From patchwork Sun Dec 6 01:18:17 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: 11953553 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 440CFC4361B for ; Sun, 6 Dec 2020 01:20:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FAE323128 for ; Sun, 6 Dec 2020 01:20:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726488AbgLFBUt (ORCPT ); Sat, 5 Dec 2020 20:20:49 -0500 Received: from esa2.hgst.iphmx.com ([68.232.143.124]:35643 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726037AbgLFBUt (ORCPT ); Sat, 5 Dec 2020 20:20:49 -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=1607218820; x=1638754820; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=FUFns0ZQm6ox08bIyStAPeZebNJokqWZzdgTWJBkH6w=; b=T1GrqXZ0ttokYT5b0iLgGAzY1dLYVaYNvwlK3LR8mGh5jIk6mebQpmG2 REkKpk+RQWR3Zaar9J575tYj7oCW6LYADXs+++cbTEupoi4aroyktnWrG xB2aNNQJvWMb7tSoBJIpOJEOPAL3cC2nEH5Rr2ri7Jlg00jh1+yLEp8Jc hLko4vjqFbWVGkby/CsJFp6thL8twd/uD3ns0Ue1SJ/jISg1kQoyqozOw bSZuzgd5LjQIpqvB14Suaf5UiSu1RRI7gxCkUeTF9aQBAVFNgrd0u2e+5 PgRfduJDOqNgvWXdmhaVHKp7rtH26JOuf1cak/h+3UzLmBhnyGOv+pPtB g==; IronPort-SDR: Xvl+jzFNmQ1BhSDjoBxWZdYhWOrIO0Y5leckQskfZYiA4+7LIGLOihX6Y86Xrljbs2X7q4ytPo R+qudSrtd0lrrCg+ff2BOODx+D8zQVA5RfszzXkIcweXh5j8G4wS1Xn6EGM2/Ecq8VUScIa73O YAIMfdTCByNzp5BNt+AkiUSfnZHw8Y4dT52tsVuusbu2+rd61m/dVQngU5CxLjx1dlrPmXLljE E/V2smkT9EJExcX/Vdh6MGpZwcevu1SAThCkpAYZBck3zYOUCQ1pGFfTE883hlFgPIb4ru5WlG QME= X-IronPort-AV: E=Sophos;i="5.78,396,1599494400"; d="scan'208";a="258231905" Received: from uls-op-cesaip02.wdc.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 06 Dec 2020 09:36:44 +0800 IronPort-SDR: VHqc6V4J5mKOzVaT0nfeV62jmeRMy/S6E8Rw2cjh48KsVili7ATpBALB5tfKRZq7QuPgkfZzHa 2y728DYB5KwstQ8+TZNJDQ5d2sizwvfOc= Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2020 17:02:29 -0800 IronPort-SDR: iuWzoU0omr+w0WQH3pDr3M7C60JKNycOEC1/dNQb4ANbT3xn8NsPY451TXb5NdMjeCwodITQkg 3VMgVaMMzETw== WDCIronportException: Internal Received: from cnf005296.ad.shared (HELO twashi.fujisawa.hgst.com) ([10.84.71.167]) by uls-op-cesaip02.wdc.com with ESMTP; 05 Dec 2020 17:18:24 -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 v3 3/3] spi: dw: Add support for the Canaan K210 SoC SPI Date: Sun, 6 Dec 2020 10:18:17 +0900 Message-Id: <20201206011817.11700-4-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201206011817.11700-1-damien.lemoal@wdc.com> References: <20201206011817.11700-1-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);