[alsa-devel] [RFC v2 2/6] ALSA: pcm: add IEC958 channel status control helper
Arnaud Pouliquen
arnaud.pouliquen at st.com
Fri Jan 22 18:48:28 CET 2016
Add IEC958 channel status helper that creates control to handle the
IEC60958 status bits.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
---
include/sound/pcm_iec958.h | 16 ++++++++
sound/core/pcm_iec958.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 115 insertions(+)
diff --git a/include/sound/pcm_iec958.h b/include/sound/pcm_iec958.h
index 36f023a..7453ace 100644
--- a/include/sound/pcm_iec958.h
+++ b/include/sound/pcm_iec958.h
@@ -3,9 +3,25 @@
#include <linux/types.h>
+/*
+ * IEC 60958 controls parameters
+ * Describes channel status and associated callback
+ */
+struct snd_pcm_iec958_params {
+ /* call when control is updated by user */
+ int (*ctrl_set)(void *pdata, u8 *status, u8 len);
+
+ struct snd_aes_iec958 *iec;
+ void *pdata; /* user private data to retrieve context */
+ struct mutex *mutex; /* use to avoid race condition */
+};
+
int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
size_t len);
int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
u8 *cs, size_t len);
+
+int snd_pcm_create_iec958_ctl(struct snd_pcm *pcm,
+ struct snd_pcm_iec958_params *params, int stream);
#endif
diff --git a/sound/core/pcm_iec958.c b/sound/core/pcm_iec958.c
index c9f8b66..8dd0415 100644
--- a/sound/core/pcm_iec958.c
+++ b/sound/core/pcm_iec958.c
@@ -7,11 +7,87 @@
*/
#include <linux/export.h>
#include <linux/types.h>
+#include <linux/wait.h>
#include <sound/asoundef.h>
+#include <sound/control.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/pcm_iec958.h>
+int snd_pcm_iec958_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_IEC958;
+ uinfo->count = 1;
+ return 0;
+}
+
+static int snd_pcm_iec958_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *uctl)
+{
+ struct snd_pcm_iec958_params *params = snd_kcontrol_chip(kcontrol);
+
+ if (params->mutex)
+ mutex_unlock(params->mutex);
+ uctl->value.iec958.status[0] = params->iec->status[0];
+ uctl->value.iec958.status[1] = params->iec->status[1];
+ uctl->value.iec958.status[2] = params->iec->status[2];
+ uctl->value.iec958.status[3] = params->iec->status[3];
+ uctl->value.iec958.status[4] = params->iec->status[4];
+ if (params->mutex)
+ mutex_unlock(params->mutex);
+ return 0;
+}
+
+static int snd_pcm_iec958_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *uctl)
+{
+ struct snd_pcm_iec958_params *params = snd_kcontrol_chip(kcontrol);
+ int err = 0;
+
+ if (params->mutex)
+ mutex_lock(params->mutex);
+ if (params->ctrl_set)
+ err = params->ctrl_set(params->pdata,
+ uctl->value.iec958.status, 5);
+ if (err < 0) {
+ if (params->mutex)
+ mutex_unlock(params->mutex);
+ return err;
+ }
+
+ params->iec->status[0] = uctl->value.iec958.status[0];
+ params->iec->status[1] = uctl->value.iec958.status[1];
+ params->iec->status[2] = uctl->value.iec958.status[2];
+ params->iec->status[3] = uctl->value.iec958.status[3];
+ params->iec->status[4] = uctl->value.iec958.status[4];
+
+ if (params->mutex)
+ mutex_unlock(params->mutex);
+
+ return 1;
+}
+
+static const struct snd_kcontrol_new iec958_ctls[] = {
+ {
+ .access = (SNDRV_CTL_ELEM_ACCESS_READWRITE |
+ SNDRV_CTL_ELEM_ACCESS_VOLATILE),
+ .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+ .name = SNDRV_CTL_NAME_IEC958("", PLAYBACK, DEFAULT),
+ .info = snd_pcm_iec958_info,
+ .get = snd_pcm_iec958_get,
+ .put = snd_pcm_iec958_put,
+ },
+ {
+ .access = (SNDRV_CTL_ELEM_ACCESS_READ |
+ SNDRV_CTL_ELEM_ACCESS_VOLATILE),
+ .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+ .name = SNDRV_CTL_NAME_IEC958("", CAPTURE, DEFAULT),
+ .info = snd_pcm_iec958_info,
+ .get = snd_pcm_iec958_get,
+ },
+};
+
static int create_iec958_consumer(uint rate, uint sample_width,
u8 *cs, size_t len)
{
@@ -111,3 +187,26 @@ int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
cs, len);
}
EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params);
+
+/**
+ * snd_pcm_create_iec958_ctl - create IEC958 channel status default control
+ * pcm: pcm device to associate to the control.
+ * iec958: snd_pcm_iec958_params structure that cntains callbacks
+ * and channel status buffer
+ * stream: stream type SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CATURE
+ * Returns: negative error code if something failed.
+ */
+int snd_pcm_create_iec958_ctl(struct snd_pcm *pcm,
+ struct snd_pcm_iec958_params *params, int stream)
+{
+ struct snd_kcontrol_new knew;
+
+ if (stream > SNDRV_PCM_STREAM_LAST)
+ return -EINVAL;
+
+ knew = iec958_ctls[stream];
+ knew.device = pcm->device;
+ knew.count = pcm->streams[stream].substream_count;
+ return snd_ctl_add(pcm->card, snd_ctl_new1(&knew, params));
+}
+EXPORT_SYMBOL(snd_pcm_create_iec958_ctl);
--
1.9.1
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