Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * Line6 Linux USB driver - 0.8.0
  3  *
  4  * Copyright (C) 2004-2009 Markus Grabner (grabner@icg.tugraz.at)
  5  *
  6  *      This program is free software; you can redistribute it and/or
  7  *      modify it under the terms of the GNU General Public License as
  8  *      published by the Free Software Foundation, version 2.
  9  *
 10  */
 11 
 12 #include "driver.h"
 13 
 14 #include <sound/core.h>
 15 #include <sound/pcm.h>
 16 #include <sound/pcm_params.h>
 17 
 18 #include "audio.h"
 19 #include "pcm.h"
 20 #include "pod.h"
 21 #include "capture.h"
 22 
 23 
 24 /*
 25         Find a free URB and submit it.
 26 */
 27 static int submit_audio_in_urb(struct snd_pcm_substream *substream)
 28 {
 29         int index;
 30         unsigned long flags;
 31         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 32         int i, urb_size;
 33         struct urb *urb_in;
 34 
 35         spin_lock_irqsave(&line6pcm->lock_audio_in, flags);
 36         index = find_first_zero_bit(&line6pcm->active_urb_in, LINE6_ISO_BUFFERS);
 37 
 38         if (index < 0 || index >= LINE6_ISO_BUFFERS) {
 39                 spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);
 40                 dev_err(s2m(substream), "no free URB found\n");
 41                 return -EINVAL;
 42         }
 43 
 44         urb_in = line6pcm->urb_audio_in[index];
 45         urb_size = 0;
 46 
 47         for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
 48                 struct usb_iso_packet_descriptor *fin = &urb_in->iso_frame_desc[i];
 49                 fin->offset = urb_size;
 50                 fin->length = line6pcm->max_packet_size;
 51                 urb_size += line6pcm->max_packet_size;
 52         }
 53 
 54         urb_in->transfer_buffer = line6pcm->buffer_in + index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
 55         urb_in->transfer_buffer_length = urb_size;
 56         urb_in->context = substream;
 57 
 58         if (usb_submit_urb(urb_in, GFP_ATOMIC) == 0)
 59                 set_bit(index, &line6pcm->active_urb_in);
 60         else
 61                 dev_err(s2m(substream), "URB in #%d submission failed\n", index);
 62 
 63         spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);
 64         return 0;
 65 }
 66 
 67 /*
 68         Submit all currently available capture URBs.
 69 */
 70 static int submit_audio_in_all_urbs(struct snd_pcm_substream *substream)
 71 {
 72         int ret, i;
 73 
 74         for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
 75                 ret = submit_audio_in_urb(substream);
 76                 if (ret < 0)
 77                         return ret;
 78         }
 79 
 80         return 0;
 81 }
 82 
 83 /*
 84         Unlink all currently active capture URBs.
 85 */
 86 static void unlink_audio_in_urbs(struct snd_line6_pcm *line6pcm)
 87 {
 88         unsigned int i;
 89 
 90         for (i = LINE6_ISO_BUFFERS; i--;) {
 91                 if (test_bit(i, &line6pcm->active_urb_in)) {
 92                         if (!test_and_set_bit(i, &line6pcm->unlink_urb_in)) {
 93                                 struct urb *u = line6pcm->urb_audio_in[i];
 94                                 usb_unlink_urb(u);
 95                         }
 96                 }
 97         }
 98 }
 99 
100 /*
101         Wait until unlinking of all currently active capture URBs has been
102         finished.
103 */
104 static void wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)
105 {
106         int timeout = HZ;
107         unsigned int i;
108         int alive;
109 
110         do {
111                 alive = 0;
112                 for (i = LINE6_ISO_BUFFERS; i--;) {
113                         if (test_bit(i, &line6pcm->active_urb_in))
114                                 alive++;
115                 }
116                 if (!alive)
117                         break;
118                 set_current_state(TASK_UNINTERRUPTIBLE);
119                 schedule_timeout(1);
120         } while (--timeout > 0);
121         if (alive)
122                 snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
123 
124         line6pcm->active_urb_in = 0;
125         line6pcm->unlink_urb_in = 0;
126 }
127 
128 /*
129         Unlink all currently active capture URBs, and wait for finishing.
130 */
131 void unlink_wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)
132 {
133         unlink_audio_in_urbs(line6pcm);
134         wait_clear_audio_in_urbs(line6pcm);
135 }
136 
137 /*
138         Callback for completed capture URB.
139 */
140 static void audio_in_callback(struct urb *urb)
141 {
142         int i, index, length = 0, shutdown = 0;
143         int frames;
144         unsigned long flags;
145 
146         struct snd_pcm_substream *substream = (struct snd_pcm_substream *)urb->context;
147         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
148         const int bytes_per_frame = line6pcm->properties->bytes_per_frame;
149         struct snd_pcm_runtime *runtime = substream->runtime;
150 
151         /* find index of URB */
152         for (index = 0; index < LINE6_ISO_BUFFERS; ++index)
153                 if (urb == line6pcm->urb_audio_in[index])
154                         break;
155 
156 #if DO_DUMP_PCM_RECEIVE
157         for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
158                 struct usb_iso_packet_descriptor *fout = &urb->iso_frame_desc[i];
159                 line6_write_hexdump(line6pcm->line6, 'C', urb->transfer_buffer + fout->offset, fout->length);
160         }
161 #endif
162 
163         spin_lock_irqsave(&line6pcm->lock_audio_in, flags);
164 
165         for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
166                 char *fbuf;
167                 int fsize;
168                 struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];
169 
170                 if (fin->status == -18) {
171                         shutdown = 1;
172                         break;
173                 }
174 
175                 fbuf = urb->transfer_buffer + fin->offset;
176                 fsize = fin->actual_length;
177                 length += fsize;
178 
179                 if (fsize > 0) {
180                         frames = fsize / bytes_per_frame;
181 
182                         if (line6pcm->pos_in_done + frames > runtime->buffer_size) {
183                                 /*
184                                         The transferred area goes over buffer boundary,
185                                         copy two separate chunks.
186                                 */
187                                 int len;
188                                 len = runtime->buffer_size - line6pcm->pos_in_done;
189 
190                                 if (len > 0) {
191                                         memcpy(runtime->dma_area + line6pcm->pos_in_done * bytes_per_frame, fbuf, len * bytes_per_frame);
192                                         memcpy(runtime->dma_area, fbuf + len * bytes_per_frame, (frames - len) * bytes_per_frame);
193                                 } else
194                                         dev_err(s2m(substream), "driver bug: len = %d\n", len);  /* this is somewhat paranoid */
195                         } else {
196                                 /* copy single chunk */
197                                 memcpy(runtime->dma_area + line6pcm->pos_in_done * bytes_per_frame, fbuf, fsize * bytes_per_frame);
198                         }
199 
200                         if ((line6pcm->pos_in_done += frames) >= runtime->buffer_size)
201                                 line6pcm->pos_in_done -= runtime->buffer_size;
202                 }
203         }
204 
205         clear_bit(index, &line6pcm->active_urb_in);
206 
207         if (test_bit(index, &line6pcm->unlink_urb_in))
208                 shutdown = 1;
209 
210         spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);
211 
212         if (!shutdown) {
213                 submit_audio_in_urb(substream);
214 
215                 if ((line6pcm->bytes_in += length) >= line6pcm->period_in) {
216                         line6pcm->bytes_in -= line6pcm->period_in;
217                         snd_pcm_period_elapsed(substream);
218                 }
219         }
220 }
221 
222 /* open capture callback */
223 static int snd_line6_capture_open(struct snd_pcm_substream *substream)
224 {
225         int err;
226         struct snd_pcm_runtime *runtime = substream->runtime;
227         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
228 
229         err = snd_pcm_hw_constraint_ratdens(runtime, 0,
230                                             SNDRV_PCM_HW_PARAM_RATE,
231                                             (&line6pcm->properties->snd_line6_rates));
232         if (err < 0)
233                 return err;
234 
235         runtime->hw = line6pcm->properties->snd_line6_capture_hw;
236         return 0;
237 }
238 
239 /* close capture callback */
240 static int snd_line6_capture_close(struct snd_pcm_substream *substream)
241 {
242         return 0;
243 }
244 
245 /* hw_params capture callback */
246 static int snd_line6_capture_hw_params(struct snd_pcm_substream *substream,
247                                        struct snd_pcm_hw_params *hw_params)
248 {
249         int ret;
250         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
251 
252         /* -- Florian Demski [FD] */
253         /* don't ask me why, but this fixes the bug on my machine */
254         if (line6pcm == NULL) {
255                 if (substream->pcm == NULL)
256                         return -ENOMEM;
257                 if (substream->pcm->private_data == NULL)
258                         return -ENOMEM;
259                 substream->private_data = substream->pcm->private_data;
260                 line6pcm = snd_pcm_substream_chip(substream);
261         }
262         /* -- [FD] end */
263 
264         ret = snd_pcm_lib_malloc_pages(substream,
265                                        params_buffer_bytes(hw_params));
266         if (ret < 0)
267                 return ret;
268 
269         line6pcm->period_in = params_period_bytes(hw_params);
270         line6pcm->buffer_in = kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS * LINE6_ISO_PACKET_SIZE_MAX, GFP_KERNEL);
271 
272         if (!line6pcm->buffer_in) {
273                 dev_err(s2m(substream), "cannot malloc buffer_in\n");
274                 return -ENOMEM;
275         }
276 
277         return 0;
278 }
279 
280 /* hw_free capture callback */
281 static int snd_line6_capture_hw_free(struct snd_pcm_substream *substream)
282 {
283         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
284         unlink_wait_clear_audio_in_urbs(line6pcm);
285 
286         kfree(line6pcm->buffer_in);
287         line6pcm->buffer_in = NULL;
288 
289         return snd_pcm_lib_free_pages(substream);
290 }
291 
292 /* trigger callback */
293 int snd_line6_capture_trigger(struct snd_pcm_substream *substream, int cmd)
294 {
295         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
296         int err;
297         line6pcm->count_in = 0;
298 
299         switch (cmd) {
300         case SNDRV_PCM_TRIGGER_START:
301                 if (!test_and_set_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags)) {
302                         err = submit_audio_in_all_urbs(substream);
303 
304                         if (err < 0) {
305                                 clear_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags);
306                                 return err;
307                         }
308                 }
309 
310                 break;
311 
312         case SNDRV_PCM_TRIGGER_STOP:
313                 if (test_and_clear_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags))
314                         unlink_audio_in_urbs(line6pcm);
315 
316                 break;
317 
318         default:
319                 return -EINVAL;
320         }
321 
322         return 0;
323 }
324 
325 /* capture pointer callback */
326 static snd_pcm_uframes_t
327 snd_line6_capture_pointer(struct snd_pcm_substream *substream)
328 {
329         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
330         return line6pcm->pos_in_done;
331 }
332 
333 /* capture operators */
334 struct snd_pcm_ops snd_line6_capture_ops = {
335         .open =        snd_line6_capture_open,
336         .close =       snd_line6_capture_close,
337         .ioctl =       snd_pcm_lib_ioctl,
338         .hw_params =   snd_line6_capture_hw_params,
339         .hw_free =     snd_line6_capture_hw_free,
340         .prepare =     snd_line6_prepare,
341         .trigger =     snd_line6_trigger,
342         .pointer =     snd_line6_capture_pointer,
343 };
344 
345 int create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
346 {
347         int i;
348 
349         /* create audio URBs and fill in constant values: */
350         for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
351                 struct urb *urb;
352 
353                 /* URB for audio in: */
354                 urb = line6pcm->urb_audio_in[i] = usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
355 
356                 if (urb == NULL) {
357                         dev_err(line6pcm->line6->ifcdev, "Out of memory\n");
358                         return -ENOMEM;
359                 }
360 
361                 urb->dev = line6pcm->line6->usbdev;
362                 urb->pipe = usb_rcvisocpipe(line6pcm->line6->usbdev, line6pcm->ep_audio_read & USB_ENDPOINT_NUMBER_MASK);
363                 urb->transfer_flags = URB_ISO_ASAP;
364                 urb->start_frame = -1;
365                 urb->number_of_packets = LINE6_ISO_PACKETS;
366                 urb->interval = LINE6_ISO_INTERVAL;
367                 urb->error_count = 0;
368                 urb->complete = audio_in_callback;
369         }
370 
371         return 0;
372 }
373 
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