diff mbox

[RFC,2/6] ALSA: pcm: add IEC958 channel status control helper

Message ID 1453210836-16218-3-git-send-email-arnaud.pouliquen@st.com (mailing list archive)
State New, archived
Headers show

Commit Message

Arnaud POULIQUEN Jan. 19, 2016, 1:40 p.m. UTC
Add IEC958 channel status helper that creates control to handle the
IEC60958 status bits.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
---
 include/sound/pcm_iec958.h | 16 +++++++++
 sound/core/pcm_iec958.c    | 90 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 106 insertions(+)

Comments

Russell King - ARM Linux Jan. 19, 2016, 5 p.m. UTC | #1
On Tue, Jan 19, 2016 at 02:40:32PM +0100, Arnaud Pouliquen wrote:
> Add IEC958 channel status helper that creates control to handle the
> IEC60958 status bits.
> 
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
> ---
>  include/sound/pcm_iec958.h | 16 +++++++++
>  sound/core/pcm_iec958.c    | 90 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 106 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..1d426bc 100644
> --- a/sound/core/pcm_iec958.c
> +++ b/sound/core/pcm_iec958.c
> @@ -7,11 +7,78 @@
>   */
>  #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);

I'm not sure it makes sense for the mutex to be optional.

> +	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) {
> +		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 0;

I think you're supposed to report whether anything changed, rather
than just zero on success.

> +}
> +
> +static const struct snd_kcontrol_new iec958_ctls[] = {
> +	{
> +		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
> +		.name = SNDRV_CTL_NAME_IEC958("", PLAYBACK, DEFAULT),

Shouldn't this have a .access member?  What if the audio driver
modifies the IEC958 status for PCM playback - shouldn't it have
the ability to have SNDRV_CTL_ELEM_ACCESS_VOLATILE added?
Arnaud POULIQUEN Jan. 20, 2016, 2:16 p.m. UTC | #2
On 01/19/2016 06:00 PM, Russell King - ARM Linux wrote:
> On Tue, Jan 19, 2016 at 02:40:32PM +0100, Arnaud Pouliquen wrote:

>> +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);
> 
> I'm not sure it makes sense for the mutex to be optional.
I have no use case in mind that justifies optional mutex.
Just did it for flexibility...
I can suppress condition to force drivers to use it.

> 
>> +	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) {
>> +		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 0;
> 
> I think you're supposed to report whether anything changed, rather
> than just zero on success.
right, need to return 1 or err
> 
>> +}
>> +
>> +static const struct snd_kcontrol_new iec958_ctls[] = {
>> +	{
>> +		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
>> +		.name = SNDRV_CTL_NAME_IEC958("", PLAYBACK, DEFAULT),
> 
> Shouldn't this have a .access member?  What if the audio driver
> modifies the IEC958 status for PCM playback - shouldn't it have
> the ability to have SNDRV_CTL_ELEM_ACCESS_VOLATILE added?
> 
i will add READ + VOLATILE access for capture, RW +VOLATILE access for
playback.
Should i also add some other controls by default, like controls for
consumer and professional mask for playback?
diff mbox

Patch

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..1d426bc 100644
--- a/sound/core/pcm_iec958.c
+++ b/sound/core/pcm_iec958.c
@@ -7,11 +7,78 @@ 
  */
 #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) {
+		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 0;
+}
+
+static const struct snd_kcontrol_new iec958_ctls[] = {
+	{
+		.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,
+	},
+	{
+		.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 +178,26 @@  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);