Re: [PATCH v4 07/16] mtd: rawnand: sunxi: rework pattern found registers

["Jernej Škrabec" <jernej.skrabec@gmail.com>]

Dne torek, 28. oktober 2025 ob 08:35:00 Srednjeevropski standardni čas je Richard Genoud napisal(a):
> On H6/H616, the register ECC_PAT_FOUND is at its own address, and not
> part of ECC status register.
> So, introduce the pattern found register offset in sunxi_nfc_caps, along
> with its mask.
> 
> Also, introduce a non compile-time field_get() because FIELD_GET() and
> u32_get_bits() don't work with non compile-time constant.
> https://lore.kernel.org/all/cover.1761588465.git.geert+renesas@glider.be

Urls should use Link: tag and be placed at the bottom.

Code itself looks fine.

Best regards,
Jernej

> 
> No functional change.
> 
> Signed-off-by: Richard Genoud <richard.genoud@bootlin.com>
> ---
>  drivers/mtd/nand/raw/sunxi_nand.c | 36 ++++++++++++++++++++++++++-----
>  1 file changed, 31 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
> index 89495d786293..021034a761b7 100644
> --- a/drivers/mtd/nand/raw/sunxi_nand.c
> +++ b/drivers/mtd/nand/raw/sunxi_nand.c
> @@ -29,6 +29,9 @@
>  #include <linux/iopoll.h>
>  #include <linux/reset.h>
>  
> +/* non compile-time field get */
> +#define field_get(_mask, _reg) (((_reg) & (_mask)) >> (ffs(_mask) - 1))
> +
>  #define NFC_REG_CTL		0x0000
>  #define NFC_REG_ST		0x0004
>  #define NFC_REG_INT		0x0008
> @@ -150,7 +153,13 @@
>  /* define bit use in NFC_ECC_ST */
>  #define NFC_ECC_ERR(x)		BIT(x)
>  #define NFC_ECC_ERR_MSK		GENMASK(15, 0)
> -#define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
> +
> +/*
> + * define bit use in NFC_REG_PAT_FOUND
> + * For A10/A23, NFC_REG_PAT_FOUND == NFC_ECC_ST register
> + */
> +#define NFC_ECC_PAT_FOUND_MSK(nfc) (nfc->caps->pat_found_mask)
> +
>  #define NFC_ECC_ERR_CNT(b, x)	(((x) >> (((b) % 4) * 8)) & 0xff)
>  
>  #define NFC_DEFAULT_TIMEOUT_MS	1000
> @@ -227,6 +236,8 @@ static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
>   * @reg_io_data:	I/O data register
>   * @reg_ecc_err_cnt:	ECC error counter register
>   * @reg_user_data:	User data register
> + * @reg_pat_found:	Data Pattern Status Register
> + * @pat_found_mask:	ECC_PAT_FOUND mask in NFC_REG_PAT_FOUND register
>   * @dma_maxburst:	DMA maxburst
>   * @ecc_strengths:	Available ECC strengths array
>   * @nstrengths:		Size of @ecc_strengths
> @@ -236,6 +247,8 @@ struct sunxi_nfc_caps {
>  	unsigned int reg_io_data;
>  	unsigned int reg_ecc_err_cnt;
>  	unsigned int reg_user_data;
> +	unsigned int reg_pat_found;
> +	unsigned int pat_found_mask;
>  	unsigned int dma_maxburst;
>  	const u8 *ecc_strengths;
>  	unsigned int nstrengths;
> @@ -776,7 +789,8 @@ static void sunxi_nfc_hw_ecc_update_stats(struct nand_chip *nand,
>  }
>  
>  static int sunxi_nfc_hw_ecc_correct(struct nand_chip *nand, u8 *data, u8 *oob,
> -				    int step, u32 status, bool *erased)
> +				    int step, u32 status, u32 pattern_found,
> +				    bool *erased)
>  {
>  	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
>  	struct nand_ecc_ctrl *ecc = &nand->ecc;
> @@ -787,7 +801,7 @@ static int sunxi_nfc_hw_ecc_correct(struct nand_chip *nand, u8 *data, u8 *oob,
>  	if (status & NFC_ECC_ERR(step))
>  		return -EBADMSG;
>  
> -	if (status & NFC_ECC_PAT_FOUND(step)) {
> +	if (pattern_found & BIT(step)) {
>  		u8 pattern;
>  
>  		if (unlikely(!(readl(nfc->regs + NFC_REG_PAT_ID) & 0x1))) {
> @@ -821,6 +835,7 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
>  	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
>  	struct nand_ecc_ctrl *ecc = &nand->ecc;
>  	int raw_mode = 0;
> +	u32 pattern_found;
>  	bool erased;
>  	int ret;
>  
> @@ -848,8 +863,12 @@ static int sunxi_nfc_hw_ecc_read_chunk(struct nand_chip *nand,
>  
>  	*cur_off = oob_off + ecc->bytes + USER_DATA_SZ;
>  
> +	pattern_found = readl(nfc->regs + nfc->caps->reg_pat_found);
> +	pattern_found = field_get(NFC_ECC_PAT_FOUND_MSK(nfc), pattern_found);
> +
>  	ret = sunxi_nfc_hw_ecc_correct(nand, data, oob_required ? oob : NULL, 0,
>  				       readl(nfc->regs + NFC_REG_ECC_ST),
> +				       pattern_found,
>  				       &erased);
>  	if (erased)
>  		return 1;
> @@ -930,7 +949,7 @@ static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf
>  	unsigned int max_bitflips = 0;
>  	int ret, i, raw_mode = 0;
>  	struct scatterlist sg;
> -	u32 status, wait;
> +	u32 status, pattern_found, wait;
>  
>  	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
>  	if (ret)
> @@ -971,6 +990,8 @@ static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf
>  		return ret;
>  
>  	status = readl(nfc->regs + NFC_REG_ECC_ST);
> +	pattern_found = readl(nfc->regs + nfc->caps->reg_pat_found);
> +	pattern_found = field_get(NFC_ECC_PAT_FOUND_MSK(nfc), pattern_found);
>  
>  	for (i = 0; i < nchunks; i++) {
>  		int data_off = i * ecc->size;
> @@ -981,7 +1002,8 @@ static int sunxi_nfc_hw_ecc_read_chunks_dma(struct nand_chip *nand, uint8_t *buf
>  
>  		ret = sunxi_nfc_hw_ecc_correct(nand, randomized ? data : NULL,
>  					       oob_required ? oob : NULL,
> -					       i, status, &erased);
> +					       i, status, pattern_found,
> +					       &erased);
>  
>  		/* ECC errors are handled in the second loop. */
>  		if (ret < 0)
> @@ -2195,6 +2217,8 @@ static const struct sunxi_nfc_caps sunxi_nfc_a10_caps = {
>  	.reg_io_data = NFC_REG_A10_IO_DATA,
>  	.reg_ecc_err_cnt = NFC_REG_A10_ECC_ERR_CNT,
>  	.reg_user_data = NFC_REG_A10_USER_DATA,
> +	.reg_pat_found = NFC_REG_ECC_ST,
> +	.pat_found_mask = GENMASK(31, 16),
>  	.dma_maxburst = 4,
>  	.ecc_strengths = sunxi_ecc_strengths_a10,
>  	.nstrengths = ARRAY_SIZE(sunxi_ecc_strengths_a10),
> @@ -2205,6 +2229,8 @@ static const struct sunxi_nfc_caps sunxi_nfc_a23_caps = {
>  	.reg_io_data = NFC_REG_A23_IO_DATA,
>  	.reg_ecc_err_cnt = NFC_REG_A10_ECC_ERR_CNT,
>  	.reg_user_data = NFC_REG_A10_USER_DATA,
> +	.reg_pat_found = NFC_REG_ECC_ST,
> +	.pat_found_mask = GENMASK(31, 16),
>  	.dma_maxburst = 8,
>  	.ecc_strengths = sunxi_ecc_strengths_a10,
>  	.nstrengths = ARRAY_SIZE(sunxi_ecc_strengths_a10),
>