Cc: Mason Yang <masonccy...@mxic.com.tw> and Boris Brezillon 
<boris.brezil...@collabora.com>

On 11.05.2023 18:21, Arseniy Krasnov wrote:
> This adds support for OTP area access on MX30LFxG18AC chip series.
> 
> Changelog:
>   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.
> 
> Signed-off-by: Arseniy Krasnov <avkras...@sberdevices.ru>
> ---
>  drivers/mtd/nand/raw/nand_macronix.c | 213 +++++++++++++++++++++++++++
>  1 file changed, 213 insertions(+)
> 
> diff --git a/drivers/mtd/nand/raw/nand_macronix.c 
> b/drivers/mtd/nand/raw/nand_macronix.c
> index 1472f925f386..2301f990678e 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.brezil...@free-electrons.com>
>   */
>  
> +#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 +331,203 @@ 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)
> +{
> +     uint8_t 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)
> +{
> +     uint8_t 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;
> +     uint64_t page;
> +     void *dma_buf;
> +     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);
> +     WARN(ret, "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)
> +{
> +     uint8_t 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);
> +     WARN(ret, "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 (!chip->parameters.supports_set_get_features)
> +             return;
> +
> +     if (match_string(supported_otp_models,
> +                      ARRAY_SIZE(supported_otp_models),
> +                      chip->parameters.model) < 0)
> +             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 +537,7 @@ 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;
>  }

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