[PATCH v24 10/34] ASoC: usb: Create SOC USB SND jack kcontrol

Wesley Cheng
2024-08-01T01:18:47Z

Expose API for creation of a jack control for notifying of available
devices that are plugged in/discovered, and that support offloading. This
allows for control names to be standardized across implementations of USB
audio offloading.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
include/sound/soc-usb.h | 17 +++++++++++
sound/soc/soc-usb.c | 62 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h
index 20394b3552cd..d6b576f971ae 100644
--- a/include/sound/soc-usb.h
+++ b/include/sound/soc-usb.h
@@ -6,6 +6,8 @@
#ifndef __LINUX_SND_SOC_USB_H
#define __LINUX_SND_SOC_USB_H

+#include <sound/soc.h>
+
/**
* struct snd_soc_usb_device
* @card_idx - sound card index associated with USB device
@@ -46,6 +48,10 @@ int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);
void *snd_soc_usb_find_priv_data(struct device *dev);

+int snd_soc_usb_setup_offload_jack(struct snd_soc_component *component,
+ struct snd_soc_jack *jack);
+int snd_soc_usb_disable_offload_jack(struct snd_soc_component *component);
+
struct snd_soc_usb *snd_soc_usb_allocate_port(struct snd_soc_component *component,
int num_streams, void *data);
void snd_soc_usb_free_port(struct snd_soc_usb *usb);
@@ -69,6 +75,17 @@ static inline void *snd_soc_usb_find_priv_data(struct device *dev)
return NULL;
}

+static inline int snd_soc_usb_setup_offload_jack(struct snd_soc_component *component,
+ struct snd_soc_jack *jack)
+{
+ return -ENODEV;
+}
+
+static inline int snd_soc_usb_disable_offload_jack(struct snd_soc_component *component)
+{
+ return -ENODEV;
+}
+
static inline struct snd_soc_usb *snd_soc_usb_allocate_port(
struct snd_soc_component *component,
int num_streams, void *data)
diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c
index b8a87e3fc6b2..fe2a75a28af4 100644
--- a/sound/soc/soc-usb.c
+++ b/sound/soc/soc-usb.c
@@ -4,8 +4,10 @@
*/
#include <linux/of.h>
#include <linux/usb.h>
-#include <sound/soc.h>
+
+#include <sound/jack.h>
#include <sound/soc-usb.h>
+
#include "../usb/card.h"

static DEFINE_MUTEX(ctx_mutex);
@@ -57,6 +59,64 @@ static struct snd_soc_usb *snd_soc_find_usb_ctx(struct device *dev)
return ctx ? ctx : NULL;
}

+/* SOC USB sound kcontrols */
+/**
+ * snd_soc_usb_setup_offload_jack() - Create USB offloading jack
+ * @component: USB DPCM backend DAI component
+ * @jack: jack structure to create
+ *
+ * Creates a jack device for notifying userspace of the availability
+ * of an offload capable device.
+ *
+ * Returns 0 on success, negative on error.
+ *
+ */
+int snd_soc_usb_setup_offload_jack(struct snd_soc_component *component,
+ struct snd_soc_jack *jack)
+{
+ int ret;
+
+ ret = snd_soc_card_jack_new(component->card, "USB Offload Playback Jack",
+ SND_JACK_HEADPHONE, jack);
+ if (ret < 0) {
+ dev_err(component->card->dev, "Unable to add USB offload jack\n");
+ return ret;
+ }
+
+ ret = snd_soc_component_set_jack(component, jack, NULL);
+ if (ret) {
+ dev_err(component->card->dev, "Failed to set jack: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_setup_offload_jack);
+
+/**
+ * snd_soc_usb_disable_offload_jack() - Disables USB offloading jack
+ * @component: USB DPCM backend DAI component
+ *
+ * Disables the offload jack device, so that further connection events
+ * won't be notified.
+ *
+ * Returns 0 on success, negative on error.
+ *
+ */
+int snd_soc_usb_disable_offload_jack(struct snd_soc_component *component)
+{
+ int ret;
+
+ ret = snd_soc_component_set_jack(component, NULL, NULL);
+ if (ret) {
+ dev_err(component->card->dev, "Failed to disable jack: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_disable_offload_jack);
+
/**
* snd_soc_usb_find_priv_data() - Retrieve private data stored
* @dev: device reference