diff options
author | Clemens Ladisch <clemens@ladisch.de> | 2005-11-20 08:07:47 -0500 |
---|---|---|
committer | Jaroslav Kysela <perex@suse.cz> | 2006-01-03 06:29:19 -0500 |
commit | 332682b1cd540dd7abbbbfc1905af8139e76e1b7 (patch) | |
tree | e2e858870972073b2e01f7f8d5948c187c11e2bb /sound/core/sound.c | |
parent | f87135f56cb266e031f5ec081dfbde7e43f55e80 (diff) |
[ALSA] dynamic minors (4/6): dynamic minor number allocation
Modules: ALSA Core,ALSA Minor Numbers
Add an option to allocate device file minor numbers dynamically.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Diffstat (limited to 'sound/core/sound.c')
-rw-r--r-- | sound/core/sound.c | 65 |
1 files changed, 46 insertions, 19 deletions
diff --git a/sound/core/sound.c b/sound/core/sound.c index 1e5eca546925..5e22283078fc 100644 --- a/sound/core/sound.c +++ b/sound/core/sound.c | |||
@@ -133,29 +133,34 @@ void *snd_lookup_minor_data(unsigned int minor, int type) | |||
133 | 133 | ||
134 | static int snd_open(struct inode *inode, struct file *file) | 134 | static int snd_open(struct inode *inode, struct file *file) |
135 | { | 135 | { |
136 | int minor = iminor(inode); | 136 | unsigned int minor = iminor(inode); |
137 | int card = SNDRV_MINOR_CARD(minor); | ||
138 | int dev = SNDRV_MINOR_DEVICE(minor); | ||
139 | struct snd_minor *mptr = NULL; | 137 | struct snd_minor *mptr = NULL; |
140 | struct file_operations *old_fops; | 138 | struct file_operations *old_fops; |
141 | int err = 0; | 139 | int err = 0; |
142 | 140 | ||
143 | if (dev != SNDRV_MINOR_GLOBAL) { | 141 | if (minor > ARRAY_SIZE(snd_minors)) |
144 | if (snd_cards[card] == NULL) { | 142 | return -ENODEV; |
143 | mptr = snd_minors[minor]; | ||
144 | if (mptr == NULL) { | ||
145 | #ifdef CONFIG_KMOD | 145 | #ifdef CONFIG_KMOD |
146 | snd_request_card(card); | 146 | int dev = SNDRV_MINOR_DEVICE(minor); |
147 | if (dev == SNDRV_MINOR_CONTROL) { | ||
148 | /* /dev/aloadC? */ | ||
149 | int card = SNDRV_MINOR_CARD(minor); | ||
147 | if (snd_cards[card] == NULL) | 150 | if (snd_cards[card] == NULL) |
148 | #endif | 151 | snd_request_card(card); |
149 | return -ENODEV; | 152 | } else if (dev == SNDRV_MINOR_GLOBAL) { |
150 | } | 153 | /* /dev/aloadSEQ */ |
151 | } else { | ||
152 | #ifdef CONFIG_KMOD | ||
153 | if ((mptr = snd_minors[minor]) == NULL) | ||
154 | snd_request_other(minor); | 154 | snd_request_other(minor); |
155 | } | ||
156 | #ifndef CONFIG_SND_DYNAMIC_MINORS | ||
157 | /* /dev/snd/{controlC?,seq} */ | ||
158 | mptr = snd_minors[minor]; | ||
159 | if (mptr == NULL) | ||
160 | #endif | ||
155 | #endif | 161 | #endif |
162 | return -ENODEV; | ||
156 | } | 163 | } |
157 | if (mptr == NULL && (mptr = snd_minors[minor]) == NULL) | ||
158 | return -ENODEV; | ||
159 | old_fops = file->f_op; | 164 | old_fops = file->f_op; |
160 | file->f_op = fops_get(mptr->f_ops); | 165 | file->f_op = fops_get(mptr->f_ops); |
161 | if (file->f_op->open) | 166 | if (file->f_op->open) |
@@ -174,6 +179,22 @@ static struct file_operations snd_fops = | |||
174 | .open = snd_open | 179 | .open = snd_open |
175 | }; | 180 | }; |
176 | 181 | ||
182 | #ifdef CONFIG_SND_DYNAMIC_MINORS | ||
183 | static int snd_find_free_minor(void) | ||
184 | { | ||
185 | int minor; | ||
186 | |||
187 | for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) { | ||
188 | /* skip minors still used statically for autoloading devices */ | ||
189 | if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL || | ||
190 | minor == SNDRV_MINOR_SEQUENCER) | ||
191 | continue; | ||
192 | if (!snd_minors[minor]) | ||
193 | return minor; | ||
194 | } | ||
195 | return -EBUSY; | ||
196 | } | ||
197 | #else | ||
177 | static int snd_kernel_minor(int type, struct snd_card *card, int dev) | 198 | static int snd_kernel_minor(int type, struct snd_card *card, int dev) |
178 | { | 199 | { |
179 | int minor; | 200 | int minor; |
@@ -200,6 +221,7 @@ static int snd_kernel_minor(int type, struct snd_card *card, int dev) | |||
200 | snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL); | 221 | snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL); |
201 | return minor; | 222 | return minor; |
202 | } | 223 | } |
224 | #endif | ||
203 | 225 | ||
204 | /** | 226 | /** |
205 | * snd_register_device - Register the ALSA device file for the card | 227 | * snd_register_device - Register the ALSA device file for the card |
@@ -219,12 +241,10 @@ int snd_register_device(int type, struct snd_card *card, int dev, | |||
219 | struct file_operations *f_ops, void *private_data, | 241 | struct file_operations *f_ops, void *private_data, |
220 | const char *name) | 242 | const char *name) |
221 | { | 243 | { |
222 | int minor = snd_kernel_minor(type, card, dev); | 244 | int minor; |
223 | struct snd_minor *preg; | 245 | struct snd_minor *preg; |
224 | struct device *device = NULL; | 246 | struct device *device = NULL; |
225 | 247 | ||
226 | if (minor < 0) | ||
227 | return minor; | ||
228 | snd_assert(name, return -EINVAL); | 248 | snd_assert(name, return -EINVAL); |
229 | preg = kmalloc(sizeof(struct snd_minor) + strlen(name) + 1, GFP_KERNEL); | 249 | preg = kmalloc(sizeof(struct snd_minor) + strlen(name) + 1, GFP_KERNEL); |
230 | if (preg == NULL) | 250 | if (preg == NULL) |
@@ -236,10 +256,17 @@ int snd_register_device(int type, struct snd_card *card, int dev, | |||
236 | preg->private_data = private_data; | 256 | preg->private_data = private_data; |
237 | strcpy(preg->name, name); | 257 | strcpy(preg->name, name); |
238 | down(&sound_mutex); | 258 | down(&sound_mutex); |
239 | if (snd_minors[minor]) { | 259 | #ifdef CONFIG_SND_DYNAMIC_MINORS |
260 | minor = snd_find_free_minor(); | ||
261 | #else | ||
262 | minor = snd_kernel_minor(type, card, dev); | ||
263 | if (minor >= 0 && snd_minors[minor]) | ||
264 | minor = -EBUSY; | ||
265 | #endif | ||
266 | if (minor < 0) { | ||
240 | up(&sound_mutex); | 267 | up(&sound_mutex); |
241 | kfree(preg); | 268 | kfree(preg); |
242 | return -EBUSY; | 269 | return minor; |
243 | } | 270 | } |
244 | snd_minors[minor] = preg; | 271 | snd_minors[minor] = preg; |
245 | if (type != SNDRV_DEVICE_TYPE_CONTROL || preg->card >= cards_limit) | 272 | if (type != SNDRV_DEVICE_TYPE_CONTROL || preg->card >= cards_limit) |