i.MX ProcessorsのトピックRe: Access SPI eeprom from u-boot

Access SPI eeprom from u-boot

jemish_1990 — Wed, 06 Apr 2016 05:48:21 GMT

Hi All,

We are using imx6q based customize board for our product. In our board we have SPI EEPORM (Part number :25AA010A). We are able to operate SPI EEPROM from kernel space. We don't have any issue.

Now we want to use same SPI EEPROM from u-boot level. I tried to to access it using "sspi" command on u-boot but didn't succeed. Every time I got below error :

sspi [<bus>:]<cs>[.<mode>] <bit_len> <dout> - Send and receive bits

<bus> - Identifies the SPI bus

<cs> - Identifies the chip select

<mode> - Identifies the SPI mode to use

<bit_len> - Number of bits to send (base 10)

<dout> - Hexadecimal string that gets sent

=> sspi 1:0.0 8 3

pre_div = 14, post_div=2

reg_ctrl = 0xe2f1

reg_config = 0x0

spi_xchg_single: bitlen 8 dout 0x8ffa5044 din 0x8ffa5064

Sending SPI 0x30

spi_xchg_single: Timeout!

Error -5 during SPI transaction

Here I have two concerns why it is showing 0x30 even though I write 3 only.

Doesn't matter whatever I write it always shows timeout error.

Can we use this utility as reference to read/write spi eeprom?

I would appreciate if anyone can suggest any other reference code that we can use.

Has any one previously use SPI from u-boot to access SPI slave?

Any suggestion or pointers would be appreciated.

As we have produce demo on 12th April 2016 this is bit crucial for us.

Thanks,

Jemish

Re: Access SPI eeprom from u-boot

igorpadykov — Wed, 06 Apr 2016 07:53:40 GMT

Hi Jemish

seems sspi is not working with i.MX as also noted on

https://community.freescale.com/thread/316920

One can use similar codes as for spi-nor, which is supported on

Sabre schematic spf-27392. spi-nor pin definitions are defined in

in ..board/freescale/mx6sabresd/mx6sabresd.c

Supported parts (spi-nor ID) in ..drivers/mtd/spi/sf_params.c

Use uboot command : sf probe, read, write, erase

Best regards

igor

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Re: Access SPI eeprom from u-boot

jemish_1990 — Wed, 06 Apr 2016 09:20:18 GMT

Hi Igor,

Thanks for you prompt response!

I tried to use sf probe utility.

I would like to know is there any hardcoding in u-boot related to SPI bus 0.

With "sspi" and "sf" commands I am not getting any error if I have give bus : 0 as an argument.

If I give bus : 1 as an argument I am getting timeout error.

Consider output of below two commands:

=> sf probe 1:0 1000000 0

spi_xchg_single: Timeout!

SF: Failed to get idcodes

Failed to initialize SPI flash at 1:0

=> sf probe 0:0 1000000 0

SF: Unsupported flash IDs: manuf 00, jedec 0000, ext_jedec 0000

Failed to initialize SPI flash at 0:0

Now interesting thing is that we don't have connected anything on SPI bus 0 (No pin mux setting for SPI0). We have SPI EEPROM on SPI bus 1.

Still if you look at the output of above two commands , when I use SPI bus 0 it don't give any timeout error.

If I give bus : 1 it is still giving timeout error.

Can you point out what is going wrong here? Same was the case with sspi command.

Thanks,

Jemish

Re: Access SPI eeprom from u-boot

igorpadykov — Wed, 06 Apr 2016 10:23:32 GMT

Hi Jemish

suggest to make debugging with oscilloscope and driver code in

..drivers/mtd/spi/sf_probe.c

~igor