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 23 static unsigned int pcm_debug; 24 module_param(pcm_debug, int, 0644); 25 MODULE_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 33 static 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 54 static 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 } 130 131 static 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 item.itv = itv; 152 item.type = s->type; 153 154 /* See if the stream is available */ 155 if (ivtv_claim_stream(&item, item.type)) { 156 /* No, it's already in use */ 157 snd_ivtv_unlock(itvsc); 158 return -EBUSY; 159 } 160 161 if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) || 162 test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) { 163 /* We're already streaming. No additional action required */ 164 snd_ivtv_unlock(itvsc); 165 return 0; 166 } 167 168 169 runtime->hw = snd_ivtv_hw_capture; 170 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); 171 itvsc->capture_pcm_substream = substream; 172 runtime->private_data = itv; 173 174 itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data; 175 176 /* Not currently streaming, so start it up */ 177 set_bit(IVTV_F_S_STREAMING, &s->s_flags); 178 ret = ivtv_start_v4l2_encode_stream(s); 179 snd_ivtv_unlock(itvsc); 180 181 return ret; 182 } 183 184 static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream) 185 { 186 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream); 187 struct v4l2_device *v4l2_dev = itvsc->v4l2_dev; 188 struct ivtv *itv = to_ivtv(v4l2_dev); 189 struct ivtv_stream *s; 190 191 /* Instruct the ivtv to stop sending packets */ 192 snd_ivtv_lock(itvsc); 193 s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM]; 194 ivtv_stop_v4l2_encode_stream(s, 0); 195 clear_bit(IVTV_F_S_STREAMING, &s->s_flags); 196 197 ivtv_release_stream(s); 198 199 itv->pcm_announce_callback = NULL; 200 snd_ivtv_unlock(itvsc); 201 202 return 0; 203 } 204 205 static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream) 206 { 207 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream); 208 209 itvsc->hwptr_done_capture = 0; 210 itvsc->capture_transfer_done = 0; 211 212 return 0; 213 } 214 215 static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 216 { 217 return 0; 218 } 219 220 static 221 snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream) 222 { 223 unsigned long flags; 224 snd_pcm_uframes_t hwptr_done; 225 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream); 226 227 spin_lock_irqsave(&itvsc->slock, flags); 228 hwptr_done = itvsc->hwptr_done_capture; 229 spin_unlock_irqrestore(&itvsc->slock, flags); 230 231 return hwptr_done; 232 } 233 234 static const struct snd_pcm_ops snd_ivtv_pcm_capture_ops = { 235 .open = snd_ivtv_pcm_capture_open, 236 .close = snd_ivtv_pcm_capture_close, 237 .prepare = snd_ivtv_pcm_prepare, 238 .trigger = snd_ivtv_pcm_trigger, 239 .pointer = snd_ivtv_pcm_pointer, 240 }; 241 242 int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc) 243 { 244 struct snd_pcm *sp; 245 struct snd_card *sc = itvsc->sc; 246 struct v4l2_device *v4l2_dev = itvsc->v4l2_dev; 247 struct ivtv *itv = to_ivtv(v4l2_dev); 248 int ret; 249 250 ret = snd_pcm_new(sc, "CX2341[56] PCM", 251 0, /* PCM device 0, the only one for this card */ 252 0, /* 0 playback substreams */ 253 1, /* 1 capture substream */ 254 &sp); 255 if (ret) { 256 IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n", 257 __func__, ret); 258 goto err_exit; 259 } 260 261 spin_lock_init(&itvsc->slock); 262 263 snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE, 264 &snd_ivtv_pcm_capture_ops); 265 snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0); 266 sp->info_flags = 0; 267 sp->private_data = itvsc; 268 strscpy(sp->name, itv->card_name, sizeof(sp->name)); 269 270 return 0; 271 272 err_exit: 273 return ret; 274 } 275