[PATCH 5/5] spi: cadence-xspi: Add workaround for old Marvell firmwares

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

From: Tanmay Jagdale <tanmay@marvell.com>

Older firmwares from Marvell used the cdns,xspi-nor compatible string
for the Marvell-specific xSPI IP, which is incompatible.

Add a workaround to support this by assuming that if the "xfer" resource
is found, it means that a Marvell IP is used.

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>
---
 drivers/spi/spi-cadence-xspi.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
index 48a109f3fcdb..d326589a6ca3 100644
--- a/drivers/spi/spi-cadence-xspi.c
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -1301,11 +1301,21 @@ static int cdns_xspi_probe(struct platform_device *pdev)
 	}
 
 #ifdef CONFIG_64BIT
-	if (cdns_xspi->driver_data->mrvl_hw_overlay) {
-		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "xfer");
-		if (!res)
-			res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "xfer");
+	if (!res)
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
+
+	if (res && !cdns_xspi->driver_data->mrvl_hw_overlay) {
+		/*
+		 * Handle old Marvell firmwares using the cdns,xspi-nor string
+		 * instead of the marvell,cn10-xspi-nor string.
+		 */
+		dev_warn(dev, "Marvell-specific xfer resource passed, but using the cdns,xspi-nor compatible string. Please fix firmware!\n");
 
+		cdns_xspi->driver_data = &marvell_driver_data;
+	}
+
+	if (cdns_xspi->driver_data->mrvl_hw_overlay) {
 		cdns_xspi->xferbase = devm_ioremap_resource(dev, res);
 		if (IS_ERR(cdns_xspi->xferbase)) {
 			dev_info(dev, "XFER register base not found, set it\n");
-- 
2.47.3