1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2002 Steve Schmidtke
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 <linux/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
set_dsp(char * name,int * add)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 
set_mixer(char * name,int * add)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 
hostaudio_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)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 
hostaudio_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)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 = memdup_user(buffer, count);
109 	if (IS_ERR(kbuf))
110 		return PTR_ERR(kbuf);
111 
112 	err = os_write_file(state->fd, kbuf, count);
113 	if (err < 0)
114 		goto out;
115 	*ppos += err;
116 
117  out:
118 	kfree(kbuf);
119 	return err;
120 }
121 
hostaudio_poll(struct file * file,struct poll_table_struct * wait)122 static __poll_t hostaudio_poll(struct file *file,
123 				struct poll_table_struct *wait)
124 {
125 #ifdef DEBUG
126 	printk(KERN_DEBUG "hostaudio: poll called (unimplemented)\n");
127 #endif
128 
129 	return 0;
130 }
131 
hostaudio_ioctl(struct file * file,unsigned int cmd,unsigned long arg)132 static long hostaudio_ioctl(struct file *file,
133 			   unsigned int cmd, unsigned long arg)
134 {
135 	struct hostaudio_state *state = file->private_data;
136 	unsigned long data = 0;
137 	int err;
138 
139 #ifdef DEBUG
140 	printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u\n", cmd);
141 #endif
142 	switch(cmd){
143 	case SNDCTL_DSP_SPEED:
144 	case SNDCTL_DSP_STEREO:
145 	case SNDCTL_DSP_GETBLKSIZE:
146 	case SNDCTL_DSP_CHANNELS:
147 	case SNDCTL_DSP_SUBDIVIDE:
148 	case SNDCTL_DSP_SETFRAGMENT:
149 		if (get_user(data, (int __user *) arg))
150 			return -EFAULT;
151 		break;
152 	default:
153 		break;
154 	}
155 
156 	err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
157 
158 	switch(cmd){
159 	case SNDCTL_DSP_SPEED:
160 	case SNDCTL_DSP_STEREO:
161 	case SNDCTL_DSP_GETBLKSIZE:
162 	case SNDCTL_DSP_CHANNELS:
163 	case SNDCTL_DSP_SUBDIVIDE:
164 	case SNDCTL_DSP_SETFRAGMENT:
165 		if (put_user(data, (int __user *) arg))
166 			return -EFAULT;
167 		break;
168 	default:
169 		break;
170 	}
171 
172 	return err;
173 }
174 
hostaudio_open(struct inode * inode,struct file * file)175 static int hostaudio_open(struct inode *inode, struct file *file)
176 {
177 	struct hostaudio_state *state;
178 	int r = 0, w = 0;
179 	int ret;
180 
181 #ifdef DEBUG
182 	kernel_param_lock(THIS_MODULE);
183 	printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
184 	kernel_param_unlock(THIS_MODULE);
185 #endif
186 
187 	state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
188 	if (state == NULL)
189 		return -ENOMEM;
190 
191 	if (file->f_mode & FMODE_READ)
192 		r = 1;
193 	if (file->f_mode & FMODE_WRITE)
194 		w = 1;
195 
196 	kernel_param_lock(THIS_MODULE);
197 	mutex_lock(&hostaudio_mutex);
198 	ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
199 	mutex_unlock(&hostaudio_mutex);
200 	kernel_param_unlock(THIS_MODULE);
201 
202 	if (ret < 0) {
203 		kfree(state);
204 		return ret;
205 	}
206 	state->fd = ret;
207 	file->private_data = state;
208 	return 0;
209 }
210 
hostaudio_release(struct inode * inode,struct file * file)211 static int hostaudio_release(struct inode *inode, struct file *file)
212 {
213 	struct hostaudio_state *state = file->private_data;
214 
215 #ifdef DEBUG
216 	printk(KERN_DEBUG "hostaudio: release called\n");
217 #endif
218 	os_close_file(state->fd);
219 	kfree(state);
220 
221 	return 0;
222 }
223 
224 /* /dev/mixer file operations */
225 
hostmixer_ioctl_mixdev(struct file * file,unsigned int cmd,unsigned long arg)226 static long hostmixer_ioctl_mixdev(struct file *file,
227 				  unsigned int cmd, unsigned long arg)
228 {
229 	struct hostmixer_state *state = file->private_data;
230 
231 #ifdef DEBUG
232 	printk(KERN_DEBUG "hostmixer: ioctl called\n");
233 #endif
234 
235 	return os_ioctl_generic(state->fd, cmd, arg);
236 }
237 
hostmixer_open_mixdev(struct inode * inode,struct file * file)238 static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
239 {
240 	struct hostmixer_state *state;
241 	int r = 0, w = 0;
242 	int ret;
243 
244 #ifdef DEBUG
245 	printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
246 #endif
247 
248 	state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
249 	if (state == NULL)
250 		return -ENOMEM;
251 
252 	if (file->f_mode & FMODE_READ)
253 		r = 1;
254 	if (file->f_mode & FMODE_WRITE)
255 		w = 1;
256 
257 	kernel_param_lock(THIS_MODULE);
258 	mutex_lock(&hostaudio_mutex);
259 	ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
260 	mutex_unlock(&hostaudio_mutex);
261 	kernel_param_unlock(THIS_MODULE);
262 
263 	if (ret < 0) {
264 		kernel_param_lock(THIS_MODULE);
265 		printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
266 		       "err = %d\n", dsp, -ret);
267 		kernel_param_unlock(THIS_MODULE);
268 		kfree(state);
269 		return ret;
270 	}
271 
272 	file->private_data = state;
273 	return 0;
274 }
275 
hostmixer_release(struct inode * inode,struct file * file)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 	.compat_ioctl	= compat_ptr_ioctl,
300 	.mmap           = NULL,
301 	.open           = hostaudio_open,
302 	.release        = hostaudio_release,
303 };
304 
305 static const struct file_operations hostmixer_fops = {
306 	.owner          = THIS_MODULE,
307 	.llseek         = no_llseek,
308 	.unlocked_ioctl	= hostmixer_ioctl_mixdev,
309 	.open           = hostmixer_open_mixdev,
310 	.release        = hostmixer_release,
311 };
312 
313 struct {
314 	int dev_audio;
315 	int dev_mixer;
316 } module_data;
317 
318 MODULE_AUTHOR("Steve Schmidtke");
319 MODULE_DESCRIPTION("UML Audio Relay");
320 MODULE_LICENSE("GPL");
321 
hostaudio_init_module(void)322 static int __init hostaudio_init_module(void)
323 {
324 	kernel_param_lock(THIS_MODULE);
325 	printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
326 	       dsp, mixer);
327 	kernel_param_unlock(THIS_MODULE);
328 
329 	module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
330 	if (module_data.dev_audio < 0) {
331 		printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
332 		return -ENODEV;
333 	}
334 
335 	module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
336 	if (module_data.dev_mixer < 0) {
337 		printk(KERN_ERR "hostmixer: couldn't register mixer "
338 		       "device!\n");
339 		unregister_sound_dsp(module_data.dev_audio);
340 		return -ENODEV;
341 	}
342 
343 	return 0;
344 }
345 
hostaudio_cleanup_module(void)346 static void __exit hostaudio_cleanup_module (void)
347 {
348 	unregister_sound_mixer(module_data.dev_mixer);
349 	unregister_sound_dsp(module_data.dev_audio);
350 }
351 
352 module_init(hostaudio_init_module);
353 module_exit(hostaudio_cleanup_module);
354