From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vignesh Raghavendra Subject: Re: [PATCH v1 0/2] spi: cadence-qspi: Add cadence-qspi support for Intel LGM SoC Date: Thu, 10 Oct 2019 09:48:06 +0530 Message-ID: <21cb17ab-b272-ce35-67fc-abce56969fee@ti.com> References: <20190916073843.39618-1-vadivel.muruganx.ramuthevar@linux.intel.com> <89e49834-8697-2917-d666-769969f074a4@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <89e49834-8697-2917-d666-769969f074a4@linux.intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: "Ramuthevar, Vadivel MuruganX" , broonie@kernel.org Cc: robh+dt@kernel.org, mark.rutland@arm.com, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, cheol.yong.kim@intel.com, qi-ming.wu@intel.com List-Id: devicetree@vger.kernel.org On 10/10/19 7:04 AM, Ramuthevar, Vadivel MuruganX wrote: > HI Vignesh, > > On 17/9/2019 12:50 AM, Vignesh Raghavendra wrote: >> Hi, >> >> On 16/09/19 1:08 PM, Ramuthevar,Vadivel MuruganX wrote: >>> patch 1: Add YAML for cadence-qspi devicetree cdocumentation. >>> patch 2: cadence-qspi controller driver to support QSPI-NAND flash >>> using existing spi-nand framework with legacy spi protocol. >> Nope, you cannot have two drivers for the same IP (i.e Cadence QSPI) >> just to support to different types of SPI memories. This is the reason >> why spi_mem_ops was introduced. >> >> Please rewrite this driver over to use spi_mem_ops (instead of using >> generic SPI xfers) so that same driver supports both SPI-NOR and >> SPI-NAND flashes. Once that's done drivers/mtd/spi-nor/cadence-quadspi.c >> can be deleted. >> >> There are few existing examples of spi_mem_ops users in drivers/spi/ >> (git grep spi_mem_ops) and materials here on how to write such a driver: >> >> [1] >> https://bootlin.com/blog/spi-mem-bringing-some-consistency-to-the-spi-memory-ecosystem/ >> >> [2] https://www.youtube.com/watch?v=PkWbuLM_gmU > As per Mark Brown and your suggestion,  I have started adapting > cadence-qaudspi driver with spi_mem_ops framework to work > QSPI-NAND/NOR as a generic driver(completely removed the legacy > SPI-XFERS),  is in progress on Intel LGM SoC. > QSPI-IP on Intel LGM  do not have DMA  support and also not part of QSPI > IP, so couldn't able to validate DMA related. > will adapt the DMA things which are existing in cadence-quadspi.c as it is. > Great, appreciate the effort! > currently TI and Altera SoC's use this Cadence-qspi IP , both are not > using DMA as per my understanding (correct me if it is wrong). > confirmed through device tree entry. > TI platforms use DMA to read data from flash in memory mapped mode (direct access controller) using mem-to-mem DMA channels. Mem-to-mem DMA channels are requested as and when needed and are not part of DT description (as they are not bound to a device) > what is your opinion on DMA related stuff? Not having DMA support would be a regression. Please keep the DAC + DMA part as is. I can help you will all the DMA related testing... Regards Vignesh > also using macronix(QSPI-NOR) > flash/Micron(QSPI-NAND). > --- > With Regards > Vadivel >>> Ramuthevar Vadivel Murugan (2): >>>    dt-bindings: spi: Add support for cadence-qspi IP Intel LGM SoC >>>    spi: cadence-qspi: Add QSPI support for Intel LGM SoC >>> >>>   .../devicetree/bindings/spi/cadence,qspi-nand.yaml |  84 +++ >>>   drivers/spi/Kconfig                                |   9 + >>>   drivers/spi/Makefile                               |   1 + >>>   drivers/spi/spi-cadence-qspi-apb.c                 | 644 >>> +++++++++++++++++++++ >>>   drivers/spi/spi-cadence-qspi-apb.h                 | 174 ++++++ >>>   drivers/spi/spi-cadence-qspi.c                     | 461 >>> +++++++++++++++ >>>   drivers/spi/spi-cadence-qspi.h                     |  73 +++ >>>   7 files changed, 1446 insertions(+) >>>   create mode 100644 >>> Documentation/devicetree/bindings/spi/cadence,qspi-nand.yaml >>>   create mode 100644 drivers/spi/spi-cadence-qspi-apb.c >>>   create mode 100644 drivers/spi/spi-cadence-qspi-apb.h >>>   create mode 100644 drivers/spi/spi-cadence-qspi.c >>>   create mode 100644 drivers/spi/spi-cadence-qspi.h >>> -- Regards Vignesh