> -----Original Message----- > From: Brian Norris [mailto:computersforpeace@xxxxxxxxx] > Sent: 28 October 2015 05:45 > To: Anup Patel > Cc: David Woodhouse; Linux MTD; Rob Herring; Pawel Moll; Mark Rutland; > Catalin Marinas; Will Deacon; Sudeep Holla; Ian Campbell; Kumar Gala; Ray Jui; > Scott Branden; Florian Fainelli; Pramod Kumar; Vikram Prakash; Sandeep > Tripathy; Linux ARM Kernel; Device Tree; Linux Kernel; bcm-kernel-feedback-list > Subject: Re: [PATCH v3 1/2] mtd: brcmnand: Force 8bit mode before doing > nand_scan_ident() > > On Fri, Oct 23, 2015 at 10:46:12AM +0530, Anup Patel wrote: > > 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 <anup.patel@xxxxxxxxxxxx> > > Reviewed-by: Ray Jui <rjui@xxxxxxxxxxxx> > > Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx> > > --- > > drivers/mtd/nand/brcmnand/brcmnand.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c > > b/drivers/mtd/nand/brcmnand/brcmnand.c > > index 4cba03d..0be8ef9 100644 > > --- a/drivers/mtd/nand/brcmnand/brcmnand.c > > +++ b/drivers/mtd/nand/brcmnand/brcmnand.c > > @@ -1888,6 +1888,7 @@ 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); @@ -1930,6 > > +1931,14 @@ 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) & > > +~BIT(23)); > > Can we get a new enum for cfg bits? Unfortunately, I never managed that in > brcmnand_set_cfg(); just magic numbers :( But I'd like to stop that if we're going > to have to touch these bits outside of brcmnand_set_cfg(). Even I felt the need to have enum for cfg bits, just like other parts of the BRCM NAND driver. > > > + > > if (nand_scan_ident(mtd, 1, NULL)) > > return -ENXIO; > > > > How about the following, as a preparatory patch? Only compile tested. > > From c5423a86dbfa33b550d2b170bda3c12ecf4d5313 Mon Sep 17 00:00:00 > 2001 > From: Brian Norris <computersforpeace@xxxxxxxxx> > Date: Tue, 27 Oct 2015 17:12:13 -0700 > Subject: [PATCH] mtd: brcmnand: factor out CFG and CFG_EXT bitfields > > These used magic numbers. Shame on me. > > Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx> > Cc: Anup Patel <anup.patel@xxxxxxxxxxxx> > --- > drivers/mtd/nand/brcmnand/brcmnand.c | 38 > +++++++++++++++++++++++++++++------- > 1 file changed, 31 insertions(+), 7 deletions(-) > > diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c > b/drivers/mtd/nand/brcmnand/brcmnand.c > index d694d876631e..c93fbc3869ee 100644 > --- a/drivers/mtd/nand/brcmnand/brcmnand.c > +++ b/drivers/mtd/nand/brcmnand/brcmnand.c > @@ -344,6 +344,28 @@ static const u8 brcmnand_cs_offsets_cs0[] = { > [BRCMNAND_CS_TIMING2] = 0x14, > }; > > +/* > + * Bitfields for the CFG and CFG_EXT registers. Pre-v7.1 controllers > +only had > + * one config register, but once the bitfields overflowed, newer > +controllers > + * (v7.1 and newer) added a CFG_EXT register and shuffled a few fields around. > + */ > +enum { > + CFG_BLK_ADR_BYTES_SHIFT = 8, > + CFG_COL_ADR_BYTES_SHIFT = 12, > + CFG_FUL_ADR_BYTES_SHIFT = 16, > + CFG_BUS_WIDTH_SHIFT = 23, > + CFG_BUS_WIDTH = > BIT(CFG_BUS_WIDTH_SHIFT), > + CFG_DEVICE_SIZE_SHIFT = 24, > + > + /* Only for pre-v7.1 (with no CFG_EXT register) */ > + CFG_PAGE_SIZE_SHIFT = 20, > + CFG_BLK_SIZE_SHIFT = 28, > + > + /* Only for v7.1+ (with CFG_EXT register) */ > + CFG_EXT_PAGE_SIZE_SHIFT = 0, > + CFG_EXT_BLK_SIZE_SHIFT = 4, > +}; > + > /* BRCMNAND_INTFC_STATUS */ > enum { > INTFC_FLASH_STATUS = GENMASK(7, 0), > @@ -1710,17 +1732,19 @@ static int brcmnand_set_cfg(struct brcmnand_host > *host, > } > device_size = fls64(cfg->device_size) - > fls64(BRCMNAND_MIN_DEVSIZE); > > - tmp = (cfg->blk_adr_bytes << 8) | > - (cfg->col_adr_bytes << 12) | > - (cfg->ful_adr_bytes << 16) | > - (!!(cfg->device_width == 16) << 23) | > - (device_size << 24); > + tmp = (cfg->blk_adr_bytes << CFG_BLK_ADR_BYTES_SHIFT) | > + (cfg->col_adr_bytes << CFG_BLK_ADR_BYTES_SHIFT) | > + (cfg->ful_adr_bytes << CFG_FUL_ADR_BYTES_SHIFT) | > + (!!(cfg->device_width == 16) << CFG_BUS_WIDTH_SHIFT) | > + (device_size << CFG_DEVICE_SIZE_SHIFT); > if (cfg_offs == cfg_ext_offs) { > - tmp |= (page_size << 20) | (block_size << 28); > + tmp |= (page_size << CFG_PAGE_SIZE_SHIFT) | > + (block_size << CFG_BLK_SIZE_SHIFT); > nand_writereg(ctrl, cfg_offs, tmp); > } else { > nand_writereg(ctrl, cfg_offs, tmp); > - tmp = page_size | (block_size << 4); > + tmp = (page_size << CFG_EXT_PAGE_SIZE_SHIFT) | > + (block_size << CFG_EXT_BLK_SIZE_SHIFT); > nand_writereg(ctrl, cfg_ext_offs, tmp); > } Your patch looks good to me. I will base this patch upon your patch and test it at my end. I will send a revised patchset which will include your patch (preserving your authorship) and tested on NS2 SVK. Thanks, Anup -- 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
