[PATCH v3 2/3] mtd: spi-nand: Set the DQS spi-mem capability if available

[Miquel Raynal]

Check whether the NAND is capable of generating a DQS signal and set the
flag accordingly.

Not wiring the DQS signal on a DQS capable chip that will be used at
frequency requiring this signal may be considered a hardware bug, so
let's assume this line will be routed "in most cases". If/when we get
issues with this assumption, a DT property describing the lacking line
in the routing can be created.

Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
 drivers/mtd/nand/spi/core.c | 4 ++++
 include/linux/mtd/spinand.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 74bb5ee83b31..b54f7a1dae85 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -2050,6 +2050,10 @@ static int spinand_probe(struct spi_mem *mem)
 	if (ret)
 		return ret;
 
+	/* Assume manufacturer drivers will enable the DQS pin if it is available */
+	if (spinand->flags & SPINAND_HAS_DQS)
+		spi_mem_set_dqs(mem);
+
 	ret = mtd_device_register(mtd, NULL, 0);
 	if (ret)
 		goto err_spinand_cleanup;
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index ec6efcfeef83..fe05b477afef 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -490,6 +490,7 @@ struct spinand_ecc_info {
 #define SPINAND_HAS_READ_PLANE_SELECT_BIT		BIT(3)
 #define SPINAND_NO_RAW_ACCESS				BIT(4)
 #define SPINAND_ODTR_PACKED_PAGE_READ			BIT(5)
+#define SPINAND_HAS_DQS					BIT(6)
 
 /**
  * struct spinand_ondie_ecc_conf - private SPI-NAND on-die ECC engine structure

-- 
2.54.0