[PATCH v2 3/3] mtd: dataflash: Make use of "extened device information"

Andrey Smirnov andrew.smirnov at gmail.com
Tue Apr 18 19:58:49 PDT 2017


On Tue, Apr 18, 2017 at 11:31 AM, Marek Vasut <marek.vasut at gmail.com> wrote:
> On 04/18/2017 04:21 PM, Andrey Smirnov wrote:
>> In anticipation of supporting chips that need it, extend the size of
>> struct flash_info's 'jedec_id' field to make room 2 byte of extended
>> device information as well as add code to fetch this data during
>> jedec_probe().
>>
>> Cc: cphealy at gmail.com
>> Cc: David Woodhouse <dwmw2 at infradead.org>
>> Cc: Brian Norris <computersforpeace at gmail.com>
>> Cc: Boris Brezillon <boris.brezillon at free-electrons.com>
>> Cc: Marek Vasut <marek.vasut at gmail.com>
>> Cc: Richard Weinberger <richard at nod.at>
>> Cc: Cyrille Pitchen <cyrille.pitchen at atmel.com>
>> Cc: linux-kernel at vger.kernel.org
>> Signed-off-by: Andrey Smirnov <andrew.smirnov at gmail.com>
>> ---
>>
>> Changes since [v1]:
>>
>>       - Formatting
>>
>> [v1] http://lkml.kernel.org/r/20170411161722.11164-1-andrew.smirnov@gmail.com
>>
>>
>>  drivers/mtd/devices/mtd_dataflash.c | 113 +++++++++++++++++++++---------------
>>  1 file changed, 65 insertions(+), 48 deletions(-)
>>
>> diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
>> index 5b7a8c3..5d694a4 100644
>> --- a/drivers/mtd/devices/mtd_dataflash.c
>> +++ b/drivers/mtd/devices/mtd_dataflash.c
>> @@ -690,7 +690,7 @@ struct flash_info {
>>       /* JEDEC id has a high byte of zero plus three data bytes:
>>        * the manufacturer id, then a two byte device id.
>>        */
>> -     u32             jedec_id;
>> +     u64             jedec_id;
>>
>>       /* The size listed here is what works with OP_ERASE_PAGE. */
>>       unsigned        nr_pages;
>> @@ -713,63 +713,34 @@ static struct flash_info dataflash_data[] = {
>>        * These newer chips also support 128-byte security registers (with
>>        * 64 bytes one-time-programmable) and software write-protection.
>>        */
>> -     { "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
>> -     { "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
>> +     { "AT45DB011B",  0x1f22000000, 512, 264, 9, SUP_POW2PS},
>> +     { "at45db011d",  0x1f22000000, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
>>
>> -     { "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
>> -     { "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
>> +     { "AT45DB021B",  0x1f23000000, 1024, 264, 9, SUP_POW2PS},
>> +     { "at45db021d",  0x1f23000000, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
>>
>> -     { "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
>> -     { "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
>> +     { "AT45DB041x",  0x1f24000000, 2048, 264, 9, SUP_POW2PS},
>> +     { "at45db041d",  0x1f24000000, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
>>
>> -     { "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
>> -     { "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
>> +     { "AT45DB081B",  0x1f25000000, 4096, 264, 9, SUP_POW2PS},
>> +     { "at45db081d",  0x1f25000000, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
>>
>> -     { "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
>> -     { "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
>> +     { "AT45DB161x",  0x1f26000000, 4096, 528, 10, SUP_POW2PS},
>> +     { "at45db161d",  0x1f26000000, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
>>
>> -     { "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},           /* rev C */
>> +     { "AT45DB321x",  0x1f27000000, 8192, 528, 10, 0},       /* rev C */
>>
>> -     { "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
>> -     { "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
>> +     { "AT45DB321x",  0x1f27010000, 8192, 528, 10, SUP_POW2PS},
>> +     { "at45db321d",  0x1f27010000, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
>>
>> -     { "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
>> -     { "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
>> +     { "AT45DB642x",  0x1f28000000, 8192, 1056, 11, SUP_POW2PS},
>> +     { "at45db642d",  0x1f28000000, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
>>  };
>>
>> -static struct flash_info *jedec_probe(struct spi_device *spi)
>> +static struct flash_info *jedec_lookup(struct spi_device *spi, u64 jedec)
>>  {
>> -     int ret, i;
>> -     u8 code = OP_READ_ID;
>> -     u8 id[3];
>> -     u32 jedec;
>> +     int status, i;
>>       struct flash_info *info;
>> -     int status;
>> -
>> -     /*
>> -      * JEDEC also defines an optional "extended device information"
>> -      * string for after vendor-specific data, after the three bytes
>> -      * we use here.  Supporting some chips might require using it.
>> -      *
>> -      * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
>> -      * That's not an error; only rev C and newer chips handle it, and
>> -      * only Atmel sells these chips.
>> -      */
>> -     ret = spi_write_then_read(spi, &code, 1, id, 3);
>> -     if (ret < 0) {
>> -             pr_debug("%s: error %d reading JEDEC ID\n",
>> -                     dev_name(&spi->dev), ret);
>> -             return ERR_PTR(ret);
>> -     }
>> -
>> -     if (id[0] != CFI_MFR_ATMEL)
>> -             return NULL;
>> -
>> -     jedec = id[0];
>> -     jedec = jedec << 8;
>> -     jedec |= id[1];
>> -     jedec = jedec << 8;
>> -     jedec |= id[2];
>
> Hm, the diff again screwed this up, oh well ...
>
>>       for (i = 0, info = dataflash_data;
>>                       i < ARRAY_SIZE(dataflash_data);
>> @@ -799,12 +770,58 @@ static struct flash_info *jedec_probe(struct spi_device *spi)
>>               }
>>       }
>>
>> +     return NULL;
>> +}
>> +
>> +static struct flash_info *jedec_probe(struct spi_device *spi)
>> +{
>> +     int ret;
>> +     u8 code = OP_READ_ID;
>> +     u8 id[8] = {0};
>> +     const unsigned int id_size = 5;
>> +     const unsigned int first_byte = sizeof(id) - id_size;
>> +     const u64 eid_mask = GENMASK_ULL(63, 16);
>> +     u64 jedec;
>> +     struct flash_info *info;
>> +
>> +     /*
>> +      * JEDEC also defines an optional "extended device information"
>> +      * string for after vendor-specific data, after the three bytes
>> +      * we use here.  Supporting some chips might require using it.
>> +      *
>> +      * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
>> +      * That's not an error; only rev C and newer chips handle it, and
>> +      * only Atmel sells these chips.
>> +      */
>> +     ret = spi_write_then_read(spi, &code, 1, &id[first_byte], id_size);
>> +     if (ret < 0) {
>> +             pr_debug("%s: error %d reading JEDEC ID\n",
>> +                     dev_name(&spi->dev), ret);
>
> I think you can turn this into:
>
> dev_err(&spi->dev, "error %d reading JEDEC ID\n", ret);

OK, will do it in a separate patch, since this is original code.

>
>> +             return ERR_PTR(ret);
>> +     }
>> +
>> +     if (id[first_byte] != CFI_MFR_ATMEL)
>> +             return NULL;
>> +
>> +     jedec = be64_to_cpup((__be64 *)id);
>> +
>> +     info = jedec_lookup(spi, jedec);
>> +     if (info)
>> +             return info;
>> +
>> +     /* Clear extended id bits and try to find a match again */
>> +     jedec &= eid_mask;
>
> Wouldn't that be jedec &= ~eid_mask; (with a tilde) if you want to clear
> them ?

eid_mask is generated as bits 63 to 16 with GENMASK_ULL, so bits 15 to
0 should already be zeroed out. I can rename it to eid_mask_inverted
so it's less confusing.

Thanks,
Andrey Smirnov



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