nand: factor out syndrome support to seperate file

In order to make it optional later.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 225 insertions, 0 deletions

diff --git a/drivers/mtd/nand/nand_hwecc_syndrome.c b/drivers/mtd/nand/nand_hwecc_syndrome.c
new file mode 100644
index 0000000000..9a66180952
--- /dev/null
+++ b/drivers/mtd/nand/nand_hwecc_syndrome.c
@@ -0,0 +1,225 @@
+#include <common.h>
+#include <errno.h>
+#include <clock.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/err.h>
+#include <linux/mtd/nand_ecc.h>
+#include <asm/byteorder.h>
+#include <asm/io.h>
+#include <malloc.h>
+#include <module.h>
+
+/**
+ * nand_read_page_syndrome - [REPLACABLE] hardware ecc syndrom based page read
+ * @mtd:	mtd info structure
+ * @chip:	nand chip info structure
+ * @buf:	buffer to store read data
+ *
+ * The hw generator calculates the error syndrome automatically. Therefor
+ * we need a special oob layout and handling.
+ */
+static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+				   uint8_t *buf)
+{
+	int i, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *p = buf;
+	uint8_t *oob = chip->oob_poi;
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		int stat;
+
+		chip->ecc.hwctl(mtd, NAND_ECC_READ);
+		chip->read_buf(mtd, p, eccsize);
+
+		if (chip->ecc.prepad) {
+			chip->read_buf(mtd, oob, chip->ecc.prepad);
+			oob += chip->ecc.prepad;
+		}
+
+		chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
+		chip->read_buf(mtd, oob, eccbytes);
+		stat = chip->ecc.correct(mtd, p, oob, NULL);
+
+		if (stat < 0)
+			mtd->ecc_stats.failed++;
+		else
+			mtd->ecc_stats.corrected += stat;
+
+		oob += eccbytes;
+
+		if (chip->ecc.postpad) {
+			chip->read_buf(mtd, oob, chip->ecc.postpad);
+			oob += chip->ecc.postpad;
+		}
+	}
+
+	/* Calculate remaining oob bytes */
+	i = mtd->oobsize - (oob - chip->oob_poi);
+	if (i)
+		chip->read_buf(mtd, oob, i);
+
+	return 0;
+}
+/**
+ * nand_write_page_syndrome - [REPLACABLE] hardware ecc syndrom based page write
+ * @mtd:	mtd info structure
+ * @chip:	nand chip info structure
+ * @buf:	data buffer
+ *
+ * The hw generator calculates the error syndrome automatically. Therefor
+ * we need a special oob layout and handling.
+ */
+#ifdef CONFIG_NAND_WRITE
+static void nand_write_page_syndrome(struct mtd_info *mtd,
+				    struct nand_chip *chip, const uint8_t *buf)
+{
+	int i, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	const uint8_t *p = buf;
+	uint8_t *oob = chip->oob_poi;
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+
+		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
+		chip->write_buf(mtd, p, eccsize);
+
+		if (chip->ecc.prepad) {
+			chip->write_buf(mtd, oob, chip->ecc.prepad);
+			oob += chip->ecc.prepad;
+		}
+
+		chip->ecc.calculate(mtd, p, oob);
+		chip->write_buf(mtd, oob, eccbytes);
+		oob += eccbytes;
+
+		if (chip->ecc.postpad) {
+			chip->write_buf(mtd, oob, chip->ecc.postpad);
+			oob += chip->ecc.postpad;
+		}
+	}
+
+	/* Calculate remaining oob bytes */
+	i = mtd->oobsize - (oob - chip->oob_poi);
+	if (i)
+		chip->write_buf(mtd, oob, i);
+}
+#endif
+
+/**
+ * nand_read_oob_syndrome - [REPLACABLE] OOB data read function for HW ECC
+ *			    with syndromes
+ * @mtd:	mtd info structure
+ * @chip:	nand chip info structure
+ * @page:	page number to read
+ * @sndcmd:	flag whether to issue read command or not
+ */
+static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+				  int page, int sndcmd)
+{
+	uint8_t *buf = chip->oob_poi;
+	int length = mtd->oobsize;
+	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
+	int eccsize = chip->ecc.size;
+	uint8_t *bufpoi = buf;
+	int i, toread, sndrnd = 0, pos;
+
+	chip->cmdfunc(mtd, NAND_CMD_READ0, chip->ecc.size, page);
+	for (i = 0; i < chip->ecc.steps; i++) {
+		if (sndrnd) {
+			pos = eccsize + i * (eccsize + chunk);
+			if (mtd->writesize > 512)
+				chip->cmdfunc(mtd, NAND_CMD_RNDOUT, pos, -1);
+			else
+				chip->cmdfunc(mtd, NAND_CMD_READ0, pos, page);
+		} else
+			sndrnd = 1;
+		toread = min_t(int, length, chunk);
+		chip->read_buf(mtd, bufpoi, toread);
+		bufpoi += toread;
+		length -= toread;
+	}
+	if (length > 0)
+		chip->read_buf(mtd, bufpoi, length);
+
+	return 1;
+}
+
+/**
+ * nand_write_oob_syndrome - [REPLACABLE] OOB data write function for HW ECC
+ *			     with syndrome - only for large page flash !
+ * @mtd:	mtd info structure
+ * @chip:	nand chip info structure
+ * @page:	page number to write
+ */
+#ifdef CONFIG_NAND_WRITE
+static int nand_write_oob_syndrome(struct mtd_info *mtd,
+				   struct nand_chip *chip, int page)
+{
+	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
+	int eccsize = chip->ecc.size, length = mtd->oobsize;
+	int i, len, pos, status = 0, sndcmd = 0, steps = chip->ecc.steps;
+	const uint8_t *bufpoi = chip->oob_poi;
+
+	/*
+	 * data-ecc-data-ecc ... ecc-oob
+	 * or
+	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
+	 */
+	if (!chip->ecc.prepad && !chip->ecc.postpad) {
+		pos = steps * (eccsize + chunk);
+		steps = 0;
+	} else
+		pos = eccsize;
+
+	chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
+	for (i = 0; i < steps; i++) {
+		if (sndcmd) {
+			if (mtd->writesize <= 512) {
+				uint32_t fill = 0xFFFFFFFF;
+
+				len = eccsize;
+				while (len > 0) {
+					int num = min_t(int, len, 4);
+					chip->write_buf(mtd, (uint8_t *)&fill,
+							num);
+					len -= num;
+				}
+			} else {
+				pos = eccsize + i * (eccsize + chunk);
+				chip->cmdfunc(mtd, NAND_CMD_RNDIN, pos, -1);
+			}
+		} else
+			sndcmd = 1;
+		len = min_t(int, length, chunk);
+		chip->write_buf(mtd, bufpoi, len);
+		bufpoi += len;
+		length -= len;
+	}
+	if (length > 0)
+		chip->write_buf(mtd, bufpoi, length);
+
+	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+	status = chip->waitfunc(mtd, chip);
+
+	return status & NAND_STATUS_FAIL ? -EIO : 0;
+}
+#endif
+
+void nand_init_ecc_hw_syndrome(struct nand_chip *chip)
+{
+		/* Use standard syndrome read/write page function ? */
+	if (!chip->ecc.read_page)
+		chip->ecc.read_page = nand_read_page_syndrome;
+	if (!chip->ecc.read_oob)
+		chip->ecc.read_oob = nand_read_oob_syndrome;
+#ifdef CONFIG_NAND_WRITE
+	if (!chip->ecc.write_page)
+		chip->ecc.write_page = nand_write_page_syndrome;
+	if (!chip->ecc.write_oob)
+		chip->ecc.write_oob = nand_write_oob_syndrome;
+#endif
+}