Re: [PATCH v4] mtd: rawnand: macronix: OTP access for MX30LFxG18AC
From: Miquel Raynal
Date: Mon Jun 12 2023 - 12:54:09 EST
Hello,
AVKrasnov@xxxxxxxxxxxxxx wrote on Tue, 23 May 2023 13:16:34 +0300:
> This adds support for OTP area access on MX30LFxG18AC chip series.
Jaime, any feedback on this? Will you test it?
How are we supposed to test the OTP is locked? I see this is still an
open point.
>
> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
> ---
> v1 -> v2:
> * Add slab.h include due to kernel test robot error.
> v2 -> v3:
> * Use 'uint64_t' as input argument for 'do_div()' instead
> of 'unsigned long' due to kernel test robot error.
> v3 -> v4:
> * Use 'dev_err()' instead of 'WARN()'.
> * Call 'match_string()' before checking 'supports_set_get_features'
> in 'macronix_nand_setup_otp().
> * Use 'u8' instead of 'uint8_t' as ./checkpatch.pl wants.
>
> drivers/mtd/nand/raw/nand_macronix.c | 216 +++++++++++++++++++++++++++
> 1 file changed, 216 insertions(+)
>
> diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
> index 1472f925f386..be1ffa93bebb 100644
> --- a/drivers/mtd/nand/raw/nand_macronix.c
> +++ b/drivers/mtd/nand/raw/nand_macronix.c
> @@ -6,6 +6,7 @@
> * Author: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
> */
>
> +#include <linux/slab.h>
> #include "linux/delay.h"
> #include "internals.h"
>
> @@ -31,6 +32,20 @@
>
> #define MXIC_CMD_POWER_DOWN 0xB9
>
> +#define ONFI_FEATURE_ADDR_30LFXG18AC_OTP 0x90
> +#define MACRONIX_30LFXG18AC_OTP_START_PAGE 0
> +#define MACRONIX_30LFXG18AC_OTP_PAGES 30
> +#define MACRONIX_30LFXG18AC_OTP_PAGE_SIZE 2112
> +#define MACRONIX_30LFXG18AC_OTP_START_BYTE \
> + (MACRONIX_30LFXG18AC_OTP_START_PAGE * \
> + MACRONIX_30LFXG18AC_OTP_PAGE_SIZE)
> +#define MACRONIX_30LFXG18AC_OTP_SIZE_BYTES \
> + (MACRONIX_30LFXG18AC_OTP_PAGES * \
> + MACRONIX_30LFXG18AC_OTP_PAGE_SIZE)
> +
> +#define MACRONIX_30LFXG18AC_OTP_EN BIT(0)
> +#define MACRONIX_30LFXG18AC_OTP_LOCKED BIT(1)
> +
> struct nand_onfi_vendor_macronix {
> u8 reserved;
> u8 reliability_func;
> @@ -316,6 +331,206 @@ static void macronix_nand_deep_power_down_support(struct nand_chip *chip)
> chip->ops.resume = mxic_nand_resume;
> }
>
> +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;
> +
> + /* Don't know how to check that OTP is locked. */
> + buf->locked = 0;
> + buf->start = MACRONIX_30LFXG18AC_OTP_START_BYTE;
> + 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 };
> +
> + feature_buf[0] = MACRONIX_30LFXG18AC_OTP_EN;
> + return nand_set_features(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 };
> +
> + return nand_set_features(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;
> + void *dma_buf;
> + u64 page;
> + int ret;
> +
> + /* 'nand_prog/read_page_op()' may use 'buf' as DMA buffer,
> + * so allocate properly aligned memory for it. This is
> + * needed because cross page accesses may lead to unaligned
> + * buffer address for DMA.
> + */
> + dma_buf = kmalloc(MACRONIX_30LFXG18AC_OTP_PAGE_SIZE, GFP_KERNEL);
> + if (!dma_buf)
> + return -ENOMEM;
> +
> + nand = mtd_to_nand(mtd);
> + nand_select_target(nand, 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;
> +
> + bytes_to_handle = min_t(size_t, len - bytes_handled,
> + MACRONIX_30LFXG18AC_OTP_PAGE_SIZE -
> + offs_in_page);
> +
> + if (write) {
> + memcpy(dma_buf, &buf[bytes_handled], bytes_to_handle);
> + ret = nand_prog_page_op(nand, page, offs_in_page,
> + dma_buf, bytes_to_handle);
> + } else {
> + ret = nand_read_page_op(nand, page, offs_in_page,
> + dma_buf, bytes_to_handle);
> + if (!ret)
> + memcpy(&buf[bytes_handled], dma_buf,
> + 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_deselect_target(nand);
> + kfree(dma_buf);
> +
> + return ret;
> +}
> +
> +static int macronix_30lfxg18ac_write_otp(struct mtd_info *mtd, loff_t to,
> + size_t len, size_t *rlen,
> + const 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)
> +{
> + u8 feature_buf[ONFI_SUBFEATURE_PARAM_LEN] = { 0 };
> + struct nand_chip *nand;
> + int ret;
> +
> + if (from != MACRONIX_30LFXG18AC_OTP_START_BYTE ||
> + len != MACRONIX_30LFXG18AC_OTP_SIZE_BYTES)
> + return -EINVAL;
> +
> + dev_dbg(&mtd->dev, "locking OTP\n");
> +
> + nand = mtd_to_nand(mtd);
> + nand_select_target(nand, 0);
> +
> + feature_buf[0] = MACRONIX_30LFXG18AC_OTP_EN |
> + MACRONIX_30LFXG18AC_OTP_LOCKED;
> + ret = nand_set_features(nand, ONFI_FEATURE_ADDR_30LFXG18AC_OTP,
> + feature_buf);
> + if (ret) {
> + dev_err(&mtd->dev,
> + "failed to lock OTP (set features): %i\n", ret);
> + nand_deselect_target(nand);
> + return ret;
> + }
> +
> + /* Do dummy page prog with zero address. */
> + feature_buf[0] = 0;
> + ret = nand_prog_page_op(nand, 0, 0, feature_buf, 1);
> + if (ret)
> + dev_err(&mtd->dev,
> + "failed to lock OTP (page prog): %i\n", ret);
> +
> + ret = macronix_30lfxg18ac_otp_disable(nand);
> + if (ret)
> + dev_err(&mtd->dev, "failed to leave OTP mode after lock\n");
> +
> + nand_deselect_target(nand);
> +
> + return ret;
> +}
> +
> +static void macronix_nand_setup_otp(struct nand_chip *chip)
> +{
> + static const char * const supported_otp_models[] = {
> + "MX30LF1G18AC",
> + "MX30LF2G18AC",
> + "MX30LF4G18AC",
> + };
> + struct mtd_info *mtd;
> +
> + if (match_string(supported_otp_models,
> + ARRAY_SIZE(supported_otp_models),
> + chip->parameters.model) < 0)
> + return;
> +
> + if (!chip->parameters.supports_set_get_features)
> + return;
> +
> + bitmap_set(chip->parameters.get_feature_list,
> + ONFI_FEATURE_ADDR_30LFXG18AC_OTP, 1);
> + bitmap_set(chip->parameters.set_feature_list,
> + ONFI_FEATURE_ADDR_30LFXG18AC_OTP, 1);
> +
> + mtd = nand_to_mtd(chip);
> + mtd->_get_fact_prot_info = macronix_30lfxg18ac_get_otp_info;
> + mtd->_read_fact_prot_reg = macronix_30lfxg18ac_read_otp;
> + 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;
> +}
> +
> static int macronix_nand_init(struct nand_chip *chip)
> {
> if (nand_is_slc(chip))
> @@ -325,6 +540,7 @@ static int macronix_nand_init(struct nand_chip *chip)
> macronix_nand_onfi_init(chip);
> macronix_nand_block_protection_support(chip);
> macronix_nand_deep_power_down_support(chip);
> + macronix_nand_setup_otp(chip);
>
> return 0;
> }
Thanks,
Miquèl