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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 8D34DC33C9B for ; Tue, 7 Jan 2020 21:02:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 630202081E for ; Tue, 7 Jan 2020 21:02:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578430935; bh=0FstCUXHfmt/wPEtDm64QswSEukEzEeXl3fqYx9rozE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ijm3QfpWHrGzkb+TLNI1MFiDh78mZulceYpm0cd2yxa2KtJa1qpaPp9BjndUBNpyt CAG6UisxSCuhpxhFpgUYa7RF3OLQGKSPNE11wgsAiGDGeyfasNQHRatJP6FCIddzE5 DVNmSFtiMzd6dO49wyVWNuCnUTMs1HZZSD55buWQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728715AbgAGVCO (ORCPT ); Tue, 7 Jan 2020 16:02:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:41326 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727431AbgAGVCN (ORCPT ); Tue, 7 Jan 2020 16:02:13 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7DDCC20678; Tue, 7 Jan 2020 21:02:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578430933; bh=0FstCUXHfmt/wPEtDm64QswSEukEzEeXl3fqYx9rozE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ohO1JH79BjYiFRr1jGjqcbT0pltTI0VaToedtnsQbA5mnjfOi8B2MuK4ijdrzvV7C gIEvWNMUb6l0bI5zxi1PSr9OFFr8FFiqa6kjCSi/QOPJtiAluq8jwZsUnZqV9ACmbz 9+2vDZLQZK5H2jOgnF7TIjYwXS9oXK8PsLuKCqBs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Keiji Hayashibara , Kunihiko Hayashi , Mark Brown Subject: [PATCH 5.4 155/191] spi: uniphier: Fix FIFO threshold Date: Tue, 7 Jan 2020 21:54:35 +0100 Message-Id: <20200107205341.260078760@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200107205332.984228665@linuxfoundation.org> References: <20200107205332.984228665@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kunihiko Hayashi commit 9cd34efbd3012171c102910ce17ee632a3cccb44 upstream. Rx threshold means the value to inform the receiver when the number of words in Rx FIFO is equal to or more than the value. Similarly, Tx threshold means the value to inform the sender when the number of words in Tx FIFO is equal to or less than the value. The controller triggers the driver to start the transfer. In case of Rx, the driver wants to detect that the specified number of words N are in Rx FIFO, so the value of Rx threshold should be N. In case of Tx, the driver wants to detect that the same number of spaces as Rx are in Tx FIFO, so the value of Tx threshold should be (FIFO size - N). For example, in order for the driver to receive at least 3 words from Rx FIFO, set 3 to Rx threshold. +-+-+-+-+-+-+-+-+ | | | | | |*|*|*| +-+-+-+-+-+-+-+-+ In order for the driver to send at least 3 words to Tx FIFO, because it needs at least 3 spaces, set 8(FIFO size) - 3 = 5 to Tx threshold. +-+-+-+-+-+-+-+-+ |*|*|*|*|*| | | | +-+-+-+-+-+-+-+-+ This adds new function uniphier_spi_set_fifo_threshold() to set threshold value to the register. And more, FIFO counts by 'words', so this renames 'fill_bytes' with 'fill_words', and fixes the calculation using bytes_per_words. Fixes: 37ffab817098 ("spi: uniphier: introduce polling mode") Cc: Keiji Hayashibara Signed-off-by: Kunihiko Hayashi Link: https://lore.kernel.org/r/1577149107-30670-2-git-send-email-hayashi.kunihiko@socionext.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-uniphier.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) --- a/drivers/spi/spi-uniphier.c +++ b/drivers/spi/spi-uniphier.c @@ -290,25 +290,32 @@ static void uniphier_spi_recv(struct uni } } -static void uniphier_spi_fill_tx_fifo(struct uniphier_spi_priv *priv) +static void uniphier_spi_set_fifo_threshold(struct uniphier_spi_priv *priv, + unsigned int threshold) { - unsigned int fifo_threshold, fill_bytes; u32 val; - fifo_threshold = DIV_ROUND_UP(priv->rx_bytes, - bytes_per_word(priv->bits_per_word)); - fifo_threshold = min(fifo_threshold, SSI_FIFO_DEPTH); - - fill_bytes = fifo_threshold - (priv->rx_bytes - priv->tx_bytes); - - /* set fifo threshold */ val = readl(priv->base + SSI_FC); val &= ~(SSI_FC_TXFTH_MASK | SSI_FC_RXFTH_MASK); - val |= FIELD_PREP(SSI_FC_TXFTH_MASK, fifo_threshold); - val |= FIELD_PREP(SSI_FC_RXFTH_MASK, fifo_threshold); + val |= FIELD_PREP(SSI_FC_TXFTH_MASK, SSI_FIFO_DEPTH - threshold); + val |= FIELD_PREP(SSI_FC_RXFTH_MASK, threshold); writel(val, priv->base + SSI_FC); +} + +static void uniphier_spi_fill_tx_fifo(struct uniphier_spi_priv *priv) +{ + unsigned int fifo_threshold, fill_words; + unsigned int bpw = bytes_per_word(priv->bits_per_word); + + fifo_threshold = DIV_ROUND_UP(priv->rx_bytes, bpw); + fifo_threshold = min(fifo_threshold, SSI_FIFO_DEPTH); + + uniphier_spi_set_fifo_threshold(priv, fifo_threshold); + + fill_words = fifo_threshold - + DIV_ROUND_UP(priv->rx_bytes - priv->tx_bytes, bpw); - while (fill_bytes--) + while (fill_words--) uniphier_spi_send(priv); }