Merge tag 'nand/for-4.13' into MTD

From Boris:
"""
This pull request contains the following core changes:

* addition of on-ecc support to Micron driver
* addition of helpers to help drivers choose most appropriate ECC
  settings
* deletion of dead-code (cached programming and ->errstat() hook)
* make sure drivers that do not support the SET/GET FEATURES command
  return ENOTSUPP use a dummy ->set/get_features implementation
  returning -ENOTSUPP (required for Micron on-die ECC)
* change the semantic of ecc->write_page() for drivers setting the
  NAND_ECC_CUSTOM_PAGE_ACCESS flag
* support exiting 'GET STATUS' command in default ->cmdfunc()
  implementations
* change the prototype of ->setup_data_interface()

A bunch of driver related changes:

* various cleanup, fixes and improvements of the MTK driver
* OMAP DT bindings fixes
* support for ->setup_data_interface() in the fsmc driver
* support for imx7 in the gpmi driver
* finalization of the denali driver rework (thanks to Masahiro for the
  work he's done on this driver)
* fix "bitflips in erased pages" handling in the ifc driver
* addition of PM ops and dynamic timing configuration to the atmel
  driver

And as usual we also have a few minor cleanup/fixes/improvements
patches across the subsystem.
"""

1 files changed, 303 insertions, 46 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index b1dd12729f19..5d865123c385 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -753,6 +753,16 @@ static void nand_command(struct mtd_info *mtd, unsigned int command,
 		return;
 
 		/* This applies to read commands */
+	case NAND_CMD_READ0:
+		/*
+		 * READ0 is sometimes used to exit GET STATUS mode. When this
+		 * is the case no address cycles are requested, and we can use
+		 * this information to detect that we should not wait for the
+		 * device to be ready.
+		 */
+		if (column == -1 && page_addr == -1)
+			return;
+
 	default:
 		/*
 		 * If we don't have access to the busy pin, we apply the given
@@ -887,6 +897,15 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
 		return;
 
 	case NAND_CMD_READ0:
+		/*
+		 * READ0 is sometimes used to exit GET STATUS mode. When this
+		 * is the case no address cycles are requested, and we can use
+		 * this information to detect that READSTART should not be
+		 * issued.
+		 */
+		if (column == -1 && page_addr == -1)
+			return;
+
 		chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
 			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
 		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
@@ -1042,12 +1061,13 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
 /**
  * nand_reset_data_interface - Reset data interface and timings
  * @chip: The NAND chip
+ * @chipnr: Internal die id
  *
  * Reset the Data interface and timings to ONFI mode 0.
  *
  * Returns 0 for success or negative error code otherwise.
  */
-static int nand_reset_data_interface(struct nand_chip *chip)
+static int nand_reset_data_interface(struct nand_chip *chip, int chipnr)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	const struct nand_data_interface *conf;
@@ -1071,7 +1091,7 @@ static int nand_reset_data_interface(struct nand_chip *chip)
 	 */
 
 	conf = nand_get_default_data_interface();
-	ret = chip->setup_data_interface(mtd, conf, false);
+	ret = chip->setup_data_interface(mtd, chipnr, conf);
 	if (ret)
 		pr_err("Failed to configure data interface to SDR timing mode 0\n");
 
@@ -1081,6 +1101,7 @@ static int nand_reset_data_interface(struct nand_chip *chip)
 /**
  * nand_setup_data_interface - Setup the best data interface and timings
  * @chip: The NAND chip
+ * @chipnr: Internal die id
  *
  * Find and configure the best data interface and NAND timings supported by
  * the chip and the driver.
@@ -1090,7 +1111,7 @@ static int nand_reset_data_interface(struct nand_chip *chip)
  *
  * Returns 0 for success or negative error code otherwise.
  */
-static int nand_setup_data_interface(struct nand_chip *chip)
+static int nand_setup_data_interface(struct nand_chip *chip, int chipnr)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	int ret;
@@ -1114,7 +1135,7 @@ static int nand_setup_data_interface(struct nand_chip *chip)
 			goto err;
 	}
 
-	ret = chip->setup_data_interface(mtd, chip->data_interface, false);
+	ret = chip->setup_data_interface(mtd, chipnr, chip->data_interface);
 err:
 	return ret;
 }
@@ -1165,8 +1186,10 @@ static int nand_init_data_interface(struct nand_chip *chip)
 		if (ret)
 			continue;
 
-		ret = chip->setup_data_interface(mtd, chip->data_interface,
-						 true);
+		/* Pass -1 to only */
+		ret = chip->setup_data_interface(mtd,
+						 NAND_DATA_IFACE_CHECK_ONLY,
+						 chip->data_interface);
 		if (!ret) {
 			chip->onfi_timing_mode_default = mode;
 			break;
@@ -1193,7 +1216,7 @@ int nand_reset(struct nand_chip *chip, int chipnr)
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	int ret;
 
-	ret = nand_reset_data_interface(chip);
+	ret = nand_reset_data_interface(chip, chipnr);
 	if (ret)
 		return ret;
 
@@ -1206,7 +1229,7 @@ int nand_reset(struct nand_chip *chip, int chipnr)
 	chip->select_chip(mtd, -1);
 
 	chip->select_chip(mtd, chipnr);
-	ret = nand_setup_data_interface(chip);
+	ret = nand_setup_data_interface(chip, chipnr);
 	chip->select_chip(mtd, -1);
 	if (ret)
 		return ret;
@@ -1421,7 +1444,10 @@ static int nand_check_erased_buf(void *buf, int len, int bitflips_threshold)
 
 	for (; len >= sizeof(long);
 	     len -= sizeof(long), bitmap += sizeof(long)) {
-		weight = hweight_long(*((unsigned long *)bitmap));
+		unsigned long d = *((unsigned long *)bitmap);
+		if (d == ~0UL)
+			continue;
+		weight = hweight_long(d);
 		bitflips += BITS_PER_LONG - weight;
 		if (unlikely(bitflips > bitflips_threshold))
 			return -EBADMSG;
@@ -1524,14 +1550,15 @@ EXPORT_SYMBOL(nand_check_erased_ecc_chunk);
  *
  * Not for syndrome calculating ECC controllers, which use a special oob layout.
  */
-static int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
-			      uint8_t *buf, int oob_required, int page)
+int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+		       uint8_t *buf, int oob_required, int page)
 {
 	chip->read_buf(mtd, buf, mtd->writesize);
 	if (oob_required)
 		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
 	return 0;
 }
+EXPORT_SYMBOL(nand_read_page_raw);
 
 /**
  * nand_read_page_raw_syndrome - [INTERN] read raw page data without ecc
@@ -2469,8 +2496,8 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from,
  *
  * Not for syndrome calculating ECC controllers, which use a special oob layout.
  */
-static int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
-			       const uint8_t *buf, int oob_required, int page)
+int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+			const uint8_t *buf, int oob_required, int page)
 {
 	chip->write_buf(mtd, buf, mtd->writesize);
 	if (oob_required)
@@ -2478,6 +2505,7 @@ static int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 
 	return 0;
 }
+EXPORT_SYMBOL(nand_write_page_raw);
 
 /**
  * nand_write_page_raw_syndrome - [INTERN] raw page write function
@@ -2715,7 +2743,7 @@ static int nand_write_page_syndrome(struct mtd_info *mtd,
  */
 static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
 		uint32_t offset, int data_len, const uint8_t *buf,
-		int oob_required, int page, int cached, int raw)
+		int oob_required, int page, int raw)
 {
 	int status, subpage;
 
@@ -2741,30 +2769,12 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	if (status < 0)
 		return status;
 
-	/*
-	 * Cached progamming disabled for now. Not sure if it's worth the
-	 * trouble. The speed gain is not very impressive. (2.3->2.6Mib/s).
-	 */
-	cached = 0;
+	if (nand_standard_page_accessors(&chip->ecc)) {
+		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
 
-	if (!cached || !NAND_HAS_CACHEPROG(chip)) {
-
-		if (nand_standard_page_accessors(&chip->ecc))
-			chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
 		status = chip->waitfunc(mtd, chip);
-		/*
-		 * See if operation failed and additional status checks are
-		 * available.
-		 */
-		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
-			status = chip->errstat(mtd, chip, FL_WRITING, status,
-					       page);
-
 		if (status & NAND_STATUS_FAIL)
 			return -EIO;
-	} else {
-		chip->cmdfunc(mtd, NAND_CMD_CACHEDPROG, -1, -1);
-		status = chip->waitfunc(mtd, chip);
 	}
 
 	return 0;
@@ -2872,7 +2882,6 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
 
 	while (1) {
 		int bytes = mtd->writesize;
-		int cached = writelen > bytes && page != blockmask;
 		uint8_t *wbuf = buf;
 		int use_bufpoi;
 		int part_pagewr = (column || writelen < mtd->writesize);
@@ -2890,7 +2899,6 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
 		if (use_bufpoi) {
 			pr_debug("%s: using write bounce buffer for buf@%p\n",
 					 __func__, buf);
-			cached = 0;
 			if (part_pagewr)
 				bytes = min_t(int, bytes - column, writelen);
 			chip->pagebuf = -1;
@@ -2909,7 +2917,7 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
 		}
 
 		ret = nand_write_page(mtd, chip, column, bytes, wbuf,
-				      oob_required, page, cached,
+				      oob_required, page,
 				      (ops->mode == MTD_OPS_RAW));
 		if (ret)
 			break;
@@ -3225,14 +3233,6 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
 
 		status = chip->erase(mtd, page & chip->pagemask);
 
-		/*
-		 * See if operation failed and additional status checks are
-		 * available
-		 */
-		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
-			status = chip->errstat(mtd, chip, FL_ERASING,
-					       status, page);
-
 		/* See if block erase succeeded */
 		if (status & NAND_STATUS_FAIL) {
 			pr_debug("%s: failed erase, page 0x%08x\n",
@@ -3419,6 +3419,25 @@ static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip,
 }
 
 /**
+ * nand_onfi_get_set_features_notsupp - set/get features stub returning
+ *					-ENOTSUPP
+ * @mtd: MTD device structure
+ * @chip: nand chip info structure
+ * @addr: feature address.
+ * @subfeature_param: the subfeature parameters, a four bytes array.
+ *
+ * Should be used by NAND controller drivers that do not support the SET/GET
+ * FEATURES operations.
+ */
+int nand_onfi_get_set_features_notsupp(struct mtd_info *mtd,
+				       struct nand_chip *chip, int addr,
+				       u8 *subfeature_param)
+{
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL(nand_onfi_get_set_features_notsupp);
+
+/**
  * nand_suspend - [MTD Interface] Suspend the NAND flash
  * @mtd: MTD device structure
  */
@@ -4177,6 +4196,7 @@ static const char * const nand_ecc_modes[] = {
 	[NAND_ECC_HW]		= "hw",
 	[NAND_ECC_HW_SYNDROME]	= "hw_syndrome",
 	[NAND_ECC_HW_OOB_FIRST]	= "hw_oob_first",
+	[NAND_ECC_ON_DIE]	= "on-die",
 };
 
 static int of_get_nand_ecc_mode(struct device_node *np)
@@ -4371,7 +4391,7 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,
 	 * For the other dies, nand_reset() will automatically switch to the
 	 * best mode for us.
 	 */
-	ret = nand_setup_data_interface(chip);
+	ret = nand_setup_data_interface(chip, 0);
 	if (ret)
 		goto err_nand_init;
 
@@ -4509,6 +4529,226 @@ static int nand_set_ecc_soft_ops(struct mtd_info *mtd)
 	}
 }
 
+/**
+ * nand_check_ecc_caps - check the sanity of preset ECC settings
+ * @chip: nand chip info structure
+ * @caps: ECC caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * When ECC step size and strength are already set, check if they are supported
+ * by the controller and the calculated ECC bytes fit within the chip's OOB.
+ * On success, the calculated ECC bytes is set.
+ */
+int nand_check_ecc_caps(struct nand_chip *chip,
+			const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int preset_step = chip->ecc.size;
+	int preset_strength = chip->ecc.strength;
+	int nsteps, ecc_bytes;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	if (!preset_step || !preset_strength)
+		return -ENODATA;
+
+	nsteps = mtd->writesize / preset_step;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+
+		if (stepinfo->stepsize != preset_step)
+			continue;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			if (stepinfo->strengths[j] != preset_strength)
+				continue;
+
+			ecc_bytes = caps->calc_ecc_bytes(preset_step,
+							 preset_strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				return ecc_bytes;
+
+			if (ecc_bytes * nsteps > oobavail) {
+				pr_err("ECC (step, strength) = (%d, %d) does not fit in OOB",
+				       preset_step, preset_strength);
+				return -ENOSPC;
+			}
+
+			chip->ecc.bytes = ecc_bytes;
+
+			return 0;
+		}
+	}
+
+	pr_err("ECC (step, strength) = (%d, %d) not supported on this controller",
+	       preset_step, preset_strength);
+
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL_GPL(nand_check_ecc_caps);
+
+/**
+ * nand_match_ecc_req - meet the chip's requirement with least ECC bytes
+ * @chip: nand chip info structure
+ * @caps: ECC engine caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * If a chip's ECC requirement is provided, try to meet it with the least
+ * number of ECC bytes (i.e. with the largest number of OOB-free bytes).
+ * On success, the chosen ECC settings are set.
+ */
+int nand_match_ecc_req(struct nand_chip *chip,
+		       const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int req_step = chip->ecc_step_ds;
+	int req_strength = chip->ecc_strength_ds;
+	int req_corr, step_size, strength, nsteps, ecc_bytes, ecc_bytes_total;
+	int best_step, best_strength, best_ecc_bytes;
+	int best_ecc_bytes_total = INT_MAX;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	/* No information provided by the NAND chip */
+	if (!req_step || !req_strength)
+		return -ENOTSUPP;
+
+	/* number of correctable bits the chip requires in a page */
+	req_corr = mtd->writesize / req_step * req_strength;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+		step_size = stepinfo->stepsize;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			strength = stepinfo->strengths[j];
+
+			/*
+			 * If both step size and strength are smaller than the
+			 * chip's requirement, it is not easy to compare the
+			 * resulted reliability.
+			 */
+			if (step_size < req_step && strength < req_strength)
+				continue;
+
+			if (mtd->writesize % step_size)
+				continue;
+
+			nsteps = mtd->writesize / step_size;
+
+			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				continue;
+			ecc_bytes_total = ecc_bytes * nsteps;
+
+			if (ecc_bytes_total > oobavail ||
+			    strength * nsteps < req_corr)
+				continue;
+
+			/*
+			 * We assume the best is to meet the chip's requrement
+			 * with the least number of ECC bytes.
+			 */
+			if (ecc_bytes_total < best_ecc_bytes_total) {
+				best_ecc_bytes_total = ecc_bytes_total;
+				best_step = step_size;
+				best_strength = strength;
+				best_ecc_bytes = ecc_bytes;
+			}
+		}
+	}
+
+	if (best_ecc_bytes_total == INT_MAX)
+		return -ENOTSUPP;
+
+	chip->ecc.size = best_step;
+	chip->ecc.strength = best_strength;
+	chip->ecc.bytes = best_ecc_bytes;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_match_ecc_req);
+
+/**
+ * nand_maximize_ecc - choose the max ECC strength available
+ * @chip: nand chip info structure
+ * @caps: ECC engine caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * Choose the max ECC strength that is supported on the controller, and can fit
+ * within the chip's OOB.  On success, the chosen ECC settings are set.
+ */
+int nand_maximize_ecc(struct nand_chip *chip,
+		      const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int step_size, strength, nsteps, ecc_bytes, corr;
+	int best_corr = 0;
+	int best_step = 0;
+	int best_strength, best_ecc_bytes;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+		step_size = stepinfo->stepsize;
+
+		/* If chip->ecc.size is already set, respect it */
+		if (chip->ecc.size && step_size != chip->ecc.size)
+			continue;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			strength = stepinfo->strengths[j];
+
+			if (mtd->writesize % step_size)
+				continue;
+
+			nsteps = mtd->writesize / step_size;
+
+			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				continue;
+
+			if (ecc_bytes * nsteps > oobavail)
+				continue;
+
+			corr = strength * nsteps;
+
+			/*
+			 * If the number of correctable bits is the same,
+			 * bigger step_size has more reliability.
+			 */
+			if (corr > best_corr ||
+			    (corr == best_corr && step_size > best_step)) {
+				best_corr = corr;
+				best_step = step_size;
+				best_strength = strength;
+				best_ecc_bytes = ecc_bytes;
+			}
+		}
+	}
+
+	if (!best_corr)
+		return -ENOTSUPP;
+
+	chip->ecc.size = best_step;
+	chip->ecc.strength = best_strength;
+	chip->ecc.bytes = best_ecc_bytes;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_maximize_ecc);
+
 /*
  * Check if the chip configuration meet the datasheet requirements.
 
@@ -4730,6 +4970,18 @@ int nand_scan_tail(struct mtd_info *mtd)
 		}
 		break;
 
+	case NAND_ECC_ON_DIE:
+		if (!ecc->read_page || !ecc->write_page) {
+			WARN(1, "No ECC functions supplied; on-die ECC not possible\n");
+			ret = -EINVAL;
+			goto err_free;
+		}
+		if (!ecc->read_oob)
+			ecc->read_oob = nand_read_oob_std;
+		if (!ecc->write_oob)
+			ecc->write_oob = nand_write_oob_std;
+		break;
+
 	case NAND_ECC_NONE:
 		pr_warn("NAND_ECC_NONE selected by board driver. This is not recommended!\n");
 		ecc->read_page = nand_read_page_raw;
@@ -4770,6 +5022,11 @@ int nand_scan_tail(struct mtd_info *mtd)
 		goto err_free;
 	}
 	ecc->total = ecc->steps * ecc->bytes;
+	if (ecc->total > mtd->oobsize) {
+		WARN(1, "Total number of ECC bytes exceeded oobsize\n");
+		ret = -EINVAL;
+		goto err_free;
+	}
 
 	/*
 	 * The number of bytes available for a client to place data into