mtd: nand: Get rid of busw parameter

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@free-electrons.com>
Acked-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 6f3ae62..16b082f 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3385,8 +3385,10 @@ 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;
@@ -3562,7 +3564,7 @@ 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;
@@ -3634,9 +3636,7 @@ static int nand_flash_detect_onfi(struct nand_chip *chip, int *busw)
        chip->blocks_per_die = le32_to_cpu(p->blocks_per_lun);
 
        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;
@@ -3669,7 +3669,7 @@ 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;
@@ -3730,9 +3730,7 @@ 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];
@@ -3821,7 +3819,7 @@ 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;
@@ -3874,7 +3872,6 @@ 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;
@@ -3915,7 +3912,6 @@ 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);
@@ -3928,7 +3924,8 @@ 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
@@ -3953,8 +3950,7 @@ 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;
@@ -3963,7 +3959,6 @@ 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;
@@ -4026,7 +4021,7 @@ 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;
@@ -4044,8 +4039,6 @@ 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;
 
@@ -4106,9 +4099,24 @@ 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;
@@ -4118,11 +4126,11 @@ 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;
        }
 
@@ -4136,9 +4144,9 @@ 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;
@@ -4158,9 +4166,8 @@ ident_done:
        }
 
        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
@@ -4169,9 +4176,8 @@ ident_done:
                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;
        }
 
@@ -4399,7 +4405,7 @@ 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);