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>

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 34df75cf42fd7a04c5c386c43b017096be7a6f40..c49294ca3c940ed98a5d1a6e1e67d99ab56b8ec6 100644 (file)
--- a/drivers/firmware/ti_sci.c
+++ b/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.