Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote on Thu, 29 Oct 2020 08:53:44 +0100: > Hello, > > mdalam@xxxxxxxxxxxxxx wrote on Wed, 28 Oct 2020 23:54:23 +0530: > > > On 2020-10-28 15:18, Miquel Raynal wrote: > > > Hello, > > > > > > Md Sadre Alam <mdalam@xxxxxxxxxxxxxx> 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 ? > > What about moving the generic code to drivers/mtd/nand/common/ and > referring to it from drivers/mtd/nand/raw/qcom_nand.c and > drivers/spi/spi-qcom.c (or such)? Actually, perhaps drivers/memory/ is the right location for the generic bits. Thanks, Miquèl
