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" but I doubt it.
The revision register on some UniPhier SoCs says the IP is 5.0 but the max_banks is encoded in the new format. The revision of this IP is often useless. In order to provide a way to calculate correct max_banks without relying on the revision register, add DENALI_CAPS_NEW_N_BANKS_FORMAT capability (quirk). Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com> --- drivers/mtd/nand/denali.c | 24 +++++++++++++++++------- drivers/mtd/nand/denali.h | 1 + 2 files changed, 18 insertions(+), 7 deletions(-) diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index 752ad98..614b4a5 100644 --- a/drivers/mtd/nand/denali.c +++ b/drivers/mtd/nand/denali.c @@ -448,17 +448,27 @@ static void find_valid_banks(struct denali_nand_info *denali) static void detect_max_banks(struct denali_nand_info *denali) { u32 features = ioread32(denali->flash_reg + FEATURES); + bool old_format; + /* - * Read the revision register, so we can calculate the max_banks - * properly: the encoding changed from rev 5.0 to 5.1 + * There are some IP versions with different n_banks encoding. + * Some people say the change happened from rev 5.0 to 5.1, while + * there exist variants with revision older than 5.1 but new encoding. + * The option flag is available in case the revision is useless. */ - u32 revision = MAKE_COMPARABLE_REVISION( + if (denali->caps & DENALI_CAPS_NEW_N_BANKS_FORMAT) + old_format = false; + else { + 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); + old_format = revision < REVISION_5_1; + } + + denali->max_banks = 1 << (features & FEATURES__N_BANKS); + + if (old_format) + denali->max_banks <<= 1; } static u16 denali_nand_timing_set(struct denali_nand_info *denali) diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h index 9bdf037..e3fe3bc 100644 --- a/drivers/mtd/nand/denali.h +++ b/drivers/mtd/nand/denali.h @@ -436,6 +436,7 @@ struct denali_nand_info { unsigned int caps; #define DENALI_CAPS_HW_ECC_FIXUP BIT(0) #define DENALI_CAPS_DMA_64BIT BIT(1) +#define DENALI_CAPS_NEW_N_BANKS_FORMAT BIT(2) }; extern int denali_init(struct denali_nand_info *denali); -- 2.7.4