mtd: rawnand: Add Macronix NAND read retry support

Add support for Macronix NAND read retry.

Macronix NANDs support specific read operation for data recovery,
which can be enabled with a SET_FEATURE.
Driver checks byte 167 of Vendor Blocks in ONFI parameter page table
to see if this high-reliability function is supported.

Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
index fad57c3..58511ae 100644 (file)
--- a/drivers/mtd/nand/raw/nand_macronix.c
+++ b/drivers/mtd/nand/raw/nand_macronix.c
@@ -8,6 +8,50 @@
 
 #include "internals.h"
 
+#define MACRONIX_READ_RETRY_BIT BIT(0)
+#define MACRONIX_NUM_READ_RETRY_MODES 6
+
+struct nand_onfi_vendor_macronix {
+       u8 reserved;
+       u8 reliability_func;
+} __packed;
+
+static int macronix_nand_setup_read_retry(struct nand_chip *chip, int mode)
+{
+       u8 feature[ONFI_SUBFEATURE_PARAM_LEN];
+
+       if (!chip->parameters.supports_set_get_features ||
+           !test_bit(ONFI_FEATURE_ADDR_READ_RETRY,
+                     chip->parameters.set_feature_list))
+               return -ENOTSUPP;
+
+       feature[0] = mode;
+       return nand_set_features(chip, ONFI_FEATURE_ADDR_READ_RETRY, feature);
+}
+
+static void macronix_nand_onfi_init(struct nand_chip *chip)
+{
+       struct nand_parameters *p = &chip->parameters;
+       struct nand_onfi_vendor_macronix *mxic;
+
+       if (!p->onfi)
+               return;
+
+       mxic = (struct nand_onfi_vendor_macronix *)p->onfi->vendor;
+       if ((mxic->reliability_func & MACRONIX_READ_RETRY_BIT) == 0)
+               return;
+
+       chip->read_retries = MACRONIX_NUM_READ_RETRY_MODES;
+       chip->setup_read_retry = macronix_nand_setup_read_retry;
+
+       if (p->supports_set_get_features) {
+               bitmap_set(p->set_feature_list,
+                          ONFI_FEATURE_ADDR_READ_RETRY, 1);
+               bitmap_set(p->get_feature_list,
+                          ONFI_FEATURE_ADDR_READ_RETRY, 1);
+       }
+}
+
 /*
  * Macronix AC series does not support using SET/GET_FEATURES to change
  * the timings unlike what is declared in the parameter page. Unflag
@@ -56,6 +100,7 @@ static int macronix_nand_init(struct nand_chip *chip)
                chip->options |= NAND_BBM_FIRSTPAGE | NAND_BBM_SECONDPAGE;
 
        macronix_nand_fix_broken_get_timings(chip);
+       macronix_nand_onfi_init(chip);
 
        return 0;
 }