Linux/AM5728: LISA map configuration

Prasad

Intellectual 405 points

Part Number: AM5728
Other Parts Discussed in Thread: DRA752

Tool/software: Linux

Hi,

We are using PSDK 02.00.00.00 (Linux) on AM5728 based custom board similar to AM5728 GP EVM.

The LISA map configuration for GP EVM (in arch/arm/cpu/armv7/omap5/sdram.c) is

/*
* DRA752 EVM board has 1.5 GB of memory
* EMIF1 --> 2Gb * 2 = 512MB
* EMIF2 --> 2Gb * 4 = 1GB
* so mapping 1GB interleaved and 512MB non-interleaved
*/
const struct dmm_lisa_map_regs lisa_map_2G_x_2_x_2_2G_x_1_x_2 = {
.dmm_lisa_map_0 = 0x0,
.dmm_lisa_map_1 = 0x80640300,
.dmm_lisa_map_2 = 0xC0500220,
.dmm_lisa_map_3 = 0xFF020100,
.is_ma_present = 0x1
};

Why is the dmm_lisa_map_3 register configured to 0xFF020100?

Can I reconfigure the LISA MAP registers as

const struct dmm_lisa_map_regs lisa_map_2G_x_2_x_2_2G_x_1_x_2 = {
.dmm_lisa_map_0 = 0x0,
.dmm_lisa_map_1 = 0x0,
.dmm_lisa_map_2 = 0x80640300,
.dmm_lisa_map_3 = 0xC0500220,
.is_ma_present = 0x1
};

What is the difference between the above two configurations? Which one of these should be used?

Regards,

Prasad.

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

The software team have been notified. They will respond here.

0 Prasad over 8 years ago in reply to Biser Gatchev-XID

Intellectual 405 points

Hi Biser,

Any updates on the query?

Regards,
Prasad.

0 Yordan Kovachev over 8 years ago in reply to Prasad

TI__Guru**** 161600 points

Hi Prasad,

These are use case dependent.
For example the value 0xFF020100 means that you have your ddr mapped on EMIF1 only (not interleaved), DMM system section size for view mapping i is 16 MB.

As for your question, if the calculated value matches your use case, then yes, you can reconfigure the dmm lisa maps.

Best Regards,
Yordan

0 Prasad over 8 years ago in reply to Yordan Kovachev

Intellectual 405 points

Thanks Yordan,

We understand that "0xFF020100 means that you have your ddr mapped on EMIF1 only (not interleaved)".

Our query is, since the total DDR memory is 1.5GB (0x80000000 - 0xE0000000)
In the first set of LISA MAP (in PSDK 02.00.00.00)
dmm_lisa_map_1 configures the region -> 0x80000000 - 0xC0000000 (1GB)
dmm_lisa_map_2 configures the region -> 0xC0000000 - 0xE0000000 (0.5GB)
But dmm_lisa_map_3 configures the region -> 0xFF000000 - 0xFFFFFFFF (16 MB)
The last 16 MB doesn't physical exist, but still mapped. Why is the non-existent memory mapped?

Regards,
Prasad.

0 Prasad over 8 years ago in reply to Prasad

Intellectual 405 points

Hi Yordan,

Can you please comment on the above query?

Regards,
Prasad.

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Linux/AM5728: LISA map configuration