From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AC95C433E1 for ; Fri, 29 May 2020 13:28:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 74D442100A for ; Fri, 29 May 2020 13:28:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726933AbgE2N20 (ORCPT ); Fri, 29 May 2020 09:28:26 -0400 Received: from mga14.intel.com ([192.55.52.115]:29787 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726549AbgE2N2Z (ORCPT ); Fri, 29 May 2020 09:28:25 -0400 IronPort-SDR: QFMzlWVV9gu/4KcBOVGh5v2I8G3iz3I5b2Ro3agD9k+/4lK4ea/sG1lzePDL49quwk37Zi8wAc z7+OUg8x8ccg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 May 2020 06:27:53 -0700 IronPort-SDR: cA+BucQzZeLIfs/tSI/C39At1sHwgt9TW3geV63sMlmZpjHfaHWUg93O3YYiBL044lyiMcdscd lT9KxA1ArQ4A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,448,1583222400"; d="scan'208";a="443389518" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga005.jf.intel.com with ESMTP; 29 May 2020 06:27:49 -0700 Received: from andy by smile with local (Exim 4.93) (envelope-from ) id 1jef39-009ce1-V3; Fri, 29 May 2020 16:27:51 +0300 Date: Fri, 29 May 2020 16:27:51 +0300 From: Andy Shevchenko To: Serge Semin Cc: Mark Brown , Serge Semin , Georgy Vlasov , Ramil Zaripov , Alexey Malahov , Maxim Kaurkin , Pavel Parkhomenko , Ekaterina Skachko , Vadim Vlasov , Alexey Kolotnikov , Thomas Bogendoerfer , Arnd Bergmann , Feng Tang , Rob Herring , linux-mips@vger.kernel.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 00/16] spi: dw: Add generic DW DMA controller support Message-ID: <20200529132751.GR1634618@smile.fi.intel.com> References: <20200529131205.31838-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200529131205.31838-1-Sergey.Semin@baikalelectronics.ru> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, May 29, 2020 at 04:11:49PM +0300, Serge Semin wrote: > Baikal-T1 SoC provides a DW DMA controller to perform low-speed peripherals > Mem-to-Dev and Dev-to-Mem transaction. This is also applicable to the DW > APB SSI devices embedded into the SoC. Currently the DMA-based transfers > are supported by the DW APB SPI driver only as a middle layer code for > Intel MID/Elkhart PCI devices. Seeing the same code can be used for normal > platform DMAC device we introduced a set of patches to fix it within this > series. > > First of all we need to add the Tx and Rx DMA channels support into the DW > APB SSI binding. Then there are several fixes and cleanups provided as a > initial preparation for the Generic DMA support integration: add Tx/Rx > finish wait methods, clear DMAC register when done or stopped, Fix native > CS being unset, enable interrupts in accordance with DMA xfer mode, > discard static DW DMA slave structures, discard unused void priv pointer > and dma_width member of the dw_spi structure, provide the DMA Tx/Rx burst > length parametrisation and make sure it's optionally set in accordance > with the DMA max-burst capability. > > In order to have the DW APB SSI MMIO driver working with DMA we need to > initialize the paddr field with the physical base address of the DW APB SSI > registers space. Then we unpin the Intel MID specific code from the > generic DMA one and placed it into the spi-dw-pci.c driver, which is a > better place for it anyway. After that the naming cleanups are performed > since the code is going to be used for a generic DMAC device. Finally the > Generic DMA initialization can be added to the generic version of the > DW APB SSI IP. > > Last but not least we traditionally convert the legacy plain text-based > dt-binding file with yaml-based one and as a cherry on a cake replace > the manually written DebugFS registers read method with a ready-to-use > for the same purpose regset32 DebugFS interface usage. > > This patchset is rebased and tested on the spi/for-next (5.7-rc5): > base-commit: fe9fce6b2cf3 ("Merge remote-tracking branch 'spi/for-5.8' into spi-next") Mark, I leave few first patches for you to decide if it's right thing to do. So, if you are okay, I'm not against them, thanks! > Link: https://lore.kernel.org/linux-spi/20200508132943.9826-1-Sergey.Semin@baikalelectronics.ru/ > Changelog v2: > - Rebase on top of the spi repository for-next branch. > - Move bindings conversion patch to the tail of the series. > - Move fixes to the head of the series. > - Apply as many changes as possible to be applied the Generic DMA > functionality support is added and the spi-dw-mid is moved to the > spi-dw-dma driver. > - Discard patch "spi: dw: Fix dma_slave_config used partly uninitialized" > since the problem has already been fixed. > - Add new patch "spi: dw: Discard unused void priv pointer". > - Add new patch "spi: dw: Discard dma_width member of the dw_spi structure". > n_bytes member of the DW SPI data can be used instead. > - Build the DMA functionality into the DW APB SSI core if required instead > of creating a separate kernel module. > - Use conditional statement instead of the ternary operator in the ref > clock getter. > > Link: https://lore.kernel.org/linux-spi/20200515104758.6934-1-Sergey.Semin@baikalelectronics.ru/ > Changelog v3: > - Use spi_delay_exec() method to wait for the DMA operation completion. > - Explicitly initialize the dw_dma_slave members on stack. > - Discard the dws->fifo_len utilization in the Tx FIFO DMA threshold > setting from the patch where we just add the default burst length > constants. > - Use min() method to calculate the optimal burst values. > - Add new patch which moves the spi-dw.c source file to spi-dw-core.c in > order to preserve the DW APB SSI core driver name. > - Add commas in the debugfs_reg32 structure initializer and after the last > entry of the dw_spi_dbgfs_regs array. > > Link: https://lore.kernel.org/linux-spi/20200521012206.14472-1-Sergey.Semin@baikalelectronics.ru > Changelog v4: > - Get back ndelay() method to wait for an SPI transfer completion. > spi_delay_exec() isn't suitable for the atomic context. > > Link: https://lore.kernel.org/linux-spi/20200522000806.7381-1-Sergey.Semin@baikalelectronics.ru > Changelog v5: > - Refactor the Tx/Rx DMA-based SPI transfers wait methods. > - Add a new patch "spi: dw: Set xfer effective_speed_hz". > - Add a new patch "spi: dw: Return any value retrieved from the > dma_transfer callback" as a preparation patch before implementing > the local DMA, Tx SPI and Rx SPI transfers wait methods. > - Add a new patch "spi: dw: Locally wait for the DMA transactions > completion", which provides a local DMA transaction complete > method > - Create a dedicated patch which adds the Rx-done wait method: > "spi: dw: Add SPI Rx-done wait method to DMA-based transfer". > - Add more detailed description of the problems the Tx/Rx-wait > methods-related patches fix. > - Wait for the SPI Tx and Rx transfers being finished in the > mid_spi_dma_transfer() method executed in the task context. > - Use spi_delay_exec() to wait for the SPI Tx/Rx completion, since now > the driver calls the wait methods in the kernel thread context. > - Use SPI_DELAY_UNIT_SCK spi_delay unit for Tx-wait delay, since SPI > xfer's are now have the effective_speed_hz initialized. > - Rx-wait for a delay correlated with the APB/SSI synchronous clock > rate instead of using the SPI bus clock rate. > > Link: https://lore.kernel.org/linux-spi/20200529035915.20790-1-Sergey.Semin@baikalelectronics.ru > Changelog v6: > - Provide a more detailed description of the patch: > 2901db35bea1 ("spi: dw: Locally wait for the DMA transfers completion") > - Calculate the Rx delay with better accuracy by moving 4-multiplication > to the head of the formulae: > ns = 4U * NSEC_PER_SEC / dws->max_freq * nents. > > Co-developed-by: Georgy Vlasov > Signed-off-by: Georgy Vlasov > Co-developed-by: Ramil Zaripov > Signed-off-by: Ramil Zaripov > Signed-off-by: Serge Semin > Cc: Alexey Malahov > Cc: Maxim Kaurkin > Cc: Pavel Parkhomenko > Cc: Ekaterina Skachko > Cc: Vadim Vlasov > Cc: Alexey Kolotnikov > Cc: Thomas Bogendoerfer > Cc: Arnd Bergmann > Cc: Andy Shevchenko > Cc: Feng Tang > Cc: Rob Herring > Cc: linux-mips@vger.kernel.org > Cc: linux-spi@vger.kernel.org > Cc: devicetree@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > > Serge Semin (16): > spi: dw: Set xfer effective_speed_hz > spi: dw: Return any value retrieved from the dma_transfer callback > spi: dw: Locally wait for the DMA transfers completion > spi: dw: Add SPI Tx-done wait method to DMA-based transfer > spi: dw: Add SPI Rx-done wait method to DMA-based transfer > spi: dw: Parameterize the DMA Rx/Tx burst length > spi: dw: Use DMA max burst to set the request thresholds > spi: dw: Fix Rx-only DMA transfers > spi: dw: Add core suffix to the DW APB SSI core source file > spi: dw: Move Non-DMA code to the DW PCIe-SPI driver > spi: dw: Remove DW DMA code dependency from DW_DMAC_PCI > spi: dw: Add DW SPI DMA/PCI/MMIO dependency on the DW SPI core > spi: dw: Cleanup generic DW DMA code namings > spi: dw: Add DMA support to the DW SPI MMIO driver > spi: dw: Use regset32 DebugFS method to create regdump file > dt-bindings: spi: Convert DW SPI binding to DT schema > > .../bindings/spi/snps,dw-apb-ssi.txt | 44 -- > .../bindings/spi/snps,dw-apb-ssi.yaml | 127 +++++ > .../devicetree/bindings/spi/spi-dw.txt | 24 - > drivers/spi/Kconfig | 15 +- > drivers/spi/Makefile | 5 +- > drivers/spi/{spi-dw.c => spi-dw-core.c} | 95 ++-- > drivers/spi/spi-dw-dma.c | 482 ++++++++++++++++++ > drivers/spi/spi-dw-mid.c | 382 -------------- > drivers/spi/spi-dw-mmio.c | 4 + > drivers/spi/spi-dw-pci.c | 50 +- > drivers/spi/spi-dw.h | 20 +- > 11 files changed, 719 insertions(+), 529 deletions(-) > delete mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt > create mode 100644 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml > delete mode 100644 Documentation/devicetree/bindings/spi/spi-dw.txt > rename drivers/spi/{spi-dw.c => spi-dw-core.c} (82%) > create mode 100644 drivers/spi/spi-dw-dma.c > delete mode 100644 drivers/spi/spi-dw-mid.c > > -- > 2.26.2 > -- With Best Regards, Andy Shevchenko