[PATCH RFC v3 2/4] nand: pl353: Add software ecc support
Punnaiah Choudary Kalluri
punnaiah.choudary.kalluri at xilinx.com
Thu Jun 26 20:03:57 PDT 2014
Added software ecc support.
Signed-off-by: Punnaiah Choudary Kalluri <punnaia at xilinx.com>
---
drivers/mtd/nand/pl353_nand.c | 163 +++++++++++++++++++++++++++++++++++++++++
1 files changed, 163 insertions(+), 0 deletions(-)
diff --git a/drivers/mtd/nand/pl353_nand.c b/drivers/mtd/nand/pl353_nand.c
index 0be8ca2..eca205f 100644
--- a/drivers/mtd/nand/pl353_nand.c
+++ b/drivers/mtd/nand/pl353_nand.c
@@ -319,6 +319,71 @@ static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
}
/**
+ * pl353_nand_read_page_raw - [Intern] read raw page data without ecc
+ * @mtd: Pointer to the mtd info structure
+ * @chip: Pointer to the NAND chip info structure
+ * @buf: Pointer to the data buffer
+ * @oob_required: Caller requires OOB data read to chip->oob_poi
+ * @page: Page number to read
+ *
+ * Return: Always return zero
+ */
+static int pl353_nand_read_page_raw(struct mtd_info *mtd,
+ struct nand_chip *chip,
+ uint8_t *buf, int oob_required, int page)
+{
+ unsigned long data_phase_addr;
+ uint8_t *p;
+
+ chip->read_buf(mtd, buf, mtd->writesize);
+
+ p = chip->oob_poi;
+ chip->read_buf(mtd, p,
+ (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+ p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+ data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
+ data_phase_addr |= PL353_NAND_CLEAR_CS;
+ chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
+
+ chip->read_buf(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+ return 0;
+}
+
+/**
+ * pl353_nand_write_page_raw - [Intern] raw page write function
+ * @mtd: Pointer to the mtd info structure
+ * @chip: Pointer to the NAND chip info structure
+ * @buf: Pointer to the data buffer
+ * @oob_required: Caller requires OOB data read to chip->oob_poi
+ *
+ * Return: Always return zero
+ */
+static int pl353_nand_write_page_raw(struct mtd_info *mtd,
+ struct nand_chip *chip,
+ const uint8_t *buf, int oob_required)
+{
+ unsigned long data_phase_addr;
+ uint8_t *p;
+
+ chip->write_buf(mtd, buf, mtd->writesize);
+
+ p = chip->oob_poi;
+ chip->write_buf(mtd, p,
+ (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+ p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+ data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
+ data_phase_addr |= PL353_NAND_CLEAR_CS;
+ data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
+ chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
+
+ chip->write_buf(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+ return 0;
+}
+
+/**
* nand_write_page_hwecc - Hardware ECC based page write function
* @mtd: Pointer to the mtd info structure
* @chip: Pointer to the NAND chip info structure
@@ -384,6 +449,39 @@ static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
}
/**
+ * pl353_nand_write_page_swecc - [REPLACABLE] software ecc based page write
+ * function
+ * @mtd: Pointer to the mtd info structure
+ * @chip: Pointer to the NAND chip info structure
+ * @buf: Pointer to the data buffer
+ * @oob_required: Caller requires OOB data read to chip->oob_poi
+ *
+ * Return: Always return zero
+ */
+static int pl353_nand_write_page_swecc(struct mtd_info *mtd,
+ struct nand_chip *chip, const uint8_t *buf,
+ int oob_required)
+{
+ int i, eccsize = chip->ecc.size;
+ int eccbytes = chip->ecc.bytes;
+ int eccsteps = chip->ecc.steps;
+ uint8_t *ecc_calc = chip->buffers->ecccalc;
+ const uint8_t *p = buf;
+ uint32_t *eccpos = chip->ecc.layout->eccpos;
+
+ /* Software ecc calculation */
+ for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
+ chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+ for (i = 0; i < chip->ecc.total; i++)
+ chip->oob_poi[eccpos[i]] = ecc_calc[i];
+
+ chip->ecc.write_page_raw(mtd, chip, buf, 1);
+
+ return 0;
+}
+
+/**
* pl353_nand_read_page_hwecc - Hardware ECC based page read function
* @mtd: Pointer to the mtd info structure
* @chip: Pointer to the NAND chip info structure
@@ -465,6 +563,52 @@ static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
}
/**
+ * pl353_nand_read_page_swecc - [REPLACABLE] software ecc based page read
+ * function
+ * @mtd: Pointer to the mtd info structure
+ * @chip: Pointer to the NAND chip info structure
+ * @buf: Pointer to the buffer to store read data
+ * @oob_required: Caller requires OOB data read to chip->oob_poi
+ * @page: Page number to read
+ *
+ * Return: Always return zero
+ */
+static int pl353_nand_read_page_swecc(struct mtd_info *mtd,
+ struct nand_chip *chip,
+ uint8_t *buf, int oob_required, int page)
+{
+ int i, eccsize = chip->ecc.size;
+ int eccbytes = chip->ecc.bytes;
+ int eccsteps = chip->ecc.steps;
+ uint8_t *p = buf;
+ uint8_t *ecc_calc = chip->buffers->ecccalc;
+ uint8_t *ecc_code = chip->buffers->ecccode;
+ uint32_t *eccpos = chip->ecc.layout->eccpos;
+
+ chip->ecc.read_page_raw(mtd, chip, buf, page, 1);
+
+ for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
+ chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+ for (i = 0; i < chip->ecc.total; i++)
+ ecc_code[i] = chip->oob_poi[eccpos[i]];
+
+ eccsteps = chip->ecc.steps;
+ p = buf;
+
+ for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+ int stat;
+
+ stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
+ if (stat < 0)
+ mtd->ecc_stats.failed++;
+ else
+ mtd->ecc_stats.corrected += stat;
+ }
+ return 0;
+}
+
+/**
* pl353_nand_select_chip - Select the flash device
* @mtd: Pointer to the mtd info structure
* @chip: Pointer to the NAND chip info structure
@@ -689,6 +833,8 @@ static int pl353_nand_ecc_init(struct mtd_info *mtd)
nand_chip->ecc.read_oob = pl353_nand_read_oob;
nand_chip->ecc.write_oob = pl353_nand_write_oob;
nand_chip->ecc.strength = 1;
+ nand_chip->ecc.read_page_raw = pl353_nand_read_page_raw;
+ nand_chip->ecc.write_page_raw = pl353_nand_write_page_raw;
switch (xnand->ecc_mode) {
case NAND_ECC_HW:
@@ -715,6 +861,23 @@ static int pl353_nand_ecc_init(struct mtd_info *mtd)
nand_chip->ecc.layout = &nand_oob_64;
break;
+ case NAND_ECC_SOFT:
+ /*
+ * The software ECC routines won't work with the
+ * SMC controller
+ */
+ nand_chip->ecc.mode = NAND_ECC_HW;
+ nand_chip->ecc.calculate = nand_calculate_ecc;
+ nand_chip->ecc.correct = nand_correct_data;
+ nand_chip->ecc.read_page = pl353_nand_read_page_swecc;
+ nand_chip->ecc.write_page = pl353_nand_write_page_swecc;
+ nand_chip->ecc.size = 256;
+ nand_chip->ecc.bytes = 3;
+ /* Bypass the controller ECC block */
+ pl353_smc_set_ecc_pg_size(mtd->writesize);
+ pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_BYPASS);
+
+ break;
default:
return -ENOTSUPP;
}
--
1.7.4
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