From: "Ramuthevar, Vadivel MuruganX" <vadivel.muruganx.ramuthevar@linux.intel.com>
To: Vignesh Raghavendra <vigneshr@ti.com>, 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
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 [thread overview]
Message-ID: <897dd6a2-e319-4e67-48aa-dfd179e11609@linux.intel.com> (raw)
In-Reply-To: <21cb17ab-b272-ce35-67fc-abce56969fee@ti.com>
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
>>>>
prev parent reply other threads:[~2019-10-10 5:09 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-16 7:38 [PATCH v1 0/2] spi: cadence-qspi: Add cadence-qspi support for Intel LGM SoC Ramuthevar,Vadivel MuruganX
2019-09-16 7:38 ` [PATCH v1 1/2] dt-bindings: spi: Add support for cadence-qspi IP " Ramuthevar,Vadivel MuruganX
2019-09-30 22:36 ` Rob Herring
2019-10-01 1:13 ` Ramuthevar, Vadivel MuruganX
2019-09-16 7:38 ` [PATCH v1 2/2] spi: cadence-qspi: Add QSPI support for " Ramuthevar,Vadivel MuruganX
2019-09-16 11:32 ` Mark Brown
[not found] ` <466b41c1-3d65-0bf4-6db7-d3b3e06b107b@linux.intel.com>
2019-09-17 15:36 ` Mark Brown
2019-09-18 5:59 ` Ramuthevar, Vadivel MuruganX
2019-09-18 12:08 ` Mark Brown
2019-09-19 5:45 ` Ramuthevar, Vadivel MuruganX
2019-09-16 13:48 ` kbuild test robot
2019-09-16 16:50 ` [PATCH v1 0/2] spi: cadence-qspi: Add cadence-qspi " Vignesh Raghavendra
2019-09-17 3:31 ` Ramuthevar, Vadivel MuruganX
2019-10-10 1:34 ` Ramuthevar, Vadivel MuruganX
2019-10-10 4:18 ` Vignesh Raghavendra
2019-10-10 5:08 ` Ramuthevar, Vadivel MuruganX [this message]
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