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SubjectRe: [PATCH linux-next v6 1/8] mtd: spi-nor: read JEDEC ID with multiple I/O protocols
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Hi Marek,

Le 09/09/2015 15:59, Marek Vasut a écrit :
> On Wednesday, September 09, 2015 at 03:24:11 PM, Cyrille Pitchen 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@atmel.com>
>> ---
>> 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;
>> +
>> + 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);
>> + if (tmp < 0) {
>> + dev_dbg(nor->dev,
>> + " error %d reading JEDEC ID (MULTI IO)\n", tmp);
>
> Don't you have one space too much in front of the " error" ?
>

Probably, I've just copied and pasted the dev_dbg() message few lines above when
the regular SPINOR_OP_RDID fails, then appended the "(MULTI IO)" string to make
think consistent but I don't mind removing the leading space.

tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
if (tmp < 0) {
dev_dbg(nor->dev, " error %d reading JEDEC ID\n", tmp);
return ERR_PTR(tmp);
}

>> + return ERR_PTR(tmp);
>> + }
>> + }
>> +
>> for (tmp = 0; tmp < ARRAY_SIZE(spi_nor_ids) - 1; tmp++) {
>> info = &spi_nor_ids[tmp];
>> if (info->id_len) {
>
> [...]
>

Best Regards,

Cyrille


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