From e7beeeec854c40c28caa53bd84fdf26e9e459f06 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Thu, 30 Mar 2017 15:45:57 +0900
Subject: [PATCH] mtd: nand: denali: allow to override revision number
Commit 271707b1d817 ("mtd: nand: denali: max_banks calculation
changed in revision 5.1") added a revision check to support the
new max_banks encoding. Its git-log states "The encoding of
max_banks changed in Denali revision 5.1".
There are exceptional cases, for example, the revision register on
some UniPhier SoCs says the IP is 5.0 but the max_banks is encoded
in the new format.
This IP updates the resister specification from time to time (often
breaking the backward compatibility), but the revision number is not
incremented correctly.
The max_banks is not only the case that needs revision checking.
Let's allow to override an incorrect revision number.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/mtd/nand/denali.c | 23 +++++++++++++----------
drivers/mtd/nand/denali.h | 3 +--
drivers/mtd/nand/denali_dt.c | 5 ++++-
3 files changed, 18 insertions(+), 13 deletions(-)
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 417a8950cf49c..16634df2e39a7 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -419,17 +419,12 @@ static void find_valid_banks(struct denali_nand_info *denali)
static void detect_max_banks(struct denali_nand_info *denali)
{
uint32_t features = ioread32(denali->flash_reg + FEATURES);
- /*
- * Read the revision register, so we can calculate the max_banks
- * properly: the encoding changed from rev 5.0 to 5.1
- */
- u32 revision = MAKE_COMPARABLE_REVISION(
- ioread32(denali->flash_reg + REVISION));
- if (revision < REVISION_5_1)
- denali->max_banks = 2 << (features & FEATURES__N_BANKS);
- else
- denali->max_banks = 1 << (features & FEATURES__N_BANKS);
+ denali->max_banks = 1 << (features & FEATURES__N_BANKS);
+
+ /* the encoding changed from rev 5.0 to 5.1 */
+ if (denali->revision < 0x0501)
+ denali->max_banks <<= 1;
}
static uint16_t denali_nand_timing_set(struct denali_nand_info *denali)
@@ -1319,6 +1314,14 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
/* Initialization code to bring the device up to a known good state */
static void denali_hw_init(struct denali_nand_info *denali)
{
+ /*
+ * The REVISION register may not be reliable. Platforms are allowed to
+ * override it.
+ */
+ if (!denali->revision)
+ denali->revision =
+ swab16(ioread32(denali->flash_reg + REVISION));
+
/*
* tell driver how many bit controller will skip before
* writing ECC code in OOB, this register may be already
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index 1f413d05a0107..ec004850652a7 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -179,8 +179,6 @@
#define REVISION 0x370
#define REVISION__VALUE 0xffff
-#define MAKE_COMPARABLE_REVISION(x) swab16((x) & REVISION__VALUE)
-#define REVISION_5_1 0x00000501
#define ONFI_DEVICE_FEATURES 0x380
#define ONFI_DEVICE_FEATURES__VALUE 0x003f
@@ -343,6 +341,7 @@ struct denali_nand_info {
int devnum; /* represent how many nands connected */
int bbtskipbytes;
int max_banks;
+ unsigned int revision;
unsigned int caps;
};
diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c
index ada38636122c5..df9ef36cc2ce3 100644
--- a/drivers/mtd/nand/denali_dt.c
+++ b/drivers/mtd/nand/denali_dt.c
@@ -30,6 +30,7 @@ struct denali_dt {
};
struct denali_dt_data {
+ unsigned int revision;
unsigned int caps;
};
@@ -60,8 +61,10 @@ static int denali_dt_probe(struct platform_device *pdev)
denali = &dt->denali;
data = of_device_get_match_data(&pdev->dev);
- if (data)
+ if (data) {
+ denali->revision = data->revision;
denali->caps = data->caps;
+ }
denali->platform = DT;
denali->dev = &pdev->dev;
--
2.30.2