drivers: firmware: scmi: Add RX channel callback support in mailbox

Implement dedicated RX channel support with separate notification callback.
TX and RX channels now use different callbacks for proper message handling.

Signed-off-by: Yongxu Wang <[email protected]>

Author: yongxu-wang15

drivers/firmware/scmi/mailbox.c

@@ -10,9 +10,21 @@
 LOG_MODULE_REGISTER(scmi_mbox);
 
 static void scmi_mbox_tx_reply_cb(const struct device *mbox,
-		mbox_channel_id_t channel_id,
-		void *user_data,
-		struct mbox_msg *data)
+				mbox_channel_id_t channel_id,
+				void *user_data,
+				struct mbox_msg *data)
+{
+	struct scmi_channel *scmi_chan = user_data;
+
+	if (scmi_chan->cb) {
+		scmi_chan->cb(scmi_chan);
+	}
+}
+
+static void scmi_mbox_rx_notify_cb(const struct device *mbox,
+				mbox_channel_id_t channel_id,
+				void *user_data,
+				struct mbox_msg *data)
 {
 	struct scmi_channel *scmi_chan = user_data;
 
@@ -71,25 +83,34 @@ static int scmi_mbox_setup_chan(const struct device *transport,
 {
 	int ret;
 	struct scmi_mbox_channel *mbox_chan;
-	struct mbox_dt_spec *tx_reply;
+	struct mbox_dt_spec *mbox_spec;
 
 	mbox_chan = chan->data;
 
-	if (mbox_chan->tx_reply.dev) {
-		tx_reply = &mbox_chan->tx_reply;
+	if (tx) {
+		mbox_spec = mbox_chan->tx_reply.dev ? &mbox_chan->tx_reply : &mbox_chan->tx;
+		ret = mbox_register_callback_dt(mbox_spec, scmi_mbox_tx_reply_cb, chan);
+		if (ret < 0) {
+			LOG_ERR("failed to register reply cb on %s",
+					mbox_chan->tx_reply.dev ? "tx_reply" : "tx");
+			return ret;
+		}
 	} else {
-		tx_reply = &mbox_chan->tx;
-	}
-
-	ret = mbox_register_callback_dt(tx_reply, scmi_mbox_tx_reply_cb, chan);
-	if (ret < 0) {
-		LOG_ERR("failed to register tx reply cb");
-		return ret;
+		if (!mbox_chan->rx.dev) {
+			LOG_ERR("RX channel not defined");
+			return -ENOTSUP;
+		}
+		mbox_spec = &mbox_chan->rx;
+		ret = mbox_register_callback_dt(&mbox_chan->rx, scmi_mbox_rx_notify_cb, chan);
+		if (ret < 0) {
+			LOG_ERR("failed to register notify cb on rx");
+			return ret;
+		}
 	}
 
-	ret = mbox_set_enabled_dt(tx_reply, true);
+	ret = mbox_set_enabled_dt(mbox_spec, true);
 	if (ret < 0) {
-		LOG_ERR("failed to enable tx reply dbell");
+		LOG_ERR("failed to enable %s dbell", tx ? "tx" : "rx");
 	}
 
 	/* enable interrupt-based communication */