From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ramuthevar, Vadivel MuruganX" Subject: Re: [PATCH v1 0/2] spi: cadence-qspi: Add cadence-qspi support for Intel LGM SoC Date: Thu, 10 Oct 2019 13:08:58 +0800 Message-ID: <897dd6a2-e319-4e67-48aa-dfd179e11609@linux.intel.com> References: <20190916073843.39618-1-vadivel.muruganx.ramuthevar@linux.intel.com> <89e49834-8697-2917-d666-769969f074a4@linux.intel.com> <21cb17ab-b272-ce35-67fc-abce56969fee@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit 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 To: Vignesh Raghavendra , broonie@kernel.org Return-path: In-Reply-To: <21cb17ab-b272-ce35-67fc-abce56969fee@ti.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org Hi Vignesh, On 10/10/2019 12:18 PM, Vignesh Raghavendra wrote: > > 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) yes, understood now, Thanks! >> 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... Sure, will keep DAC + DMA, as we discussed earlier use QUIRKS to differentiate and follow the same. --- With Regards Vadivel > 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 >>>>