[PATCH v4 47/58] mtd: rawnand: lpc32xx_mlc: retain chip state across removal

[James Hilliard]

Drain chip operations before releasing interrupts, DMA and controller
resources. Retain the embedded NAND chip and controller until the final
MTD reference releases their metadata.

Run NAND cleanup during disconnection; the final core-owned put only
releases retained allocation and layout data.

Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Piotr Wojtaszczyk <piotr.wojtaszczyk@xxxxxxxxxxx>
Cc: Vladimir Zapolskiy <vz@xxxxxxxxx>
Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>
---
 drivers/mtd/nand/raw/lpc32xx_mlc.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/raw/lpc32xx_mlc.c b/drivers/mtd/nand/raw/lpc32xx_mlc.c
index 408b2aba2fdd..633d09471760 100644
--- a/drivers/mtd/nand/raw/lpc32xx_mlc.c
+++ b/drivers/mtd/nand/raw/lpc32xx_mlc.c
@@ -687,9 +687,14 @@ static int lpc32xx_nand_probe(struct platform_device *pdev)
 	int res;
 
 	/* Allocate memory for the device structure (and zero it) */
-	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
+	host = kzalloc_obj(*host);
 	if (!host)
 		return -ENOMEM;
+	nand_chip = &host->nand_chip;
+	nand_chip->controller = &nand_chip->legacy.dummy_controller;
+	res = devm_nand_controller_init(&pdev->dev, nand_chip->controller, host);
+	if (res)
+		return res;
 
 	host->pdev = pdev;
 
@@ -794,10 +799,16 @@ static int lpc32xx_nand_probe(struct platform_device *pdev)
 
 	mtd->name = DRV_NAME;
 
-	res = mtd_device_register(mtd, host->ncfg->parts,
-				  host->ncfg->num_parts);
+	res = nand_set_lifetime(nand_chip, NULL);
 	if (res)
 		goto cleanup_nand;
+	res = mtd_device_register(mtd, host->ncfg->parts,
+				  host->ncfg->num_parts);
+	if (res) {
+		nand_disconnect(nand_chip);
+		mtd_put_master(mtd);
+		goto free_irq;
+	}
 
 	return 0;
 
@@ -830,7 +841,7 @@ static void lpc32xx_nand_remove(struct platform_device *pdev)
 
 	ret = mtd_device_unregister(nand_to_mtd(chip));
 	WARN_ON(ret);
-	nand_cleanup(chip);
+	nand_disconnect(chip);
 
 	free_irq(host->irq, host);
 	if (use_dma)
@@ -841,6 +852,7 @@ static void lpc32xx_nand_remove(struct platform_device *pdev)
 
 	lpc32xx_wp_enable(host);
 	gpiod_put(host->wp_gpio);
+	mtd_put_master(nand_to_mtd(chip));
 }
 
 static int lpc32xx_nand_resume(struct platform_device *pdev)

-- 
2.53.0