diff options
Diffstat (limited to 'drivers/media/pci/cx18/cx18-alsa-pcm.c')
| -rw-r--r-- | drivers/media/pci/cx18/cx18-alsa-pcm.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/drivers/media/pci/cx18/cx18-alsa-pcm.c b/drivers/media/pci/cx18/cx18-alsa-pcm.c new file mode 100644 index 000000000..bed28b4b4 --- /dev/null +++ b/drivers/media/pci/cx18/cx18-alsa-pcm.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ALSA PCM device for the + * ALSA interface to cx18 PCM capture streams + * + * Copyright (C) 2009 Andy Walls <awalls@md.metrocast.net> + * Copyright (C) 2009 Devin Heitmueller <dheitmueller@kernellabs.com> + * + * Portions of this work were sponsored by ONELAN Limited. + */ + +#include <linux/init.h> +#include <linux/kernel.h> + +#include <media/v4l2-device.h> + +#include <sound/core.h> +#include <sound/pcm.h> + +#include "cx18-driver.h" +#include "cx18-queue.h" +#include "cx18-streams.h" +#include "cx18-fileops.h" +#include "cx18-alsa.h" +#include "cx18-alsa-pcm.h" + +static unsigned int pcm_debug; +module_param(pcm_debug, int, 0644); +MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm"); + +#define dprintk(fmt, arg...) do { \ + if (pcm_debug) \ + printk(KERN_INFO "cx18-alsa-pcm %s: " fmt, \ + __func__, ##arg); \ + } while (0) + +static const struct snd_pcm_hardware snd_cx18_hw_capture = { + .info = SNDRV_PCM_INFO_BLOCK_TRANSFER | + SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_MMAP_VALID, + + .formats = SNDRV_PCM_FMTBIT_S16_LE, + + .rates = SNDRV_PCM_RATE_48000, + + .rate_min = 48000, + .rate_max = 48000, + .channels_min = 2, + .channels_max = 2, + .buffer_bytes_max = 62720 * 8, /* just about the value in usbaudio.c */ + .period_bytes_min = 64, /* 12544/2, */ + .period_bytes_max = 12544, + .periods_min = 2, + .periods_max = 98, /* 12544, */ +}; + +void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data, + size_t num_bytes) +{ + struct snd_pcm_substream *substream; + struct snd_pcm_runtime *runtime; + unsigned int oldptr; + unsigned int stride; + int period_elapsed = 0; + int length; + + dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc, + pcm_data, num_bytes); + + substream = cxsc->capture_pcm_substream; + if (substream == NULL) { + dprintk("substream was NULL\n"); + return; + } + + runtime = substream->runtime; + if (runtime == NULL) { + dprintk("runtime was NULL\n"); + return; + } + + stride = runtime->frame_bits >> 3; + if (stride == 0) { + dprintk("stride is zero\n"); + return; + } + + length = num_bytes / stride; + if (length == 0) { + dprintk("%s: length was zero\n", __func__); + return; + } + + if (runtime->dma_area == NULL) { + dprintk("dma area was NULL - ignoring\n"); + return; + } + + oldptr = cxsc->hwptr_done_capture; + if (oldptr + length >= runtime->buffer_size) { + unsigned int cnt = + runtime->buffer_size - oldptr; + memcpy(runtime->dma_area + oldptr * stride, pcm_data, + cnt * stride); + memcpy(runtime->dma_area, pcm_data + cnt * stride, + length * stride - cnt * stride); + } else { + memcpy(runtime->dma_area + oldptr * stride, pcm_data, + length * stride); + } + snd_pcm_stream_lock(substream); + + cxsc->hwptr_done_capture += length; + if (cxsc->hwptr_done_capture >= + runtime->buffer_size) + cxsc->hwptr_done_capture -= + runtime->buffer_size; + + cxsc->capture_transfer_done += length; + if (cxsc->capture_transfer_done >= + runtime->period_size) { + cxsc->capture_transfer_done -= + runtime->period_size; + period_elapsed = 1; + } + + snd_pcm_stream_unlock(substream); + + if (period_elapsed) + snd_pcm_period_elapsed(substream); +} + +static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream) +{ + struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream); + struct snd_pcm_runtime *runtime = substream->runtime; + struct v4l2_device *v4l2_dev = cxsc->v4l2_dev; + struct cx18 *cx = to_cx18(v4l2_dev); + struct cx18_stream *s; + struct cx18_open_id item; + int ret; + + /* Instruct the cx18 to start sending packets */ + snd_cx18_lock(cxsc); + s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM]; + + item.cx = cx; + item.type = s->type; + item.open_id = cx->open_id++; + + /* See if the stream is available */ + if (cx18_claim_stream(&item, item.type)) { + /* No, it's already in use */ + snd_cx18_unlock(cxsc); + return -EBUSY; + } + + if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) || + test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) { + /* We're already streaming. No additional action required */ + snd_cx18_unlock(cxsc); + return 0; + } + + + runtime->hw = snd_cx18_hw_capture; + snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); + cxsc->capture_pcm_substream = substream; + runtime->private_data = cx; + + cx->pcm_announce_callback = cx18_alsa_announce_pcm_data; + + /* Not currently streaming, so start it up */ + set_bit(CX18_F_S_STREAMING, &s->s_flags); + ret = cx18_start_v4l2_encode_stream(s); + snd_cx18_unlock(cxsc); + + return ret; +} + +static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream) +{ + struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream); + struct v4l2_device *v4l2_dev = cxsc->v4l2_dev; + struct cx18 *cx = to_cx18(v4l2_dev); + struct cx18_stream *s; + + /* Instruct the cx18 to stop sending packets */ + snd_cx18_lock(cxsc); + s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM]; + cx18_stop_v4l2_encode_stream(s, 0); + clear_bit(CX18_F_S_STREAMING, &s->s_flags); + + cx18_release_stream(s); + + cx->pcm_announce_callback = NULL; + snd_cx18_unlock(cxsc); + + return 0; +} + +static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream) +{ + struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream); + + cxsc->hwptr_done_capture = 0; + cxsc->capture_transfer_done = 0; + + return 0; +} + +static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd) +{ + return 0; +} + +static +snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream) +{ + unsigned long flags; + snd_pcm_uframes_t hwptr_done; + struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream); + + spin_lock_irqsave(&cxsc->slock, flags); + hwptr_done = cxsc->hwptr_done_capture; + spin_unlock_irqrestore(&cxsc->slock, flags); + + return hwptr_done; +} + +static const struct snd_pcm_ops snd_cx18_pcm_capture_ops = { + .open = snd_cx18_pcm_capture_open, + .close = snd_cx18_pcm_capture_close, + .prepare = snd_cx18_pcm_prepare, + .trigger = snd_cx18_pcm_trigger, + .pointer = snd_cx18_pcm_pointer, +}; + +int snd_cx18_pcm_create(struct snd_cx18_card *cxsc) +{ + struct snd_pcm *sp; + struct snd_card *sc = cxsc->sc; + struct v4l2_device *v4l2_dev = cxsc->v4l2_dev; + struct cx18 *cx = to_cx18(v4l2_dev); + int ret; + + ret = snd_pcm_new(sc, "CX23418 PCM", + 0, /* PCM device 0, the only one for this card */ + 0, /* 0 playback substreams */ + 1, /* 1 capture substream */ + &sp); + if (ret) { + CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n", + __func__, ret); + goto err_exit; + } + + spin_lock_init(&cxsc->slock); + + snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE, + &snd_cx18_pcm_capture_ops); + snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0); + sp->info_flags = 0; + sp->private_data = cxsc; + strscpy(sp->name, cx->card_name, sizeof(sp->name)); + + return 0; + +err_exit: + return ret; +} |