xref: /openbmc/linux/arch/um/drivers/hostaudio_kern.c (revision a2818ee4)
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 <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
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 = 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 
122 static __poll_t hostaudio_poll(struct file *file,
123 				struct poll_table_struct *wait)
124 {
125 	__poll_t mask = 0;
126 
127 #ifdef DEBUG
128 	printk(KERN_DEBUG "hostaudio: poll called (unimplemented)\n");
129 #endif
130 
131 	return mask;
132 }
133 
134 static long hostaudio_ioctl(struct file *file,
135 			   unsigned int cmd, unsigned long arg)
136 {
137 	struct hostaudio_state *state = file->private_data;
138 	unsigned long data = 0;
139 	int err;
140 
141 #ifdef DEBUG
142 	printk(KERN_DEBUG "hostaudio: ioctl called, cmd = %u\n", cmd);
143 #endif
144 	switch(cmd){
145 	case SNDCTL_DSP_SPEED:
146 	case SNDCTL_DSP_STEREO:
147 	case SNDCTL_DSP_GETBLKSIZE:
148 	case SNDCTL_DSP_CHANNELS:
149 	case SNDCTL_DSP_SUBDIVIDE:
150 	case SNDCTL_DSP_SETFRAGMENT:
151 		if (get_user(data, (int __user *) arg))
152 			return -EFAULT;
153 		break;
154 	default:
155 		break;
156 	}
157 
158 	err = os_ioctl_generic(state->fd, cmd, (unsigned long) &data);
159 
160 	switch(cmd){
161 	case SNDCTL_DSP_SPEED:
162 	case SNDCTL_DSP_STEREO:
163 	case SNDCTL_DSP_GETBLKSIZE:
164 	case SNDCTL_DSP_CHANNELS:
165 	case SNDCTL_DSP_SUBDIVIDE:
166 	case SNDCTL_DSP_SETFRAGMENT:
167 		if (put_user(data, (int __user *) arg))
168 			return -EFAULT;
169 		break;
170 	default:
171 		break;
172 	}
173 
174 	return err;
175 }
176 
177 static int hostaudio_open(struct inode *inode, struct file *file)
178 {
179 	struct hostaudio_state *state;
180 	int r = 0, w = 0;
181 	int ret;
182 
183 #ifdef DEBUG
184 	kernel_param_lock(THIS_MODULE);
185 	printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
186 	kernel_param_unlock(THIS_MODULE);
187 #endif
188 
189 	state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
190 	if (state == NULL)
191 		return -ENOMEM;
192 
193 	if (file->f_mode & FMODE_READ)
194 		r = 1;
195 	if (file->f_mode & FMODE_WRITE)
196 		w = 1;
197 
198 	kernel_param_lock(THIS_MODULE);
199 	mutex_lock(&hostaudio_mutex);
200 	ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
201 	mutex_unlock(&hostaudio_mutex);
202 	kernel_param_unlock(THIS_MODULE);
203 
204 	if (ret < 0) {
205 		kfree(state);
206 		return ret;
207 	}
208 	state->fd = ret;
209 	file->private_data = state;
210 	return 0;
211 }
212 
213 static int hostaudio_release(struct inode *inode, struct file *file)
214 {
215 	struct hostaudio_state *state = file->private_data;
216 
217 #ifdef DEBUG
218 	printk(KERN_DEBUG "hostaudio: release called\n");
219 #endif
220 	os_close_file(state->fd);
221 	kfree(state);
222 
223 	return 0;
224 }
225 
226 /* /dev/mixer file operations */
227 
228 static long hostmixer_ioctl_mixdev(struct file *file,
229 				  unsigned int cmd, unsigned long arg)
230 {
231 	struct hostmixer_state *state = file->private_data;
232 
233 #ifdef DEBUG
234 	printk(KERN_DEBUG "hostmixer: ioctl called\n");
235 #endif
236 
237 	return os_ioctl_generic(state->fd, cmd, arg);
238 }
239 
240 static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
241 {
242 	struct hostmixer_state *state;
243 	int r = 0, w = 0;
244 	int ret;
245 
246 #ifdef DEBUG
247 	printk(KERN_DEBUG "hostmixer: open called (host: %s)\n", mixer);
248 #endif
249 
250 	state = kmalloc(sizeof(struct hostmixer_state), GFP_KERNEL);
251 	if (state == NULL)
252 		return -ENOMEM;
253 
254 	if (file->f_mode & FMODE_READ)
255 		r = 1;
256 	if (file->f_mode & FMODE_WRITE)
257 		w = 1;
258 
259 	kernel_param_lock(THIS_MODULE);
260 	mutex_lock(&hostaudio_mutex);
261 	ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
262 	mutex_unlock(&hostaudio_mutex);
263 	kernel_param_unlock(THIS_MODULE);
264 
265 	if (ret < 0) {
266 		kernel_param_lock(THIS_MODULE);
267 		printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
268 		       "err = %d\n", dsp, -ret);
269 		kernel_param_unlock(THIS_MODULE);
270 		kfree(state);
271 		return ret;
272 	}
273 
274 	file->private_data = state;
275 	return 0;
276 }
277 
278 static int hostmixer_release(struct inode *inode, struct file *file)
279 {
280 	struct hostmixer_state *state = file->private_data;
281 
282 #ifdef DEBUG
283 	printk(KERN_DEBUG "hostmixer: release called\n");
284 #endif
285 
286 	os_close_file(state->fd);
287 	kfree(state);
288 
289 	return 0;
290 }
291 
292 /* kernel module operations */
293 
294 static const struct file_operations hostaudio_fops = {
295 	.owner          = THIS_MODULE,
296 	.llseek         = no_llseek,
297 	.read           = hostaudio_read,
298 	.write          = hostaudio_write,
299 	.poll           = hostaudio_poll,
300 	.unlocked_ioctl	= hostaudio_ioctl,
301 	.mmap           = NULL,
302 	.open           = hostaudio_open,
303 	.release        = hostaudio_release,
304 };
305 
306 static const struct file_operations hostmixer_fops = {
307 	.owner          = THIS_MODULE,
308 	.llseek         = no_llseek,
309 	.unlocked_ioctl	= hostmixer_ioctl_mixdev,
310 	.open           = hostmixer_open_mixdev,
311 	.release        = hostmixer_release,
312 };
313 
314 struct {
315 	int dev_audio;
316 	int dev_mixer;
317 } module_data;
318 
319 MODULE_AUTHOR("Steve Schmidtke");
320 MODULE_DESCRIPTION("UML Audio Relay");
321 MODULE_LICENSE("GPL");
322 
323 static int __init hostaudio_init_module(void)
324 {
325 	kernel_param_lock(THIS_MODULE);
326 	printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
327 	       dsp, mixer);
328 	kernel_param_unlock(THIS_MODULE);
329 
330 	module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
331 	if (module_data.dev_audio < 0) {
332 		printk(KERN_ERR "hostaudio: couldn't register DSP device!\n");
333 		return -ENODEV;
334 	}
335 
336 	module_data.dev_mixer = register_sound_mixer(&hostmixer_fops, -1);
337 	if (module_data.dev_mixer < 0) {
338 		printk(KERN_ERR "hostmixer: couldn't register mixer "
339 		       "device!\n");
340 		unregister_sound_dsp(module_data.dev_audio);
341 		return -ENODEV;
342 	}
343 
344 	return 0;
345 }
346 
347 static void __exit hostaudio_cleanup_module (void)
348 {
349 	unregister_sound_mixer(module_data.dev_mixer);
350 	unregister_sound_dsp(module_data.dev_audio);
351 }
352 
353 module_init(hostaudio_init_module);
354 module_exit(hostaudio_cleanup_module);
355