xref: /linux/arch/um/drivers/hostaudio_kern.c (revision a234ca0faa65dcd5cc473915bd925130ebb7b74b)
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/smp_lock.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 #ifndef MODULE
44 static int set_dsp(char *name, int *add)
45 {
46 	dsp = name;
47 	return 0;
48 }
49 
50 __uml_setup("dsp=", set_dsp, "dsp=<dsp device>\n" DSP_HELP);
51 
52 static int set_mixer(char *name, int *add)
53 {
54 	mixer = name;
55 	return 0;
56 }
57 
58 __uml_setup("mixer=", set_mixer, "mixer=<mixer device>\n" MIXER_HELP);
59 
60 #else /*MODULE*/
61 
62 module_param(dsp, charp, 0644);
63 MODULE_PARM_DESC(dsp, DSP_HELP);
64 
65 module_param(mixer, charp, 0644);
66 MODULE_PARM_DESC(mixer, MIXER_HELP);
67 
68 #endif
69 
70 /* /dev/dsp file operations */
71 
72 static ssize_t hostaudio_read(struct file *file, char __user *buffer,
73 			      size_t count, loff_t *ppos)
74 {
75 	struct hostaudio_state *state = file->private_data;
76 	void *kbuf;
77 	int err;
78 
79 #ifdef DEBUG
80 	printk(KERN_DEBUG "hostaudio: read called, count = %d\n", count);
81 #endif
82 
83 	kbuf = kmalloc(count, GFP_KERNEL);
84 	if (kbuf == NULL)
85 		return -ENOMEM;
86 
87 	err = os_read_file(state->fd, kbuf, count);
88 	if (err < 0)
89 		goto out;
90 
91 	if (copy_to_user(buffer, kbuf, err))
92 		err = -EFAULT;
93 
94 out:
95 	kfree(kbuf);
96 	return err;
97 }
98 
99 static ssize_t hostaudio_write(struct file *file, const char __user *buffer,
100 			       size_t count, loff_t *ppos)
101 {
102 	struct hostaudio_state *state = file->private_data;
103 	void *kbuf;
104 	int err;
105 
106 #ifdef DEBUG
107 	printk(KERN_DEBUG "hostaudio: write called, count = %d\n", count);
108 #endif
109 
110 	kbuf = kmalloc(count, GFP_KERNEL);
111 	if (kbuf == NULL)
112 		return -ENOMEM;
113 
114 	err = -EFAULT;
115 	if (copy_from_user(kbuf, buffer, count))
116 		goto out;
117 
118 	err = os_write_file(state->fd, kbuf, count);
119 	if (err < 0)
120 		goto out;
121 	*ppos += err;
122 
123  out:
124 	kfree(kbuf);
125 	return err;
126 }
127 
128 static unsigned int hostaudio_poll(struct file *file,
129 				   struct poll_table_struct *wait)
130 {
131 	unsigned int mask = 0;
132 
133 #ifdef DEBUG
134 	printk(KERN_DEBUG "hostaudio: poll called (unimplemented)\n");
135 #endif
136 
137 	return mask;
138 }
139 
140 static long hostaudio_ioctl(struct file *file,
141 			   unsigned int cmd, unsigned long arg)
142 {
143 	struct hostaudio_state *state = file->private_data;
144 	unsigned long data = 0;
145 	int err;
146 
147 #ifdef DEBUG
148 	printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u\n", cmd);
149 #endif
150 	switch(cmd){
151 	case SNDCTL_DSP_SPEED:
152 	case SNDCTL_DSP_STEREO:
153 	case SNDCTL_DSP_GETBLKSIZE:
154 	case SNDCTL_DSP_CHANNELS:
155 	case SNDCTL_DSP_SUBDIVIDE:
156 	case SNDCTL_DSP_SETFRAGMENT:
157 		if (get_user(data, (int __user *) arg))
158 			return -EFAULT;
159 		break;
160 	default:
161 		break;
162 	}
163 
164 	err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
165 
166 	switch(cmd){
167 	case SNDCTL_DSP_SPEED:
168 	case SNDCTL_DSP_STEREO:
169 	case SNDCTL_DSP_GETBLKSIZE:
170 	case SNDCTL_DSP_CHANNELS:
171 	case SNDCTL_DSP_SUBDIVIDE:
172 	case SNDCTL_DSP_SETFRAGMENT:
173 		if (put_user(data, (int __user *) arg))
174 			return -EFAULT;
175 		break;
176 	default:
177 		break;
178 	}
179 
180 	return err;
181 }
182 
183 static int hostaudio_open(struct inode *inode, struct file *file)
184 {
185 	struct hostaudio_state *state;
186 	int r = 0, w = 0;
187 	int ret;
188 
189 #ifdef DEBUG
190 	kparam_block_sysfs_write(dsp);
191 	printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
192 	kparam_unblock_sysfs_write(dsp);
193 #endif
194 
195 	state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
196 	if (state == NULL)
197 		return -ENOMEM;
198 
199 	if (file->f_mode & FMODE_READ)
200 		r = 1;
201 	if (file->f_mode & FMODE_WRITE)
202 		w = 1;
203 
204 	kparam_block_sysfs_write(dsp);
205 	lock_kernel();
206 	ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
207 	unlock_kernel();
208 	kparam_unblock_sysfs_write(dsp);
209 
210 	if (ret < 0) {
211 		kfree(state);
212 		return ret;
213 	}
214 	state->fd = ret;
215 	file->private_data = state;
216 	return 0;
217 }
218 
219 static int hostaudio_release(struct inode *inode, struct file *file)
220 {
221 	struct hostaudio_state *state = file->private_data;
222 
223 #ifdef DEBUG
224 	printk(KERN_DEBUG "hostaudio: release called\n");
225 #endif
226 	os_close_file(state->fd);
227 	kfree(state);
228 
229 	return 0;
230 }
231 
232 /* /dev/mixer file operations */
233 
234 static long hostmixer_ioctl_mixdev(struct file *file,
235 				  unsigned int cmd, unsigned long arg)
236 {
237 	struct hostmixer_state *state = file->private_data;
238 
239 #ifdef DEBUG
240 	printk(KERN_DEBUG "hostmixer: ioctl called\n");
241 #endif
242 
243 	return os_ioctl_generic(state->fd, cmd, arg);
244 }
245 
246 static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
247 {
248 	struct hostmixer_state *state;
249 	int r = 0, w = 0;
250 	int ret;
251 
252 #ifdef DEBUG
253 	printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
254 #endif
255 
256 	state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
257 	if (state == NULL)
258 		return -ENOMEM;
259 
260 	if (file->f_mode & FMODE_READ)
261 		r = 1;
262 	if (file->f_mode & FMODE_WRITE)
263 		w = 1;
264 
265 	kparam_block_sysfs_write(mixer);
266 	lock_kernel();
267 	ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
268 	unlock_kernel();
269 	kparam_unblock_sysfs_write(mixer);
270 
271 	if (ret < 0) {
272 		kparam_block_sysfs_write(dsp);
273 		printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
274 		       "err = %d\n", dsp, -ret);
275 		kparam_unblock_sysfs_write(dsp);
276 		kfree(state);
277 		return ret;
278 	}
279 
280 	file->private_data = state;
281 	return 0;
282 }
283 
284 static int hostmixer_release(struct inode *inode, struct file *file)
285 {
286 	struct hostmixer_state *state = file->private_data;
287 
288 #ifdef DEBUG
289 	printk(KERN_DEBUG "hostmixer: release called\n");
290 #endif
291 
292 	os_close_file(state->fd);
293 	kfree(state);
294 
295 	return 0;
296 }
297 
298 /* kernel module operations */
299 
300 static const struct file_operations hostaudio_fops = {
301 	.owner          = THIS_MODULE,
302 	.llseek         = no_llseek,
303 	.read           = hostaudio_read,
304 	.write          = hostaudio_write,
305 	.poll           = hostaudio_poll,
306 	.unlocked_ioctl	= hostaudio_ioctl,
307 	.mmap           = NULL,
308 	.open           = hostaudio_open,
309 	.release        = hostaudio_release,
310 };
311 
312 static const struct file_operations hostmixer_fops = {
313 	.owner          = THIS_MODULE,
314 	.llseek         = no_llseek,
315 	.unlocked_ioctl	= hostmixer_ioctl_mixdev,
316 	.open           = hostmixer_open_mixdev,
317 	.release        = hostmixer_release,
318 };
319 
320 struct {
321 	int dev_audio;
322 	int dev_mixer;
323 } module_data;
324 
325 MODULE_AUTHOR("Steve Schmidtke");
326 MODULE_DESCRIPTION("UML Audio Relay");
327 MODULE_LICENSE("GPL");
328 
329 static int __init hostaudio_init_module(void)
330 {
331 	__kernel_param_lock();
332 	printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
333 	       dsp, mixer);
334 	__kernel_param_unlock();
335 
336 	module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
337 	if (module_data.dev_audio < 0) {
338 		printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
339 		return -ENODEV;
340 	}
341 
342 	module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
343 	if (module_data.dev_mixer < 0) {
344 		printk(KERN_ERR "hostmixer: couldn't register mixer "
345 		       "device!\n");
346 		unregister_sound_dsp(module_data.dev_audio);
347 		return -ENODEV;
348 	}
349 
350 	return 0;
351 }
352 
353 static void __exit hostaudio_cleanup_module (void)
354 {
355 	unregister_sound_mixer(module_data.dev_mixer);
356 	unregister_sound_dsp(module_data.dev_audio);
357 }
358 
359 module_init(hostaudio_init_module);
360 module_exit(hostaudio_cleanup_module);
361