Messages in this thread | | | Date | Fri, 29 Jan 2021 10:35:12 +0530 | From | mdalam@codeauro ... | Subject | Re: [PATCH V3] mtd: rawnand: qcom: update last code word register |
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On 2021-01-29 03:41, Miquel Raynal wrote: > Hello, > > mdalam@codeaurora.org wrote on Fri, 29 Jan 2021 03:18:46 +0530: > >> On 2021-01-14 21:23, Miquel Raynal wrote: >> > Hello, >> > >> > Md Sadre Alam <mdalam@codeaurora.org> 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
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