subsys:usb:device:audio: Support volume control

dts/bindings/usb/usb-audio-feature-volume.yaml

@@ -0,0 +1,37 @@
+# Copyright (c) 2023, LISTENAI
+# SPDX-License-Identifier: Apache-2.0
+#
+# Specific fields for USB volume control.
+
+description: USB volume control specific fields.
+
+compatible: "usb-audio-feature-volume"
+
+include: base.yaml
+
+properties:
+  volume-max:
+    type: int
+    default: 0x0A00
+    description: |
+      attention: this attribute is a signed value.
+      This attribute represents the maximum volume level.
+      The range from +127.9961 dB (0x7FFF) down to -127.9961 dB (0x8001).
+      Valid range: 0 - 0xFFFF
+  volume-min:
+    type: int
+    default: 0xBA00
+    description: |
+      attention: this attribute is a signed value.
+      This attribute represents the minimum volume level.
+      The range from +127.9961 dB (0x7FFF) down to -127.9961 dB (0x8001).
+      Valid range: 0 - 0xFFFF
+  volume-res:
+    type: int
+    default: 0x100
+    description: |
+      attention: this attribute can only take positive values.
+      This attribute represents the volume resolution(step).
+      1 = 1/256 dB or 0.00390625 dB.
+      0x100(256) = 1dB.
+      Valid range: 1 - 0x7FFF

dts/bindings/usb/usb-audio-hp.yaml

@@ -7,7 +7,7 @@ description: USB Audio headphones specific fields.
 
 compatible: "usb-audio-hp"
 
-include: usb-audio.yaml
+include: [usb-audio.yaml, usb-audio-feature-volume.yaml]
 
 properties:
   resolution:

dts/bindings/usb/usb-audio-hs.yaml

@@ -7,7 +7,7 @@ description: USB Audio headset specific fields.
 
 compatible: "usb-audio-hs"
 
-include: usb-audio.yaml
+include: [usb-audio.yaml, usb-audio-feature-volume.yaml]
 
 properties:
   mic-resolution:
@@ -167,7 +167,6 @@ properties:
     type: boolean
     description: |
       Enable Volume feature.
-      Currently not supported.
   hp-feature-tone-control:
     type: boolean
     description: |

samples/subsys/usb/audio/headphones_microphone/app.overlay

@@ -10,6 +10,11 @@
 		feature-mute;
 		channel-l;
 		channel-r;
+
+		feature-volume;
+		volume-max = <0x0500>;
+		volume-min = <0xBA00>;
+		volume-res = <0x100>;
 	};
 	mic_0 {
 		compatible = "usb-audio-mic";

samples/subsys/usb/audio/headphones_microphone/src/main.c

@@ -45,10 +45,17 @@ static void data_received(const struct device *dev,
 static void feature_update(const struct device *dev,
 			   const struct usb_audio_fu_evt *evt)
 {
+	int16_t volume = 0;
+
 	LOG_DBG("Control selector %d for channel %d updated",
 		evt->cs, evt->channel);
 	switch (evt->cs) {
 	case USB_AUDIO_FU_MUTE_CONTROL:
+		break;
+	case USB_AUDIO_FU_VOLUME_CONTROL:
+		volume = *((int16_t *)(evt->val));
+		LOG_INF("set volume: %d", volume);
+		break;
 	default:
 		break;
 	}

samples/subsys/usb/audio/headset/app.overlay

@@ -14,5 +14,10 @@
 		hp-feature-mute;
 		hp-channel-l;
 		hp-channel-r;
+
+		hp-feature-volume;
+		volume-max = <0x0500>;
+		volume-min = <0xBA00>;
+		volume-res = <0x100>;
 	};
 };

samples/subsys/usb/audio/headset/src/main.c

@@ -43,10 +43,17 @@ static void data_received(const struct device *dev,
 static void feature_update(const struct device *dev,
 			   const struct usb_audio_fu_evt *evt)
 {
+	int16_t volume = 0;
+
 	LOG_DBG("Control selector %d for channel %d updated",
 		evt->cs, evt->channel);
 	switch (evt->cs) {
 	case USB_AUDIO_FU_MUTE_CONTROL:
+		break;
+	case USB_AUDIO_FU_VOLUME_CONTROL:
+		volume = *((int16_t *)(evt->val));
+		LOG_INF("set volume: %d", volume);
+		break;
 	default:
 		break;
 	}

subsys/usb/device/class/audio/audio.c

@@ -24,6 +24,12 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(usb_audio, CONFIG_USB_AUDIO_LOG_LEVEL);
 
+struct feature_volume {
+	int16_t volume_max;
+	int16_t volume_min;
+	int16_t volume_res;
+};
+
 /* Device data structure */
 struct usb_audio_dev_data {
 	const struct usb_audio_ops *ops;
@@ -41,6 +47,9 @@ struct usb_audio_dev_data {
 	/* Not applicable for Headphones, left with 0 */
 	uint16_t in_frame_size;
 
+	/* Not applicable for not support volume feature device */
+	struct feature_volume volumes;
+
 	bool rx_enable;
 	bool tx_enable;
 };
@@ -146,11 +155,14 @@ static struct usb_ep_cfg_data dev##_usb_audio_ep_data_##i[] = {		  \
 
 #define DEFINE_AUDIO_DEV_DATA(dev, i, __out_pool, __in_pool_size)   \
 	static uint8_t dev##_controls_##i[FEATURES_SIZE(dev, i)] = {0};\
-	static struct usb_audio_dev_data dev##_audio_dev_data_##i = \
-		{ .pool = __out_pool,				    \
-		  .in_frame_size = __in_pool_size,		    \
-		  .controls = {dev##_controls_##i, NULL},	    \
-		  .ch_cnt = {(CH_CNT(dev, i) + 1), 0}		    \
+	static struct usb_audio_dev_data dev##_audio_dev_data_##i =	\
+		{ .pool = __out_pool,					\
+		  .in_frame_size = __in_pool_size,			\
+		  .controls = {dev##_controls_##i, NULL},		\
+		  .ch_cnt = {(CH_CNT(dev, i) + 1), 0},			\
+		  .volumes.volume_max = GET_VOLUME(dev, i, volume_max), \
+		  .volumes.volume_min = GET_VOLUME(dev, i, volume_min), \
+		  .volumes.volume_res = GET_VOLUME(dev, i, volume_res), \
 		}
 
 #define DEFINE_AUDIO_DEV_DATA_BIDIR(dev, i, __out_pool, __in_pool_size)	   \
@@ -161,7 +173,10 @@ static struct usb_ep_cfg_data dev##_usb_audio_ep_data_##i[] = {		  \
 		  .in_frame_size = __in_pool_size,			   \
 		  .controls = {dev##_controls0_##i, dev##_controls1_##i},  \
 		  .ch_cnt = {(CH_CNT(dev##_MIC, i) + 1),		   \
-			     (CH_CNT(dev##_HP, i) + 1)}			   \
+			     (CH_CNT(dev##_HP, i) + 1)},		   \
+		  .volumes.volume_max = GET_VOLUME(dev, i, volume_max),	   \
+		  .volumes.volume_min = GET_VOLUME(dev, i, volume_min),	   \
+		  .volumes.volume_res = GET_VOLUME(dev, i, volume_res),	   \
 		}
 
 /**
@@ -541,6 +556,67 @@ static int handle_fu_mute_req(struct usb_audio_dev_data *audio_dev_data,
 	return -EINVAL;
 }
 
+
+static int handle_fu_volume_req(struct usb_audio_dev_data *audio_dev_data,
+				struct usb_setup_packet *setup, int32_t *len, uint8_t **data,
+				struct usb_audio_fu_evt *evt, uint8_t device)
+{
+	uint8_t ch = (setup->wValue) & 0xFF;
+	uint8_t ch_cnt = audio_dev_data->ch_cnt[device];
+	uint8_t *controls = audio_dev_data->controls[device];
+	uint8_t *control_val = &controls[POS(VOLUME, ch, ch_cnt)];
+	int16_t target_vol = 0;
+	int16_t temp_vol = 0;
+
+	if (usb_reqtype_is_to_device(setup)) {
+		/* Check if *len has valid value */
+		if (*len != LEN(1, VOLUME)) {
+			LOG_ERR("*len: %d, LEN(1, VOLUME): %d", *len, LEN(1, VOLUME));
+			return -EINVAL;
+		}
+		if (setup->bRequest == USB_AUDIO_SET_CUR) {
+			target_vol = *((int16_t *)*data);
+			if (!IN_RANGE(target_vol, audio_dev_data->volumes.volume_min,
+				      audio_dev_data->volumes.volume_max)) {
+				LOG_ERR("Volume out of range: %d", target_vol);
+				return -EINVAL;
+			}
+			if (target_vol % audio_dev_data->volumes.volume_res != 0) {
+				target_vol = ROUND_UP(target_vol,
+					audio_dev_data->volumes.volume_res);
+			}
+			evt->val = control_val;
+			evt->val_len = *len;
+			*((int16_t *)evt->val) = sys_le16_to_cpu(target_vol);
+			return 0;
+		}
+	} else {
+		if (setup->bRequest == USB_AUDIO_GET_CUR) {
+			*len = LEN(ch_cnt, VOLUME);
+			temp_vol = sys_cpu_to_le16(*(int16_t *)control_val);
+			memcpy(*data, &temp_vol, *len);
+			return 0;
+		} else if (setup->bRequest == USB_AUDIO_GET_MIN) {
+			*len = sizeof(audio_dev_data->volumes.volume_min);
+			temp_vol = sys_cpu_to_le16(audio_dev_data->volumes.volume_min);
+			memcpy(*data, &temp_vol, *len);
+			return 0;
+		} else if (setup->bRequest == USB_AUDIO_GET_MAX) {
+			*len = sizeof(audio_dev_data->volumes.volume_max);
+			temp_vol = sys_cpu_to_le16(audio_dev_data->volumes.volume_max);
+			memcpy(*data, &temp_vol, *len);
+			return 0;
+		} else if (setup->bRequest == USB_AUDIO_GET_RES) {
+			*len = sizeof(audio_dev_data->volumes.volume_res);
+			temp_vol = sys_cpu_to_le16(audio_dev_data->volumes.volume_res);
+			memcpy(*data, &temp_vol, *len);
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
 /**
  * @brief Handler for feature unit requests.
  *
@@ -590,6 +666,10 @@ static int handle_feature_unit_req(struct usb_audio_dev_data *audio_dev_data,
 		ret = handle_fu_mute_req(audio_dev_data, pSetup,
 					 len, data, &evt, device);
 		break;
+	case USB_AUDIO_FU_VOLUME_CONTROL:
+		ret = handle_fu_volume_req(audio_dev_data, pSetup,
+					 len, data, &evt, device);
+		break;
 	default:
 		return -ENOTSUP;
 	}

subsys/usb/device/class/audio/usb_audio_internal.h

@@ -160,6 +160,11 @@
 #define GET_RES_HS_MIC(i) DT_PROP(DT_INST(i, COMPAT_HS), mic_resolution)
 #define GET_RES(dev, i) GET_RES_##dev(i)
 
+#define GET_VOLUME_HS(i, prop) DT_PROP_OR(DT_INST(i, COMPAT_HS), prop, 0)
+#define GET_VOLUME_HP(i, prop) DT_PROP_OR(DT_INST(i, COMPAT_HP), prop, 0)
+#define GET_VOLUME_MIC(i, prop) DT_PROP_OR(DT_INST(i, COMPAT_MIC), prop, 0)
+#define GET_VOLUME(dev, i, prop) GET_VOLUME_##dev(i, prop)
+
 #define SYNC_TYPE_HP(i)     3
 #define SYNC_TYPE_MIC(i)    DT_ENUM_IDX(DT_INST(i, COMPAT_MIC), sync_type)
 #define SYNC_TYPE_HS_HP(i)  3