Re: [PATCH V3] mtd: rawnand: qcom: update last code word register
From: mdalam
Date: Fri Jan 29 2021 - 00:06:25 EST
On 2021-01-29 03:41, Miquel Raynal wrote:
Hello,
mdalam@xxxxxxxxxxxxxx wrote on Fri, 29 Jan 2021 03:18:46 +0530:
On 2021-01-14 21:23, Miquel Raynal wrote:
> Hello,
>
> Md Sadre Alam <mdalam@xxxxxxxxxxxxxx> wrote on Sun, 10 Jan 2021
> 09:31:45 +0530:
>
>> From QPIC version 2.0 onwards new register got added to
>
> a
>
>> read last codeword. This change will update the same.
>
> the? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Please reword this sentence.
Fixed this in V4 patch.
>
>> For first three code word READ_LOCATION_n register will be
>> use.For last code word READ_LOCATION_LAST_CW_n register will be
>> use.
>
> "For the first three codewords, READ_LOCATION_n registers will be used.
> The last codeword register will be accessed through
> READ_LOCATION_LAST_CW_n."
>
> Also, please specify what these registers store.
The location register is mainly use for reading controller
buffer via BAM mode. The bits of the register
"NAND_READ_LOCATION_LAST_CW_n, n=0..4"
as follow:
Perhaps what I do not understand is: when is this "last_cw" register
more useful than the previous set?
From QPIC Version 2.0 onwards it is mandatory to use
"NAND_READ_LOCATION_LAST_CW_n, n=0..4"
register to extract last code word data from controller buffer. Using
register "NAND_READ_LOCATION_n, n=0..4"
we can extract all code words except last code word.
[9:0]-bits : (OFFSET) This bit defines the offset from the buffer
base address to be picked up for DMA.
[25:16]-bits: (SIZE) This bit of every register will define the
size of the chunk for DMA.
31-bit : (LAST) If this bit is set, the controller takes the
particular register to specify the last chunk
of data made available for DMA. This chunk is
part of the internal buffer of the controller.
>
Thanks,
Miquèl