From patchwork Fri Mar 30 07:22:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Suloev X-Patchwork-Id: 10317183 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4D68A602A7 for ; Fri, 30 Mar 2018 07:23:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 358CC2A37A for ; Fri, 30 Mar 2018 07:23:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 29F782A395; Fri, 30 Mar 2018 07:23:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A52282A37A for ; Fri, 30 Mar 2018 07:23:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752511AbeC3HXA (ORCPT ); Fri, 30 Mar 2018 03:23:00 -0400 Received: from smtp57.i.mail.ru ([217.69.128.37]:44002 "EHLO smtp57.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752479AbeC3HW6 (ORCPT ); Fri, 30 Mar 2018 03:22:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=orpaltech.com; s=mailru; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=ch5fLw4ZTbg9mawLLdoq14TDfaGsEmlMf/NJlzU+V4w=; b=ad/gk0IiHiUbETo69O6m6yUWXLXwFl6LlKspClprET5kDnptdDfY71hoArbrLI+4XbfpKtlltQV/S4scoFsT4nnmgx8OtPHGAvHEbwwcpHUvBkQUuOzpGllb5dDDnXR+zhZWOfL8ysdiOZe3D59pl+NGUJraWvDVyuIcZyyWL8s=; Received: by smtp57.i.mail.ru with esmtpa (envelope-from ) id 1f1oND-0001IV-SO; Fri, 30 Mar 2018 10:22:56 +0300 From: Sergey Suloev To: Mark Brown , Maxime Ripard , Chen-Yu Tsai Cc: linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sergey Suloev Subject: [PATCH 3/6] spi: sun6i: restrict transfer length in PIO-mode Date: Fri, 30 Mar 2018 10:22:40 +0300 Message-Id: <20180330072243.19368-4-ssuloev@orpaltech.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180330072243.19368-1-ssuloev@orpaltech.com> References: <20180330072243.19368-1-ssuloev@orpaltech.com> Authentication-Results: smtp57.i.mail.ru; auth=pass smtp.auth=ssuloev@orpaltech.com smtp.mailfrom=ssuloev@orpaltech.com X-7FA49CB5: 0D63561A33F958A5B7F54A902D0F0784BC0A8B6031D50A001576A4EF249F5C27725E5C173C3A84C39D7D3120FB43BDE36BD6C8C29FA68577BA6625F88748EAEFC4224003CC836476C0CAF46E325F83A50BF2EBBBDD9D6B0F05F538519369F3743B503F486389A921A5CC5B56E945C8DA X-Mailru-Sender: C5364AD02485212F3ACDC11E67D84917DACED8E026476E636067E701E60E7E96069BFC61DABEEB110841D3AAAB1726C63DDE9B364B0DF289264D2CD8C2503E8C22A194DADEED8EEDCA01A23BA9CD1BE7ED14614B50AE0675 X-Mras: OK Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There is no need to handle 3/4 empty/full interrupts as the maximum supported transfer length in PIO mode is 128 bytes for sun6i- and 64 bytes for sun8i-family SoCs. Signed-off-by: Sergey Suloev --- drivers/spi/spi-sun6i.c | 61 ++++++++++++++----------------------------------- 1 file changed, 17 insertions(+), 44 deletions(-) diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c index f992a7d..13396bd 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c @@ -207,7 +207,10 @@ static void sun6i_spi_set_cs(struct spi_device *spi, bool enable) static size_t sun6i_spi_max_transfer_size(struct spi_device *spi) { - return SUN6I_MAX_XFER_SIZE - 1; + struct spi_master *master = spi->master; + struct sun6i_spi *sspi = spi_master_get_devdata(master); + + return sspi->fifo_depth; } static int sun6i_spi_prepare_message(struct spi_master *master, @@ -259,13 +262,18 @@ static int sun6i_spi_transfer_one(struct spi_master *master, struct sun6i_spi *sspi = spi_master_get_devdata(master); unsigned int mclk_rate, div, timeout; unsigned int start, end, tx_time; - unsigned int trig_level; unsigned int tx_len = 0; int ret = 0; u32 reg; - if (tfr->len > SUN6I_MAX_XFER_SIZE) - return -EINVAL; + /* A zero length transfer never finishes if programmed + in the hardware */ + if (!tfr->len) + return 0; + + /* Don't support transfer larger than the FIFO */ + if (tfr->len > sspi->fifo_depth) + return -EMSGSIZE; reinit_completion(&sspi->done); sspi->tx_buf = tfr->tx_buf; @@ -279,17 +287,6 @@ static int sun6i_spi_transfer_one(struct spi_master *master, sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG, SUN6I_FIFO_CTL_RF_RST | SUN6I_FIFO_CTL_TF_RST); - /* - * Setup FIFO interrupt trigger level - * Here we choose 3/4 of the full fifo depth, as it's the hardcoded - * value used in old generation of Allwinner SPI controller. - * (See spi-sun4i.c) - */ - trig_level = sspi->fifo_depth / 4 * 3; - sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG, - (trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS) | - (trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS)); - /* Ensure that we have a parent clock fast enough */ mclk_rate = clk_get_rate(sspi->mclk); @@ -338,12 +335,8 @@ static int sun6i_spi_transfer_one(struct spi_master *master, /* Fill the TX FIFO */ sun6i_spi_fill_fifo(sspi, sspi->fifo_depth); - /* Enable the interrupts */ - sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC); - sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC | - SUN6I_INT_CTL_RF_RDY); - if (tx_len > sspi->fifo_depth) - sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ); + /* Enable transfer complete interrupt */ + sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC); /* Start the transfer */ reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG); @@ -372,7 +365,9 @@ out: static irqreturn_t sun6i_spi_handler(int irq, void *dev_id) { struct sun6i_spi *sspi = dev_id; - u32 status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG); + u32 status; + + status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG); /* Transfer complete */ if (status & SUN6I_INT_CTL_TC) { @@ -382,28 +377,6 @@ static irqreturn_t sun6i_spi_handler(int irq, void *dev_id) return IRQ_HANDLED; } - /* Receive FIFO 3/4 full */ - if (status & SUN6I_INT_CTL_RF_RDY) { - sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH); - /* Only clear the interrupt _after_ draining the FIFO */ - sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_RDY); - return IRQ_HANDLED; - } - - /* Transmit FIFO 3/4 empty */ - if (status & SUN6I_INT_CTL_TF_ERQ) { - sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH); - - if (!sspi->len) - /* nothing left to transmit */ - sun6i_spi_disable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ); - - /* Only clear the interrupt _after_ re-seeding the FIFO */ - sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TF_ERQ); - - return IRQ_HANDLED; - } - return IRQ_NONE; }