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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> | |
c6994e6f BW |
13 | #include <linux/device.h> |
14 | #include <linux/delay.h> | |
15 | #include <linux/ctype.h> | |
16 | #include <linux/random.h> | |
17 | #include <linux/syscalls.h> | |
18 | ||
19 | #include "u_audio.h" | |
20 | ||
21 | /* | |
22 | * This component encapsulates the ALSA devices for USB audio gadget | |
23 | */ | |
24 | ||
25 | #define FILE_PCM_PLAYBACK "/dev/snd/pcmC0D0p" | |
26 | #define FILE_PCM_CAPTURE "/dev/snd/pcmC0D0c" | |
27 | #define FILE_CONTROL "/dev/snd/controlC0" | |
28 | ||
29 | static char *fn_play = FILE_PCM_PLAYBACK; | |
30 | module_param(fn_play, charp, S_IRUGO); | |
31 | MODULE_PARM_DESC(fn_play, "Playback PCM device file name"); | |
32 | ||
33 | static char *fn_cap = FILE_PCM_CAPTURE; | |
34 | module_param(fn_cap, charp, S_IRUGO); | |
35 | MODULE_PARM_DESC(fn_cap, "Capture PCM device file name"); | |
36 | ||
37 | static char *fn_cntl = FILE_CONTROL; | |
38 | module_param(fn_cntl, charp, S_IRUGO); | |
39 | MODULE_PARM_DESC(fn_cntl, "Control device file name"); | |
40 | ||
41 | /*-------------------------------------------------------------------------*/ | |
42 | ||
43 | /** | |
44 | * Some ALSA internal helper functions | |
45 | */ | |
46 | static int snd_interval_refine_set(struct snd_interval *i, unsigned int val) | |
47 | { | |
48 | struct snd_interval t; | |
49 | t.empty = 0; | |
50 | t.min = t.max = val; | |
51 | t.openmin = t.openmax = 0; | |
52 | t.integer = 1; | |
53 | return snd_interval_refine(i, &t); | |
54 | } | |
55 | ||
56 | static int _snd_pcm_hw_param_set(struct snd_pcm_hw_params *params, | |
57 | snd_pcm_hw_param_t var, unsigned int val, | |
58 | int dir) | |
59 | { | |
60 | int changed; | |
61 | if (hw_is_mask(var)) { | |
62 | struct snd_mask *m = hw_param_mask(params, var); | |
63 | if (val == 0 && dir < 0) { | |
64 | changed = -EINVAL; | |
65 | snd_mask_none(m); | |
66 | } else { | |
67 | if (dir > 0) | |
68 | val++; | |
69 | else if (dir < 0) | |
70 | val--; | |
71 | changed = snd_mask_refine_set( | |
72 | hw_param_mask(params, var), val); | |
73 | } | |
74 | } else if (hw_is_interval(var)) { | |
75 | struct snd_interval *i = hw_param_interval(params, var); | |
76 | if (val == 0 && dir < 0) { | |
77 | changed = -EINVAL; | |
78 | snd_interval_none(i); | |
79 | } else if (dir == 0) | |
80 | changed = snd_interval_refine_set(i, val); | |
81 | else { | |
82 | struct snd_interval t; | |
83 | t.openmin = 1; | |
84 | t.openmax = 1; | |
85 | t.empty = 0; | |
86 | t.integer = 0; | |
87 | if (dir < 0) { | |
88 | t.min = val - 1; | |
89 | t.max = val; | |
90 | } else { | |
91 | t.min = val; | |
92 | t.max = val+1; | |
93 | } | |
94 | changed = snd_interval_refine(i, &t); | |
95 | } | |
96 | } else | |
97 | return -EINVAL; | |
98 | if (changed) { | |
99 | params->cmask |= 1 << var; | |
100 | params->rmask |= 1 << var; | |
101 | } | |
102 | return changed; | |
103 | } | |
104 | /*-------------------------------------------------------------------------*/ | |
105 | ||
106 | /** | |
107 | * Set default hardware params | |
108 | */ | |
109 | static int playback_default_hw_params(struct gaudio_snd_dev *snd) | |
110 | { | |
111 | struct snd_pcm_substream *substream = snd->substream; | |
112 | struct snd_pcm_hw_params *params; | |
113 | snd_pcm_sframes_t result; | |
114 | ||
115 | /* | |
116 | * SNDRV_PCM_ACCESS_RW_INTERLEAVED, | |
117 | * SNDRV_PCM_FORMAT_S16_LE | |
118 | * CHANNELS: 2 | |
119 | * RATE: 48000 | |
120 | */ | |
121 | snd->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED; | |
122 | snd->format = SNDRV_PCM_FORMAT_S16_LE; | |
123 | snd->channels = 2; | |
124 | snd->rate = 48000; | |
125 | ||
126 | params = kzalloc(sizeof(*params), GFP_KERNEL); | |
127 | if (!params) | |
128 | return -ENOMEM; | |
129 | ||
130 | _snd_pcm_hw_params_any(params); | |
131 | _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_ACCESS, | |
132 | snd->access, 0); | |
133 | _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_FORMAT, | |
134 | snd->format, 0); | |
135 | _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_CHANNELS, | |
136 | snd->channels, 0); | |
137 | _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_RATE, | |
138 | snd->rate, 0); | |
139 | ||
140 | snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL); | |
141 | snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_HW_PARAMS, params); | |
142 | ||
143 | result = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_PREPARE, NULL); | |
144 | if (result < 0) { | |
145 | ERROR(snd->card, | |
146 | "Preparing sound card failed: %d\n", (int)result); | |
147 | kfree(params); | |
148 | return result; | |
149 | } | |
150 | ||
151 | /* Store the hardware parameters */ | |
152 | snd->access = params_access(params); | |
153 | snd->format = params_format(params); | |
154 | snd->channels = params_channels(params); | |
155 | snd->rate = params_rate(params); | |
156 | ||
157 | kfree(params); | |
158 | ||
159 | INFO(snd->card, | |
160 | "Hardware params: access %x, format %x, channels %d, rate %d\n", | |
161 | snd->access, snd->format, snd->channels, snd->rate); | |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
166 | /** | |
167 | * Playback audio buffer data by ALSA PCM device | |
168 | */ | |
169 | static size_t u_audio_playback(struct gaudio *card, void *buf, size_t count) | |
170 | { | |
171 | struct gaudio_snd_dev *snd = &card->playback; | |
172 | struct snd_pcm_substream *substream = snd->substream; | |
173 | struct snd_pcm_runtime *runtime = substream->runtime; | |
174 | mm_segment_t old_fs; | |
175 | ssize_t result; | |
176 | snd_pcm_sframes_t frames; | |
177 | ||
178 | try_again: | |
179 | if (runtime->status->state == SNDRV_PCM_STATE_XRUN || | |
180 | runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) { | |
181 | result = snd_pcm_kernel_ioctl(substream, | |
182 | SNDRV_PCM_IOCTL_PREPARE, NULL); | |
183 | if (result < 0) { | |
184 | ERROR(card, "Preparing sound card failed: %d\n", | |
185 | (int)result); | |
186 | return result; | |
187 | } | |
188 | } | |
189 | ||
190 | frames = bytes_to_frames(runtime, count); | |
191 | old_fs = get_fs(); | |
192 | set_fs(KERNEL_DS); | |
193 | result = snd_pcm_lib_write(snd->substream, buf, frames); | |
194 | if (result != frames) { | |
195 | ERROR(card, "Playback error: %d\n", (int)result); | |
196 | set_fs(old_fs); | |
197 | goto try_again; | |
198 | } | |
199 | set_fs(old_fs); | |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | static int u_audio_get_playback_channels(struct gaudio *card) | |
205 | { | |
206 | return card->playback.channels; | |
207 | } | |
208 | ||
209 | static int u_audio_get_playback_rate(struct gaudio *card) | |
210 | { | |
211 | return card->playback.rate; | |
212 | } | |
213 | ||
214 | /** | |
215 | * Open ALSA PCM and control device files | |
216 | * Initial the PCM or control device | |
217 | */ | |
218 | static int gaudio_open_snd_dev(struct gaudio *card) | |
219 | { | |
220 | struct snd_pcm_file *pcm_file; | |
221 | struct gaudio_snd_dev *snd; | |
222 | ||
223 | if (!card) | |
224 | return -ENODEV; | |
225 | ||
226 | /* Open control device */ | |
227 | snd = &card->control; | |
228 | snd->filp = filp_open(fn_cntl, O_RDWR, 0); | |
229 | if (IS_ERR(snd->filp)) { | |
230 | int ret = PTR_ERR(snd->filp); | |
231 | ERROR(card, "unable to open sound control device file: %s\n", | |
232 | fn_cntl); | |
233 | snd->filp = NULL; | |
234 | return ret; | |
235 | } | |
236 | snd->card = card; | |
237 | ||
238 | /* Open PCM playback device and setup substream */ | |
239 | snd = &card->playback; | |
240 | snd->filp = filp_open(fn_play, O_WRONLY, 0); | |
241 | if (IS_ERR(snd->filp)) { | |
242 | ERROR(card, "No such PCM playback device: %s\n", fn_play); | |
243 | snd->filp = NULL; | |
244 | } | |
245 | pcm_file = snd->filp->private_data; | |
246 | snd->substream = pcm_file->substream; | |
247 | snd->card = card; | |
248 | playback_default_hw_params(snd); | |
249 | ||
250 | /* Open PCM capture device and setup substream */ | |
251 | snd = &card->capture; | |
252 | snd->filp = filp_open(fn_cap, O_RDONLY, 0); | |
253 | if (IS_ERR(snd->filp)) { | |
254 | ERROR(card, "No such PCM capture device: %s\n", fn_cap); | |
e792b1b0 RC |
255 | snd->substream = NULL; |
256 | snd->card = NULL; | |
257 | } else { | |
258 | pcm_file = snd->filp->private_data; | |
259 | snd->substream = pcm_file->substream; | |
260 | snd->card = card; | |
c6994e6f | 261 | } |
c6994e6f BW |
262 | |
263 | return 0; | |
264 | } | |
265 | ||
266 | /** | |
267 | * Close ALSA PCM and control device files | |
268 | */ | |
269 | static int gaudio_close_snd_dev(struct gaudio *gau) | |
270 | { | |
271 | struct gaudio_snd_dev *snd; | |
272 | ||
273 | /* Close control device */ | |
274 | snd = &gau->control; | |
275 | if (!IS_ERR(snd->filp)) | |
276 | filp_close(snd->filp, current->files); | |
277 | ||
278 | /* Close PCM playback device and setup substream */ | |
279 | snd = &gau->playback; | |
280 | if (!IS_ERR(snd->filp)) | |
281 | filp_close(snd->filp, current->files); | |
282 | ||
283 | /* Close PCM capture device and setup substream */ | |
284 | snd = &gau->capture; | |
285 | if (!IS_ERR(snd->filp)) | |
286 | filp_close(snd->filp, current->files); | |
287 | ||
288 | return 0; | |
289 | } | |
290 | ||
291 | /** | |
292 | * gaudio_setup - setup ALSA interface and preparing for USB transfer | |
293 | * | |
294 | * This sets up PCM, mixer or MIDI ALSA devices fore USB gadget using. | |
295 | * | |
296 | * Returns negative errno, or zero on success | |
297 | */ | |
298 | int __init gaudio_setup(struct gaudio *card) | |
299 | { | |
300 | int ret; | |
301 | ||
302 | ret = gaudio_open_snd_dev(card); | |
303 | if (ret) | |
304 | ERROR(card, "we need at least one control device\n"); | |
305 | ||
306 | return ret; | |
307 | ||
308 | } | |
309 | ||
310 | /** | |
311 | * gaudio_cleanup - remove ALSA device interface | |
312 | * | |
313 | * This is called to free all resources allocated by @gaudio_setup(). | |
314 | */ | |
315 | void gaudio_cleanup(struct gaudio *card) | |
316 | { | |
317 | if (card) | |
318 | gaudio_close_snd_dev(card); | |
319 | } | |
320 |