[PATCH v1] mtd: rawnand: macronix: OTP access for MX30LFxG18AC

[Arseniy Krasnov]

cc: Miquel Raynal

On 30.11.2023 14:24, Arseniy Krasnov wrote:
> Support for OTP area access on MX30LFxG18AC chip series.
> 
> Signed-off-by: Arseniy Krasnov <avkrasnov at salutedevices.com>
> ---
>  drivers/mtd/nand/raw/nand_macronix.c | 170 +++++++++++++++++++++++++++
>  1 file changed, 170 insertions(+)
> 
> diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
> index dc972e5909..4c6ddd9233 100644
> --- a/drivers/mtd/nand/raw/nand_macronix.c
> +++ b/drivers/mtd/nand/raw/nand_macronix.c
> @@ -16,13 +16,183 @@
>   * GNU General Public License for more details.
>   */
>  
> +#include <dm/device_compat.h>
>  #include <linux/mtd/rawnand.h>
>  
> +#define ONFI_FEATURE_ADDR_30LFXG18AC_OTP	0x90
> +#define MACRONIX_30LFXG18AC_OTP_START_PAGE	2
> +#define MACRONIX_30LFXG18AC_OTP_PAGES		30
> +#define MACRONIX_30LFXG18AC_OTP_PAGE_SIZE	2112
> +#define MACRONIX_30LFXG18AC_OTP_SIZE_BYTES	\
> +	(MACRONIX_30LFXG18AC_OTP_PAGES *	\
> +	 MACRONIX_30LFXG18AC_OTP_PAGE_SIZE)
> +
> +#define MACRONIX_30LFXG18AC_OTP_EN		BIT(0)
> +
> +static int macronix_30lfxg18ac_get_otp_info(struct mtd_info *mtd, size_t len,
> +					    size_t *retlen,
> +					    struct otp_info *buf)
> +{
> +	if (len < sizeof(*buf))
> +		return -EINVAL;
> +
> +	/* Always report that OTP is unlocked. Reason is that this
> +	 * type of flash chip doesn't provide way to check that OTP
> +	 * is locked or not: subfeature parameter is implemented as
> +	 * volatile register. Technically OTP region could be locked
> +	 * and become readonly, but as there is no way to check it,
> +	 * don't allow to lock it ('_lock_user_prot_reg' callback
> +	 * always returns -EOPNOTSUPP) and thus we report that OTP
> +	 * is unlocked.
> +	 */
> +	buf->locked = 0;
> +	buf->start = 0;
> +	buf->length = MACRONIX_30LFXG18AC_OTP_SIZE_BYTES;
> +
> +	*retlen = sizeof(*buf);
> +
> +	return 0;
> +}
> +
> +static int macronix_30lfxg18ac_otp_enable(struct nand_chip *nand)
> +{
> +	u8 feature_buf[ONFI_SUBFEATURE_PARAM_LEN] = { 0 };
> +	struct mtd_info *mtd;
> +
> +	mtd = nand_to_mtd(nand);
> +	feature_buf[0] = MACRONIX_30LFXG18AC_OTP_EN;
> +
> +	return nand->onfi_set_features(mtd, nand, ONFI_FEATURE_ADDR_30LFXG18AC_OTP, feature_buf);
> +}
> +
> +static int macronix_30lfxg18ac_otp_disable(struct nand_chip *nand)
> +{
> +	u8 feature_buf[ONFI_SUBFEATURE_PARAM_LEN] = { 0 };
> +	struct mtd_info *mtd;
> +
> +	mtd = nand_to_mtd(nand);
> +	return nand->onfi_set_features(mtd, nand, ONFI_FEATURE_ADDR_30LFXG18AC_OTP, feature_buf);
> +}
> +
> +static int __macronix_30lfxg18ac_rw_otp(struct mtd_info *mtd,
> +					loff_t offs_in_flash,
> +					size_t len, size_t *retlen,
> +					u_char *buf, bool write)
> +{
> +	struct nand_chip *nand;
> +	size_t bytes_handled;
> +	off_t offs_in_page;
> +	u64 page;
> +	int ret;
> +
> +	nand = mtd_to_nand(mtd);
> +	nand->select_chip(mtd, 0);
> +
> +	ret = macronix_30lfxg18ac_otp_enable(nand);
> +	if (ret)
> +		goto out_otp;
> +
> +	page = offs_in_flash;
> +	/* 'page' will be result of division. */
> +	offs_in_page = do_div(page, MACRONIX_30LFXG18AC_OTP_PAGE_SIZE);
> +	bytes_handled = 0;
> +
> +	while (bytes_handled < len &&
> +	       page < MACRONIX_30LFXG18AC_OTP_PAGES) {
> +		size_t bytes_to_handle;
> +		u64 phys_page = page + MACRONIX_30LFXG18AC_OTP_START_PAGE;
> +
> +		bytes_to_handle = min_t(size_t, len - bytes_handled,
> +					MACRONIX_30LFXG18AC_OTP_PAGE_SIZE -
> +					offs_in_page);
> +
> +		if (write)
> +			ret = nand_prog_page_op(nand, phys_page, offs_in_page,
> +						&buf[bytes_handled], bytes_to_handle);
> +		else
> +			ret = nand_read_page_op(nand, phys_page, offs_in_page,
> +						&buf[bytes_handled], bytes_to_handle);
> +		if (ret)
> +			goto out_otp;
> +
> +		bytes_handled += bytes_to_handle;
> +		offs_in_page = 0;
> +		page++;
> +	}
> +
> +	*retlen = bytes_handled;
> +
> +out_otp:
> +	if (ret)
> +		dev_err(mtd->dev, "failed to perform OTP IO: %i\n", ret);
> +
> +	ret = macronix_30lfxg18ac_otp_disable(nand);
> +	if (ret)
> +		dev_err(mtd->dev, "failed to leave OTP mode after %s\n",
> +			write ? "write" : "read");
> +
> +	nand->select_chip(mtd, -1);
> +
> +	return ret;
> +}
> +
> +static int macronix_30lfxg18ac_write_otp(struct mtd_info *mtd, loff_t to,
> +					 size_t len, size_t *rlen,
> +					 u_char *buf)
> +{
> +	return __macronix_30lfxg18ac_rw_otp(mtd, to, len, rlen, (u_char *)buf,
> +					    true);
> +}
> +
> +static int macronix_30lfxg18ac_read_otp(struct mtd_info *mtd, loff_t from,
> +					size_t len, size_t *rlen,
> +					u_char *buf)
> +{
> +	return __macronix_30lfxg18ac_rw_otp(mtd, from, len, rlen, buf, false);
> +}
> +
> +static int macronix_30lfxg18ac_lock_otp(struct mtd_info *mtd, loff_t from,
> +					size_t len)
> +{
> +	/* See comment in 'macronix_30lfxg18ac_get_otp_info()'. */
> +	return -EOPNOTSUPP;
> +}
> +
> +static void macronix_nand_setup_otp(struct nand_chip *chip)
> +{
> +	static const char * const supported_otp_models[] = {
> +		"MX30LF1G18AC",
> +		"MX30LF2G18AC",
> +		"MX30LF4G18AC",
> +	};
> +	int i;
> +
> +	if (!chip->onfi_version ||
> +	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
> +	      & ONFI_OPT_CMD_SET_GET_FEATURES))
> +		return;
> +
> +	for (i = 0; i < ARRAY_SIZE(supported_otp_models); i++) {
> +		if (!strcmp(chip->onfi_params.model, supported_otp_models[i])) {
> +			struct mtd_info *mtd;
> +
> +			mtd = nand_to_mtd(chip);
> +			mtd->_get_user_prot_info = macronix_30lfxg18ac_get_otp_info;
> +			mtd->_read_user_prot_reg = macronix_30lfxg18ac_read_otp;
> +			mtd->_write_user_prot_reg = macronix_30lfxg18ac_write_otp;
> +			mtd->_lock_user_prot_reg = macronix_30lfxg18ac_lock_otp;
> +			return;
> +		}
> +	}
> +}
> +
>  static int macronix_nand_init(struct nand_chip *chip)
>  {
>  	if (nand_is_slc(chip))
>  		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
>  
> +	macronix_nand_setup_otp(chip);
> +
>  	return 0;
>  }
>