This patch is alternative implementation for following commit which introduced NAND_BUSWIDTH_AUTO for detection of bus-width during device probe commit 64b37b2a63eb2f80b65c7185f0013f8ffc637ae3 Author: Matthieu CASTET <matthieu.castet@xxxxxxxxxx> AuthorDate: 2012-11-06 As NAND device is identified only during nand_scan_ident(), so this patch assumes that NAND driver may un-initialized or partially congigured while calling nand_scan_ident(). Hence, this patch does following: 1. Temporarily configures 'bus-width=x8' mode before reading ONFI parameters, as required by ONFI specification [1]. 2. Reconfigures the driver with correct bus-width determined by either reading ONFI param, or the nand_flash_id[] table. This patch removes any dependency on either 'DT binding' or 'platform data' to specify the NAND device bus-width. [*] Reference: ONFI spec version 3.1 (section 3.5.3. Target Initialization) "The Read ID and Read Parameter Page commands only use the lower 8-bits of the data bus. The host shall not issue commands that use a word data width on x16 devices until the host determines the device supports a 16-bit data bus width in the parameter page." Signed-off-by: Pekon Gupta <pekon@xxxxxx> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxxxxxxxxxx> --- drivers/mtd/nand/nand_base.c | 43 +++++++++++++------------------------------ 1 file changed, 13 insertions(+), 30 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index bd39f7b..3ff9944 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -2942,15 +2942,6 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip, chip->read_byte(mtd) != 'F' || chip->read_byte(mtd) != 'I') return 0; - /* - * ONFI must be probed in 8-bit mode or with NAND_BUSWIDTH_AUTO, not - * with NAND_BUSWIDTH_16 - */ - if (chip->options & NAND_BUSWIDTH_16) { - pr_err("ONFI cannot be probed in 16-bit mode; aborting\n"); - return 0; - } - chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1); for (i = 0; i < 3; i++) { chip->read_buf(mtd, (uint8_t *)p, sizeof(*p)); @@ -3335,13 +3326,21 @@ static bool find_full_id_nand(struct mtd_info *mtd, struct nand_chip *chip, */ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd, struct nand_chip *chip, - int busw, int *maf_id, int *dev_id, struct nand_flash_dev *type) { int i, maf_idx; + int busw = 0; u8 id_data[8]; + /* + * The device detection is done in 8-bit mode. The real bus width + * will be autodetected (either ONFI or flash-based), the + * defaults re-configured and the chip->options updated. + */ + nand_set_defaults(chip, 0); + chip->options &= ~NAND_BUSWIDTH_16; + /* Select the device */ chip->select_chip(mtd, 0); @@ -3431,22 +3430,10 @@ ident_done: break; } - if (chip->options & NAND_BUSWIDTH_AUTO) { - WARN_ON(chip->options & NAND_BUSWIDTH_16); + /* Configure driver using detected bus-width */ + if (busw) { chip->options |= busw; nand_set_defaults(chip, busw); - } else if (busw != (chip->options & NAND_BUSWIDTH_16)) { - /* - * Check, if buswidth is correct. Hardware drivers should set - * chip correct! - */ - pr_info("NAND device: Manufacturer ID:" - " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, - *dev_id, nand_manuf_ids[maf_idx].name, mtd->name); - pr_warn("NAND bus width %d instead %d bit\n", - (chip->options & NAND_BUSWIDTH_16) ? 16 : 8, - busw ? 16 : 8); - return ERR_PTR(-EINVAL); } nand_decode_bbm_options(mtd, chip, id_data); @@ -3497,17 +3484,13 @@ ident_done: int nand_scan_ident(struct mtd_info *mtd, int maxchips, struct nand_flash_dev *table) { - int i, busw, nand_maf_id, nand_dev_id; + int i, nand_maf_id, nand_dev_id; struct nand_chip *chip = mtd->priv; struct nand_flash_dev *type; - /* Get buswidth to select the correct functions */ - busw = chip->options & NAND_BUSWIDTH_16; - /* Set the default functions */ - nand_set_defaults(chip, busw); /* Read the flash type */ - type = nand_get_flash_type(mtd, chip, busw, + type = nand_get_flash_type(mtd, chip, &nand_maf_id, &nand_dev_id, table); if (IS_ERR(type)) { -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html