From 4d1ea982a9beb4e47bba41131973329e2a012b38 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Fri, 30 Oct 2015 12:29:20 +0530 Subject: [PATCH] mtd: brcmnand: Force 8bit mode before doing nand_scan_ident() Just like other NAND controllers, the NAND READID command only works in 8bit mode for all versions of BRCMNAND controller. This patch forces 8bit mode for each NAND CS in brcmnand_init_cs() before doing nand_scan_ident() to ensure that BRCMNAND controller is in 8bit mode when NAND READID command is issued. Signed-off-by: Anup Patel Reviewed-by: Ray Jui Reviewed-by: Scott Branden Signed-off-by: Brian Norris --- drivers/mtd/nand/brcmnand/brcmnand.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c index 3bd31a6055b6..12c6190c6e33 100644 --- a/drivers/mtd/nand/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/brcmnand/brcmnand.c @@ -1913,6 +1913,7 @@ static int brcmnand_init_cs(struct brcmnand_host *host) struct mtd_info *mtd; struct nand_chip *chip; int ret; + u16 cfg_offs; struct mtd_part_parser_data ppdata = { .of_node = dn }; ret = of_property_read_u32(dn, "reg", &host->cs); @@ -1955,6 +1956,15 @@ static int brcmnand_init_cs(struct brcmnand_host *host) chip->controller = &ctrl->controller; + /* + * The bootloader might have configured 16bit mode but + * NAND READID command only works in 8bit mode. We force + * 8bit mode here to ensure that NAND READID commands works. + */ + cfg_offs = brcmnand_cs_offset(ctrl, host->cs, BRCMNAND_CS_CFG); + nand_writereg(ctrl, cfg_offs, + nand_readreg(ctrl, cfg_offs) & ~CFG_BUS_WIDTH); + if (nand_scan_ident(mtd, 1, NULL)) return -ENXIO;