Re: [PATCH v4 15/35] mtd: rawnand: mxc: convert driver to nand_scan()

[Boris Brezillon <boris.brezillon@bootlin.com>]

On Fri, 20 Jul 2018 17:15:07 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> Two helpers have been added to the core to make ECC-related
> configuration between the detection phase and the final NAND scan. Use
> these hooks and convert the driver to just use nand_scan() instead of
> both nand_scan_ident() and nand_scan_tail().
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>

> ---
>  drivers/mtd/nand/raw/mxc_nand.c | 136 +++++++++++++++++++++-------------------
>  1 file changed, 71 insertions(+), 65 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/mxc_nand.c b/drivers/mtd/nand/raw/mxc_nand.c
> index c6eff61e909d..4c9214dea424 100644
> --- a/drivers/mtd/nand/raw/mxc_nand.c
> +++ b/drivers/mtd/nand/raw/mxc_nand.c
> @@ -1691,6 +1691,74 @@ static int mxcnd_probe_dt(struct mxc_nand_host *host)
>  }
>  #endif
>  
> +static int mxcnd_attach_chip(struct nand_chip *chip)
> +{
> +	struct mtd_info *mtd = nand_to_mtd(chip);
> +	struct mxc_nand_host *host = nand_get_controller_data(chip);
> +	struct device *dev = mtd->dev.parent;
> +
> +	switch (chip->ecc.mode) {
> +	case NAND_ECC_HW:
> +		chip->ecc.read_page = mxc_nand_read_page;
> +		chip->ecc.read_page_raw = mxc_nand_read_page_raw;
> +		chip->ecc.read_oob = mxc_nand_read_oob;
> +		chip->ecc.write_page = mxc_nand_write_page_ecc;
> +		chip->ecc.write_page_raw = mxc_nand_write_page_raw;
> +		chip->ecc.write_oob = mxc_nand_write_oob;
> +		break;
> +
> +	case NAND_ECC_SOFT:
> +		break;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (chip->bbt_options & NAND_BBT_USE_FLASH) {
> +		chip->bbt_td = &bbt_main_descr;
> +		chip->bbt_md = &bbt_mirror_descr;
> +	}
> +
> +	/* Allocate the right size buffer now */
> +	devm_kfree(dev, (void *)host->data_buf);
> +	host->data_buf = devm_kzalloc(dev, mtd->writesize + mtd->oobsize,
> +				      GFP_KERNEL);
> +	if (!host->data_buf)
> +		return -ENOMEM;
> +
> +	/* Call preset again, with correct writesize chip time */
> +	host->devtype_data->preset(mtd);
> +
> +	if (!chip->ecc.bytes) {
> +		if (host->eccsize == 8)
> +			chip->ecc.bytes = 18;
> +		else if (host->eccsize == 4)
> +			chip->ecc.bytes = 9;
> +	}
> +
> +	/*
> +	 * Experimentation shows that i.MX NFC can only handle up to 218 oob
> +	 * bytes. Limit used_oobsize to 218 so as to not confuse copy_spare()
> +	 * into copying invalid data to/from the spare IO buffer, as this
> +	 * might cause ECC data corruption when doing sub-page write to a
> +	 * partially written page.
> +	 */
> +	host->used_oobsize = min(mtd->oobsize, 218U);
> +
> +	if (chip->ecc.mode == NAND_ECC_HW) {
> +		if (is_imx21_nfc(host) || is_imx27_nfc(host))
> +			chip->ecc.strength = 1;
> +		else
> +			chip->ecc.strength = (host->eccsize == 4) ? 4 : 8;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct nand_controller_ops mxcnd_controller_ops = {
> +	.attach_chip = mxcnd_attach_chip,
> +};
> +
>  static int mxcnd_probe(struct platform_device *pdev)
>  {
>  	struct nand_chip *this;
> @@ -1830,71 +1898,9 @@ static int mxcnd_probe(struct platform_device *pdev)
>  		host->devtype_data->irq_control(host, 1);
>  	}
>  
> -	/* first scan to find the device and get the page size */
> -	err = nand_scan_ident(mtd, is_imx25_nfc(host) ? 4 : 1, NULL);
> -	if (err)
> -		goto escan;
> -
> -	switch (this->ecc.mode) {
> -	case NAND_ECC_HW:
> -		this->ecc.read_page = mxc_nand_read_page;
> -		this->ecc.read_page_raw = mxc_nand_read_page_raw;
> -		this->ecc.read_oob = mxc_nand_read_oob;
> -		this->ecc.write_page = mxc_nand_write_page_ecc;
> -		this->ecc.write_page_raw = mxc_nand_write_page_raw;
> -		this->ecc.write_oob = mxc_nand_write_oob;
> -		break;
> -
> -	case NAND_ECC_SOFT:
> -		break;
> -
> -	default:
> -		err = -EINVAL;
> -		goto escan;
> -	}
> -
> -	if (this->bbt_options & NAND_BBT_USE_FLASH) {
> -		this->bbt_td = &bbt_main_descr;
> -		this->bbt_md = &bbt_mirror_descr;
> -	}
> -
> -	/* allocate the right size buffer now */
> -	devm_kfree(&pdev->dev, (void *)host->data_buf);
> -	host->data_buf = devm_kzalloc(&pdev->dev, mtd->writesize + mtd->oobsize,
> -					GFP_KERNEL);
> -	if (!host->data_buf) {
> -		err = -ENOMEM;
> -		goto escan;
> -	}
> -
> -	/* Call preset again, with correct writesize this time */
> -	host->devtype_data->preset(mtd);
> -
> -	if (!this->ecc.bytes) {
> -		if (host->eccsize == 8)
> -			this->ecc.bytes = 18;
> -		else if (host->eccsize == 4)
> -			this->ecc.bytes = 9;
> -	}
> -
> -	/*
> -	 * Experimentation shows that i.MX NFC can only handle up to 218 oob
> -	 * bytes. Limit used_oobsize to 218 so as to not confuse copy_spare()
> -	 * into copying invalid data to/from the spare IO buffer, as this
> -	 * might cause ECC data corruption when doing sub-page write to a
> -	 * partially written page.
> -	 */
> -	host->used_oobsize = min(mtd->oobsize, 218U);
> -
> -	if (this->ecc.mode == NAND_ECC_HW) {
> -		if (is_imx21_nfc(host) || is_imx27_nfc(host))
> -			this->ecc.strength = 1;
> -		else
> -			this->ecc.strength = (host->eccsize == 4) ? 4 : 8;
> -	}
> -
> -	/* second phase scan */
> -	err = nand_scan_tail(mtd);
> +	/* Scan the NAND device */
> +	this->dummy_controller.ops = &mxcnd_controller_ops;
> +	err = nand_scan(mtd, is_imx25_nfc(host) ? 4 : 1);
>  	if (err)
>  		goto escan;
>