Hi, On Wed, Sep 9, 2015 at 3:24 PM, Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx> wrote: > When their quad or dual I/O mode is enabled, Micron and Macronix spi-nor > memories don't reply to the regular Read ID (0x9f) command. Instead they > reply to a new dedicated command Read ID Multiple I/O (0xaf). > > If the Read ID (0x9f) command fails (the read ID is all 1's or all 0's), > then the Read ID Multiple I/O (0xaf) is used, first with SPI 4-4-4 protocol > (supported by both Micron and Macronix memories), lately with SPI-2-2-2 > protocol (supported only by Micron memories). > > Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx> > --- > drivers/mtd/spi-nor/spi-nor.c | 28 +++++++++++++++++++++++++++- > include/linux/mtd/spi-nor.h | 23 +++++++++++++++++++++-- > 2 files changed, 48 insertions(+), 3 deletions(-) > > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c > index f59aedfe1462..80a0db078aaa 100644 > --- a/drivers/mtd/spi-nor/spi-nor.c > +++ b/drivers/mtd/spi-nor/spi-nor.c > @@ -703,8 +703,9 @@ static const struct flash_info spi_nor_ids[] = { > > static const struct flash_info *spi_nor_read_id(struct spi_nor *nor) > { > - int tmp; > + int i, tmp; > u8 id[SPI_NOR_MAX_ID_LEN]; > + enum spi_protocol proto[2] = {SPI_PROTO_4_4_4, SPI_PROTO_2_2_2}; > const struct flash_info *info; > > tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN); > @@ -713,6 +714,25 @@ static const struct flash_info *spi_nor_read_id(struct spi_nor *nor) > return ERR_PTR(tmp); > } > > + /* Special case for Micron/Macronix qspi nor. */ > + for (i = 0; i < ARRAY_SIZE(proto); ++i) { > + if (!((id[0] == 0xff && id[1] == 0xff && id[2] == 0xff) || > + (id[0] == 0x00 && id[1] == 0x00 && id[2] == 0x00))) > + break; you should probably do something like if (proto == SPI_PROTO_2_2_2 && !(nor->flags & SPI_NOR_DUAL)) continue; if (proto == SPI_PROTO_4_4_4 && !(nor->flags & SPI_NOR_QUAD)) continue; > + > + nor->erase_proto = proto[i]; > + nor->read_proto = proto[i]; > + nor->write_proto = proto[i]; > + nor->reg_proto = proto[i]; > + tmp = nor->read_reg(nor, SPINOR_OP_MIO_RDID, > + id, SPI_NOR_MAX_ID_LEN); Not sure if it has any releveance that the MIO_RDID commands can only return the first three id bytes, and not the full id. > + if (tmp < 0) { > + dev_dbg(nor->dev, > + " error %d reading JEDEC ID (MULTI IO)\n", tmp); > + return ERR_PTR(tmp); Or continue here, as the controller might return an error if it does not support the protocol. > + } > + } > + > for (tmp = 0; tmp < ARRAY_SIZE(spi_nor_ids) - 1; tmp++) { > info = &spi_nor_ids[tmp]; > if (info->id_len) { > @@ -1013,6 +1033,12 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) > if (ret) > return ret; > > + /* Reset SPI protocol for all commands */ > + nor->erase_proto = SPI_PROTO_1_1_1; > + nor->read_proto = SPI_PROTO_1_1_1; > + nor->write_proto = SPI_PROTO_1_1_1; > + nor->reg_proto = SPI_PROTO_1_1_1; > + > if (name) > info = spi_nor_match_id(name); > /* Try to auto-detect if chip name wasn't specified or not found */ > diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h > index e5409524bb0a..66a5f144728a 100644 > --- a/include/linux/mtd/spi-nor.h > +++ b/include/linux/mtd/spi-nor.h > @@ -57,8 +57,9 @@ > #define SPINOR_OP_BRWR 0x17 /* Bank register write */ > > /* Used for Micron flashes only. */ > -#define SPINOR_OP_RD_EVCR 0x65 /* Read EVCR register */ > -#define SPINOR_OP_WD_EVCR 0x61 /* Write EVCR register */ > +#define SPINOR_OP_MIO_RDID 0xaf /* Multiple I/O Read JEDEC ID */ > +#define SPINOR_OP_RD_EVCR 0x65 /* Read EVCR register */ > +#define SPINOR_OP_WD_EVCR 0x61 /* Write EVCR register */ > > /* Status Register bits. */ > #define SR_WIP 1 /* Write in progress */ > @@ -87,6 +88,16 @@ enum read_mode { > SPI_NOR_QUAD, > }; > > +enum spi_protocol { > + SPI_PROTO_1_1_1, /* SPI */ > + SPI_PROTO_1_1_2, /* Dual Output */ > + SPI_PROTO_1_1_4, /* Quad Output */ > + SPI_PROTO_1_2_2, /* Dual IO */ > + SPI_PROTO_1_4_4, /* Quad IO */ > + SPI_PROTO_2_2_2, /* Dual Command */ > + SPI_PROTO_4_4_4, /* Quad Command */ > +}; I wonder if the spi-nor controller should somehow store which of these protocols it can support, so we can check for support before using any of the dual/quad (i/o) commands. Also I think you should split out the new readid command usage from the rest of the SPI_PROTO stuff, as they are only semirelated. And for good definsive programming, you should first make the spi-nor controller drivers aware of the protocol stuff before starting to use it, else you risk breaking controllers silently. > + > /** > * struct spi_nor_xfer_cfg - Structure for defining a Serial Flash transfer > * @wren: command for "Write Enable", or 0x00 for not required > @@ -142,6 +153,10 @@ enum spi_nor_option_flags { > * @sst_write_second: used by the SST write operation > * @flags: flag options for the current SPI-NOR (SNOR_F_*) > * @cfg: used by the read_xfer/write_xfer > + * @erase_proto: the SPI protocol used by erase operations > + * @read_proto: the SPI protocol used by read operations > + * @write_proto: the SPI protocol used by write operations > + * @reg_proto the SPI protocol used by read_reg/write_reg operations > * @cmd_buf: used by the write_reg > * @prepare: [OPTIONAL] do some preparations for the > * read/write/erase/lock/unlock operations > @@ -169,6 +184,10 @@ struct spi_nor { > u8 read_opcode; > u8 read_dummy; > u8 program_opcode; > + enum spi_protocol erase_proto; > + enum spi_protocol read_proto; > + enum spi_protocol write_proto; > + enum spi_protocol reg_proto; > enum read_mode flash_read; > bool sst_write_second; > u32 flags; Regards Jonas -- 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