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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-03-30 08:45:57 +0200 |
|---|---|---|
| committer | Boris Brezillon <boris.brezillon@free-electrons.com> | 2017-04-25 14:18:37 +0200 |
| commit | e7beeeec854c40c28caa53bd84fdf26e9e459f06 (patch) | |
| tree | 3e473fee320968bee3d762306697cf16e6f3b4b8 /drivers/mtd/nand/denali.c | |
| parent | mtd: nand: denali_dt: use pdev instead of ofdev for platform_device (diff) | |
| download | linux-e7beeeec854c40c28caa53bd84fdf26e9e459f06.tar.xz linux-e7beeeec854c40c28caa53bd84fdf26e9e459f06.zip | |
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>
Diffstat (limited to 'drivers/mtd/nand/denali.c')
| -rw-r--r-- | drivers/mtd/nand/denali.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index 417a8950cf49..16634df2e39a 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) @@ -1320,6 +1315,14 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col, 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 * set by firmware. So we read this value out. |