[PATCH v5 02/23] mtd: nand: add a shorthand to generate nand_ecc_caps structure

Masahiro Yamada
2017-06-07T11:53:44Z

struct nand_ecc_caps was designed as flexible as possible to support
multiple stepsizes (like sunxi_nand.c).

So, we need to write multiple arrays even for the simplest case.
I guess many controllers support a single stepsize, so here is a
shorthand macro for the case.

It allows to describe like ...

NAND_ECC_CAPS_SINGLE(denali_pci_ecc_caps, denali_calc_ecc_bytes, 512, 8, 15);

... instead of

static const int denali_pci_ecc_strengths[] = {8, 15};
static const struct nand_ecc_step_info denali_pci_ecc_stepinfo = {
.stepsize = 512,
.strengths = denali_pci_ecc_strengths,
.nstrengths = ARRAY_SIZE(denali_pci_ecc_strengths),
};
static const struct nand_ecc_caps denali_pci_ecc_caps = {
.stepinfos = &denali_pci_ecc_stepinfo,
.nstepinfos = 1,
.calc_ecc_bytes = denali_calc_ecc_bytes,
};

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5:
- Newly added

Changes in v4: None
Changes in v3: None
Changes in v2: None

include/linux/mtd/nand.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index c28a5792eed6..c08954a39657 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -500,6 +500,20 @@ struct nand_ecc_caps {
int (*calc_ecc_bytes)(int step_size, int strength);
};

+/* a shorthand to generate struct nand_ecc_caps with only one ECC stepsize */
+#define NAND_ECC_CAPS_SINGLE(__name, __calc, __step, ...) \
+static const int __name##_strengths[] = { __VA_ARGS__ }; \
+static const struct nand_ecc_step_info __name##_stepinfo = { \
+ .stepsize = __step, \
+ .strengths = __name##_strengths, \
+ .nstrengths = ARRAY_SIZE(__name##_strengths), \
+}; \
+static const struct nand_ecc_caps __name = { \
+ .stepinfos = &__name##_stepinfo, \
+ .nstepinfos = 1, \
+ .calc_ecc_bytes = __calc, \
+}
+
/**
* struct nand_ecc_ctrl - Control structure for ECC
* @mode: ECC mode
--
2.7.4