Merge tag 'for-linus-3.5-20120601' of git://git.infradead.org/linux-mtd

Pull mtd update from David Woodhouse:
 - More robust parsing especially of xattr data in JFFS2
 - Updates to mxc_nand and gpmi drivers to support new boards and device tree
 - Improve consistency of information about ECC strength in NAND devices
 - Clean up partition handling of plat_nand
 - Support NAND drivers without dedicated access to OOB area
 - BCH hardware ECC support for OMAP
 - Other fixes and cleanups, and a few new device IDs

Fixed trivial conflict in drivers/mtd/nand/gpmi-nand/gpmi-nand.c due to
added include files next to each other.

* tag 'for-linus-3.5-20120601' of git://git.infradead.org/linux-mtd: (75 commits)
  mtd: mxc_nand: move ecc strengh setup before nand_scan_tail
  mtd: block2mtd: fix recursive call of mtd_writev
  mtd: gpmi-nand: define ecc.strength
  mtd: of_parts: fix breakage in Kconfig
  mtd: nand: fix scan_read_raw_oob
  mtd: docg3 fix in-middle of blocks reads
  mtd: cfi_cmdset_0002: Slight cleanup of fixup messages
  mtd: add fixup for S29NS512P NOR flash.
  jffs2: allow to complete xattr integrity check on first GC scan
  jffs2: allow to discriminate between recoverable and non-recoverable errors
  mtd: nand: omap: add support for hardware BCH ecc
  ARM: OMAP3: gpmc: add BCH ecc api and modes
  mtd: nand: check the return code of 'read_oob/read_oob_raw'
  mtd: nand: remove 'sndcmd' parameter of 'read_oob/read_oob_raw'
  mtd: m25p80: Add support for Winbond W25Q80BW
  jffs2: get rid of jffs2_sync_super
  jffs2: remove unnecessary GC pass on sync
  jffs2: remove unnecessary GC pass on umount
  jffs2: remove lock_super
  mtd: gpmi: add gpmi support for mx6q
  ...

1 files changed, 251 insertions, 2 deletions

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index c2b0bba9d8b3..d7f681d0c9b9 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -21,6 +21,10 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 
+#ifdef CONFIG_MTD_NAND_OMAP_BCH
+#include <linux/bch.h>
+#endif
+
 #include <plat/dma.h>
 #include <plat/gpmc.h>
 #include <plat/nand.h>
@@ -127,6 +131,11 @@ struct omap_nand_info {
 	} iomode;
 	u_char				*buf;
 	int					buf_len;
+
+#ifdef CONFIG_MTD_NAND_OMAP_BCH
+	struct bch_control             *bch;
+	struct nand_ecclayout           ecclayout;
+#endif
 };
 
 /**
@@ -402,7 +411,7 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
 			PREFETCH_FIFOTHRESHOLD_MAX, 0x1, len, is_write);
 	if (ret)
 		/* PFPW engine is busy, use cpu copy method */
-		goto out_copy;
+		goto out_copy_unmap;
 
 	init_completion(&info->comp);
 
@@ -421,6 +430,8 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
 	dma_unmap_single(&info->pdev->dev, dma_addr, len, dir);
 	return 0;
 
+out_copy_unmap:
+	dma_unmap_single(&info->pdev->dev, dma_addr, len, dir);
 out_copy:
 	if (info->nand.options & NAND_BUSWIDTH_16)
 		is_write == 0 ? omap_read_buf16(mtd, (u_char *) addr, len)
@@ -879,7 +890,7 @@ static int omap_wait(struct mtd_info *mtd, struct nand_chip *chip)
 	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
 							mtd);
 	unsigned long timeo = jiffies;
-	int status = NAND_STATUS_FAIL, state = this->state;
+	int status, state = this->state;
 
 	if (state == FL_ERASING)
 		timeo += (HZ * 400) / 1000;
@@ -894,6 +905,8 @@ static int omap_wait(struct mtd_info *mtd, struct nand_chip *chip)
 			break;
 		cond_resched();
 	}
+
+	status = gpmc_nand_read(info->gpmc_cs, GPMC_NAND_DATA);
 	return status;
 }
 
@@ -925,6 +938,226 @@ static int omap_dev_ready(struct mtd_info *mtd)
 	return 1;
 }
 
+#ifdef CONFIG_MTD_NAND_OMAP_BCH
+
+/**
+ * omap3_enable_hwecc_bch - Program OMAP3 GPMC to perform BCH ECC correction
+ * @mtd: MTD device structure
+ * @mode: Read/Write mode
+ */
+static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode)
+{
+	int nerrors;
+	unsigned int dev_width;
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+						   mtd);
+	struct nand_chip *chip = mtd->priv;
+
+	nerrors = (info->nand.ecc.bytes == 13) ? 8 : 4;
+	dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
+	/*
+	 * Program GPMC to perform correction on one 512-byte sector at a time.
+	 * Using 4 sectors at a time (i.e. ecc.size = 2048) is also possible and
+	 * gives a slight (5%) performance gain (but requires additional code).
+	 */
+	(void)gpmc_enable_hwecc_bch(info->gpmc_cs, mode, dev_width, 1, nerrors);
+}
+
+/**
+ * omap3_calculate_ecc_bch4 - Generate 7 bytes of ECC bytes
+ * @mtd: MTD device structure
+ * @dat: The pointer to data on which ecc is computed
+ * @ecc_code: The ecc_code buffer
+ */
+static int omap3_calculate_ecc_bch4(struct mtd_info *mtd, const u_char *dat,
+				    u_char *ecc_code)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+						   mtd);
+	return gpmc_calculate_ecc_bch4(info->gpmc_cs, dat, ecc_code);
+}
+
+/**
+ * omap3_calculate_ecc_bch8 - Generate 13 bytes of ECC bytes
+ * @mtd: MTD device structure
+ * @dat: The pointer to data on which ecc is computed
+ * @ecc_code: The ecc_code buffer
+ */
+static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
+				    u_char *ecc_code)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+						   mtd);
+	return gpmc_calculate_ecc_bch8(info->gpmc_cs, dat, ecc_code);
+}
+
+/**
+ * omap3_correct_data_bch - Decode received data and correct errors
+ * @mtd: MTD device structure
+ * @data: page data
+ * @read_ecc: ecc read from nand flash
+ * @calc_ecc: ecc read from HW ECC registers
+ */
+static int omap3_correct_data_bch(struct mtd_info *mtd, u_char *data,
+				  u_char *read_ecc, u_char *calc_ecc)
+{
+	int i, count;
+	/* cannot correct more than 8 errors */
+	unsigned int errloc[8];
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+						   mtd);
+
+	count = decode_bch(info->bch, NULL, 512, read_ecc, calc_ecc, NULL,
+			   errloc);
+	if (count > 0) {
+		/* correct errors */
+		for (i = 0; i < count; i++) {
+			/* correct data only, not ecc bytes */
+			if (errloc[i] < 8*512)
+				data[errloc[i]/8] ^= 1 << (errloc[i] & 7);
+			pr_debug("corrected bitflip %u\n", errloc[i]);
+		}
+	} else if (count < 0) {
+		pr_err("ecc unrecoverable error\n");
+	}
+	return count;
+}
+
+/**
+ * omap3_free_bch - Release BCH ecc resources
+ * @mtd: MTD device structure
+ */
+static void omap3_free_bch(struct mtd_info *mtd)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+						   mtd);
+	if (info->bch) {
+		free_bch(info->bch);
+		info->bch = NULL;
+	}
+}
+
+/**
+ * omap3_init_bch - Initialize BCH ECC
+ * @mtd: MTD device structure
+ * @ecc_opt: OMAP ECC mode (OMAP_ECC_BCH4_CODE_HW or OMAP_ECC_BCH8_CODE_HW)
+ */
+static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
+{
+	int ret, max_errors;
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+						   mtd);
+#ifdef CONFIG_MTD_NAND_OMAP_BCH8
+	const int hw_errors = 8;
+#else
+	const int hw_errors = 4;
+#endif
+	info->bch = NULL;
+
+	max_errors = (ecc_opt == OMAP_ECC_BCH8_CODE_HW) ? 8 : 4;
+	if (max_errors != hw_errors) {
+		pr_err("cannot configure %d-bit BCH ecc, only %d-bit supported",
+		       max_errors, hw_errors);
+		goto fail;
+	}
+
+	/* initialize GPMC BCH engine */
+	ret = gpmc_init_hwecc_bch(info->gpmc_cs, 1, max_errors);
+	if (ret)
+		goto fail;
+
+	/* software bch library is only used to detect and locate errors */
+	info->bch = init_bch(13, max_errors, 0x201b /* hw polynomial */);
+	if (!info->bch)
+		goto fail;
+
+	info->nand.ecc.size    = 512;
+	info->nand.ecc.hwctl   = omap3_enable_hwecc_bch;
+	info->nand.ecc.correct = omap3_correct_data_bch;
+	info->nand.ecc.mode    = NAND_ECC_HW;
+
+	/*
+	 * The number of corrected errors in an ecc block that will trigger
+	 * block scrubbing defaults to the ecc strength (4 or 8).
+	 * Set mtd->bitflip_threshold here to define a custom threshold.
+	 */
+
+	if (max_errors == 8) {
+		info->nand.ecc.strength  = 8;
+		info->nand.ecc.bytes     = 13;
+		info->nand.ecc.calculate = omap3_calculate_ecc_bch8;
+	} else {
+		info->nand.ecc.strength  = 4;
+		info->nand.ecc.bytes     = 7;
+		info->nand.ecc.calculate = omap3_calculate_ecc_bch4;
+	}
+
+	pr_info("enabling NAND BCH ecc with %d-bit correction\n", max_errors);
+	return 0;
+fail:
+	omap3_free_bch(mtd);
+	return -1;
+}
+
+/**
+ * omap3_init_bch_tail - Build an oob layout for BCH ECC correction.
+ * @mtd: MTD device structure
+ */
+static int omap3_init_bch_tail(struct mtd_info *mtd)
+{
+	int i, steps;
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+						   mtd);
+	struct nand_ecclayout *layout = &info->ecclayout;
+
+	/* build oob layout */
+	steps = mtd->writesize/info->nand.ecc.size;
+	layout->eccbytes = steps*info->nand.ecc.bytes;
+
+	/* do not bother creating special oob layouts for small page devices */
+	if (mtd->oobsize < 64) {
+		pr_err("BCH ecc is not supported on small page devices\n");
+		goto fail;
+	}
+
+	/* reserve 2 bytes for bad block marker */
+	if (layout->eccbytes+2 > mtd->oobsize) {
+		pr_err("no oob layout available for oobsize %d eccbytes %u\n",
+		       mtd->oobsize, layout->eccbytes);
+		goto fail;
+	}
+
+	/* put ecc bytes at oob tail */
+	for (i = 0; i < layout->eccbytes; i++)
+		layout->eccpos[i] = mtd->oobsize-layout->eccbytes+i;
+
+	layout->oobfree[0].offset = 2;
+	layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes;
+	info->nand.ecc.layout = layout;
+
+	if (!(info->nand.options & NAND_BUSWIDTH_16))
+		info->nand.badblock_pattern = &bb_descrip_flashbased;
+	return 0;
+fail:
+	omap3_free_bch(mtd);
+	return -1;
+}
+
+#else
+static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
+{
+	pr_err("CONFIG_MTD_NAND_OMAP_BCH is not enabled\n");
+	return -1;
+}
+static int omap3_init_bch_tail(struct mtd_info *mtd)
+{
+	return -1;
+}
+static void omap3_free_bch(struct mtd_info *mtd)
+{
+}
+#endif /* CONFIG_MTD_NAND_OMAP_BCH */
+
 static int __devinit omap_nand_probe(struct platform_device *pdev)
 {
 	struct omap_nand_info		*info;
@@ -1063,6 +1296,13 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
 		info->nand.ecc.hwctl            = omap_enable_hwecc;
 		info->nand.ecc.correct          = omap_correct_data;
 		info->nand.ecc.mode             = NAND_ECC_HW;
+	} else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
+		   (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) {
+		err = omap3_init_bch(&info->mtd, pdata->ecc_opt);
+		if (err) {
+			err = -EINVAL;
+			goto out_release_mem_region;
+		}
 	}
 
 	/* DIP switches on some boards change between 8 and 16 bit
@@ -1094,6 +1334,14 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
 					(offset + omap_oobinfo.eccbytes);
 
 		info->nand.ecc.layout = &omap_oobinfo;
+	} else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
+		   (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) {
+		/* build OOB layout for BCH ECC correction */
+		err = omap3_init_bch_tail(&info->mtd);
+		if (err) {
+			err = -EINVAL;
+			goto out_release_mem_region;
+		}
 	}
 
 	/* second phase scan */
@@ -1122,6 +1370,7 @@ static int omap_nand_remove(struct platform_device *pdev)
 	struct mtd_info *mtd = platform_get_drvdata(pdev);
 	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
 							mtd);
+	omap3_free_bch(&info->mtd);
 
 	platform_set_drvdata(pdev, NULL);
 	if (info->dma_ch != -1)