spi: axi-spi-engine: Emit trace events for spi transfers

As this spi host controller driver implements the
.transfer_one_message() callback, it has to care about these traces
it-self. With the transfers being compiled it's difficult to determine
where handling of one transfer ends and the next begins, so just
generate the start events in batch before the hardware fifo is fed and
the end events when their completion triggered.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20241031111646.747692-2-u.kleine-koenig@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-axi-spi-engine.c

@@ -15,6 +15,7 @@
 #include <linux/overflow.h>
 #include <linux/platform_device.h>
 #include <linux/spi/spi.h>
+#include <trace/events/spi.h>
 
 #define SPI_ENGINE_REG_RESET			0x40
 
@@ -590,6 +591,13 @@ static int spi_engine_transfer_one_message(struct spi_controller *host,
 
 	reinit_completion(&spi_engine->msg_complete);
 
+	if (trace_spi_transfer_start_enabled()) {
+		struct spi_transfer *xfer;
+
+		list_for_each_entry(xfer, &msg->transfers, transfer_list)
+			trace_spi_transfer_start(msg, xfer);
+	}
+
 	spin_lock_irqsave(&spi_engine->lock, flags);
 
 	if (spi_engine_write_cmd_fifo(spi_engine, msg))
@@ -617,6 +625,13 @@ static int spi_engine_transfer_one_message(struct spi_controller *host,
 		msg->status = -ETIMEDOUT;
 	}
 
+	if (trace_spi_transfer_stop_enabled()) {
+		struct spi_transfer *xfer;
+
+		list_for_each_entry(xfer, &msg->transfers, transfer_list)
+			trace_spi_transfer_stop(msg, xfer);
+	}
+
 	spi_finalize_current_message(host);
 
 	return msg->status;