firmware: ti_sci: Support transfers without response

Check the header flags if an response is expected or not. If it is not
expected skip the receive part of ti_sci_do_xfer(). This prepares the
driver for one-way messages as prepare_sleep for Partial-IO.

Reviewed-by: Kendall Willis <k-willis@ti.com>
Signed-off-by: Markus Schneider-Pargmann (TI.com) <msp@baylibre.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Sebin Francis <sebin.francis@ti.com>
Link: https://patch.msgid.link/20251103-topic-am62-partialio-v6-12-b4-v10-1-0557e858d747@baylibre.com
Signed-off-by: Nishanth Menon <nm@ti.com>

Author: scosu

drivers/firmware/ti_sci.c

@@ -398,6 +398,9 @@ static void ti_sci_put_one_xfer(struct ti_sci_xfers_info *minfo,
 static inline int ti_sci_do_xfer(struct ti_sci_info *info,
 				 struct ti_sci_xfer *xfer)
 {
+	struct ti_sci_msg_hdr *hdr = (struct ti_sci_msg_hdr *)xfer->tx_message.buf;
+	bool response_expected = !!(hdr->flags & (TI_SCI_FLAG_REQ_ACK_ON_PROCESSED |
+						  TI_SCI_FLAG_REQ_ACK_ON_RECEIVED));
 	int ret;
 	int timeout;
 	struct device *dev = info->dev;
@@ -409,12 +412,12 @@ static inline int ti_sci_do_xfer(struct ti_sci_info *info,
 
 	ret = 0;
 
-	if (system_state <= SYSTEM_RUNNING) {
+	if (response_expected && system_state <= SYSTEM_RUNNING) {
 		/* And we wait for the response. */
 		timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms);
 		if (!wait_for_completion_timeout(&xfer->done, timeout))
 			ret = -ETIMEDOUT;
-	} else {
+	} else if (response_expected) {
 		/*
 		 * If we are !running, we cannot use wait_for_completion_timeout
 		 * during noirq phase, so we must manually poll the completion.