From patchwork Fri Jun 19 11:31:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lars Povlsen X-Patchwork-Id: 11613947 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3B79F138C for ; Fri, 19 Jun 2020 11:31:37 +0000 (UTC) Received: by mail.kernel.org (Postfix) id 366862083B; Fri, 19 Jun 2020 11:31:37 +0000 (UTC) Delivered-To: soc@kernel.org Received: from esa6.microchip.iphmx.com (esa6.microchip.iphmx.com [216.71.154.253]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D081C207FC; Fri, 19 Jun 2020 11:31:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b="fzglu1oT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D081C207FC Authentication-Results: mail.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=microchip.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=Lars.Povlsen@microchip.com DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1592566296; x=1624102296; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Vr7IJg82w/CxJvBCjz5G7ZncKTloNcb8/f99H0MqnqE=; b=fzglu1oTViND1L5BtYDqwaTikxwQrPq7Ja+B10QFAKWf7V1QcMPpVtAd c7ceU+CknqRQ+4uudamy1cWTim9068Y7tQktx9a1u3DS+f8+yfFPF+u/J A4o4qp64GWt2Mz+d59cAMI+biT/JDLbWQsn2b4BvUCkQuJnk2/bafRrAw XRePK1598e0IDilytKC8si+qiJVMVrrTvaM5m3irMsK6fnGRURe+pwSA4 AKcJjJtLBUXJBlZOI97SRxYqGMyiGeoWBswH2y5btmPg97AYb4r8TndQ0 U7frNMqf7f10fD/dz4yq19o9vJ/p7ha4mWWu+cLxB0TmTEDCPKIUmOnlT w==; IronPort-SDR: ovZN+q40DWbaLSrFs6pWzRK3NpqROuHV46otC456nLKeagstpAR5XWzA4d/KafQBZd58wwYIb1 yr5qJ8PLB8cI/n17tVOMIJcGxC2Lp8qT1TgX8CQip2HNUp187R+r3e8S44kbM5M7A2zZTkqrsS n39MTY/jCbSYn107W0tcNIsXPcdzhEaME9CamDaZaVM2arNHGQQGC3zbOfhzeuSDZH4J4PWsGi Sgd3JLErv0N23lSzjwVDDmR69t21WlpYpf0xTaUzQNMBO+PaBM95g5H9m+qrKgNltpP+xeYim5 cpo= X-IronPort-AV: E=Sophos;i="5.75,255,1589266800"; d="scan'208";a="16373015" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa6.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 19 Jun 2020 04:31:35 -0700 Received: from chn-vm-ex01.mchp-main.com (10.10.85.143) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 19 Jun 2020 04:31:28 -0700 Received: from soft-dev15.microsemi.net (10.10.115.15) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server id 15.1.1979.3 via Frontend Transport; Fri, 19 Jun 2020 04:31:26 -0700 From: Lars Povlsen List-Id: To: Mark Brown , SoC Team CC: Lars Povlsen , Microchip Linux Driver Support , , , , , Serge Semin , Serge Semin Subject: [PATCH v2 1/6] spi: dw: Add support for RX sample delay register Date: Fri, 19 Jun 2020 13:31:16 +0200 Message-ID: <20200619113121.9984-2-lars.povlsen@microchip.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619113121.9984-1-lars.povlsen@microchip.com> References: <20200619113121.9984-1-lars.povlsen@microchip.com> MIME-Version: 1.0 This add support for the RX_SAMPLE_DLY register. If enabled in the Designware IP, it allows tuning of the rx data signal by means of an internal rx sample fifo. The register is controlled by the snps,rx-sample-delay-ns DT property, which is defined per SPI slave. The register is located at offset 0xf0, and if the option is not enabled in the IP, changing the register will have no effect. The register will only be written if any slave defines a nonzero value (after scaling by the clock period). Signed-off-by: Lars Povlsen --- drivers/spi/spi-dw-core.c | 20 ++++++++++++++++++++ drivers/spi/spi-dw.h | 2 ++ 2 files changed, 22 insertions(+) diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c index 323c66c5db506..d249f25cbff7f 100644 --- a/drivers/spi/spi-dw-core.c +++ b/drivers/spi/spi-dw-core.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "spi-dw.h" @@ -26,6 +27,8 @@ struct chip_data { u16 clk_div; /* baud rate divider */ u32 speed_hz; /* baud rate */ + + u32 rx_sample_dly; /* RX sample delay */ }; #ifdef CONFIG_DEBUG_FS @@ -52,6 +55,7 @@ static const struct debugfs_reg32 dw_spi_dbgfs_regs[] = { DW_SPI_DBGFS_REG("DMACR", DW_SPI_DMACR), DW_SPI_DBGFS_REG("DMATDLR", DW_SPI_DMATDLR), DW_SPI_DBGFS_REG("DMARDLR", DW_SPI_DMARDLR), + DW_SPI_DBGFS_REG("RX_SAMPLE_DLY", DW_SPI_RX_SAMPLE_DLY), }; static int dw_spi_debugfs_init(struct dw_spi *dws) @@ -328,6 +332,12 @@ static int dw_spi_transfer_one(struct spi_controller *master, if (master->can_dma && master->can_dma(master, spi, transfer)) dws->dma_mapped = master->cur_msg_mapped; + /* Update RX sample delay if required */ + if (dws->curr_rx_sample_dly != chip->rx_sample_dly) { + dw_writel(dws, DW_SPI_RX_SAMPLE_DLY, chip->rx_sample_dly); + dws->curr_rx_sample_dly = chip->rx_sample_dly; + } + /* For poll mode just disable all interrupts */ spi_mask_intr(dws, 0xff); @@ -380,10 +390,20 @@ static int dw_spi_setup(struct spi_device *spi) /* Only alloc on first setup */ chip = spi_get_ctldata(spi); if (!chip) { + struct dw_spi *dws = spi_controller_get_devdata(spi->controller); + u32 rx_sample_dly; + chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); if (!chip) return -ENOMEM; spi_set_ctldata(spi, chip); + /* Is rx_sample_dly defined for a slave? */ + if (device_property_read_u32(&spi->dev, + "snps,rx-sample-delay-ns", + &rx_sample_dly) == 0) + chip->rx_sample_dly = DIV_ROUND_CLOSEST(rx_sample_dly, + NSEC_PER_SEC / + dws->max_freq); } chip->tmode = SPI_TMOD_TR; diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h index 151ba316619e6..f9243bf2a662b 100644 --- a/drivers/spi/spi-dw.h +++ b/drivers/spi/spi-dw.h @@ -34,6 +34,7 @@ #define DW_SPI_IDR 0x58 #define DW_SPI_VERSION 0x5c #define DW_SPI_DR 0x60 +#define DW_SPI_RX_SAMPLE_DLY 0xf0 #define DW_SPI_CS_OVERRIDE 0xf4 /* Bit fields in CTRLR0 */ @@ -140,6 +141,7 @@ struct dw_spi { u8 n_bytes; /* current is a 1/2 bytes op */ irqreturn_t (*transfer_handler)(struct dw_spi *dws); u32 current_freq; /* frequency in hz */ + u32 curr_rx_sample_dly; /* DMA info */ struct dma_chan *txchan;