[U-Boot] [UBOOT][PATCHv4 6/6] README: qspi usecase and testing documentation.

[Jagan Teki]

May be your are missing my comments in previous post.
- Please place these these readme files in doc/SPI/*
- Please use the doc/SPI/status.txt as an example format for writing
new readme files.

On Sat, Oct 5, 2013 at 1:15 AM, Sourav Poddar <sourav.poddar at ti.com> wrote:
> On Saturday 05 October 2013 12:08 AM, Jagan Teki wrote:
>>
>> Hi Sourav,
>>
>> Please place these these readme files in doc/SPI/*
>> All these patches tested on top of u-boot-spi.git master-probe?
>
> Yes, this are tested on the above branch.
>
>> On Fri, Oct 4, 2013 at 8:21 PM, Sourav Poddar<sourav.poddar at ti.com>
>> wrote:
>>>
>>> Contains documentation and testing details for qspi flash
>>> interface.
>>>
>>> Signed-off-by: Sourav Poddar<sourav.poddar at ti.com>
>>> ---
>>>   doc/README.ti_qspi_dra_test |   38 ++++++++++++++++++++++++++++++++++
>>>   doc/README.ti_qspi_flash    |   47
>>> +++++++++++++++++++++++++++++++++++++++++++
>>>   2 files changed, 85 insertions(+), 0 deletions(-)
>>>   create mode 100644 doc/README.ti_qspi_dra_test
>>>   create mode 100644 doc/README.ti_qspi_flash
>>>
>>> diff --git a/doc/README.ti_qspi_dra_test b/doc/README.ti_qspi_dra_test
>>> new file mode 100644
>>> index 0000000..c4540ea
>>> --- /dev/null
>>> +++ b/doc/README.ti_qspi_dra_test
>>> @@ -0,0 +1,38 @@
>>> +-------------------------------------------------
>>> +   Simple steps used to test the QSPI at U-Boot
>>> +-------------------------------------------------
>>> +
>>> +For #1, build the patched U-Boot and load MLO/u-boot.img
>>> +
>>> +----------------------------------
>>> +Boot from another medium like MMC
>>> +----------------------------------
>>> +
>>> +DRA752 EVM # mmc dev 0
>>> +DRA752 EVM # fatload mmc 0 0x82000000 MLO
>>> +DRA752 EVM # fatload mmc 0 0x83000000 u-boot.img
>>> +
>>> +--------------------------------------------------
>>> +Commands to erase/write u-boot/mlo to flash device
>>> +--------------------------------------------------
>>> +
>>> +DRA752 EVM # sf probe 0
>>> +[should detect the S25FL256S serial flash device]
>>> +
>>> +DRA752 EVM # sf erase 0 10000
>>> +DRA752 EVM # sf erase 10000 10000
>>> +DRA752 EVM # sf erase 20000 10000
>>> +DRA752 EVM # sf erase 30000 10000
>>> +DRA752 EVM # sf erase 40000 10000
>>> +DRA752 EVM # sf erase 50000 10000
>>> +DRA752 EVM # sf erase 60000 10000
>>> +
>>> +DRA752 EVM # sf write 82000000 0 10000
>>> +DRA752 EVM # sf write 83000000 20000 70000
>>> +
>>
>> These test procedure steps were done in real hw.
>> Seems like written once, could be generic if you test these steps on
>> real hw  and palce the same
>> log here...
>>
>>> +For #2, set sysboot to QSPI-1 boot mode(SYSBOOT[5:0] = 100110) and power
>>> +on. ROM should find the GP header at offset 0 and load/execute SPL. SPL
>>> +then detects that ROM was in QSPI-1 mode (boot code 10) and attempts to
>>> +find a U-Boot image header at offset 0x20000 (set in the config file)
>>> +and proceeds to load that image using the U-Boot image payload
>>> offset/size
>>> +from the header. It will then start U-Boot.
>>> diff --git a/doc/README.ti_qspi_flash b/doc/README.ti_qspi_flash
>>> new file mode 100644
>>> index 0000000..1b86d01
>>> --- /dev/null
>>> +++ b/doc/README.ti_qspi_flash
>>> @@ -0,0 +1,47 @@
>>> +QSPI U-boot support
>>> +------------------
>>> +
>>> +Host processor is connected to serial flash device via qpsi
>>> +interface. QSPI is a kind of spi module that allows single,
>>> +dual and quad read access to external spi devices. The module
>>> +has a memory mapped interface which provide direct interface
>>> +for accessing data form external spi devices.
>>> +
>>> +The one QSPI in the device is primarily intended for fast booting
>>> +from Quad SPI flash devices.
>>> +
>>> +Usecase
>>> +-------
>>> +
>>> +MLO/u-boot.img will be flashed from SD/MMC to the flash device
>>> +using serial flash erase and write commands. Then, switch settings
>>> +will be changed to qspi boot. Then, the ROM code will read MLO
>>> +from the predefined location in the flash, where it was flashed and
>>> +execute it after storing it in SDRAM. Then, the MLO will read
>>> +u-boot.img from flash and execute it from SDRAM.
>>> +
>>> +SPI mode
>>> +-------
>>> +SPI mode uses mtd spi framework for transfer and reception of data.
>>> +Can be used in:
>>> +1. Normal mode: use single pin for transfers
>>> +2. Dual Mode: use two pins for transfers.
>>> +3. Quad mode: use four pin for transfer
>>> +
>>> +Memory mapped read mode
>>> +-----------------------
>>> +In this, SPI controller is configured using configuration port and then
>>> +controler is switched to memory mapped port for data read.
>>> +
>>> +Driver
>>> +------
>>> +drivers/qspi/ti_qspi.c
>>> +    - Newly created file which is responsible for configuring the
>>> +       qspi controller and also for providing the low level api which
>>> +       is responsible for transferring the datas from host controller
>>> +       to flash device and vice versa.
>>> +
>>> +Testing
>>> +-------
>>> +A seperated file named README.dra_qspi_test has been created which gives
>>> all the
>>> +details about the commands required to test qspi at u-boot level.
>>> --
>>> 1.7.1
>>>
>> Please use the doc/SPI/status.txt as an example format for writing new
>> readme files.
>>
>



-- 
Thanks,
Jagan.
--------
Jagannadha Sutradharudu Teki,
E: jagannadh.teki at gmail.com, P: +91-9676773388
Engineer - System Software Hacker
U-boot - SPI Custodian and Zynq APSOC
Ln: http://www.linkedin.com/in/jaganteki