[PATCH v2] Add support for trigger-start/stop for simple audio card

[PATCH v2] Add support for trigger-start/stop for simple audio card

[Maxim Kochetkov]

Support for trigger-start/stop for simple audio card.

Maxim Kochetkov (3):
  ASoC: simple-card-utils: introduce asoc_simple_parse_triggers()
  ASoC: dt-bindings: simple-card: add triggers properties
  ASoC: simple-card: add triggers parsing from DT node support

 .../bindings/sound/simple-card.yaml           | 31 +++++++++++++
 include/sound/simple_card_utils.h             |  3 ++
 sound/soc/generic/simple-card-utils.c         | 45 +++++++++++++++++++
 sound/soc/generic/simple-card.c               |  4 ++
 4 files changed, 83 insertions(+)

-- 
2.40.1

[PATCH v2] ASoC: simple-card-utils: introduce asoc_simple_parse_triggers()

[Maxim Kochetkov]

This function parses DT DAI link triggers params and assigns
the appropriate fields in struct snd_soc_dai_link.
It supports two triggers trigger-stop and trigger-start.

Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
---
 include/sound/simple_card_utils.h     |  3 ++
 sound/soc/generic/simple-card-utils.c | 45 +++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/include/sound/simple_card_utils.h b/include/sound/simple_card_utils.h
index b450d5873227..ea8c17f7b280 100644
--- a/include/sound/simple_card_utils.h
+++ b/include/sound/simple_card_utils.h
@@ -180,6 +180,9 @@ int asoc_simple_parse_widgets(struct snd_soc_card *card,
 				      char *prefix);
 int asoc_simple_parse_pin_switches(struct snd_soc_card *card,
 				   char *prefix);
+int asoc_simple_parse_triggers(struct device_node *node,
+			       char *prefix,
+			       struct snd_soc_dai_link *dai_link);
 
 int asoc_simple_init_jack(struct snd_soc_card *card,
 			       struct asoc_simple_jack *sjack,
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index 3019626b0592..58f5c672184a 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -737,6 +737,51 @@ int asoc_simple_parse_pin_switches(struct snd_soc_card *card,
 }
 EXPORT_SYMBOL_GPL(asoc_simple_parse_pin_switches);
 
+static enum snd_soc_trigger_order asoc_simple_parse_trigger(
+					struct device_node *node,
+					char *prefix,
+					char *trigger_name)
+{
+	enum snd_soc_trigger_order trigger = SND_SOC_TRIGGER_ORDER_DEFAULT;
+	struct {
+		char *name;
+		unsigned int val;
+	} of_trigger_table[] = {
+		{ "default",	SND_SOC_TRIGGER_ORDER_DEFAULT },
+		{ "ldc",	SND_SOC_TRIGGER_ORDER_LDC },
+	};
+	const char *str;
+	char prop[128];
+	int ret;
+
+	if (!prefix)
+		prefix = "";
+
+	snprintf(prop, sizeof(prop), "%s%s", prefix, trigger_name);
+
+	ret = of_property_read_string(node, prop, &str);
+	if (ret == 0) {
+		for (int i = 0; i < ARRAY_SIZE(of_trigger_table); i++) {
+			if (strcmp(str, of_trigger_table[i].name) == 0) {
+				trigger = of_trigger_table[i].val;
+				break;
+			}
+		}
+	}
+
+	return trigger;
+}
+
+int asoc_simple_parse_triggers(struct device_node *node,
+			       char *prefix,
+			       struct snd_soc_dai_link *dai_link)
+{
+	dai_link->trigger_stop = asoc_simple_parse_trigger(node, prefix, "trigger-stop");
+	dai_link->trigger_start = asoc_simple_parse_trigger(node, prefix, "trigger-start");
+	return 0;
+}
+EXPORT_SYMBOL_GPL(asoc_simple_parse_triggers);
+
 int asoc_simple_init_jack(struct snd_soc_card *card,
 			  struct asoc_simple_jack *sjack,
 			  int is_hp, char *prefix,
-- 
2.40.1

[PATCH v2] ASoC: dt-bindings: simple-card: add triggers properties

[Maxim Kochetkov]

The trigger-start/stop properties allows to specify DAI link
trigger ordering method.

Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
---
 .../bindings/sound/simple-card.yaml           | 31 +++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/simple-card.yaml b/Documentation/devicetree/bindings/sound/simple-card.yaml
index 59ac2d1d1ccf..f1878d470d83 100644
--- a/Documentation/devicetree/bindings/sound/simple-card.yaml
+++ b/Documentation/devicetree/bindings/sound/simple-card.yaml
@@ -99,6 +99,28 @@ definitions:
     description: the widget names for which pin switches must be created.
     $ref: /schemas/types.yaml#/definitions/string-array
 
+  trigger-start:
+    description: |-
+      Start trigger ordering method:
+      default: Link->Component->DAI
+      ldc: Link->DAI->Component
+    $ref: /schemas/types.yaml#/definitions/string
+    items:
+      enum:
+        - default
+        - ldc
+
+  trigger-stop:
+    description: |-
+      Stop trigger ordering method:
+      default: DAI->Component->Link
+      ldc: Component->DAI->Link
+    $ref: /schemas/types.yaml#/definitions/string
+    items:
+      enum:
+        - default
+        - ldc
+
   format:
     description: audio format.
     items:
@@ -210,6 +232,10 @@ properties:
     maxItems: 1
   simple-audio-card,mic-det-gpio:
     maxItems: 1
+  simple-audio-card,trigger-start:
+    $ref: "#/definitions/trigger-start"
+  simple-audio-card,trigger-stop:
+    $ref: "#/definitions/trigger-stop"
 
 patternProperties:
   "^simple-audio-card,cpu(@[0-9a-f]+)?$":
@@ -259,6 +285,11 @@ patternProperties:
         maxItems: 1
       mic-det-gpio:
         maxItems: 1
+      trigger-start:
+        $ref: "#/definitions/trigger-start"
+      trigger-stop:
+        $ref: "#/definitions/trigger-stop"
+
 
     patternProperties:
       "^cpu(-[0-9]+)?$":
-- 
2.40.1

Re: [PATCH v2] ASoC: dt-bindings: simple-card: add triggers properties

[Rob Herring]

On Sat, Jul 15, 2023 at 11:30:43AM +0300, Maxim Kochetkov wrote:
> The trigger-start/stop properties allows to specify DAI link
> trigger ordering method.

Obviously. Why do you need these? What problem does it solve?

I don't think these belong in simple-card. What's next? What if you need 
delays between each step? This is the problem with 'simple' or 'generic' 
bindings. It's a never ending addition of properties which are not well 
thought out.

> 
> Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
> ---
>  .../bindings/sound/simple-card.yaml           | 31 +++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/sound/simple-card.yaml b/Documentation/devicetree/bindings/sound/simple-card.yaml
> index 59ac2d1d1ccf..f1878d470d83 100644
> --- a/Documentation/devicetree/bindings/sound/simple-card.yaml
> +++ b/Documentation/devicetree/bindings/sound/simple-card.yaml
> @@ -99,6 +99,28 @@ definitions:
>      description: the widget names for which pin switches must be created.
>      $ref: /schemas/types.yaml#/definitions/string-array
>  
> +  trigger-start:
> +    description: |-
> +      Start trigger ordering method:
> +      default: Link->Component->DAI
> +      ldc: Link->DAI->Component
> +    $ref: /schemas/types.yaml#/definitions/string
> +    items:
> +      enum:
> +        - default

Why do you need a value of 'default'? What's the default when the 
property is not present?

> +        - ldc
> +
> +  trigger-stop:
> +    description: |-
> +      Stop trigger ordering method:
> +      default: DAI->Component->Link
> +      ldc: Component->DAI->Link
> +    $ref: /schemas/types.yaml#/definitions/string
> +    items:
> +      enum:
> +        - default
> +        - ldc
> +
>    format:
>      description: audio format.
>      items:
> @@ -210,6 +232,10 @@ properties:
>      maxItems: 1
>    simple-audio-card,mic-det-gpio:
>      maxItems: 1
> +  simple-audio-card,trigger-start:
> +    $ref: "#/definitions/trigger-start"
> +  simple-audio-card,trigger-stop:
> +    $ref: "#/definitions/trigger-stop"

Don't continue this 'simple-audio-card,' prefix pattern. With it, no 
other binding can use these properties.

>  
>  patternProperties:
>    "^simple-audio-card,cpu(@[0-9a-f]+)?$":
> @@ -259,6 +285,11 @@ patternProperties:
>          maxItems: 1
>        mic-det-gpio:
>          maxItems: 1
> +      trigger-start:
> +        $ref: "#/definitions/trigger-start"
> +      trigger-stop:
> +        $ref: "#/definitions/trigger-stop"
> +
>  
>      patternProperties:
>        "^cpu(-[0-9]+)?$":
> -- 
> 2.40.1
> 

Re: [PATCH v2] ASoC: dt-bindings: simple-card: add triggers properties

[Maxim Kochetkov]

On 19.07.2023 01:08, Rob Herring wrote:
> On Sat, Jul 15, 2023 at 11:30:43AM +0300, Maxim Kochetkov wrote:
>> The trigger-start/stop properties allows to specify DAI link
>> trigger ordering method.
> 
> Obviously. Why do you need these? What problem does it solve?

It allows using simple card for some DMA-based CPU component which 
requires different start/stop sequence (stop DMA before CPU component, 
start DMA after CPU component).
There are a lot of boards which have no audio codec on board. It has 
only I2S/TDM/etc... and you can attach any external codec on its pins. 
It looks like simple audio card is enough for this cases. It is much 
better than to copy-paste simple audio card code to the new custom 
driver with new combination of CPU/codec.

> 
> I don't think these belong in simple-card. What's next? What if you need
> delays between each step? This is the problem with 'simple' or 'generic'
> bindings. It's a never ending addition of properties which are not well
> thought out.

Can you please suggest the better way to specify start/stop trigger 
order via DT?

>> +  trigger-start:
>> +    description: |-
>> +      Start trigger ordering method:
>> +      default: Link->Component->DAI
>> +      ldc: Link->DAI->Component
>> +    $ref: /schemas/types.yaml#/definitions/string
>> +    items:
>> +      enum:
>> +        - default
> 
> Why do you need a value of 'default'? What's the default when the
> property is not present?
It comes from
enum snd_soc_trigger_order {
	SND_SOC_TRIGGER_ORDER_DEFAULT	= 0,	
	SND_SOC_TRIGGER_ORDER_LDC,		
	SND_SOC_TRIGGER_ORDER_MAX,
};
default value is 0 (SND_SOC_TRIGGER_ORDER_DEFAULT)

>>     format:
>>       description: audio format.
>>       items:
>> @@ -210,6 +232,10 @@ properties:
>>       maxItems: 1
>>     simple-audio-card,mic-det-gpio:
>>       maxItems: 1
>> +  simple-audio-card,trigger-start:
>> +    $ref: "#/definitions/trigger-start"
>> +  simple-audio-card,trigger-stop:
>> +    $ref: "#/definitions/trigger-stop"
> 
> Don't continue this 'simple-audio-card,' prefix pattern. With it, no
> other binding can use these properties.

Ok.

> 
>>   
>>   patternProperties:
>>     "^simple-audio-card,cpu(@[0-9a-f]+)?$":
>> @@ -259,6 +285,11 @@ patternProperties:
>>           maxItems: 1
>>         mic-det-gpio:
>>           maxItems: 1
>> +      trigger-start:
>> +        $ref: "#/definitions/trigger-start"
>> +      trigger-stop:
>> +        $ref: "#/definitions/trigger-stop"
>> +

Should I keep only this section?

[PATCH v2] ASoC: simple-card: add triggers parsing from DT node support

[Maxim Kochetkov]

It may be useful to specify trigger-start/stop for some DMA-based
simple audio card. So add this "trigger-start/stop" device tree
entry parser.

Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
---
 sound/soc/generic/simple-card.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index a78babf44f38..f934534d5c94 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -181,6 +181,10 @@ static int simple_link_init(struct asoc_simple_priv *priv,
 	struct snd_soc_dai_link *dai_link = simple_priv_to_link(priv, li->link);
 	int ret;
 
+	ret = asoc_simple_parse_triggers(node, prefix, dai_link);
+	if (ret)
+		return ret;
+
 	ret = asoc_simple_parse_daifmt(dev, node, codec,
 				       prefix, &dai_link->dai_fmt);
 	if (ret < 0)
-- 
2.40.1