xref: /linux/arch/um/drivers/hostaudio_kern.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Copyright (C) 2002 Steve Schmidtke
3  * Licensed under the GPL
4  */
5 
6 #include <linux/fs.h>
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/sound.h>
10 #include <linux/soundcard.h>
11 #include <linux/mutex.h>
12 #include <asm/uaccess.h>
13 #include <init.h>
14 #include <os.h>
15 
16 struct hostaudio_state {
17 	int fd;
18 };
19 
20 struct hostmixer_state {
21 	int fd;
22 };
23 
24 #define HOSTAUDIO_DEV_DSP "/dev/sound/dsp"
25 #define HOSTAUDIO_DEV_MIXER "/dev/sound/mixer"
26 
27 /*
28  * Changed either at boot time or module load time.  At boot, this is
29  * single-threaded; at module load, multiple modules would each have
30  * their own copy of these variables.
31  */
32 static char *dsp = HOSTAUDIO_DEV_DSP;
33 static char *mixer = HOSTAUDIO_DEV_MIXER;
34 
35 #define DSP_HELP \
36 "    This is used to specify the host dsp device to the hostaudio driver.\n" \
37 "    The default is \"" HOSTAUDIO_DEV_DSP "\".\n\n"
38 
39 #define MIXER_HELP \
40 "    This is used to specify the host mixer device to the hostaudio driver.\n"\
41 "    The default is \"" HOSTAUDIO_DEV_MIXER "\".\n\n"
42 
43 module_param(dsp, charp, 0644);
44 MODULE_PARM_DESC(dsp, DSP_HELP);
45 module_param(mixer, charp, 0644);
46 MODULE_PARM_DESC(mixer, MIXER_HELP);
47 
48 #ifndef MODULE
49 static int set_dsp(char *name, int *add)
50 {
51 	dsp = name;
52 	return 0;
53 }
54 
55 __uml_setup("dsp=", set_dsp, "dsp=<dsp device>\n" DSP_HELP);
56 
57 static int set_mixer(char *name, int *add)
58 {
59 	mixer = name;
60 	return 0;
61 }
62 
63 __uml_setup("mixer=", set_mixer, "mixer=<mixer device>\n" MIXER_HELP);
64 #endif
65 
66 static DEFINE_MUTEX(hostaudio_mutex);
67 
68 /* /dev/dsp file operations */
69 
70 static ssize_t hostaudio_read(struct file *file, char __user *buffer,
71 			      size_t count, loff_t *ppos)
72 {
73 	struct hostaudio_state *state = file->private_data;
74 	void *kbuf;
75 	int err;
76 
77 #ifdef DEBUG
78 	printk(KERN_DEBUG "hostaudio: read called, count = %d\n", count);
79 #endif
80 
81 	kbuf = kmalloc(count, GFP_KERNEL);
82 	if (kbuf == NULL)
83 		return -ENOMEM;
84 
85 	err = os_read_file(state->fd, kbuf, count);
86 	if (err < 0)
87 		goto out;
88 
89 	if (copy_to_user(buffer, kbuf, err))
90 		err = -EFAULT;
91 
92 out:
93 	kfree(kbuf);
94 	return err;
95 }
96 
97 static ssize_t hostaudio_write(struct file *file, const char __user *buffer,
98 			       size_t count, loff_t *ppos)
99 {
100 	struct hostaudio_state *state = file->private_data;
101 	void *kbuf;
102 	int err;
103 
104 #ifdef DEBUG
105 	printk(KERN_DEBUG "hostaudio: write called, count = %d\n", count);
106 #endif
107 
108 	kbuf = kmalloc(count, GFP_KERNEL);
109 	if (kbuf == NULL)
110 		return -ENOMEM;
111 
112 	err = -EFAULT;
113 	if (copy_from_user(kbuf, buffer, count))
114 		goto out;
115 
116 	err = os_write_file(state->fd, kbuf, count);
117 	if (err < 0)
118 		goto out;
119 	*ppos += err;
120 
121  out:
122 	kfree(kbuf);
123 	return err;
124 }
125 
126 static unsigned int hostaudio_poll(struct file *file,
127 				   struct poll_table_struct *wait)
128 {
129 	unsigned int mask = 0;
130 
131 #ifdef DEBUG
132 	printk(KERN_DEBUG "hostaudio: poll called (unimplemented)\n");
133 #endif
134 
135 	return mask;
136 }
137 
138 static long hostaudio_ioctl(struct file *file,
139 			   unsigned int cmd, unsigned long arg)
140 {
141 	struct hostaudio_state *state = file->private_data;
142 	unsigned long data = 0;
143 	int err;
144 
145 #ifdef DEBUG
146 	printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u\n", cmd);
147 #endif
148 	switch(cmd){
149 	case SNDCTL_DSP_SPEED:
150 	case SNDCTL_DSP_STEREO:
151 	case SNDCTL_DSP_GETBLKSIZE:
152 	case SNDCTL_DSP_CHANNELS:
153 	case SNDCTL_DSP_SUBDIVIDE:
154 	case SNDCTL_DSP_SETFRAGMENT:
155 		if (get_user(data, (int __user *) arg))
156 			return -EFAULT;
157 		break;
158 	default:
159 		break;
160 	}
161 
162 	err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
163 
164 	switch(cmd){
165 	case SNDCTL_DSP_SPEED:
166 	case SNDCTL_DSP_STEREO:
167 	case SNDCTL_DSP_GETBLKSIZE:
168 	case SNDCTL_DSP_CHANNELS:
169 	case SNDCTL_DSP_SUBDIVIDE:
170 	case SNDCTL_DSP_SETFRAGMENT:
171 		if (put_user(data, (int __user *) arg))
172 			return -EFAULT;
173 		break;
174 	default:
175 		break;
176 	}
177 
178 	return err;
179 }
180 
181 static int hostaudio_open(struct inode *inode, struct file *file)
182 {
183 	struct hostaudio_state *state;
184 	int r = 0, w = 0;
185 	int ret;
186 
187 #ifdef DEBUG
188 	kernel_param_lock(THIS_MODULE);
189 	printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
190 	kernel_param_unlock(THIS_MODULE);
191 #endif
192 
193 	state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
194 	if (state == NULL)
195 		return -ENOMEM;
196 
197 	if (file->f_mode & FMODE_READ)
198 		r = 1;
199 	if (file->f_mode & FMODE_WRITE)
200 		w = 1;
201 
202 	kernel_param_lock(THIS_MODULE);
203 	mutex_lock(&hostaudio_mutex);
204 	ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
205 	mutex_unlock(&hostaudio_mutex);
206 	kernel_param_unlock(THIS_MODULE);
207 
208 	if (ret < 0) {
209 		kfree(state);
210 		return ret;
211 	}
212 	state->fd = ret;
213 	file->private_data = state;
214 	return 0;
215 }
216 
217 static int hostaudio_release(struct inode *inode, struct file *file)
218 {
219 	struct hostaudio_state *state = file->private_data;
220 
221 #ifdef DEBUG
222 	printk(KERN_DEBUG "hostaudio: release called\n");
223 #endif
224 	os_close_file(state->fd);
225 	kfree(state);
226 
227 	return 0;
228 }
229 
230 /* /dev/mixer file operations */
231 
232 static long hostmixer_ioctl_mixdev(struct file *file,
233 				  unsigned int cmd, unsigned long arg)
234 {
235 	struct hostmixer_state *state = file->private_data;
236 
237 #ifdef DEBUG
238 	printk(KERN_DEBUG "hostmixer: ioctl called\n");
239 #endif
240 
241 	return os_ioctl_generic(state->fd, cmd, arg);
242 }
243 
244 static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
245 {
246 	struct hostmixer_state *state;
247 	int r = 0, w = 0;
248 	int ret;
249 
250 #ifdef DEBUG
251 	printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
252 #endif
253 
254 	state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
255 	if (state == NULL)
256 		return -ENOMEM;
257 
258 	if (file->f_mode & FMODE_READ)
259 		r = 1;
260 	if (file->f_mode & FMODE_WRITE)
261 		w = 1;
262 
263 	kernel_param_lock(THIS_MODULE);
264 	mutex_lock(&hostaudio_mutex);
265 	ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
266 	mutex_unlock(&hostaudio_mutex);
267 	kernel_param_unlock(THIS_MODULE);
268 
269 	if (ret < 0) {
270 		kernel_param_lock(THIS_MODULE);
271 		printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
272 		       "err = %d\n", dsp, -ret);
273 		kernel_param_unlock(THIS_MODULE);
274 		kfree(state);
275 		return ret;
276 	}
277 
278 	file->private_data = state;
279 	return 0;
280 }
281 
282 static int hostmixer_release(struct inode *inode, struct file *file)
283 {
284 	struct hostmixer_state *state = file->private_data;
285 
286 #ifdef DEBUG
287 	printk(KERN_DEBUG "hostmixer: release called\n");
288 #endif
289 
290 	os_close_file(state->fd);
291 	kfree(state);
292 
293 	return 0;
294 }
295 
296 /* kernel module operations */
297 
298 static const struct file_operations hostaudio_fops = {
299 	.owner          = THIS_MODULE,
300 	.llseek         = no_llseek,
301 	.read           = hostaudio_read,
302 	.write          = hostaudio_write,
303 	.poll           = hostaudio_poll,
304 	.unlocked_ioctl	= hostaudio_ioctl,
305 	.mmap           = NULL,
306 	.open           = hostaudio_open,
307 	.release        = hostaudio_release,
308 };
309 
310 static const struct file_operations hostmixer_fops = {
311 	.owner          = THIS_MODULE,
312 	.llseek         = no_llseek,
313 	.unlocked_ioctl	= hostmixer_ioctl_mixdev,
314 	.open           = hostmixer_open_mixdev,
315 	.release        = hostmixer_release,
316 };
317 
318 struct {
319 	int dev_audio;
320 	int dev_mixer;
321 } module_data;
322 
323 MODULE_AUTHOR("Steve Schmidtke");
324 MODULE_DESCRIPTION("UML Audio Relay");
325 MODULE_LICENSE("GPL");
326 
327 static int __init hostaudio_init_module(void)
328 {
329 	kernel_param_lock(THIS_MODULE);
330 	printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
331 	       dsp, mixer);
332 	kernel_param_unlock(THIS_MODULE);
333 
334 	module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
335 	if (module_data.dev_audio < 0) {
336 		printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
337 		return -ENODEV;
338 	}
339 
340 	module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
341 	if (module_data.dev_mixer < 0) {
342 		printk(KERN_ERR "hostmixer: couldn't register mixer "
343 		       "device!\n");
344 		unregister_sound_dsp(module_data.dev_audio);
345 		return -ENODEV;
346 	}
347 
348 	return 0;
349 }
350 
351 static void __exit hostaudio_cleanup_module (void)
352 {
353 	unregister_sound_mixer(module_data.dev_mixer);
354 	unregister_sound_dsp(module_data.dev_audio);
355 }
356 
357 module_init(hostaudio_init_module);
358 module_exit(hostaudio_cleanup_module);
359