diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index a052e0ab19e4..98a2ab3b6844 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -333,6 +333,7 @@ static const struct lpss_device_desc bsw_i2c_dev_desc = {
 
 static const struct property_entry bsw_spi_properties[] = {
 	PROPERTY_ENTRY_U32("intel,spi-pxa2xx-type", LPSS_BSW_SSP),
+	PROPERTY_ENTRY_U32("num-cs", 2),
 	{ }
 };