mtd: rawnand: macronix: OTP access for MX30LFxG18AC

Support for OTP area access on MX30LFxG18AC chip series.

Link: https://lore.kernel.org/all/20231130112405.92196-1-avkrasnov@salutedevices.com
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
index dc972e59092241c1dc1ba062992e9214f4fec545..4c6ddd92331522b75f48660bcbf1f73510b51356 100644 (file)
--- 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;
 }