[PATCH v2] mtd: fsl-quadspi: Fix module unbound

[Fabio Estevam]

From: Fabio Estevam <fabio.estevam at freescale.com>

When removing the fsl-quadspi module and running 'cat /proc/mtd' afterwards,
we see garbage data like:

$ rmmod  fsl-quadspi
$ cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00000000 00000000 "(null)"
mtd0: 00000000 00000000 "(null)"
mtd0: 00000000 00000000 "(null)"
...
mtd0: a22296c6c756e28 00000000 "(null)"
mtd0: a22296c6c756e28 3064746d "(null)"

The reason for this is due to the wrong mtd index used in
mtd_device_unregister() in the remove function. This index mismatch is caused
by the usage of the 'qspi-has-second-chip' property in the probe function.

Such property is not really necessary and we can simplify the index logic
calculation to avoid the'holes'.

Thanks to Brian Norris for his suggestion.

Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
---
Changes since v1:
- Instead of adjusting the index in the remove function, let's get rid of
the 'qspi-has-second-chip' property completely.

 .../devicetree/bindings/mtd/fsl-quadspi.txt        |  9 --------
 drivers/mtd/spi-nor/fsl-quadspi.c                  | 24 ++++++++--------------
 2 files changed, 8 insertions(+), 25 deletions(-)

diff --git a/Documentation/devicetree/bindings/mtd/fsl-quadspi.txt b/Documentation/devicetree/bindings/mtd/fsl-quadspi.txt
index 823d134..b8e96ec 100644
--- a/Documentation/devicetree/bindings/mtd/fsl-quadspi.txt
+++ b/Documentation/devicetree/bindings/mtd/fsl-quadspi.txt
@@ -9,15 +9,6 @@ Required properties:
   - clocks : The clocks needed by the QuadSPI controller
   - clock-names : the name of the clocks
 
-Optional properties:
-  - fsl,qspi-has-second-chip: The controller has two buses, bus A and bus B.
-                              Each bus can be connected with two NOR flashes.
-			      Most of the time, each bus only has one NOR flash
-			      connected, this is the default case.
-			      But if there are two NOR flashes connected to the
-			      bus, you should enable this property.
-			      (Please check the board's schematic.)
-
 Example:
 
 qspi0: quadspi at 40044000 {
diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 39763b9..8cdd73f 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -212,7 +212,7 @@ static struct fsl_qspi_devtype_data imx6sx_data = {
 	.txfifo = 512
 };
 
-#define FSL_QSPI_MAX_CHIP	4
+#define FSL_QSPI_MAX_CHIP	2
 struct fsl_qspi {
 	struct mtd_info mtd[FSL_QSPI_MAX_CHIP];
 	struct spi_nor nor[FSL_QSPI_MAX_CHIP];
@@ -661,7 +661,7 @@ MODULE_DEVICE_TABLE(of, fsl_qspi_dt_ids);
 
 static void fsl_qspi_set_base_addr(struct fsl_qspi *q, struct spi_nor *nor)
 {
-	q->chip_base_addr = q->nor_size * (nor - q->nor);
+	q->chip_base_addr += (q->nor_size * 2);
 }
 
 static int fsl_qspi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
@@ -782,8 +782,7 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct spi_nor *nor;
 	struct mtd_info *mtd;
-	int ret, i = 0;
-	bool has_second_chip = false;
+	int ret, i;
 	const struct of_device_id *of_id =
 			of_match_device(fsl_qspi_dt_ids, &pdev->dev);
 
@@ -791,8 +790,8 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 	if (!q)
 		return -ENOMEM;
 
-	q->nor_num = of_get_child_count(dev->of_node);
-	if (!q->nor_num || q->nor_num > FSL_QSPI_MAX_CHIP)
+	ret = of_get_child_count(dev->of_node);
+	if (!ret || ret > FSL_QSPI_MAX_CHIP)
 		return -ENODEV;
 
 	/* find the resources */
@@ -859,19 +858,12 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 	if (ret)
 		goto irq_failed;
 
-	if (of_get_property(np, "fsl,qspi-has-second-chip", NULL))
-		has_second_chip = true;
-
 	/* iterate the subnodes. */
 	for_each_available_child_of_node(dev->of_node, np) {
 		char modalias[40];
 
-		/* skip the holes */
-		if (!has_second_chip)
-			i *= 2;
-
-		nor = &q->nor[i];
-		mtd = &q->mtd[i];
+		nor = &q->nor[q->nor_num];
+		mtd = &q->mtd[q->nor_num];
 
 		nor->mtd = mtd;
 		nor->dev = dev;
@@ -929,7 +921,7 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 		if (nor->page_size > q->devtype_data->txfifo)
 			nor->page_size = q->devtype_data->txfifo;
 
-		i++;
+		q->nor_num++;
 	}
 
 	/* finish the rest init. */
-- 
1.9.1