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c6994e6f BW |
1 | /* |
2 | * u_audio.c -- ALSA audio utilities for Gadget stack | |
3 | * | |
4 | * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org> | |
5 | * Copyright (C) 2008 Analog Devices, Inc | |
6 | * | |
7 | * Enter bugs at http://blackfin.uclinux.org/ | |
8 | * | |
9 | * Licensed under the GPL-2 or later. | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/utsname.h> | |
14 | #include <linux/device.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/ctype.h> | |
17 | #include <linux/random.h> | |
18 | #include <linux/syscalls.h> | |
19 | ||
20 | #include "u_audio.h" | |
21 | ||
22 | /* | |
23 | * This component encapsulates the ALSA devices for USB audio gadget | |
24 | */ | |
25 | ||
26 | #define FILE_PCM_PLAYBACK "/dev/snd/pcmC0D0p" | |
27 | #define FILE_PCM_CAPTURE "/dev/snd/pcmC0D0c" | |
28 | #define FILE_CONTROL "/dev/snd/controlC0" | |
29 | ||
30 | static char *fn_play = FILE_PCM_PLAYBACK; | |
31 | module_param(fn_play, charp, S_IRUGO); | |
32 | MODULE_PARM_DESC(fn_play, "Playback PCM device file name"); | |
33 | ||
34 | static char *fn_cap = FILE_PCM_CAPTURE; | |
35 | module_param(fn_cap, charp, S_IRUGO); | |
36 | MODULE_PARM_DESC(fn_cap, "Capture PCM device file name"); | |
37 | ||
38 | static char *fn_cntl = FILE_CONTROL; | |
39 | module_param(fn_cntl, charp, S_IRUGO); | |
40 | MODULE_PARM_DESC(fn_cntl, "Control device file name"); | |
41 | ||
42 | /*-------------------------------------------------------------------------*/ | |
43 | ||
44 | /** | |
45 | * Some ALSA internal helper functions | |
46 | */ | |
47 | static int snd_interval_refine_set(struct snd_interval *i, unsigned int val) | |
48 | { | |
49 | struct snd_interval t; | |
50 | t.empty = 0; | |
51 | t.min = t.max = val; | |
52 | t.openmin = t.openmax = 0; | |
53 | t.integer = 1; | |
54 | return snd_interval_refine(i, &t); | |
55 | } | |
56 | ||
57 | static int _snd_pcm_hw_param_set(struct snd_pcm_hw_params *params, | |
58 | snd_pcm_hw_param_t var, unsigned int val, | |
59 | int dir) | |
60 | { | |
61 | int changed; | |
62 | if (hw_is_mask(var)) { | |
63 | struct snd_mask *m = hw_param_mask(params, var); | |
64 | if (val == 0 && dir < 0) { | |
65 | changed = -EINVAL; | |
66 | snd_mask_none(m); | |
67 | } else { | |
68 | if (dir > 0) | |
69 | val++; | |
70 | else if (dir < 0) | |
71 | val--; | |
72 | changed = snd_mask_refine_set( | |
73 | hw_param_mask(params, var), val); | |
74 | } | |
75 | } else if (hw_is_interval(var)) { | |
76 | struct snd_interval *i = hw_param_interval(params, var); | |
77 | if (val == 0 && dir < 0) { | |
78 | changed = -EINVAL; | |
79 | snd_interval_none(i); | |
80 | } else if (dir == 0) | |
81 | changed = snd_interval_refine_set(i, val); | |
82 | else { | |
83 | struct snd_interval t; | |
84 | t.openmin = 1; | |
85 | t.openmax = 1; | |
86 | t.empty = 0; | |
87 | t.integer = 0; | |
88 | if (dir < 0) { | |
89 | t.min = val - 1; | |
90 | t.max = val; | |
91 | } else { | |
92 | t.min = val; | |
93 | t.max = val+1; | |
94 | } | |
95 | changed = snd_interval_refine(i, &t); | |
96 | } | |
97 | } else | |
98 | return -EINVAL; | |
99 | if (changed) { | |
100 | params->cmask |= 1 << var; | |
101 | params->rmask |= 1 << var; | |
102 | } | |
103 | return changed; | |
104 | } | |
105 | /*-------------------------------------------------------------------------*/ | |
106 | ||
107 | /** | |
108 | * Set default hardware params | |
109 | */ | |
110 | static int playback_default_hw_params(struct gaudio_snd_dev *snd) | |
111 | { | |
112 | struct snd_pcm_substream *substream = snd->substream; | |
113 | struct snd_pcm_hw_params *params; | |
114 | snd_pcm_sframes_t result; | |
115 | ||
116 | /* | |
117 | * SNDRV_PCM_ACCESS_RW_INTERLEAVED, | |
118 | * SNDRV_PCM_FORMAT_S16_LE | |
119 | * CHANNELS: 2 | |
120 | * RATE: 48000 | |
121 | */ | |
122 | snd->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED; | |
123 | snd->format = SNDRV_PCM_FORMAT_S16_LE; | |
124 | snd->channels = 2; | |
125 | snd->rate = 48000; | |
126 | ||
127 | params = kzalloc(sizeof(*params), GFP_KERNEL); | |
128 | if (!params) | |
129 | return -ENOMEM; | |
130 | ||
131 | _snd_pcm_hw_params_any(params); | |
132 | _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_ACCESS, | |
133 | snd->access, 0); | |
134 | _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_FORMAT, | |
135 | snd->format, 0); | |
136 | _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_CHANNELS, | |
137 | snd->channels, 0); | |
138 | _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_RATE, | |
139 | snd->rate, 0); | |
140 | ||
141 | snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL); | |
142 | snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_HW_PARAMS, params); | |
143 | ||
144 | result = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_PREPARE, NULL); | |
145 | if (result < 0) { | |
146 | ERROR(snd->card, | |
147 | "Preparing sound card failed: %d\n", (int)result); | |
148 | kfree(params); | |
149 | return result; | |
150 | } | |
151 | ||
152 | /* Store the hardware parameters */ | |
153 | snd->access = params_access(params); | |
154 | snd->format = params_format(params); | |
155 | snd->channels = params_channels(params); | |
156 | snd->rate = params_rate(params); | |
157 | ||
158 | kfree(params); | |
159 | ||
160 | INFO(snd->card, | |
161 | "Hardware params: access %x, format %x, channels %d, rate %d\n", | |
162 | snd->access, snd->format, snd->channels, snd->rate); | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
167 | /** | |
168 | * Playback audio buffer data by ALSA PCM device | |
169 | */ | |
170 | static size_t u_audio_playback(struct gaudio *card, void *buf, size_t count) | |
171 | { | |
172 | struct gaudio_snd_dev *snd = &card->playback; | |
173 | struct snd_pcm_substream *substream = snd->substream; | |
174 | struct snd_pcm_runtime *runtime = substream->runtime; | |
175 | mm_segment_t old_fs; | |
176 | ssize_t result; | |
177 | snd_pcm_sframes_t frames; | |
178 | ||
179 | try_again: | |
180 | if (runtime->status->state == SNDRV_PCM_STATE_XRUN || | |
181 | runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) { | |
182 | result = snd_pcm_kernel_ioctl(substream, | |
183 | SNDRV_PCM_IOCTL_PREPARE, NULL); | |
184 | if (result < 0) { | |
185 | ERROR(card, "Preparing sound card failed: %d\n", | |
186 | (int)result); | |
187 | return result; | |
188 | } | |
189 | } | |
190 | ||
191 | frames = bytes_to_frames(runtime, count); | |
192 | old_fs = get_fs(); | |
193 | set_fs(KERNEL_DS); | |
194 | result = snd_pcm_lib_write(snd->substream, buf, frames); | |
195 | if (result != frames) { | |
196 | ERROR(card, "Playback error: %d\n", (int)result); | |
197 | set_fs(old_fs); | |
198 | goto try_again; | |
199 | } | |
200 | set_fs(old_fs); | |
201 | ||
202 | return 0; | |
203 | } | |
204 | ||
205 | static int u_audio_get_playback_channels(struct gaudio *card) | |
206 | { | |
207 | return card->playback.channels; | |
208 | } | |
209 | ||
210 | static int u_audio_get_playback_rate(struct gaudio *card) | |
211 | { | |
212 | return card->playback.rate; | |
213 | } | |
214 | ||
215 | /** | |
216 | * Open ALSA PCM and control device files | |
217 | * Initial the PCM or control device | |
218 | */ | |
219 | static int gaudio_open_snd_dev(struct gaudio *card) | |
220 | { | |
221 | struct snd_pcm_file *pcm_file; | |
222 | struct gaudio_snd_dev *snd; | |
223 | ||
224 | if (!card) | |
225 | return -ENODEV; | |
226 | ||
227 | /* Open control device */ | |
228 | snd = &card->control; | |
229 | snd->filp = filp_open(fn_cntl, O_RDWR, 0); | |
230 | if (IS_ERR(snd->filp)) { | |
231 | int ret = PTR_ERR(snd->filp); | |
232 | ERROR(card, "unable to open sound control device file: %s\n", | |
233 | fn_cntl); | |
234 | snd->filp = NULL; | |
235 | return ret; | |
236 | } | |
237 | snd->card = card; | |
238 | ||
239 | /* Open PCM playback device and setup substream */ | |
240 | snd = &card->playback; | |
241 | snd->filp = filp_open(fn_play, O_WRONLY, 0); | |
242 | if (IS_ERR(snd->filp)) { | |
243 | ERROR(card, "No such PCM playback device: %s\n", fn_play); | |
244 | snd->filp = NULL; | |
245 | } | |
246 | pcm_file = snd->filp->private_data; | |
247 | snd->substream = pcm_file->substream; | |
248 | snd->card = card; | |
249 | playback_default_hw_params(snd); | |
250 | ||
251 | /* Open PCM capture device and setup substream */ | |
252 | snd = &card->capture; | |
253 | snd->filp = filp_open(fn_cap, O_RDONLY, 0); | |
254 | if (IS_ERR(snd->filp)) { | |
255 | ERROR(card, "No such PCM capture device: %s\n", fn_cap); | |
256 | snd->filp = NULL; | |
257 | } | |
258 | pcm_file = snd->filp->private_data; | |
259 | snd->substream = pcm_file->substream; | |
260 | snd->card = card; | |
261 | ||
262 | return 0; | |
263 | } | |
264 | ||
265 | /** | |
266 | * Close ALSA PCM and control device files | |
267 | */ | |
268 | static int gaudio_close_snd_dev(struct gaudio *gau) | |
269 | { | |
270 | struct gaudio_snd_dev *snd; | |
271 | ||
272 | /* Close control device */ | |
273 | snd = &gau->control; | |
274 | if (!IS_ERR(snd->filp)) | |
275 | filp_close(snd->filp, current->files); | |
276 | ||
277 | /* Close PCM playback device and setup substream */ | |
278 | snd = &gau->playback; | |
279 | if (!IS_ERR(snd->filp)) | |
280 | filp_close(snd->filp, current->files); | |
281 | ||
282 | /* Close PCM capture device and setup substream */ | |
283 | snd = &gau->capture; | |
284 | if (!IS_ERR(snd->filp)) | |
285 | filp_close(snd->filp, current->files); | |
286 | ||
287 | return 0; | |
288 | } | |
289 | ||
290 | /** | |
291 | * gaudio_setup - setup ALSA interface and preparing for USB transfer | |
292 | * | |
293 | * This sets up PCM, mixer or MIDI ALSA devices fore USB gadget using. | |
294 | * | |
295 | * Returns negative errno, or zero on success | |
296 | */ | |
297 | int __init gaudio_setup(struct gaudio *card) | |
298 | { | |
299 | int ret; | |
300 | ||
301 | ret = gaudio_open_snd_dev(card); | |
302 | if (ret) | |
303 | ERROR(card, "we need at least one control device\n"); | |
304 | ||
305 | return ret; | |
306 | ||
307 | } | |
308 | ||
309 | /** | |
310 | * gaudio_cleanup - remove ALSA device interface | |
311 | * | |
312 | * This is called to free all resources allocated by @gaudio_setup(). | |
313 | */ | |
314 | void gaudio_cleanup(struct gaudio *card) | |
315 | { | |
316 | if (card) | |
317 | gaudio_close_snd_dev(card); | |
318 | } | |
319 |