ASoC: SOF: ipc4: Handle ALSA kcontrol change notification from firmware

The control change notification is sent as module notification with a
standardized event_id (higher 16 bit is 0xA15A).
Add generic code to handle the module notification and invoke the control
update callback if the notification is an ALSA kcontrol change message.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20231124150853.18648-5-peter.ujfalusi@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/ipc4.c

@@ -78,6 +78,9 @@ static const struct sof_ipc4_fw_status {
 	{165, "Reserved (ADSP_IPC_PIPELINE_ALREADY_EXISTS removed)"},
 };
 
+typedef void (*ipc4_notification_handler)(struct snd_sof_dev *sdev,
+					  struct sof_ipc4_msg *msg);
+
 static int sof_ipc4_check_reply_status(struct snd_sof_dev *sdev, u32 status)
 {
 	int i, ret;
@@ -610,9 +613,55 @@ static int ipc4_fw_ready(struct snd_sof_dev *sdev, struct sof_ipc4_msg *ipc4_msg
 	return sof_ipc4_init_msg_memory(sdev);
 }
 
+static void sof_ipc4_module_notification_handler(struct snd_sof_dev *sdev,
+						 struct sof_ipc4_msg *ipc4_msg)
+{
+	struct sof_ipc4_notify_module_data *data = ipc4_msg->data_ptr;
+
+	/*
+	 * If the notification includes additional, module specific data, then
+	 * we need to re-allocate the buffer and re-read the whole payload,
+	 * including the event_data
+	 */
+	if (data->event_data_size) {
+		void *new;
+		int ret;
+
+		ipc4_msg->data_size += data->event_data_size;
+
+		new = krealloc(ipc4_msg->data_ptr, ipc4_msg->data_size, GFP_KERNEL);
+		if (!new) {
+			ipc4_msg->data_size -= data->event_data_size;
+			return;
+		}
+
+		/* re-read the whole payload */
+		ipc4_msg->data_ptr = new;
+		ret = snd_sof_ipc_msg_data(sdev, NULL, ipc4_msg->data_ptr,
+					   ipc4_msg->data_size);
+		if (ret < 0) {
+			dev_err(sdev->dev,
+				"Failed to read the full module notification: %d\n",
+				ret);
+			return;
+		}
+		data = ipc4_msg->data_ptr;
+	}
+
+	/* Handle ALSA kcontrol notification */
+	if ((data->event_id & SOF_IPC4_NOTIFY_MODULE_EVENTID_ALSA_MAGIC_MASK) ==
+	    SOF_IPC4_NOTIFY_MODULE_EVENTID_ALSA_MAGIC_VAL) {
+		const struct sof_ipc_tplg_ops *tplg_ops = sdev->ipc->ops->tplg;
+
+		if (tplg_ops->control->update)
+			tplg_ops->control->update(sdev, ipc4_msg);
+	}
+}
+
 static void sof_ipc4_rx_msg(struct snd_sof_dev *sdev)
 {
 	struct sof_ipc4_msg *ipc4_msg = sdev->ipc->msg.rx_data;
+	ipc4_notification_handler handler_func = NULL;
 	size_t data_size = 0;
 	int err;
 
@@ -648,6 +697,10 @@ static void sof_ipc4_rx_msg(struct snd_sof_dev *sdev)
 	case SOF_IPC4_NOTIFY_EXCEPTION_CAUGHT:
 		snd_sof_dsp_panic(sdev, 0, true);
 		break;
+	case SOF_IPC4_NOTIFY_MODULE_NOTIFICATION:
+		data_size = sizeof(struct sof_ipc4_notify_module_data);
+		handler_func = sof_ipc4_module_notification_handler;
+		break;
 	default:
 		dev_dbg(sdev->dev, "Unhandled DSP message: %#x|%#x\n",
 			ipc4_msg->primary, ipc4_msg->extension);
@@ -663,6 +716,10 @@ static void sof_ipc4_rx_msg(struct snd_sof_dev *sdev)
 		snd_sof_ipc_msg_data(sdev, NULL, ipc4_msg->data_ptr, ipc4_msg->data_size);
 	}
 
+	/* Handle notifications with payload */
+	if (handler_func)
+		handler_func(sdev, ipc4_msg);
+
 	sof_ipc4_log_header(sdev->dev, "ipc rx done ", ipc4_msg, true);
 
 	if (data_size) {