spi: spi-axi: extend support for the `delay` field

The AXI SPI engine driver uses the `delay_usecs` field from `spi_transfer`
to configure delays, which the controller will execute.
This change extends the logic to also include the `delay` value, in case it
is used (instead if `delay_usecs`).
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-20-alexandru.ardelean@analog.comSigned-off-by: Mark Brown <broonie@kernel.org>

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

@@ -163,10 +163,21 @@ static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
 }
 
 static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry,
-	struct spi_engine *spi_engine, unsigned int clk_div, unsigned int delay)
+	struct spi_engine *spi_engine, unsigned int clk_div,
+	struct spi_transfer *xfer)
 {
 	unsigned int spi_clk = clk_get_rate(spi_engine->ref_clk);
 	unsigned int t;
+	int delay;
+
+	if (xfer->delay_usecs) {
+		delay = xfer->delay_usecs;
+	} else {
+		delay = spi_delay_to_ns(&xfer->delay, xfer);
+		if (delay < 0)
+			return;
+		delay /= 1000;
+	}
 
 	if (delay == 0)
 		return;
@@ -218,8 +229,7 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine,
 			spi_engine_gen_cs(p, dry, spi, true);
 
 		spi_engine_gen_xfer(p, dry, xfer);
-		spi_engine_gen_sleep(p, dry, spi_engine, clk_div,
-			xfer->delay_usecs);
+		spi_engine_gen_sleep(p, dry, spi_engine, clk_div, xfer);
 
 		cs_change = xfer->cs_change;
 		if (list_is_last(&xfer->transfer_list, &msg->transfers))