Messages in this thread | | | Date | Wed, 28 Oct 2020 23:54:23 +0530 | From | mdalam@codeauro ... | Subject | Re: [PATCH 0/5] mtd: rawnand: qcom: Add support for QSPI nand |
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On 2020-10-28 15:18, Miquel Raynal wrote: > Hello, > > Md Sadre Alam <mdalam@codeaurora.org> wrote on Sat, 10 Oct 2020 > 11:01:37 +0530: > >> QPIC 2.0 supports Serial NAND support in addition to all features and >> commands in QPIC 1.0 for parallel NAND. Parallel and Serial NAND >> cannot >> operate simultaneously. QSPI nand devices will connect to QPIC >> IO_MACRO >> block of QPIC controller. There is a separate IO_MACRO clock for >> IO_MACRO >> block. Default IO_MACRO block divide the input clock by 4. so if >> IO_MACRO >> input clock is 320MHz then on bus it will be 80MHz, so QSPI nand >> device >> should also support this frequency. >> >> QPIC provides 4 data pins to QSPI nand. In standard SPI mode (x1 mode) >> data >> transfer will occur on only 2 pins one pin for Serial data in and one >> for >> serial data out. In QUAD SPI mode (x4 mode) data transfer will occur >> at all >> the four data lines. QPIC controller supports command for x1 mode and >> x4 mode. >> >> Md Sadre Alam (5): >> dt-bindings: qcom_nandc: IPQ5018 QPIC NAND documentation >> mtd: rawnand: qcom: Add initial support for qspi nand >> mtd: rawnand: qcom: Read QPIC version >> mtd: rawnand: qcom: Enable support for erase,read & write for serial >> nand. >> mtd: rawnand: qcom: Add support for serial training. >> >> .../devicetree/bindings/mtd/qcom_nandc.txt | 3 + >> drivers/mtd/nand/raw/nand_ids.c | 13 + >> drivers/mtd/nand/raw/qcom_nandc.c | 502 >> ++++++++++++++++++++- >> 3 files changed, 494 insertions(+), 24 deletions(-) >> > > I'm sorry but this series clearly breaks the current layering. I cannot > authorize SPI-NAND code to fall into the raw NAND subsystem. >
I am agree with you, we should not add SPI-NAND changes inside raw NAND subsystem.
> As both typologies cannot be used at the same time, I guess you should > have another driver handling this feature under the spi/ subsystem + > a few declarations in the SPI-NAND devices list. >
Initially I was started writing separate driver under SPI-NAND subsystem then I realized that more than 85% of raw/qcom_nand.c code getting duplicated.
That's why I have added this SPI-NAND change in raw/qcom_nand.c since more than 85% of code will be reused.
If I will add this change inside SPI-NAND subsystem then much of raw/qcom_nand.c code will get duplicated. Would it be ok ?
> Thanks, > Miquèl
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