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

From: Marek Vasut
Date: Wed Apr 19 2017 - 04:48:37 EST

On 04/19/2017 04:58 AM, Andrey Smirnov wrote:
> 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.

OK

>>> + 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.

I think that's a good idea and you can make the mask u32 instead of u64.
But isn't eid_mask_inverted the same as id_mask ?

--
Best regards,
Marek Vasut