[PATCH v11 3/3] mtd: spi-nor: spansion: Add s25hl-t/s25hs-t IDs and fixups

Tue Apr 19 23:58:50 PDT 2022

On 4/20/2022 3:11 PM, Tudor.Ambarus at microchip.com wrote:
> On 4/20/22 08:34, Takahiro Kuwano wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> Hi Tudor,
>>
>> Thank you for your feedback.
>>
>> On 4/19/2022 6:32 PM, Tudor.Ambarus at microchip.com wrote:
>>> On 4/18/22 08:41, tkuw584924 at gmail.com wrote:
>>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>>
>>>> From: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
>>>>
>>>> The S25HL-T/S25HS-T family is the Infineon SEMPER Flash with Quad SPI.
>>>>
>>>> For the single-die package parts (512Mb and 1Gb), only bottom 4KB and
>>>> uniform sector sizes are supported. This is due to missing or incorrect
>>>> entries in SMPT. Fixup for other sector sizes configurations will be
>>>> followed up as needed.
>>>>
>>>> Tested on Xilinx Zynq-7000 FPGA board.
>>>>
>>>> Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
>>>> ---
>>>> Changes in v11:
>>>>   - Cleanup fixups based on other patches in this series
>>>>
>>>> Changes in v10:
>>>>   - Cleanup fixups and ID table based on other patches in this series
>>>>
>>>> Changes in v9:
>>>>   - Use late_init() hook to fix mode clocks and writesize
>>>>   - Use PARSE_SFDP instead of NO_SFDP_FLAGS
>>>>   - Use MFR_FLAGS for USE_CLSR
>>>>   - Add comment block to explain about addr mode in post_bfpt_fixups()
>>>>
>>>> Changes in v8:
>>>>   - Call write_disable in error case only
>>>>   - Use spi_nor_read_reg() helper
>>>>   - Use nor->bouncebuf instead of variable on stack
>>>>   - Update ID table to use FLAGS macro
>>>>
>>>> Changes in v7:
>>>>   - Add missing device info table in v6
>>>>
>>>> Changes in v6:
>>>>   - Remove 2Gb multi die pacakge support
>>>>
>>>> Changes in v5:
>>>>   - Add NO_CHIP_ERASE flag to S25HL02GT and S25HS02GT
>>>>
>>>> Changes in v4:
>>>>   - Merge block comments about SMPT in s25hx_t_post_sfdp_fixups()
>>>>   - Remove USE_CLSR flags from S25HL02GT and S25HS02GT
>>>>
>>>> Changes in v3:
>>>>   - Remove S25HL256T and S25HS256T
>>>>   - Add S25HL02GT and S25HS02GT
>>>>   - Add support for multi-die package parts support
>>>>   - Remove erase_map fix for top/split sector layout
>>>>   - Set ECC data unit size (16B) to writesize
>>>>
>>>>  drivers/mtd/spi-nor/spansion.c | 54 ++++++++++++++++++++++++++++++++++
>>>>  1 file changed, 54 insertions(+)
>>>>
>>>> diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
>>>> index 493240ebfd70..dd37b829efbc 100644
>>>> --- a/drivers/mtd/spi-nor/spansion.c
>>>> +++ b/drivers/mtd/spi-nor/spansion.c
>>>> @@ -208,6 +208,44 @@ static int cypress_nor_set_page_size(struct spi_nor *nor, u8 addr_width)
>>>>         return 0;
>>>>  }
>>>>
>>>> +static int
>>>> +s25hx_t_post_bfpt_fixups(struct spi_nor *nor,
>>>> +                        const struct sfdp_parameter_header *bfpt_header,
>>>> +                        const struct sfdp_bfpt *bfpt)
>>>> +{
>>>> +       int ret;
>>>> +
>>>> +       /*
>>>> +        * From BFPT, the nor->addr_width is set to 3. In Read Any Reg op, the
>>>> +        * Flash takes 3-byte or 4-byte addr depending current addr mode. Since
>>>> +        * Read Any Reg op is called in this hook and SMPT parse, we would sync
>>>
>>> Hi, Takahiro,
>>>
>>> I would like some details, please.
>>> 1/ with "this hook" you refer to cypress_nor_set_page_size(). Why can't you use a
>>> addr_width of value 3 when reading SPINOR_REG_CYPRESS_CFR3V?
>>>
>> If we are sure that the Flash is in 3-byte address mode, we can use the value 3
>> for reading CFR3V. However, the Flash's address mode may be changed prior to
>> Linux MTD probe in some use cases. Actually, in u-boot, it is set to 4-byte
>> address mode. We need to set the Flash's address mode in known state and update
> 
> addr_width is set via CFR2Volatile, can we reset the flash at probe instead? Then
> you'll be sure that the flash is in its default state.
> 
Resetting the Flash to revert back to default state should work for this. However,
we still have SMPT issue below.

>> nor->addr_width accordingly. Due to SMPT issue below, value of 4 would be better
>> choice.
>>
>>> 2/ Where in SMPT parse? I looked through the code and couldn't find the Read Any
>>> Reg op used. Why do you need an addr_width of value 4 in SMPT parse?
>>>
>> In the spi_nor_get_map_in_use(), the nor->read_opcode is set to 0x65 (=Read Any Reg).
>> The spi_nor_smpt_addr_width() returns the value of the nor->addr_width due to
> 
> ok
> 
>> SMPT_CMD_ADDRESS_LEN_USE_CURRENT. The nor->addr_width is set to 4 in the
>> spi_nor_parse_4bait() before SMPT parse. Therefore, the host issues Read Any Reg
> 
> if 4bait is parsed before SMPT and nor->addr_width is already set to 4 in parse_4bait,
> then you don't have to do anything for SMPT, right?
> 
Currently 4bait is parsed before SMPT. So, if we are sure the Flash is in 4-byte address
mode (by u-boot, for example), we don't have to do anything. If the Flash is in 3-byte
address mode (default), SMPT parse does not work correctly.

Please see this about 4BAIT and SMPT issue.
https://patchwork.ozlabs.org/project/linux-mtd/patch/20201212115817.5122-1-vigneshr@ti.com/

I introduced another workaround for SMPT issue in my previous series.
https://patchwork.ozlabs.org/project/linux-mtd/patch/9a2d323b2c18485d13f271e3bb213b96fea0e7e1.1649641729.git.Takahiro.Kuwano@infineon.com/
I withdrew this because this does not work if Flash address mode is not default state.
But if we can reset the Flash at probe, this should work.

>> with 4-byte address. We need to set the Flash into 4-byte address mode in advance.
>>
>>>
>>>> +        * Flash's addr mode and nor->addr_width here.
>>>> +        */
>>>> +       ret = spi_nor_set_4byte_addr_mode(nor, true);
>>>> +       if (ret)
>>>> +               return ret;
>>>> +       nor->addr_width = 4;
>>>> +
>>>> +       /* Replace Quad Enable with volatile version */
>>>> +       nor->params->quad_enable = cypress_nor_quad_enable_volatile;
>>>> +
>>>> +       return cypress_nor_set_page_size(nor, nor->addr_width);
>>>> +}
>>>> +
>>>> +void s25hx_t_late_init(struct spi_nor *nor)
>>>> +{
>>>> +       /* Fast Read 4B requires mode cycles */
>>>> +       nor->params->reads[SNOR_CMD_READ_FAST].num_mode_clocks = 8;
>>>
>>> Isn't this info already handled in BFPT? What value of num_mode_clocks
>>> do you obtain from BFPT for the non-4B opcode?
>>>
>> There is no parameter in BFPT that describes about Fast Read 1-1-1 op
>> (as we can see 'struct sfdp_bfpt_read' in sfdp.c).
>> The value of num_mode_clocks for Fast Read 1-1-1 is set to 0 in
>> spi_nor_init_default_params().
>>
> 
> I see, thanks!

Thanks,
Takahiro