[U-Boot] sf: Remove spansion_s25fss_disable_4KB_erase

[Jagan Teki]

Ping?

On Mon, Mar 20, 2017 at 9:42 PM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
> Hi,
>
> Let's start the discussion, if possible we may add linux-mtd ML.
>
> Here is the details: from attached pdf Page no:2
>
> In spansion S25FS-S family the physical sectors are grouped as
> normal and parameter sectors. Parameter sectors are 4kB in size
> with 8 set located at the bottom or top address of a device.
> Normal sectors are similar to other flash family with sizes of
> 64kB or 32 kB.
>
> Do we agree till this point?
>
> To erase whole flash using sector erase(D8h or DCh) won't effect
> the parameter sectors, so in order to erase these we must use 4K
> sector erase commands (20h or 21h) separately.
>
> So better to erase the whole flash using 4K sector erase instead
> of detecting these family parts again and do two different erase
> operations.
>
> On Tue, Dec 13, 2016 at 10:57 AM, Yao Yuan <yao.yuan at nxp.com> wrote:
>> Hi Jagan,
>>
>> Do you have any comments?
>>
>> Thanks for your work and you know it's important for QSPI with S25FS512S.
>>
>> It seems S25FS512S can't support the SECT_4K, right?
>> And it better to retain the disable_4kb, but we can add a flag in dts to select whether enable it.
>>
>> Best Regards,
>> Yao
>>
>> From: Yao Yuan
>> Sent: Wednesday, November 30, 2016 3:23 PM
>> To: 'Jagan Teki' <jagan at openedev.com>
>> Subject: sf: Remove spansion_s25fss_disable_4KB_erase
>>
>> Hi Jagan,
>>
>> I have noticed that you have a patch to:
>>
>> commit 116e005cfd00021424f5f81eeedd355e4ca72f07
>> Author: Jagan Teki <jagan at amarulasolutions.com<mailto:jagan at amarulasolutions.com>>
>> Date:   Tue Nov 15 22:57:42 2016 +0530
>>
>> - Removed spansion_s25fss_disable_4KB_erase code
>> - Add SECT_4K for S25FS512S chip
>>
>> Do you have any test for this patch?
>> Because with this patch, my QSPI driver can't working with S25FS512S.
>>
>> As you said,
>> In spansion S25FS-S family the physical sectors are grouped as normal and parameter sectors.
>> Parameter sectors are 4kB in size with 8 set located at the bottom or top address of a device.
>> Normal sectors are similar to other flash family with sizes of 64kB or 32 kB.
>>
>> Base on the RM and in my understand, not all the erase sectors are 4-kb.
>>
>> In my case regions are:
>>
>> 1. 0-32KiB (8*4KiB) - 4K_ERASE (0x20/0x21)
>>
>> 2. 32 - 256 - SE_CMD (0xd8/0xdc)
>>
>> 3. Rest of the flash SE_CMD (0xd8/0xdc)
>>
>> 4. To erase whole flash you can also use CHIP_ERASE_CMD
>>
>> (0x60/0xC7) command, you just need to add one more mtd
>>
>> partition that will cover whole flash.
>>
>> So we can't add SECT_4K for S25FS512S chip.
>> If we add SECT_4K for S25FS512S chip, that means all the erase sectors are 4-kb.
>> But I think it's not right.
>>
>> And disable 4kb is necessary for me, I also suggestion to add a flag to select whether enable 4-kb.
>>
>> if (of_property_read_bool(np, "spi-nor, disable-4kb")) {
>>
>>                 spansion_s25fs_disable_4kb_erase();
>>
>> }
>>
>> else
>>
>> ...
>>
>>
>>
>> In dts:
>>
>> &qspi {
>>
>> qflash0: s25fs512s at 0 {
>>
>> compatible = "spansion, s25fs512s";
>>
>>                 spi-nor, disable-4kb
>>
>> #address-cells = <1>;
>>
>> #size-cells = <1>;
>>
>> spi-max-frequency = <20000000>;
>>
>> reg = <0>;
>>
>> };
>>
>>
>> Attachment is the RM for S25FS-S.
>
> thanks!
> --
> Jagan Teki
> Free Software Engineer | www.openedev.com
> U-Boot, Linux | Upstream Maintainer
> Hyderabad, India.



-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.