Merge tag 'nand/for-6.9' into mtd/next

Raw NAND

The main series brought is an update of the Broadcom support to support
all BCMBCA SoCs and their specificity (ECC, write protection,
configuration straps), plus a few misc fixes and changes in the main
driver. Device tree updates are also part of this PR, initially because
of a misunderstanding on my side.

The STM32_FMC2 controller driver is also upgraded to properly support
MP1 and MP25 SoCs.

A new compatible is added for an Atmel flavor.

Among all these feature changes, there is as well a load of continuous
read related fixes, avoiding more corner conditions and clarifying the
logic. Finally a few miscellaneous fixes are made to the core, the
lpx32xx_mlc, fsl_lbc, Meson and Atmel controller driver, as well as
final one in the Hynix vendor driver.

SPI-NAND

The ESMT support has been extended to match 5 bytes ID to avoid
collisions. Winbond support on its side receives support for W25N04KV
chips.

1 files changed, 59 insertions, 29 deletions

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 3b3ce2926f5d..d7dbbd469b89 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -1211,21 +1211,36 @@ static int nand_lp_exec_read_page_op(struct nand_chip *chip, unsigned int page,
 	return nand_exec_op(chip, &op);
 }
 
+static unsigned int rawnand_last_page_of_lun(unsigned int pages_per_lun, unsigned int lun)
+{
+	/* lun is expected to be very small */
+	return (lun * pages_per_lun) + pages_per_lun - 1;
+}
+
 static void rawnand_cap_cont_reads(struct nand_chip *chip)
 {
 	struct nand_memory_organization *memorg;
-	unsigned int pages_per_lun, first_lun, last_lun;
+	unsigned int ppl, first_lun, last_lun;
 
 	memorg = nanddev_get_memorg(&chip->base);
-	pages_per_lun = memorg->pages_per_eraseblock * memorg->eraseblocks_per_lun;
-	first_lun = chip->cont_read.first_page / pages_per_lun;
-	last_lun = chip->cont_read.last_page / pages_per_lun;
+	ppl = memorg->pages_per_eraseblock * memorg->eraseblocks_per_lun;
+	first_lun = chip->cont_read.first_page / ppl;
+	last_lun = chip->cont_read.last_page / ppl;
 
 	/* Prevent sequential cache reads across LUN boundaries */
 	if (first_lun != last_lun)
-		chip->cont_read.pause_page = first_lun * pages_per_lun + pages_per_lun - 1;
+		chip->cont_read.pause_page = rawnand_last_page_of_lun(ppl, first_lun);
 	else
 		chip->cont_read.pause_page = chip->cont_read.last_page;
+
+	if (chip->cont_read.first_page == chip->cont_read.pause_page) {
+		chip->cont_read.first_page++;
+		chip->cont_read.pause_page = min(chip->cont_read.last_page,
+						 rawnand_last_page_of_lun(ppl, first_lun + 1));
+	}
+
+	if (chip->cont_read.first_page >= chip->cont_read.last_page)
+		chip->cont_read.ongoing = false;
 }
 
 static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int page,
@@ -1292,12 +1307,11 @@ static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int p
 	if (!chip->cont_read.ongoing)
 		return 0;
 
-	if (page == chip->cont_read.pause_page &&
-	    page != chip->cont_read.last_page) {
-		chip->cont_read.first_page = chip->cont_read.pause_page + 1;
-		rawnand_cap_cont_reads(chip);
-	} else if (page == chip->cont_read.last_page) {
+	if (page == chip->cont_read.last_page) {
 		chip->cont_read.ongoing = false;
+	} else if (page == chip->cont_read.pause_page) {
+		chip->cont_read.first_page++;
+		rawnand_cap_cont_reads(chip);
 	}
 
 	return 0;
@@ -3466,30 +3480,36 @@ static void rawnand_enable_cont_reads(struct nand_chip *chip, unsigned int page,
 				      u32 readlen, int col)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
-	unsigned int end_page, end_col;
+	unsigned int first_page, last_page;
 
 	chip->cont_read.ongoing = false;
 
 	if (!chip->controller->supported_op.cont_read)
 		return;
 
-	end_page = DIV_ROUND_UP(col + readlen, mtd->writesize);
-	end_col = (col + readlen) % mtd->writesize;
+	/*
+	 * Don't bother making any calculations if the length is too small.
+	 * Side effect: avoids possible integer underflows below.
+	 */
+	if (readlen < (2 * mtd->writesize))
+		return;
 
+	/* Derive the page where continuous read should start (the first full page read) */
+	first_page = page;
 	if (col)
-		page++;
+		first_page++;
 
-	if (end_col && end_page)
-		end_page--;
+	/* Derive the page where continuous read should stop (the last full page read) */
+	last_page = page + ((col + readlen) / mtd->writesize) - 1;
 
-	if (page + 1 > end_page)
-		return;
-
-	chip->cont_read.first_page = page;
-	chip->cont_read.last_page = end_page;
-	chip->cont_read.ongoing = true;
-
-	rawnand_cap_cont_reads(chip);
+	/* Configure and enable continuous read when suitable */
+	if (first_page < last_page) {
+		chip->cont_read.first_page = first_page;
+		chip->cont_read.last_page = last_page;
+		chip->cont_read.ongoing = true;
+		/* May reset the ongoing flag */
+		rawnand_cap_cont_reads(chip);
+	}
 }
 
 static void rawnand_cont_read_skip_first_page(struct nand_chip *chip, unsigned int page)
@@ -3498,10 +3518,7 @@ static void rawnand_cont_read_skip_first_page(struct nand_chip *chip, unsigned i
 		return;
 
 	chip->cont_read.first_page++;
-	if (chip->cont_read.first_page == chip->cont_read.pause_page)
-		chip->cont_read.first_page++;
-	if (chip->cont_read.first_page >= chip->cont_read.last_page)
-		chip->cont_read.ongoing = false;
+	rawnand_cap_cont_reads(chip);
 }
 
 /**
@@ -3577,7 +3594,8 @@ static int nand_do_read_ops(struct nand_chip *chip, loff_t from,
 	oob = ops->oobbuf;
 	oob_required = oob ? 1 : 0;
 
-	rawnand_enable_cont_reads(chip, page, readlen, col);
+	if (likely(ops->mode != MTD_OPS_RAW))
+		rawnand_enable_cont_reads(chip, page, readlen, col);
 
 	while (1) {
 		struct mtd_ecc_stats ecc_stats = mtd->ecc_stats;
@@ -3710,6 +3728,9 @@ read_retry:
 	}
 	nand_deselect_target(chip);
 
+	if (WARN_ON_ONCE(chip->cont_read.ongoing))
+		chip->cont_read.ongoing = false;
+
 	ops->retlen = ops->len - (size_t) readlen;
 	if (oob)
 		ops->oobretlen = ops->ooblen - oobreadlen;
@@ -5195,6 +5216,15 @@ static void rawnand_late_check_supported_ops(struct nand_chip *chip)
 	if (!nand_has_exec_op(chip))
 		return;
 
+	/*
+	 * For now, continuous reads can only be used with the core page helpers.
+	 * This can be extended later.
+	 */
+	if (!(chip->ecc.read_page == nand_read_page_hwecc ||
+	      chip->ecc.read_page == nand_read_page_syndrome ||
+	      chip->ecc.read_page == nand_read_page_swecc))
+		return;
+
 	rawnand_check_cont_read_support(chip);
 }