[PATCH v3] mtd: rawnand: Add Macronix NAND read retry support

Mason Yang
2019-06-03T02:19:19Z

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>
---
drivers/mtd/nand/raw/nand_macronix.c | 45 ++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)

diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
index fad57c3..58511ae 100644
--- 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;
}
--
1.9.1