[PATCH v2] mtd: spinand: Enable QE on all dies

[han.xu@oss.nxp.com]

From: Han Xu <han.xu@nxp.com>

The QUAD ENABLE (QE) bit is stored in a per-die configuration
register on some SPI-NAND devices. When a device contains multiple
dies, updating the QE bit only on the currently selected die can
leave the remaining dies operating in non-quad mode.
 
Iterate over all targets and update the QE setting on each die
during initialization to ensure consistent quad I/O operation
across the entire device.

Tested on ISSI IS38SMW04G8B.

Fixes: 7529df465248 ("mtd: nand: Add core infrastructure to support SPI NANDs")
Cc: stable@vger.kernel.org
Signed-off-by: Han Xu <han.xu@nxp.com>
---
Changes in v2:
- Add CC stable
- Link to v1: https://patch.msgid.link/20260807-spinand_qe-v1-1-c102c79834a3@nxp.com

To: Miquel Raynal <miquel.raynal@bootlin.com>
To: Richard Weinberger <richard@nod.at>
To: Vignesh Raghavendra <vigneshr@ti.com>
To: Peter Pan <peterpandong@micron.com>
To: Boris Brezillon <bbrezillon@kernel.org>
Cc: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/mtd/nand/spi/core.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 35365b67dd8e..744662533f37 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -281,8 +281,26 @@ static int spinand_init_cfg_cache(struct spinand_device *spinand)
 static int spinand_init_quad_enable(struct spinand_device *spinand,
 				    bool enable)
 {
-	return spinand_upd_cfg(spinand, CFG_QUAD_ENABLE,
-			       enable ? CFG_QUAD_ENABLE : 0);
+	struct nand_device *nand = spinand_to_nand(spinand);
+	unsigned int target;
+	int ret;
+
+	/*
+	 * QE is a per-die setting on some devices. Program each target
+	 * individually when enabling or disabling quad I/O mode.
+	 */
+	for (target = 0; target < nand->memorg.ntargets; target++) {
+		ret = spinand_select_target(spinand, target);
+		if (ret)
+			return ret;
+
+		ret = spinand_upd_cfg(spinand, CFG_QUAD_ENABLE,
+				      enable ? CFG_QUAD_ENABLE : 0);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 static int spinand_ecc_enable(struct spinand_device *spinand,

---
base-commit: 113f62225e98febabba0fee00afd29d4eaf65abb
change-id: 20260807-spinand_qe-dd6148042f63

Best regards,
--  
Han Xu <han.xu@nxp.com>


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