[PATCH 45/58] mtd: rawnand: sh_flctl: retain chip state across removal

[James Hilliard]

Unregister and disconnect the NAND chip before releasing the DMA
channel. Retain chip and controller storage until the last MTD reference
is dropped.

Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
 drivers/mtd/nand/raw/sh_flctl.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/raw/sh_flctl.c b/drivers/mtd/nand/raw/sh_flctl.c
index 97f733e481ff..291d809d0ea1 100644
--- a/drivers/mtd/nand/raw/sh_flctl.c
+++ b/drivers/mtd/nand/raw/sh_flctl.c
@@ -1109,6 +1109,11 @@ static struct sh_flctl_platform_data *flctl_parse_dt(struct device *dev)
 	return pdata;
 }
 
+static void flctl_release(struct nand_controller *controller)
+{
+	kfree(container_of(controller, struct sh_flctl, chip.legacy.dummy_controller));
+}
+
 static int flctl_probe(struct platform_device *pdev)
 {
 	struct resource *res;
@@ -1119,9 +1124,14 @@ static int flctl_probe(struct platform_device *pdev)
 	int ret;
 	int irq;
 
-	flctl = devm_kzalloc(&pdev->dev, sizeof(struct sh_flctl), GFP_KERNEL);
+	flctl = kzalloc_obj(*flctl);
 	if (!flctl)
 		return -ENOMEM;
+	nand = &flctl->chip;
+	nand->controller = &nand->legacy.dummy_controller;
+	ret = devm_nand_controller_init(&pdev->dev, nand->controller, flctl_release);
+	if (ret)
+		return ret;
 
 	flctl->reg = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 	if (IS_ERR(flctl->reg))
@@ -1187,9 +1197,15 @@ static int flctl_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_chip;
 
-	ret = mtd_device_register(flctl_mtd, pdata->parts, pdata->nr_parts);
+	ret = nand_set_release(nand, NULL);
 	if (ret)
 		goto cleanup_nand;
+	ret = mtd_device_register(flctl_mtd, pdata->parts, pdata->nr_parts);
+	if (ret) {
+		nand_disconnect(nand);
+		mtd_put_master(flctl_mtd);
+		goto err_chip;
+	}
 
 	return 0;
 
@@ -1207,11 +1223,12 @@ static void flctl_remove(struct platform_device *pdev)
 	struct nand_chip *chip = &flctl->chip;
 	int ret;
 
-	flctl_release_dma(flctl);
 	ret = mtd_device_unregister(nand_to_mtd(chip));
 	WARN_ON(ret);
-	nand_cleanup(chip);
+	nand_disconnect(chip);
+	flctl_release_dma(flctl);
 	pm_runtime_disable(&pdev->dev);
+	mtd_put_master(nand_to_mtd(chip));
 }
 
 static struct platform_driver flctl_driver = {

-- 
2.53.0