[PATCH v2 2/6] spi: cadence-xspi: Reconfigure to STIG mode before SPI message

[Paul Cercueil <paul.cercueil@bootlin.com>]

From: Tanmay Jagdale <tanmay@marvell.com>

The .transfer_one_message() function uses the STIG mode, therefore the
xSPI needs to be configured to STIG mode before starting any transfer.

Without this, .transfer_one_message() simply won't work, at least on the
CN10K SoC.

Fixes: 931e389ded0f ("spi: cadence: Add Marvell xfer operation support")
Signed-off-by: Tanmay Jagdale <tanmay@marvell.com>
Co-developed-by: Paul Cercueil <paul.cercueil@bootlin.com>
Signed-off-by: Paul Cercueil <paul.cercueil@bootlin.com>

---

v2: Adapt the code slightly to work on top of [1/6]
---
 drivers/spi/spi-cadence-xspi.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
index a584a3c395d0..87b986a318f3 100644
--- a/drivers/spi/spi-cadence-xspi.c
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -367,6 +367,20 @@ static int cdns_xspi_wait_for_controller_idle(struct cdns_xspi_dev *cdns_xspi)
 					  100, 1000);
 }
 
+static int cdns_xspi_set_stig_mode(struct cdns_xspi_dev *cdns_xspi)
+{
+	int ret;
+
+	ret = cdns_xspi_wait_for_controller_idle(cdns_xspi);
+	if (ret < 0)
+		return -EIO;
+
+	writel(FIELD_PREP(CDNS_XSPI_CTRL_WORK_MODE, CDNS_XSPI_WORK_MODE_STIG),
+	       cdns_xspi->iobase + CDNS_XSPI_CTRL_CONFIG_REG);
+
+	return 0;
+}
+
 static void cdns_xspi_trigger_command(struct cdns_xspi_dev *cdns_xspi,
 				      u32 cmd_regs[6])
 {
@@ -536,12 +550,9 @@ static int cdns_xspi_send_stig_command(struct cdns_xspi_dev *cdns_xspi,
 	int ret;
 	int dummybytes = op->dummy.nbytes;
 
-	ret = cdns_xspi_wait_for_controller_idle(cdns_xspi);
-	if (ret < 0)
-		return -EIO;
-
-	writel(FIELD_PREP(CDNS_XSPI_CTRL_WORK_MODE, CDNS_XSPI_WORK_MODE_STIG),
-	       cdns_xspi->iobase + CDNS_XSPI_CTRL_CONFIG_REG);
+	ret = cdns_xspi_set_stig_mode(cdns_xspi);
+	if (ret)
+		return ret;
 
 	cdns_xspi->set_interrupts_handler(cdns_xspi, true);
 	cdns_xspi->sdma_error = false;
@@ -1112,7 +1123,13 @@ static int cdns_xspi_transfer_one_message_b0(struct spi_controller *controller,
 	int current_transfer_len;
 	int cs = spi_get_chipselect(spi, 0);
 	int cs_change = 0;
-	int ret = -EIO;
+	int ret;
+
+	ret = cdns_xspi_set_stig_mode(cdns_xspi);
+	if (ret)
+		goto out;
+
+	ret = -EIO;
 
 	/* Enable xfer state machine */
 	if (!cdns_xspi->xfer_in_progress) {
-- 
2.47.3