Commit 271707b1d817 ("mtd: nand: denali: max_banks calculation
changed in revision 5.1") supported the new encoding of the "n_banks"
bits of the "features" register, but there is an unfortunate case
not covered by that commit.
Panasonic (its System LSI Business Division is now Socionext) bought
a couple of versions of this IP. The IP released for Panasonic
around Feb. 2012 is revision 5 and uses the old encoding for n_banks
(2 << n_banks). While the one released around Nov. 2012 is also
revision 5, but it uses the new encoding (1 << n_banks).
The revision register cannot distinguish these two incompatible
hardware. I guess this IP series is not well-organized. I could not
find any solution but giving max_banks from DT property.
This commit works around the problem by allowing DT to set the
max_banks forcibly. Of course, this DT property can be optional if
the auto detection based on the hardware registers works well.
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
---
Changes in v2:
- rebase on v4.6-rc1
- add Rob's Acked-by
- Rephrase git-log slightly
Documentation/devicetree/bindings/mtd/denali-nand.txt | 4 ++++
drivers/mtd/nand/denali.c | 3 ++-
drivers/mtd/nand/denali_dt.c | 3 +++
3 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/mtd/denali-nand.txt b/Documentation/devicetree/bindings/mtd/denali-nand.txt
index b04d03a..6154c77 100644
--- a/Documentation/devicetree/bindings/mtd/denali-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/denali-nand.txt
@@ -7,6 +7,10 @@ Required properties:
- interrupts : The interrupt number.
- dm-mask : DMA bit mask
+Optional properties:
+ - max-banks : Maximum number of banks supported by hardware. If not
+ specified, it is determined based on the "features" register of hardware.
+
The device tree may optionally contain sub-nodes describing partitions of the
address space. See partition.txt for more detail.
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 30bf5f6..e18b569 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -1353,7 +1353,8 @@ static void denali_hw_init(struct denali_nand_info *denali)
*/
denali->bbtskipbytes = ioread32(denali->flash_reg +
SPARE_AREA_SKIP_BYTES);
- detect_max_banks(denali);
+ if (!denali->max_banks)
+ detect_max_banks(denali);
denali_nand_reset(denali);
iowrite32(0x0F, denali->flash_reg + RB_PIN_ENABLED);
iowrite32(CHIP_EN_DONT_CARE__FLAG,
diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c
index 0cb1e8d..be55db8 100644
--- a/drivers/mtd/nand/denali_dt.c
+++ b/drivers/mtd/nand/denali_dt.c
@@ -85,6 +85,9 @@ static int denali_dt_probe(struct platform_device *ofdev)
denali->dev->dma_mask = NULL;
}
+ of_property_read_u32(ofdev->dev.of_node, "max-banks",
+ &denali->max_banks);
+
dt->clk = devm_clk_get(&ofdev->dev, NULL);
if (IS_ERR(dt->clk)) {
dev_err(&ofdev->dev, "no clk available\n");
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
