mtd: nand: fsmc: Add BCH4 SW ECC support for SPEAr600

This patch adds support for 4-bit ECC BCH4 for the SPEAr600 SoC. This can
be used by boards equipped with a NAND chip that requires 4-bit ECC strength.
The SPEAr600 HW ECC only supports 1-bit ECC strength.

To enable SW BCH4, you need to specify this in your config header:

#define CONFIG_NAND_ECC_BCH
#define CONFIG_BCH

And use the command "nandecc bch4" to select this ECC scheme upon runtime.

Tested on SPEAr600 x600 board.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Scott Wood <scottwood@freescale.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
This commit is contained in:
Stefan Roese 2015-09-02 14:29:12 +02:00 committed by Tom Rini
parent b9599dd857
commit 1a103c6caa

View file

@ -13,6 +13,7 @@
#include <asm/io.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/mtd/nand_bch.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/fsmc_nand.h>
#include <asm/arch/hardware.h>
@ -390,6 +391,45 @@ static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
return 0;
}
#ifndef CONFIG_SPL_BUILD
/*
* fsmc_nand_switch_ecc - switch the ECC operation between different engines
*
* @eccstrength - the number of bits that could be corrected
* (1 - HW, 4 - SW BCH4)
*/
int __maybe_unused fsmc_nand_switch_ecc(uint32_t eccstrength)
{
struct nand_chip *nand;
struct mtd_info *mtd;
int err;
mtd = &nand_info[nand_curr_device];
nand = mtd->priv;
/* Setup the ecc configurations again */
if (eccstrength == 1) {
nand->ecc.mode = NAND_ECC_HW;
nand->ecc.bytes = 3;
nand->ecc.strength = 1;
nand->ecc.layout = &fsmc_ecc1_layout;
nand->ecc.correct = nand_correct_data;
} else {
nand->ecc.mode = NAND_ECC_SOFT_BCH;
nand->ecc.calculate = nand_bch_calculate_ecc;
nand->ecc.correct = nand_bch_correct_data;
nand->ecc.bytes = 7;
nand->ecc.strength = 4;
nand->ecc.layout = NULL;
}
/* Update NAND handling after ECC mode switch */
err = nand_scan_tail(mtd);
return err;
}
#endif /* CONFIG_SPL_BUILD */
int fsmc_nand_init(struct nand_chip *nand)
{
static int chip_nr;