From patchwork Thu Nov 26 02:00:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 333411 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 5743CC64E7A for ; Thu, 26 Nov 2020 02:01:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3562206B7 for ; Thu, 26 Nov 2020 02:01:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="MNTjtYrQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732332AbgKZCAz (ORCPT ); Wed, 25 Nov 2020 21:00:55 -0500 Received: from esa3.hgst.iphmx.com ([216.71.153.141]:17443 "EHLO esa3.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732204AbgKZCAz (ORCPT ); Wed, 25 Nov 2020 21:00:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1606356054; x=1637892054; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=FUFns0ZQm6ox08bIyStAPeZebNJokqWZzdgTWJBkH6w=; b=MNTjtYrQMv6CoTSRAdldsDrcxPUKD0NSXUCRTC3bI3iGCUZODfVFjAHq DtCf7ko5DA5AHScYIV54J/AsDw1Ser4NnfdtE4nV1NBP8gGmZczvU1eIi vruFKKyCt7U1+liccrmwWoqiCNCV562HqSizyqBevYQCJmIW1Y4XlfZzQ K8XGP6U5wYw7g1c1akTNT/a3N1HuZQSIewOp1rjdzyu46MWmRdeQdMER8 /sKYagqpRH0fylpHn2DXrUEuzPDI06Auv2cTqxAG8JQTP7VI77dgtAs93 754cF/yLuRIvQ6hJAxPBFGn3zuegViqE7DgHH2sUcKTFQvwIR2C82VljX g==; IronPort-SDR: 8FXI9w4CFsGrQIj5n5kCUpXp3IfVW+gQT4ntieL3LNEMBnoHm5EhIUEIs5u8mM8P7goTpEVNKb UMHHNc5ggOFqe+MqnvCidxc6ULMRwOBaJAQaFelGohLhMHzAQlfcbets1/9PNZYNpH5iskn194 NYHL20n8kWsH9ibAM3u0jf30Rm9bBqcbfgnrV1bf/GngmV9sdO+KmfnhiFFVExLHF8VttqUdVC BOwKxB6VOqNsy6EiQBL0JEjAhVdcGbZlLuMDdXggIUbb/PTeFTjYMuEu1aRXusdlYkBBJ3MIxh Kd8= X-IronPort-AV: E=Sophos;i="5.78,370,1599494400"; d="scan'208";a="157980297" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 26 Nov 2020 10:00:54 +0800 IronPort-SDR: 5fC1pKNJ8aDkN7dSNqj3YOuMhd9TTqhcx74Lq655xjfeIT0n60wJ8UqzLwFBjpUhovouDT+I3z l9gjEP6Ym7RhJpIInd7W2fSklJSW8eDHU= Received: from uls-op-cesaip01.wdc.com ([10.248.3.36]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Nov 2020 17:46:37 -0800 IronPort-SDR: ODSIuWrDP3/zSNT8TTLI8jX6JpHpYCuofm/0eEltZoDJNQeBhFGiRl3DA+4pVaSV/L6BJE4D2m 1ByJpF1LEPrg== WDCIronportException: Internal Received: from 57m2vf2.ad.shared (HELO twashi.fujisawa.hgst.com) ([10.84.71.135]) by uls-op-cesaip01.wdc.com with ESMTP; 25 Nov 2020 18:00:53 -0800 From: Damien Le Moal To: Serge Semin , Mark Brown , linux-spi@vger.kernel.org, Rob Herring , devicetree@vger.kernel.org Cc: Sean Anderson Subject: [PATCH v2 2/3] spi: dw: Add support for the Canaan K210 SoC SPI Date: Thu, 26 Nov 2020 11:00:48 +0900 Message-Id: <20201126020049.35712-3-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201126020049.35712-1-damien.lemoal@wdc.com> References: <20201126020049.35712-1-damien.lemoal@wdc.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org The Canaan Kendryte K210 RISC-V SoC includes a DW apb_ssi v4 controller which is documented to have a 32 words deep TX and RX FIFO. The FIFO length detection in spi_hw_init() correctly detects this value. However, when the controller RX FIFO is filled up to 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. This likely due to a hardware bug which can be avoided by force setting the fifo_len field of struct dw_spi to 31. Define the dw_spi_canaan_k210_init() function to force set fifo_len to 31 when the device node compatible string is "canaan,k210-spi". Signed-off-by: Damien Le Moal Acked-by: Serge Semin --- drivers/spi/spi-dw-mmio.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c index d0cc5bf4fa4e..17c06039a74d 100644 --- a/drivers/spi/spi-dw-mmio.c +++ b/drivers/spi/spi-dw-mmio.c @@ -222,6 +222,21 @@ static int dw_spi_keembay_init(struct platform_device *pdev, return 0; } +static int dw_spi_canaan_k210_init(struct platform_device *pdev, + struct dw_spi_mmio *dwsmmio) +{ + /* + * The Canaan Kendryte K210 SoC DW apb_ssi v4 spi controller is + * documented to have a 32 word deep TX and RX FIFO, which + * spi_hw_init() detects. However, when the RX FIFO is filled up to + * 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. Avoid this + * problem by force setting fifo_len to 31. + */ + dwsmmio->dws.fifo_len = 31; + + return 0; +} + static int dw_spi_mmio_probe(struct platform_device *pdev) { int (*init_func)(struct platform_device *pdev, @@ -335,6 +350,7 @@ static const struct of_device_id dw_spi_mmio_of_match[] = { { .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_dwc_ssi_init}, { .compatible = "intel,keembay-ssi", .data = dw_spi_keembay_init}, { .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init}, + { .compatible = "canaan,k210-spi", dw_spi_canaan_k210_init}, { /* end of table */} }; MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);