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

From: Andrey Smirnov
Date: Tue Apr 18 2017 - 22:59:08 EST

On Tue, Apr 18, 2017 at 11:31 AM, Marek Vasut <marek.vasut@xxxxxxxxx> 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@xxxxxxxxx
>> Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
>> Cc: Brian Norris <computersforpeace@xxxxxxxxx>
>> Cc: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
>> Cc: Marek Vasut <marek.vasut@xxxxxxxxx>
>> Cc: Richard Weinberger <richard@xxxxxx>
>> Cc: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
>> Cc: linux-kernel@xxxxxxxxxxxxxxx
>> Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
>> ---
>>
>> Changes since [v1]:
>>
>> - Formatting
>>
>> [v1] http://lkml.kernel.org/r/20170411161722.11164-1-andrew.smirnov@xxxxxxxxx
>>
>>
>> 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