mtd: nand: support Micron READ RETRY
Micron provides READ RETRY support via the ONFI vendor-specific
parameter block (to indicate how many read-retry modes are available)
and the ONFI {GET,SET}_FEATURES commands with a vendor-specific feature
address (to support reading/switching the current read-retry mode).
The recommended sequence is as follows:
1. Perform PAGE_READ operation
2. If no ECC error, we are done
3. Run SET_FEATURES with feature address 89h, mode 1
4. Retry PAGE_READ operation
5. If ECC error and there are remaining supported modes, increment the
mode and return to step 3. Otherwise, this is a true ECC error.
6. Run SET_FEATURES with feature address 89h, mode 0, to return to the
default state.
This patch implements the chip->setup_read_retry() callback for
Micron and fills in the chip->read_retries.
Tested on Micron MT29F32G08CBADA, which supports 8 read-retry modes.
The Micron vendor-specific table was checked against the datasheets for
the following Micron NAND:
Needs retry Cell-type Part number Vendor revision Byte 180
----------- --------- ---------------- --------------- ------------
No SLC MT29F16G08ABABA 1 Reserved (0)
No MLC MT29F32G08CBABA 1 Reserved (0)
No SLC MT29F1G08AACWP 1 0
Yes MLC MT29F32G08CBADA 1 08h
Yes MLC MT29F64G08CBABA 2 08h
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 4c2f39f..b8c74cd 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2979,6 +2979,30 @@
return ret;
}
+static int nand_setup_read_retry_micron(struct mtd_info *mtd, int retry_mode)
+{
+ struct nand_chip *chip = mtd->priv;
+ uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {retry_mode};
+
+ return chip->onfi_set_features(mtd, chip, ONFI_FEATURE_ADDR_READ_RETRY,
+ feature);
+}
+
+/*
+ * Configure chip properties from Micron vendor-specific ONFI table
+ */
+static void nand_onfi_detect_micron(struct nand_chip *chip,
+ struct nand_onfi_params *p)
+{
+ struct nand_onfi_vendor_micron *micron = (void *)p->vendor;
+
+ if (le16_to_cpu(p->vendor_revision) < 1)
+ return;
+
+ chip->read_retries = micron->read_retry_options;
+ chip->setup_read_retry = nand_setup_read_retry_micron;
+}
+
/*
* Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
*/
@@ -3085,6 +3109,9 @@
pr_warn("Could not retrieve ONFI ECC requirements\n");
}
+ if (p->jedec_id == NAND_MFR_MICRON)
+ nand_onfi_detect_micron(chip, p);
+
return 1;
}