[PATCH v6 03/17] mtd: nand: Get rid of busw parameter

From: Boris Brezillon
Date: Mon Jan 09 2017 - 09:29:30 EST


Auto-detection functions are passed a busw parameter to retrieve the actual
NAND bus width and eventually set the correct value in chip->options.
Rework the nand_get_flash_type() function to get rid of this extra
parameter and let detection code directly set the NAND_BUSWIDTH_16 flag in
chip->options if needed.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Acked-by: Richard Weinberger <richard@xxxxxx>
Reviewed-by: Marek Vasut <marek.vasut@xxxxxxxxx>
---
drivers/mtd/nand/nand_base.c | 68 ++++++++++++++++++++++++--------------------
1 file changed, 37 insertions(+), 31 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 309f2e113d39..3a31b705af6f 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3348,8 +3348,10 @@ static void nand_shutdown(struct mtd_info *mtd)
}

/* Set default functions */
-static void nand_set_defaults(struct nand_chip *chip, int busw)
+static void nand_set_defaults(struct nand_chip *chip)
{
+ unsigned int busw = chip->options & NAND_BUSWIDTH_16;
+
/* check for proper chip_delay setup, set 20us if not */
if (!chip->chip_delay)
chip->chip_delay = 20;
@@ -3525,7 +3527,7 @@ static void nand_onfi_detect_micron(struct nand_chip *chip,
/*
* Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
*/
-static int nand_flash_detect_onfi(struct nand_chip *chip, int *busw)
+static int nand_flash_detect_onfi(struct nand_chip *chip)
{
struct mtd_info *mtd = nand_to_mtd(chip);
struct nand_onfi_params *p = &chip->onfi_params;
@@ -3594,9 +3596,7 @@ static int nand_flash_detect_onfi(struct nand_chip *chip, int *busw)
chip->bits_per_cell = p->bits_per_cell;

if (onfi_feature(chip) & ONFI_FEATURE_16_BIT_BUS)
- *busw = NAND_BUSWIDTH_16;
- else
- *busw = 0;
+ chip->options |= NAND_BUSWIDTH_16;

if (p->ecc_bits != 0xff) {
chip->ecc_strength_ds = p->ecc_bits;
@@ -3629,7 +3629,7 @@ static int nand_flash_detect_onfi(struct nand_chip *chip, int *busw)
/*
* Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
*/
-static int nand_flash_detect_jedec(struct nand_chip *chip, int *busw)
+static int nand_flash_detect_jedec(struct nand_chip *chip)
{
struct mtd_info *mtd = nand_to_mtd(chip);
struct nand_jedec_params *p = &chip->jedec_params;
@@ -3690,9 +3690,7 @@ static int nand_flash_detect_jedec(struct nand_chip *chip, int *busw)
chip->bits_per_cell = p->bits_per_cell;

if (jedec_feature(chip) & JEDEC_FEATURE_16_BIT_BUS)
- *busw = NAND_BUSWIDTH_16;
- else
- *busw = 0;
+ chip->options |= NAND_BUSWIDTH_16;

/* ECC info */
ecc = &p->ecc_info[0];
@@ -3781,7 +3779,7 @@ static int nand_get_bits_per_cell(u8 cellinfo)
* chip. The rest of the parameters must be decoded according to generic or
* manufacturer-specific "extended ID" decoding patterns.
*/
-static void nand_decode_ext_id(struct nand_chip *chip, int *busw)
+static void nand_decode_ext_id(struct nand_chip *chip)
{
struct mtd_info *mtd = nand_to_mtd(chip);
int extid, id_len = chip->id.len;
@@ -3834,7 +3832,6 @@ static void nand_decode_ext_id(struct nand_chip *chip, int *busw)
/* Calc blocksize */
mtd->erasesize = (128 * 1024) <<
(((extid >> 1) & 0x04) | (extid & 0x03));
- *busw = 0;
} else if (id_len == 6 && id_data[0] == NAND_MFR_HYNIX &&
!nand_is_slc(chip)) {
unsigned int tmp;
@@ -3875,7 +3872,6 @@ static void nand_decode_ext_id(struct nand_chip *chip, int *busw)
mtd->erasesize = 768 * 1024;
else
mtd->erasesize = (64 * 1024) << tmp;
- *busw = 0;
} else {
/* Calc pagesize */
mtd->writesize = 1024 << (extid & 0x03);
@@ -3888,7 +3884,8 @@ static void nand_decode_ext_id(struct nand_chip *chip, int *busw)
mtd->erasesize = (64 * 1024) << (extid & 0x03);
extid >>= 2;
/* Get buswidth information */
- *busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
+ if (extid & 0x1)
+ chip->options |= NAND_BUSWIDTH_16;

/*
* Toshiba 24nm raw SLC (i.e., not BENAND) have 32B OOB per
@@ -3913,8 +3910,7 @@ static void nand_decode_ext_id(struct nand_chip *chip, int *busw)
* decodes a matching ID table entry and assigns the MTD size parameters for
* the chip.
*/
-static void nand_decode_id(struct nand_chip *chip, struct nand_flash_dev *type,
- int *busw)
+static void nand_decode_id(struct nand_chip *chip, struct nand_flash_dev *type)
{
struct mtd_info *mtd = nand_to_mtd(chip);
u8 *id_data = chip->id.data;
@@ -3923,7 +3919,6 @@ static void nand_decode_id(struct nand_chip *chip, struct nand_flash_dev *type,
mtd->erasesize = type->erasesize;
mtd->writesize = type->pagesize;
mtd->oobsize = mtd->writesize / 32;
- *busw = type->options & NAND_BUSWIDTH_16;

/* All legacy ID NAND are small-page, SLC */
chip->bits_per_cell = 1;
@@ -3986,7 +3981,7 @@ static inline bool is_full_id_nand(struct nand_flash_dev *type)
}

static bool find_full_id_nand(struct nand_chip *chip,
- struct nand_flash_dev *type, int *busw)
+ struct nand_flash_dev *type)
{
struct mtd_info *mtd = nand_to_mtd(chip);
u8 *id_data = chip->id.data;
@@ -4004,8 +3999,6 @@ static bool find_full_id_nand(struct nand_chip *chip,
chip->onfi_timing_mode_default =
type->onfi_timing_mode_default;

- *busw = type->options & NAND_BUSWIDTH_16;
-
if (!mtd->name)
mtd->name = type->name;

@@ -4066,9 +4059,24 @@ static int nand_get_flash_type(struct nand_chip *chip,
if (!type)
type = nand_flash_ids;

+ /*
+ * Save the NAND_BUSWIDTH_16 flag before letting auto-detection logic
+ * override it.
+ * This is required to make sure initial NAND bus width set by the
+ * NAND controller driver is coherent with the real NAND bus width
+ * (extracted by auto-detection code).
+ */
+ busw = chip->options & NAND_BUSWIDTH_16;
+
+ /*
+ * The flag is only set (never cleared), reset it to its default value
+ * before starting auto-detection.
+ */
+ chip->options &= ~NAND_BUSWIDTH_16;
+
for (; type->name != NULL; type++) {
if (is_full_id_nand(type)) {
- if (find_full_id_nand(chip, type, &busw))
+ if (find_full_id_nand(chip, type))
goto ident_done;
} else if (dev_id == type->dev_id) {
break;
@@ -4078,11 +4086,11 @@ static int nand_get_flash_type(struct nand_chip *chip,
chip->onfi_version = 0;
if (!type->name || !type->pagesize) {
/* Check if the chip is ONFI compliant */
- if (nand_flash_detect_onfi(chip, &busw))
+ if (nand_flash_detect_onfi(chip))
goto ident_done;

/* Check if the chip is JEDEC compliant */
- if (nand_flash_detect_jedec(chip, &busw))
+ if (nand_flash_detect_jedec(chip))
goto ident_done;
}

@@ -4096,9 +4104,9 @@ static int nand_get_flash_type(struct nand_chip *chip,

if (!type->pagesize) {
/* Decode parameters from extended ID */
- nand_decode_ext_id(chip, &busw);
+ nand_decode_ext_id(chip);
} else {
- nand_decode_id(chip, type, &busw);
+ nand_decode_id(chip, type);
}
/* Get chip options */
chip->options |= type->options;
@@ -4118,9 +4126,8 @@ static int nand_get_flash_type(struct nand_chip *chip,
}

if (chip->options & NAND_BUSWIDTH_AUTO) {
- WARN_ON(chip->options & NAND_BUSWIDTH_16);
- chip->options |= busw;
- nand_set_defaults(chip, busw);
+ WARN_ON(busw & NAND_BUSWIDTH_16);
+ nand_set_defaults(chip);
} else if (busw != (chip->options & NAND_BUSWIDTH_16)) {
/*
* Check, if buswidth is correct. Hardware drivers should set
@@ -4129,9 +4136,8 @@ static int nand_get_flash_type(struct nand_chip *chip,
pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
maf_id, dev_id);
pr_info("%s %s\n", nand_manuf_ids[maf_idx].name, mtd->name);
- pr_warn("bus width %d instead %d bit\n",
- (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
- busw ? 16 : 8);
+ pr_warn("bus width %d instead of %d bits\n", busw ? 16 : 8,
+ (chip->options & NAND_BUSWIDTH_16) ? 16 : 8);
return -EINVAL;
}

@@ -4359,7 +4365,7 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,
return -EINVAL;
}
/* Set the default functions */
- nand_set_defaults(chip, chip->options & NAND_BUSWIDTH_16);
+ nand_set_defaults(chip);

/* Read the flash type */
ret = nand_get_flash_type(chip, table);
--
2.7.4