ivtv-alsa-pcm.c (6893B)
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * ALSA PCM device for the 4 * ALSA interface to ivtv PCM capture streams 5 * 6 * Copyright (C) 2009,2012 Andy Walls <awalls@md.metrocast.net> 7 * Copyright (C) 2009 Devin Heitmueller <dheitmueller@kernellabs.com> 8 * 9 * Portions of this work were sponsored by ONELAN Limited for the cx18 driver 10 */ 11 12#include "ivtv-driver.h" 13#include "ivtv-queue.h" 14#include "ivtv-streams.h" 15#include "ivtv-fileops.h" 16#include "ivtv-alsa.h" 17#include "ivtv-alsa-pcm.h" 18 19#include <sound/core.h> 20#include <sound/pcm.h> 21 22 23static unsigned int pcm_debug; 24module_param(pcm_debug, int, 0644); 25MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm"); 26 27#define dprintk(fmt, arg...) \ 28 do { \ 29 if (pcm_debug) \ 30 pr_info("ivtv-alsa-pcm %s: " fmt, __func__, ##arg); \ 31 } while (0) 32 33static const struct snd_pcm_hardware snd_ivtv_hw_capture = { 34 .info = SNDRV_PCM_INFO_BLOCK_TRANSFER | 35 SNDRV_PCM_INFO_MMAP | 36 SNDRV_PCM_INFO_INTERLEAVED | 37 SNDRV_PCM_INFO_MMAP_VALID, 38 39 .formats = SNDRV_PCM_FMTBIT_S16_LE, 40 41 .rates = SNDRV_PCM_RATE_48000, 42 43 .rate_min = 48000, 44 .rate_max = 48000, 45 .channels_min = 2, 46 .channels_max = 2, 47 .buffer_bytes_max = 62720 * 8, /* just about the value in usbaudio.c */ 48 .period_bytes_min = 64, /* 12544/2, */ 49 .period_bytes_max = 12544, 50 .periods_min = 2, 51 .periods_max = 98, /* 12544, */ 52}; 53 54static void ivtv_alsa_announce_pcm_data(struct snd_ivtv_card *itvsc, 55 u8 *pcm_data, 56 size_t num_bytes) 57{ 58 struct snd_pcm_substream *substream; 59 struct snd_pcm_runtime *runtime; 60 unsigned int oldptr; 61 unsigned int stride; 62 int period_elapsed = 0; 63 int length; 64 65 dprintk("ivtv alsa announce ptr=%p data=%p num_bytes=%zu\n", itvsc, 66 pcm_data, num_bytes); 67 68 substream = itvsc->capture_pcm_substream; 69 if (substream == NULL) { 70 dprintk("substream was NULL\n"); 71 return; 72 } 73 74 runtime = substream->runtime; 75 if (runtime == NULL) { 76 dprintk("runtime was NULL\n"); 77 return; 78 } 79 80 stride = runtime->frame_bits >> 3; 81 if (stride == 0) { 82 dprintk("stride is zero\n"); 83 return; 84 } 85 86 length = num_bytes / stride; 87 if (length == 0) { 88 dprintk("%s: length was zero\n", __func__); 89 return; 90 } 91 92 if (runtime->dma_area == NULL) { 93 dprintk("dma area was NULL - ignoring\n"); 94 return; 95 } 96 97 oldptr = itvsc->hwptr_done_capture; 98 if (oldptr + length >= runtime->buffer_size) { 99 unsigned int cnt = 100 runtime->buffer_size - oldptr; 101 memcpy(runtime->dma_area + oldptr * stride, pcm_data, 102 cnt * stride); 103 memcpy(runtime->dma_area, pcm_data + cnt * stride, 104 length * stride - cnt * stride); 105 } else { 106 memcpy(runtime->dma_area + oldptr * stride, pcm_data, 107 length * stride); 108 } 109 snd_pcm_stream_lock(substream); 110 111 itvsc->hwptr_done_capture += length; 112 if (itvsc->hwptr_done_capture >= 113 runtime->buffer_size) 114 itvsc->hwptr_done_capture -= 115 runtime->buffer_size; 116 117 itvsc->capture_transfer_done += length; 118 if (itvsc->capture_transfer_done >= 119 runtime->period_size) { 120 itvsc->capture_transfer_done -= 121 runtime->period_size; 122 period_elapsed = 1; 123 } 124 125 snd_pcm_stream_unlock(substream); 126 127 if (period_elapsed) 128 snd_pcm_period_elapsed(substream); 129} 130 131static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream) 132{ 133 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream); 134 struct snd_pcm_runtime *runtime = substream->runtime; 135 struct v4l2_device *v4l2_dev = itvsc->v4l2_dev; 136 struct ivtv *itv = to_ivtv(v4l2_dev); 137 struct ivtv_stream *s; 138 struct ivtv_open_id item; 139 int ret; 140 141 /* Instruct the CX2341[56] to start sending packets */ 142 snd_ivtv_lock(itvsc); 143 144 if (ivtv_init_on_first_open(itv)) { 145 snd_ivtv_unlock(itvsc); 146 return -ENXIO; 147 } 148 149 s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM]; 150 151 v4l2_fh_init(&item.fh, &s->vdev); 152 item.itv = itv; 153 item.type = s->type; 154 155 /* See if the stream is available */ 156 if (ivtv_claim_stream(&item, item.type)) { 157 /* No, it's already in use */ 158 v4l2_fh_exit(&item.fh); 159 snd_ivtv_unlock(itvsc); 160 return -EBUSY; 161 } 162 163 if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) || 164 test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) { 165 /* We're already streaming. No additional action required */ 166 snd_ivtv_unlock(itvsc); 167 return 0; 168 } 169 170 171 runtime->hw = snd_ivtv_hw_capture; 172 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); 173 itvsc->capture_pcm_substream = substream; 174 runtime->private_data = itv; 175 176 itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data; 177 178 /* Not currently streaming, so start it up */ 179 set_bit(IVTV_F_S_STREAMING, &s->s_flags); 180 ret = ivtv_start_v4l2_encode_stream(s); 181 snd_ivtv_unlock(itvsc); 182 183 return ret; 184} 185 186static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream) 187{ 188 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream); 189 struct v4l2_device *v4l2_dev = itvsc->v4l2_dev; 190 struct ivtv *itv = to_ivtv(v4l2_dev); 191 struct ivtv_stream *s; 192 193 /* Instruct the ivtv to stop sending packets */ 194 snd_ivtv_lock(itvsc); 195 s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM]; 196 ivtv_stop_v4l2_encode_stream(s, 0); 197 clear_bit(IVTV_F_S_STREAMING, &s->s_flags); 198 199 ivtv_release_stream(s); 200 201 itv->pcm_announce_callback = NULL; 202 snd_ivtv_unlock(itvsc); 203 204 return 0; 205} 206 207static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream) 208{ 209 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream); 210 211 itvsc->hwptr_done_capture = 0; 212 itvsc->capture_transfer_done = 0; 213 214 return 0; 215} 216 217static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 218{ 219 return 0; 220} 221 222static 223snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream) 224{ 225 unsigned long flags; 226 snd_pcm_uframes_t hwptr_done; 227 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream); 228 229 spin_lock_irqsave(&itvsc->slock, flags); 230 hwptr_done = itvsc->hwptr_done_capture; 231 spin_unlock_irqrestore(&itvsc->slock, flags); 232 233 return hwptr_done; 234} 235 236static const struct snd_pcm_ops snd_ivtv_pcm_capture_ops = { 237 .open = snd_ivtv_pcm_capture_open, 238 .close = snd_ivtv_pcm_capture_close, 239 .prepare = snd_ivtv_pcm_prepare, 240 .trigger = snd_ivtv_pcm_trigger, 241 .pointer = snd_ivtv_pcm_pointer, 242}; 243 244int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc) 245{ 246 struct snd_pcm *sp; 247 struct snd_card *sc = itvsc->sc; 248 struct v4l2_device *v4l2_dev = itvsc->v4l2_dev; 249 struct ivtv *itv = to_ivtv(v4l2_dev); 250 int ret; 251 252 ret = snd_pcm_new(sc, "CX2341[56] PCM", 253 0, /* PCM device 0, the only one for this card */ 254 0, /* 0 playback substreams */ 255 1, /* 1 capture substream */ 256 &sp); 257 if (ret) { 258 IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n", 259 __func__, ret); 260 goto err_exit; 261 } 262 263 spin_lock_init(&itvsc->slock); 264 265 snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE, 266 &snd_ivtv_pcm_capture_ops); 267 snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0); 268 sp->info_flags = 0; 269 sp->private_data = itvsc; 270 strscpy(sp->name, itv->card_name, sizeof(sp->name)); 271 272 return 0; 273 274err_exit: 275 return ret; 276}