { |
c7e0b5bf | 203 | struct snd_seq_device *dev; |
1da177e4 | 204 | int err; |
f15ee210 | 205 | static const struct snd_device_ops dops = { |
1da177e4 LT |
206 | .dev_free = snd_seq_device_dev_free, |
207 | .dev_register = snd_seq_device_dev_register, | |
208 | .dev_disconnect = snd_seq_device_dev_disconnect, | |
1da177e4 LT |
209 | }; |
210 | ||
211 | if (result) | |
212 | *result = NULL; | |
213 | ||
7eaa943c TI |
214 | if (snd_BUG_ON(!id)) |
215 | return -EINVAL; | |
1da177e4 | 216 | |
7c37ae5c TI |
217 | dev = kzalloc(sizeof(*dev) + argsize, GFP_KERNEL); |
218 | if (!dev) | |
1da177e4 | 219 | return -ENOMEM; |
1da177e4 LT |
220 | |
221 | /* set up device info */ | |
222 | dev->card = card; | |
223 | dev->device = device; | |
af03c243 | 224 | dev->id = id; |
1da177e4 | 225 | dev->argsize = argsize; |
1da177e4 | 226 | |
7c37ae5c TI |
227 | device_initialize(&dev->dev); |
228 | dev->dev.parent = &card->card_dev; | |
229 | dev->dev.bus = &snd_seq_bus_type; | |
230 | dev->dev.release = snd_seq_dev_release; | |
231 | dev_set_name(&dev->dev, "%s-%d-%d", dev->id, card->number, device); | |
1da177e4 | 232 | |
7c37ae5c TI |
233 | /* add this device to the list */ |
234 | err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops); | |
235 | if (err < 0) { | |
236 | put_device(&dev->dev); | |
1da177e4 LT |
237 | return err; |
238 | } | |
239 | ||
240 | if (result) | |
241 | *result = dev; | |
242 | ||
243 | return 0; | |
244 | } | |
b6a42670 | 245 | EXPORT_SYMBOL(snd_seq_device_new); |
1da177e4 LT |
246 | |
247 | /* | |
05662205 | 248 | * driver registration |
1da177e4 | 249 | */ |
05662205 | 250 | int __snd_seq_driver_register(struct snd_seq_driver *drv, struct module *mod) |
1da177e4 | 251 | { |
05662205 | 252 | if (WARN_ON(!drv->driver.name || !drv->id)) |
1da177e4 | 253 | return -EINVAL; |
05662205 TI |
254 | drv->driver.bus = &snd_seq_bus_type; |
255 | drv->driver.owner = mod; | |
256 | return driver_register(&drv->driver); | |
7c37ae5c | 257 | } |
05662205 | 258 | EXPORT_SYMBOL_GPL(__snd_seq_driver_register); |
1da177e4 | 259 | |
05662205 | 260 | void snd_seq_driver_unregister(struct snd_seq_driver *drv) |
1da177e4 | 261 | { |
05662205 | 262 | driver_unregister(&drv->driver); |
1da177e4 | 263 | } |
05662205 | 264 | EXPORT_SYMBOL_GPL(snd_seq_driver_unregister); |
1da177e4 LT |
265 | |
266 | /* | |
267 | * module part | |
268 | */ | |
269 | ||
7c37ae5c | 270 | static int __init seq_dev_proc_init(void) |
1da177e4 | 271 | { |
b816db9d | 272 | #ifdef CONFIG_SND_PROC_FS |
c7e0b5bf TI |
273 | info_entry = snd_info_create_module_entry(THIS_MODULE, "drivers", |
274 | snd_seq_root); | |
1da177e4 LT |
275 | if (info_entry == NULL) |
276 | return -ENOMEM; | |
277 | info_entry->content = SNDRV_INFO_CONTENT_TEXT; | |
1da177e4 LT |
278 | info_entry->c.text.read = snd_seq_device_info; |
279 | if (snd_info_register(info_entry) < 0) { | |
280 | snd_info_free_entry(info_entry); | |
281 | return -ENOMEM; | |
282 | } | |
04f141a8 | 283 | #endif |
1da177e4 LT |
284 | return 0; |
285 | } | |
286 | ||
7c37ae5c TI |
287 | static int __init alsa_seq_device_init(void) |
288 | { | |
289 | int err; | |
290 | ||
291 | err = bus_register(&snd_seq_bus_type); | |
292 | if (err < 0) | |
293 | return err; | |
294 | err = seq_dev_proc_init(); | |
295 | if (err < 0) | |
296 | bus_unregister(&snd_seq_bus_type); | |
297 | return err; | |
298 | } | |
299 | ||
1da177e4 LT |
300 | static void __exit alsa_seq_device_exit(void) |
301 | { | |
68ab6108 TI |
302 | #ifdef CONFIG_MODULES |
303 | cancel_work_sync(&autoload_work); | |
304 | #endif | |
b816db9d | 305 | #ifdef CONFIG_SND_PROC_FS |
746d4a02 | 306 | snd_info_free_entry(info_entry); |
04f141a8 | 307 | #endif |
7c37ae5c | 308 | bus_unregister(&snd_seq_bus_type); |
1da177e4 LT |
309 | } |
310 | ||
4945f1fd | 311 | subsys_initcall(alsa_seq_device_init) |
1da177e4 | 312 | module_exit(alsa_seq_device_exit) |