xref: /linux/arch/um/drivers/hostaudio_kern.c (revision cc4589ebfae6f8dbb5cf880a0a67eedab3416492)
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 	printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
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 	lock_kernel();
203 	ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
204 	unlock_kernel();
205 
206 	if (ret < 0) {
207 		kfree(state);
208 		return ret;
209 	}
210 	state->fd = ret;
211 	file->private_data = state;
212 	return 0;
213 }
214 
215 static int hostaudio_release(struct inode *inode, struct file *file)
216 {
217 	struct hostaudio_state *state = file->private_data;
218 
219 #ifdef DEBUG
220 	printk(KERN_DEBUG "hostaudio: release called\n");
221 #endif
222 	os_close_file(state->fd);
223 	kfree(state);
224 
225 	return 0;
226 }
227 
228 /* /dev/mixer file operations */
229 
230 static long hostmixer_ioctl_mixdev(struct file *file,
231 				  unsigned int cmd, unsigned long arg)
232 {
233 	struct hostmixer_state *state = file->private_data;
234 
235 #ifdef DEBUG
236 	printk(KERN_DEBUG "hostmixer: ioctl called\n");
237 #endif
238 
239 	return os_ioctl_generic(state->fd, cmd, arg);
240 }
241 
242 static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
243 {
244 	struct hostmixer_state *state;
245 	int r = 0, w = 0;
246 	int ret;
247 
248 #ifdef DEBUG
249 	printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
250 #endif
251 
252 	state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
253 	if (state == NULL)
254 		return -ENOMEM;
255 
256 	if (file->f_mode & FMODE_READ)
257 		r = 1;
258 	if (file->f_mode & FMODE_WRITE)
259 		w = 1;
260 
261 	lock_kernel();
262 	ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
263 	unlock_kernel();
264 
265 	if (ret < 0) {
266 		printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
267 		       "err = %d\n", dsp, -ret);
268 		kfree(state);
269 		return ret;
270 	}
271 
272 	file->private_data = state;
273 	return 0;
274 }
275 
276 static int hostmixer_release(struct inode *inode, struct file *file)
277 {
278 	struct hostmixer_state *state = file->private_data;
279 
280 #ifdef DEBUG
281 	printk(KERN_DEBUG "hostmixer: release called\n");
282 #endif
283 
284 	os_close_file(state->fd);
285 	kfree(state);
286 
287 	return 0;
288 }
289 
290 /* kernel module operations */
291 
292 static const struct file_operations hostaudio_fops = {
293 	.owner          = THIS_MODULE,
294 	.llseek         = no_llseek,
295 	.read           = hostaudio_read,
296 	.write          = hostaudio_write,
297 	.poll           = hostaudio_poll,
298 	.unlocked_ioctl	= hostaudio_ioctl,
299 	.mmap           = NULL,
300 	.open           = hostaudio_open,
301 	.release        = hostaudio_release,
302 };
303 
304 static const struct file_operations hostmixer_fops = {
305 	.owner          = THIS_MODULE,
306 	.llseek         = no_llseek,
307 	.unlocked_ioctl	= hostmixer_ioctl_mixdev,
308 	.open           = hostmixer_open_mixdev,
309 	.release        = hostmixer_release,
310 };
311 
312 struct {
313 	int dev_audio;
314 	int dev_mixer;
315 } module_data;
316 
317 MODULE_AUTHOR("Steve Schmidtke");
318 MODULE_DESCRIPTION("UML Audio Relay");
319 MODULE_LICENSE("GPL");
320 
321 static int __init hostaudio_init_module(void)
322 {
323 	printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
324 	       dsp, mixer);
325 
326 	module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
327 	if (module_data.dev_audio < 0) {
328 		printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
329 		return -ENODEV;
330 	}
331 
332 	module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
333 	if (module_data.dev_mixer < 0) {
334 		printk(KERN_ERR "hostmixer: couldn't register mixer "
335 		       "device!\n");
336 		unregister_sound_dsp(module_data.dev_audio);
337 		return -ENODEV;
338 	}
339 
340 	return 0;
341 }
342 
343 static void __exit hostaudio_cleanup_module (void)
344 {
345 	unregister_sound_mixer(module_data.dev_mixer);
346 	unregister_sound_dsp(module_data.dev_audio);
347 }
348 
349 module_init(hostaudio_init_module);
350 module_exit(hostaudio_cleanup_module);
351