From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.free-electrons.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1c6EEx-000319-5x for linux-mtd@lists.infradead.org; Mon, 14 Nov 2016 10:11:52 +0000 Date: Mon, 14 Nov 2016 11:11:22 +0100 From: Boris Brezillon To: Marc Gonzalez Cc: Richard Weinberger , linux-mtd , Mason , Sebastian Frias Subject: Re: [PATCH] mtd: nand: Support controllers with custom page accessors Message-ID: <20161114111122.27804c4e@bbrezillon> In-Reply-To: <5829883A.8080307@sigmadesigns.com> References: <5829883A.8080307@sigmadesigns.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Marc, On Mon, 14 Nov 2016 10:47:38 +0100 Marc Gonzalez wrote: > If your controller already sends the required NAND commands when > reading or writing a page, then the framework is not supposed to > send READ0 and SEQIN/PAGEPROG respectively. > > Signed-off-by: Marc Gonzalez > --- > drivers/mtd/nand/nand_base.c | 31 ++++++++++++++++++++++++++++--- > drivers/mtd/nand/tango_nand.c | 21 ++++++++++++--------- > include/linux/mtd/nand.h | 12 ++++++++++++ > 3 files changed, 52 insertions(+), 12 deletions(-) > > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > index 50cdf37cb8e4..b8ea6b397c16 100644 > --- a/drivers/mtd/nand/nand_base.c > +++ b/drivers/mtd/nand/nand_base.c > @@ -1970,7 +1970,8 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from, > __func__, buf); > > read_retry: > - chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page); > + if (nand_default_page_accessors(&chip->ecc)) > + chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page); > > /* > * Now read the page into the buffer. Absent an error, > @@ -2658,7 +2659,8 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip, > else > subpage = 0; > > - chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page); > + if (nand_default_page_accessors(&chip->ecc)) > + chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page); > > if (unlikely(raw)) > status = chip->ecc.write_page_raw(mtd, chip, buf, > @@ -2681,7 +2683,8 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip, > > if (!cached || !NAND_HAS_CACHEPROG(chip)) { > > - chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1); > + if (nand_default_page_accessors(&chip->ecc)) > + chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1); > status = chip->waitfunc(mtd, chip); > /* > * See if operation failed and additional status checks are > @@ -4539,6 +4542,25 @@ static bool nand_ecc_strength_good(struct mtd_info *mtd) > return corr >= ds_corr && ecc->strength >= chip->ecc_strength_ds; > } > > +static bool invalid_ecc_page_accessors(struct nand_chip *chip) > +{ > + struct nand_ecc_ctrl *ecc = &chip->ecc; > + > + if (nand_default_page_accessors(ecc)) > + return false; > + > + /* > + * NAND_ECC_CUSTOM_PAGE_ACCESS flag is set, make sure the NAND > + * controller driver implements all the page accessors because > + * default helpers are not suitable when the core does not > + * send the READ0/PAGEPROG commands. > + */ > + return (!ecc->read_page || !ecc->write_page || > + !ecc->read_page_raw || !ecc->write_page_raw || > + (NAND_HAS_SUBPAGE_READ(chip) && !ecc->read_subpage) || > + (NAND_HAS_SUBPAGE_WRITE(chip) && !ecc->write_subpage)); > +} > + > /** > * nand_scan_tail - [NAND Interface] Scan for the NAND device > * @mtd: MTD device structure > @@ -4559,6 +4581,9 @@ int nand_scan_tail(struct mtd_info *mtd) > !(chip->bbt_options & NAND_BBT_USE_FLASH))) > return -EINVAL; > > + if (WARN_ON(invalid_ecc_page_accessors(chip))) > + return -EINVAL; > + > if (!(chip->options & NAND_OWN_BUFFERS)) { > nbuf = kzalloc(sizeof(*nbuf) + mtd->writesize > + mtd->oobsize * 3, GFP_KERNEL); > diff --git a/drivers/mtd/nand/tango_nand.c b/drivers/mtd/nand/tango_nand.c > index fd8cf414cb2b..7ed35348993e 100644 > --- a/drivers/mtd/nand/tango_nand.c > +++ b/drivers/mtd/nand/tango_nand.c > @@ -343,7 +343,7 @@ static void aux_write(struct nand_chip *chip, const u8 **buf, int len, int *pos) > * buf = | PKT_0 | ... | PKT_N | > * +-----------------+-----+-----------------+ > */ > -static int raw_read(struct nand_chip *chip, u8 *buf, u8 *oob) > +static void raw_read(struct nand_chip *chip, u8 *buf, u8 *oob) This change is completely unrelated to the custom page accessors patch. Please separate the function prototype changes in a separate patch. > { > u8 *oob_orig = oob; > const int page_size = chip->mtd.writesize; > @@ -367,11 +367,9 @@ static int raw_read(struct nand_chip *chip, u8 *buf, u8 *oob) > aux_read(chip, &oob_orig, BBM_SIZE, &pos); > aux_read(chip, &buf, pkt_size - rem, &pos); > aux_read(chip, &oob, ecc_size, &pos); > - > - return 0; > } > > -static int raw_write(struct nand_chip *chip, const u8 *buf, const u8 *oob) > +static void raw_write(struct nand_chip *chip, const u8 *buf, const u8 * > { > const u8 *oob_orig = oob; > const int page_size = chip->mtd.writesize; > @@ -395,27 +393,31 @@ static int raw_write(struct nand_chip *chip, const u8 *buf, const u8 *oob) > aux_write(chip, &oob_orig, BBM_SIZE, &pos); > aux_write(chip, &buf, pkt_size - rem, &pos); > aux_write(chip, &oob, ecc_size, &pos); > - > - return 0; > } > > static int tango_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip, > u8 *buf, int oob_required, int page) > { > - return raw_read(chip, buf, chip->oob_poi); > + chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page); > + raw_read(chip, buf, chip->oob_poi); > + return 0; > } > > static int tango_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip, > const u8 *buf, int oob_required, int page) > { > - return raw_write(chip, buf, chip->oob_poi); > + chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0, page); > + raw_write(chip, buf, chip->oob_poi); > + chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1); > + return 0; > } > > static int tango_read_oob(struct mtd_info *mtd, struct nand_chip *chip, > int page) > { > chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page); > - return raw_read(chip, NULL, chip->oob_poi); > + raw_read(chip, NULL, chip->oob_poi); > + return 0; > } > > static int tango_write_oob(struct mtd_info *mtd, struct nand_chip *chip, > @@ -553,6 +555,7 @@ static int chip_init(struct device *dev, struct device_node *np) > ecc->write_page = tango_write_page; > ecc->read_oob = tango_read_oob; > ecc->write_oob = tango_write_oob; > + ecc->options = NAND_ECC_CUSTOM_PAGE_ACCESS; > > err = nand_scan_tail(mtd); > if (err) > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > index 06d0c9d740f7..a95a27a30005 100644 > --- a/include/linux/mtd/nand.h > +++ b/include/linux/mtd/nand.h > @@ -142,6 +142,12 @@ enum nand_ecc_algo { > */ > #define NAND_ECC_GENERIC_ERASED_CHECK BIT(0) > #define NAND_ECC_MAXIMIZE BIT(1) > +/* > + * If your controller already sends the required NAND commands when > + * reading or writing a page, then the framework is not supposed to > + * send READ0 and SEQIN/PAGEPROG respectively. > + */ > +#define NAND_ECC_CUSTOM_PAGE_ACCESS BIT(2) > > /* Bit mask for flags passed to do_nand_read_ecc */ > #define NAND_GET_DEVICE 0x80 > @@ -186,6 +192,7 @@ enum nand_ecc_algo { > /* Macros to identify the above */ > #define NAND_HAS_CACHEPROG(chip) ((chip->options & NAND_CACHEPRG)) > #define NAND_HAS_SUBPAGE_READ(chip) ((chip->options & NAND_SUBPAGE_READ)) > +#define NAND_HAS_SUBPAGE_WRITE(chip) !(chip->options & NAND_NO_SUBPAGE_WRITE) (chip)->options Just in case the chip parameter is something like that &x->chip. > > /* Non chip related options */ > /* This option skips the bbt scan during initialization. */ > @@ -568,6 +575,11 @@ struct nand_ecc_ctrl { > int page); > }; > > +static inline int nand_default_page_accessors(struct nand_ecc_ctrl *ecc) Not sure the term default is correct here: some drivers implement their own ->read/write_page() methods, but expect the core to send the READ/PROG commands. How about renaming it nand_standard_page_accessors()? > +{ > + return !(ecc->options & NAND_ECC_CUSTOM_PAGE_ACCESS); > +} > + > /** > * struct nand_buffers - buffer structure for read/write > * @ecccalc: buffer pointer for calculated ECC, size is oobsize.