Re: [PATCH v4 03/15] mtd: nand: get rid of busw parameter

From: Marek Vasut
Date: Wed Jan 04 2017 - 13:38:13 EST


On 01/03/2017 02:01 PM, Boris Brezillon wrote:
> 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>

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);
>


--
Best regards,
Marek Vasut