Re: [PATCH v4 7/9] mtd: rawnand: ingenic: Add support for the JZ4740

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Paul,

Paul Cercueil <paul@crapouillou.net> wrote on Sat,  9 Feb 2019 16:23:03
-0300:

> Add support for probing the ingenic-nand driver on the JZ4740 SoC from
> Ingenic, and the jz4740-ecc driver to support the JZ4740-specific
> ECC hardware.
> 
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> ---
> 
> Changes:
> 
> v2: New patch
> 
> v3: Also add support for the hardware ECC of the JZ4740 in this patch
> 
> v4: - Fix formatting issues
>     - Add MODULE_* macros
> 
>  drivers/mtd/nand/raw/ingenic/Kconfig        |  10 ++
>  drivers/mtd/nand/raw/ingenic/Makefile       |   1 +
>  drivers/mtd/nand/raw/ingenic/ingenic_nand.c |  48 +++++--
>  drivers/mtd/nand/raw/ingenic/jz4740_ecc.c   | 196 ++++++++++++++++++++++++++++
>  4 files changed, 244 insertions(+), 11 deletions(-)
>  create mode 100644 drivers/mtd/nand/raw/ingenic/jz4740_ecc.c
> 

[...]

>  	switch (chip->ecc.mode) {
>  	case NAND_ECC_HW:
> @@ -270,8 +279,8 @@ static int ingenic_nand_init_chip(struct platform_device *pdev,
>  		return -ENOMEM;
>  	mtd->dev.parent = dev;
>  
> -	chip->legacy.IO_ADDR_R = cs->base + OFFSET_DATA;
> -	chip->legacy.IO_ADDR_W = cs->base + OFFSET_DATA;
> +	chip->legacy.IO_ADDR_R = cs->base + nfc->soc_info->data_offset;
> +	chip->legacy.IO_ADDR_W = cs->base + nfc->soc_info->data_offset;
>  	chip->legacy.chip_delay = RB_DELAY_US;
>  	chip->options = NAND_NO_SUBPAGE_WRITE;
>  	chip->legacy.select_chip = ingenic_nand_select_chip;

I think Boris already asked for it, but it would be really great that
you update this driver to not use any legacy interface anymore.

> diff --git a/drivers/mtd/nand/raw/ingenic/jz4740_ecc.c b/drivers/mtd/nand/raw/ingenic/jz4740_ecc.c
> new file mode 100644
> index 000000000000..83b42881720e
> --- /dev/null
> +++ b/drivers/mtd/nand/raw/ingenic/jz4740_ecc.c
> @@ -0,0 +1,196 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * JZ4740 ECC controller driver
> + *
> + * Copyright (c) 2019 Paul Cercueil <paul@crapouillou.net>
> + *
> + * based on jz4740-nand.c
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +
> +#include "ingenic_ecc.h"
> +
> +#define JZ_REG_NAND_ECC_CTRL	0x00
> +#define JZ_REG_NAND_DATA	0x04
> +#define JZ_REG_NAND_PAR0	0x08
> +#define JZ_REG_NAND_PAR1	0x0C
> +#define JZ_REG_NAND_PAR2	0x10
> +#define JZ_REG_NAND_IRQ_STAT	0x14
> +#define JZ_REG_NAND_IRQ_CTRL	0x18
> +#define JZ_REG_NAND_ERR(x)	(0x1C + ((x) << 2))
> +
> +#define JZ_NAND_ECC_CTRL_PAR_READY	BIT(4)
> +#define JZ_NAND_ECC_CTRL_ENCODING	BIT(3)
> +#define JZ_NAND_ECC_CTRL_RS		BIT(2)
> +#define JZ_NAND_ECC_CTRL_RESET		BIT(1)
> +#define JZ_NAND_ECC_CTRL_ENABLE		BIT(0)
> +
> +#define JZ_NAND_STATUS_ERR_COUNT	(BIT(31) | BIT(30) | BIT(29))
> +#define JZ_NAND_STATUS_PAD_FINISH	BIT(4)
> +#define JZ_NAND_STATUS_DEC_FINISH	BIT(3)
> +#define JZ_NAND_STATUS_ENC_FINISH	BIT(2)
> +#define JZ_NAND_STATUS_UNCOR_ERROR	BIT(1)
> +#define JZ_NAND_STATUS_ERROR		BIT(0)
> +
> +static const uint8_t empty_block_ecc[] = {
> +	0xcd, 0x9d, 0x90, 0x58, 0xf4, 0x8b, 0xff, 0xb7, 0x6f
> +};
> +
> +static void jz4740_ecc_init(struct ingenic_ecc *ecc, bool encode)
> +{
> +	uint32_t reg;
> +
> +	/* Clear interrupt status */
> +	writel(0, ecc->base + JZ_REG_NAND_IRQ_STAT);
> +
> +	/* Initialize and enable ECC hardware */
> +	reg = readl(ecc->base + JZ_REG_NAND_ECC_CTRL);
> +	reg |= JZ_NAND_ECC_CTRL_RESET;
> +	reg |= JZ_NAND_ECC_CTRL_ENABLE;
> +	reg |= JZ_NAND_ECC_CTRL_RS;
> +	if (encode)
> +		reg |= JZ_NAND_ECC_CTRL_ENCODING;
> +	else
> +		reg &= ~JZ_NAND_ECC_CTRL_ENCODING;
> +
> +	writel(reg, ecc->base + JZ_REG_NAND_ECC_CTRL);
> +}
> +
> +static int jz4740_ecc_calculate(struct ingenic_ecc *ecc,
> +				struct ingenic_ecc_params *params,
> +				const u8 *buf, u8 *ecc_code)
> +{
> +	uint32_t reg, status;
> +	unsigned int timeout = 1000;
> +	int i;
> +
> +	jz4740_ecc_init(ecc, true);
> +
> +	do {
> +		status = readl(ecc->base + JZ_REG_NAND_IRQ_STAT);
> +	} while (!(status & JZ_NAND_STATUS_ENC_FINISH) && --timeout);
> +
> +	if (timeout == 0)
> +		return -ETIMEDOUT;
> +
> +	reg = readl(ecc->base + JZ_REG_NAND_ECC_CTRL);
> +	reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
> +	writel(reg, ecc->base + JZ_REG_NAND_ECC_CTRL);
> +
> +	for (i = 0; i < params->bytes; ++i)
> +		ecc_code[i] = readb(ecc->base + JZ_REG_NAND_PAR0 + i);
> +
> +	/* If the written data is completely 0xff, we also want to write 0xff as
> +	 * ecc, otherwise we will get in trouble when doing subpage writes.
> +	 */

Comment formatting

s/ecc/ECC/ in plain English

> +	if (memcmp(ecc_code, empty_block_ecc, ARRAY_SIZE(empty_block_ecc)) == 0)
> +		memset(ecc_code, 0xff, ARRAY_SIZE(empty_block_ecc));
> +
> +	return 0;
> +}
> +


Thanks,
Miquèl

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