1 /*
2  *  ALSA PCM device for the
3  *  ALSA interface to cx18 PCM capture streams
4  *
5  *  Copyright (C) 2009  Andy Walls <awalls@md.metrocast.net>
6  *  Copyright (C) 2009  Devin Heitmueller <dheitmueller@kernellabs.com>
7  *
8  *  Portions of this work were sponsored by ONELAN Limited.
9  *
10  *  This program is free software; you can redistribute it and/or modify
11  *  it under the terms of the GNU General Public License as published by
12  *  the Free Software Foundation; either version 2 of the License, or
13  *  (at your option) any later version.
14  *
15  *  This program is distributed in the hope that it will be useful,
16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *  GNU General Public License for more details.
19  */
20 
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/vmalloc.h>
24 
25 #include <media/v4l2-device.h>
26 
27 #include <sound/core.h>
28 #include <sound/pcm.h>
29 
30 #include "cx18-driver.h"
31 #include "cx18-queue.h"
32 #include "cx18-streams.h"
33 #include "cx18-fileops.h"
34 #include "cx18-alsa.h"
35 #include "cx18-alsa-pcm.h"
36 
37 static unsigned int pcm_debug;
38 module_param(pcm_debug, int, 0644);
39 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
40 
41 #define dprintk(fmt, arg...) do {					\
42 	    if (pcm_debug)						\
43 		printk(KERN_INFO "cx18-alsa-pcm %s: " fmt,		\
44 				  __func__, ##arg);			\
45 	} while (0)
46 
47 static const struct snd_pcm_hardware snd_cx18_hw_capture = {
48 	.info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
49 		SNDRV_PCM_INFO_MMAP           |
50 		SNDRV_PCM_INFO_INTERLEAVED    |
51 		SNDRV_PCM_INFO_MMAP_VALID,
52 
53 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
54 
55 	.rates = SNDRV_PCM_RATE_48000,
56 
57 	.rate_min = 48000,
58 	.rate_max = 48000,
59 	.channels_min = 2,
60 	.channels_max = 2,
61 	.buffer_bytes_max = 62720 * 8,	/* just about the value in usbaudio.c */
62 	.period_bytes_min = 64,		/* 12544/2, */
63 	.period_bytes_max = 12544,
64 	.periods_min = 2,
65 	.periods_max = 98,		/* 12544, */
66 };
67 
68 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
69 				 size_t num_bytes)
70 {
71 	struct snd_pcm_substream *substream;
72 	struct snd_pcm_runtime *runtime;
73 	unsigned int oldptr;
74 	unsigned int stride;
75 	int period_elapsed = 0;
76 	int length;
77 
78 	dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc,
79 		pcm_data, num_bytes);
80 
81 	substream = cxsc->capture_pcm_substream;
82 	if (substream == NULL) {
83 		dprintk("substream was NULL\n");
84 		return;
85 	}
86 
87 	runtime = substream->runtime;
88 	if (runtime == NULL) {
89 		dprintk("runtime was NULL\n");
90 		return;
91 	}
92 
93 	stride = runtime->frame_bits >> 3;
94 	if (stride == 0) {
95 		dprintk("stride is zero\n");
96 		return;
97 	}
98 
99 	length = num_bytes / stride;
100 	if (length == 0) {
101 		dprintk("%s: length was zero\n", __func__);
102 		return;
103 	}
104 
105 	if (runtime->dma_area == NULL) {
106 		dprintk("dma area was NULL - ignoring\n");
107 		return;
108 	}
109 
110 	oldptr = cxsc->hwptr_done_capture;
111 	if (oldptr + length >= runtime->buffer_size) {
112 		unsigned int cnt =
113 			runtime->buffer_size - oldptr;
114 		memcpy(runtime->dma_area + oldptr * stride, pcm_data,
115 		       cnt * stride);
116 		memcpy(runtime->dma_area, pcm_data + cnt * stride,
117 		       length * stride - cnt * stride);
118 	} else {
119 		memcpy(runtime->dma_area + oldptr * stride, pcm_data,
120 		       length * stride);
121 	}
122 	snd_pcm_stream_lock(substream);
123 
124 	cxsc->hwptr_done_capture += length;
125 	if (cxsc->hwptr_done_capture >=
126 	    runtime->buffer_size)
127 		cxsc->hwptr_done_capture -=
128 			runtime->buffer_size;
129 
130 	cxsc->capture_transfer_done += length;
131 	if (cxsc->capture_transfer_done >=
132 	    runtime->period_size) {
133 		cxsc->capture_transfer_done -=
134 			runtime->period_size;
135 		period_elapsed = 1;
136 	}
137 
138 	snd_pcm_stream_unlock(substream);
139 
140 	if (period_elapsed)
141 		snd_pcm_period_elapsed(substream);
142 }
143 
144 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
145 {
146 	struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
147 	struct snd_pcm_runtime *runtime = substream->runtime;
148 	struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
149 	struct cx18 *cx = to_cx18(v4l2_dev);
150 	struct cx18_stream *s;
151 	struct cx18_open_id item;
152 	int ret;
153 
154 	/* Instruct the cx18 to start sending packets */
155 	snd_cx18_lock(cxsc);
156 	s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
157 
158 	item.cx = cx;
159 	item.type = s->type;
160 	item.open_id = cx->open_id++;
161 
162 	/* See if the stream is available */
163 	if (cx18_claim_stream(&item, item.type)) {
164 		/* No, it's already in use */
165 		snd_cx18_unlock(cxsc);
166 		return -EBUSY;
167 	}
168 
169 	if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
170 	    test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
171 		/* We're already streaming.  No additional action required */
172 		snd_cx18_unlock(cxsc);
173 		return 0;
174 	}
175 
176 
177 	runtime->hw = snd_cx18_hw_capture;
178 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
179 	cxsc->capture_pcm_substream = substream;
180 	runtime->private_data = cx;
181 
182 	cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
183 
184 	/* Not currently streaming, so start it up */
185 	set_bit(CX18_F_S_STREAMING, &s->s_flags);
186 	ret = cx18_start_v4l2_encode_stream(s);
187 	snd_cx18_unlock(cxsc);
188 
189 	return ret;
190 }
191 
192 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
193 {
194 	struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
195 	struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
196 	struct cx18 *cx = to_cx18(v4l2_dev);
197 	struct cx18_stream *s;
198 
199 	/* Instruct the cx18 to stop sending packets */
200 	snd_cx18_lock(cxsc);
201 	s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
202 	cx18_stop_v4l2_encode_stream(s, 0);
203 	clear_bit(CX18_F_S_STREAMING, &s->s_flags);
204 
205 	cx18_release_stream(s);
206 
207 	cx->pcm_announce_callback = NULL;
208 	snd_cx18_unlock(cxsc);
209 
210 	return 0;
211 }
212 
213 static int snd_cx18_pcm_ioctl(struct snd_pcm_substream *substream,
214 		     unsigned int cmd, void *arg)
215 {
216 	struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
217 	int ret;
218 
219 	snd_cx18_lock(cxsc);
220 	ret = snd_pcm_lib_ioctl(substream, cmd, arg);
221 	snd_cx18_unlock(cxsc);
222 	return ret;
223 }
224 
225 
226 static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
227 					size_t size)
228 {
229 	struct snd_pcm_runtime *runtime = subs->runtime;
230 
231 	dprintk("Allocating vbuffer\n");
232 	if (runtime->dma_area) {
233 		if (runtime->dma_bytes > size)
234 			return 0;
235 
236 		vfree(runtime->dma_area);
237 	}
238 	runtime->dma_area = vmalloc(size);
239 	if (!runtime->dma_area)
240 		return -ENOMEM;
241 
242 	runtime->dma_bytes = size;
243 
244 	return 0;
245 }
246 
247 static int snd_cx18_pcm_hw_params(struct snd_pcm_substream *substream,
248 			 struct snd_pcm_hw_params *params)
249 {
250 	dprintk("%s called\n", __func__);
251 
252 	return snd_pcm_alloc_vmalloc_buffer(substream,
253 					   params_buffer_bytes(params));
254 }
255 
256 static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
257 {
258 	struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
259 	unsigned long flags;
260 	unsigned char *dma_area = NULL;
261 
262 	spin_lock_irqsave(&cxsc->slock, flags);
263 	if (substream->runtime->dma_area) {
264 		dprintk("freeing pcm capture region\n");
265 		dma_area = substream->runtime->dma_area;
266 		substream->runtime->dma_area = NULL;
267 	}
268 	spin_unlock_irqrestore(&cxsc->slock, flags);
269 	vfree(dma_area);
270 
271 	return 0;
272 }
273 
274 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
275 {
276 	struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
277 
278 	cxsc->hwptr_done_capture = 0;
279 	cxsc->capture_transfer_done = 0;
280 
281 	return 0;
282 }
283 
284 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
285 {
286 	return 0;
287 }
288 
289 static
290 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
291 {
292 	unsigned long flags;
293 	snd_pcm_uframes_t hwptr_done;
294 	struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
295 
296 	spin_lock_irqsave(&cxsc->slock, flags);
297 	hwptr_done = cxsc->hwptr_done_capture;
298 	spin_unlock_irqrestore(&cxsc->slock, flags);
299 
300 	return hwptr_done;
301 }
302 
303 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
304 					     unsigned long offset)
305 {
306 	void *pageptr = subs->runtime->dma_area + offset;
307 
308 	return vmalloc_to_page(pageptr);
309 }
310 
311 static const struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
312 	.open		= snd_cx18_pcm_capture_open,
313 	.close		= snd_cx18_pcm_capture_close,
314 	.ioctl		= snd_cx18_pcm_ioctl,
315 	.hw_params	= snd_cx18_pcm_hw_params,
316 	.hw_free	= snd_cx18_pcm_hw_free,
317 	.prepare	= snd_cx18_pcm_prepare,
318 	.trigger	= snd_cx18_pcm_trigger,
319 	.pointer	= snd_cx18_pcm_pointer,
320 	.page		= snd_pcm_get_vmalloc_page,
321 };
322 
323 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
324 {
325 	struct snd_pcm *sp;
326 	struct snd_card *sc = cxsc->sc;
327 	struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
328 	struct cx18 *cx = to_cx18(v4l2_dev);
329 	int ret;
330 
331 	ret = snd_pcm_new(sc, "CX23418 PCM",
332 			  0, /* PCM device 0, the only one for this card */
333 			  0, /* 0 playback substreams */
334 			  1, /* 1 capture substream */
335 			  &sp);
336 	if (ret) {
337 		CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
338 			      __func__, ret);
339 		goto err_exit;
340 	}
341 
342 	spin_lock_init(&cxsc->slock);
343 
344 	snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
345 			&snd_cx18_pcm_capture_ops);
346 	sp->info_flags = 0;
347 	sp->private_data = cxsc;
348 	strscpy(sp->name, cx->card_name, sizeof(sp->name));
349 
350 	return 0;
351 
352 err_exit:
353 	return ret;
354 }
355