mtd: rawnand: macronix: OTP access for MX30LFxG18AC

Support for OTP area access on MX30LFxG18AC chip series.

Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230615094015.3780078-1-AVKrasnov@sberdevices.ru

diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
index 385957e..e229de3 100644 (file)
--- 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@free-electrons.com>
  */
 
+#include <linux/slab.h>
 #include "linux/delay.h"
 #include "internals.h"
 
@@ -31,6 +32,16 @@
 
 #define MXIC_CMD_POWER_DOWN 0xB9
 
+#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)
+
 struct nand_onfi_vendor_macronix {
        u8 reserved;
        u8 reliability_func;
@@ -315,6 +326,161 @@ 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;
+
+       /* 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 };
+
+       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;
+       u64 page;
+       int ret;
+
+       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;
+               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_deselect_target(nand);
+
+       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)
+{
+       /* 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",
+       };
+       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_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))
@@ -324,6 +490,7 @@ 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;
 }