MRAM Issue in T4240RDB

[bhagathchandar]

HI,

            In T4240 RDB we are facing the MRAM access issue. we have compiled and ported the Kernel, Filesystem and DTB from the SDK package. When kernel is booting, the below error message is displayed

[ 2.445961] fsl_erandom: nonblocking pool is initialized100008
[ 2.455177] m25p80 spi32766.0: unrecognized JEDEC id bytes: ff, ff, ff
[ 2.465620] fsl_espi ffe110000.spi: at 0x8000080080bce000 (irq = 53)

. How to resolve this issue and how to access the MRAM (Read/Write in kernel) ?#

Thanks in Advance.

[Pavel]

Look at the Chapter 14 of NXP SDK 2.0-1703 documentation:

https://www.nxp.com/docs/en/supporting-information/QORIQ-SDK-2.0-IC-REV0.pdf

This Chapter contains information about using eSPI under Linux.

Have a great day,
Pavel Chubakov

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[bhagathchandar]

Hi Pavel,

We have followed the as per the procedure provided in the docment -QorIQ SDK v2.0-1703 Documentation,section - 7.15 . But during Kernel Booting we are getting the bellow,

fsl_espi ffe110000.spi: cs=0, init_csmode=0x100008
m25p80 spi32766.0: unrecognized JEDEC id bytes: 00, 00, 00

We have tried to access the MRAM in Kernel. But the CS is not getting asserted during MRAM Access as per the steps provided in the QorIQ SDK v2.0-1703 Documentation,section - 7.15. 

We are using MR25H40 Everspin IC. About our MRAM in DTS,

spi@110000 {
flash@0 {
#address-cells = <1>;
#size-cells = <1>;
compatible = "m25p80";
reg = <0>;
spi-max-frequency = <40000000>;
};
};

 Any Solution to solve the Issue?

Steps to configure and access the MRAM in Kernel?

[bhagathchandar]

Hi,

Still we are stuck at this issue. Can Any suggestion or idea to resolve this issue?