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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * ALSA PCM device for the4 * ALSA interface to cx18 PCM capture streams5 *6 * Copyright (C) 2009 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.10 */11 12#include <linux/init.h>13#include <linux/kernel.h>14 15#include <media/v4l2-device.h>16 17#include <sound/core.h>18#include <sound/pcm.h>19 20#include "cx18-driver.h"21#include "cx18-queue.h"22#include "cx18-streams.h"23#include "cx18-fileops.h"24#include "cx18-alsa.h"25#include "cx18-alsa-pcm.h"26 27static unsigned int pcm_debug;28module_param(pcm_debug, int, 0644);29MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");30 31#define dprintk(fmt, arg...) do { \32 if (pcm_debug) \33 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt, \34 __func__, ##arg); \35 } while (0)36 37static const struct snd_pcm_hardware snd_cx18_hw_capture = {38 .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |39 SNDRV_PCM_INFO_MMAP |40 SNDRV_PCM_INFO_INTERLEAVED |41 SNDRV_PCM_INFO_MMAP_VALID,42 43 .formats = SNDRV_PCM_FMTBIT_S16_LE,44 45 .rates = SNDRV_PCM_RATE_48000,46 47 .rate_min = 48000,48 .rate_max = 48000,49 .channels_min = 2,50 .channels_max = 2,51 .buffer_bytes_max = 62720 * 8, /* just about the value in usbaudio.c */52 .period_bytes_min = 64, /* 12544/2, */53 .period_bytes_max = 12544,54 .periods_min = 2,55 .periods_max = 98, /* 12544, */56};57 58void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,59 size_t num_bytes)60{61 struct snd_pcm_substream *substream;62 struct snd_pcm_runtime *runtime;63 unsigned int oldptr;64 unsigned int stride;65 int period_elapsed = 0;66 int length;67 68 dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc,69 pcm_data, num_bytes);70 71 substream = cxsc->capture_pcm_substream;72 if (substream == NULL) {73 dprintk("substream was NULL\n");74 return;75 }76 77 runtime = substream->runtime;78 if (runtime == NULL) {79 dprintk("runtime was NULL\n");80 return;81 }82 83 stride = runtime->frame_bits >> 3;84 if (stride == 0) {85 dprintk("stride is zero\n");86 return;87 }88 89 length = num_bytes / stride;90 if (length == 0) {91 dprintk("%s: length was zero\n", __func__);92 return;93 }94 95 if (runtime->dma_area == NULL) {96 dprintk("dma area was NULL - ignoring\n");97 return;98 }99 100 oldptr = cxsc->hwptr_done_capture;101 if (oldptr + length >= runtime->buffer_size) {102 unsigned int cnt =103 runtime->buffer_size - oldptr;104 memcpy(runtime->dma_area + oldptr * stride, pcm_data,105 cnt * stride);106 memcpy(runtime->dma_area, pcm_data + cnt * stride,107 length * stride - cnt * stride);108 } else {109 memcpy(runtime->dma_area + oldptr * stride, pcm_data,110 length * stride);111 }112 snd_pcm_stream_lock(substream);113 114 cxsc->hwptr_done_capture += length;115 if (cxsc->hwptr_done_capture >=116 runtime->buffer_size)117 cxsc->hwptr_done_capture -=118 runtime->buffer_size;119 120 cxsc->capture_transfer_done += length;121 if (cxsc->capture_transfer_done >=122 runtime->period_size) {123 cxsc->capture_transfer_done -=124 runtime->period_size;125 period_elapsed = 1;126 }127 128 snd_pcm_stream_unlock(substream);129 130 if (period_elapsed)131 snd_pcm_period_elapsed(substream);132}133 134static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)135{136 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);137 struct snd_pcm_runtime *runtime = substream->runtime;138 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;139 struct cx18 *cx = to_cx18(v4l2_dev);140 struct cx18_stream *s;141 struct cx18_open_id item;142 int ret;143 144 /* Instruct the cx18 to start sending packets */145 snd_cx18_lock(cxsc);146 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];147 148 item.cx = cx;149 item.type = s->type;150 item.open_id = cx->open_id++;151 152 /* See if the stream is available */153 if (cx18_claim_stream(&item, item.type)) {154 /* No, it's already in use */155 snd_cx18_unlock(cxsc);156 return -EBUSY;157 }158 159 if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||160 test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {161 /* We're already streaming. No additional action required */162 snd_cx18_unlock(cxsc);163 return 0;164 }165 166 167 runtime->hw = snd_cx18_hw_capture;168 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);169 cxsc->capture_pcm_substream = substream;170 runtime->private_data = cx;171 172 cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;173 174 /* Not currently streaming, so start it up */175 set_bit(CX18_F_S_STREAMING, &s->s_flags);176 ret = cx18_start_v4l2_encode_stream(s);177 snd_cx18_unlock(cxsc);178 179 return ret;180}181 182static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)183{184 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);185 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;186 struct cx18 *cx = to_cx18(v4l2_dev);187 struct cx18_stream *s;188 189 /* Instruct the cx18 to stop sending packets */190 snd_cx18_lock(cxsc);191 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];192 cx18_stop_v4l2_encode_stream(s, 0);193 clear_bit(CX18_F_S_STREAMING, &s->s_flags);194 195 cx18_release_stream(s);196 197 cx->pcm_announce_callback = NULL;198 snd_cx18_unlock(cxsc);199 200 return 0;201}202 203static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)204{205 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);206 207 cxsc->hwptr_done_capture = 0;208 cxsc->capture_transfer_done = 0;209 210 return 0;211}212 213static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)214{215 return 0;216}217 218static219snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)220{221 unsigned long flags;222 snd_pcm_uframes_t hwptr_done;223 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);224 225 spin_lock_irqsave(&cxsc->slock, flags);226 hwptr_done = cxsc->hwptr_done_capture;227 spin_unlock_irqrestore(&cxsc->slock, flags);228 229 return hwptr_done;230}231 232static const struct snd_pcm_ops snd_cx18_pcm_capture_ops = {233 .open = snd_cx18_pcm_capture_open,234 .close = snd_cx18_pcm_capture_close,235 .prepare = snd_cx18_pcm_prepare,236 .trigger = snd_cx18_pcm_trigger,237 .pointer = snd_cx18_pcm_pointer,238};239 240int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)241{242 struct snd_pcm *sp;243 struct snd_card *sc = cxsc->sc;244 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;245 struct cx18 *cx = to_cx18(v4l2_dev);246 int ret;247 248 ret = snd_pcm_new(sc, "CX23418 PCM",249 0, /* PCM device 0, the only one for this card */250 0, /* 0 playback substreams */251 1, /* 1 capture substream */252 &sp);253 if (ret) {254 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",255 __func__, ret);256 goto err_exit;257 }258 259 spin_lock_init(&cxsc->slock);260 261 snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,262 &snd_cx18_pcm_capture_ops);263 snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);264 sp->info_flags = 0;265 sp->private_data = cxsc;266 strscpy(sp->name, cx->card_name, sizeof(sp->name));267 268 return 0;269 270err_exit:271 return ret;272}273