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path: root/drivers/media/pci/cx18/cx18-alsa-pcm.c
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Diffstat (limited to 'drivers/media/pci/cx18/cx18-alsa-pcm.c')
-rw-r--r--drivers/media/pci/cx18/cx18-alsa-pcm.c272
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 0000000000..bed28b4b41
--- /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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 03:55:56 +0000