From patchwork Fri Mar 30 12:50:44 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Suloev X-Patchwork-Id: 10317689 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 E38FB60212 for ; Fri, 30 Mar 2018 12:52:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D46BA28B8B for ; Fri, 30 Mar 2018 12:52:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C97842A321; Fri, 30 Mar 2018 12:52:04 +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=unavailable 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 6FB9828B8B for ; Fri, 30 Mar 2018 12:52:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752043AbeC3MvB (ORCPT ); Fri, 30 Mar 2018 08:51:01 -0400 Received: from smtp58.i.mail.ru ([217.69.128.38]:37048 "EHLO smtp58.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751118AbeC3Mu7 (ORCPT ); Fri, 30 Mar 2018 08:50:59 -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=tPm7NEcttoHVs5FuBzI8G6TAExgQa6qtP05gTFBiEfg=; b=hBtch5a1z44nRM7yFrbYG6fzMToiy1+1NN0ZsZdBo9W6CRoUEcJVV+V2gMezmVPO9B4SAeLdb5Q8bULZqf//U9/QLUMKQLJTHXPSnfFtFH/i7l2hLr56o4ALezOc8LwsX1rEH4dP0JdperAekLdX/YtiwHLiYA02cxtbkByMt+w=; Received: by smtp58.i.mail.ru with esmtpa (envelope-from ) id 1f1tUf-0001cV-3M; Fri, 30 Mar 2018 15:50:57 +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 v2 3/6] spi: sun6i: restrict transfer length in PIO-mode Date: Fri, 30 Mar 2018 15:50:44 +0300 Message-Id: <20180330125047.13936-4-ssuloev@orpaltech.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180330125047.13936-1-ssuloev@orpaltech.com> References: <20180330125047.13936-1-ssuloev@orpaltech.com> Authentication-Results: smtp58.i.mail.ru; auth=pass smtp.auth=ssuloev@orpaltech.com smtp.mailfrom=ssuloev@orpaltech.com X-7FA49CB5: 0D63561A33F958A51B8C93763DBCA0D826FD46E76099F7CD7F5E42990F99D6EB725E5C173C3A84C30584FF81F342DA07BE8AA6CEE2C329A633F64B4C514AF25EC4224003CC836476C0CAF46E325F83A50BF2EBBBDD9D6B0F5D41B9178041F3E72623479134186CDE6BA297DBC24807EABDAD6C7F3747799A X-Mailru-Sender: C5364AD02485212F3ACDC11E67D84917073C6333C09018E9E446065F77D7F605069BFC61DABEEB110841D3AAAB1726C63DDE9B364B0DF289264D2CD8C2503E8C22A194DADEED8EEDCA01A23BA9CD1BE7ED14614B50AE0675 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 78acc1f..4db1f20 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, @@ -250,13 +253,18 @@ 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; @@ -270,17 +278,6 @@ 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)); - reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG); /* @@ -342,12 +339,8 @@ 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); @@ -376,7 +369,9 @@ 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) { @@ -386,28 +381,6 @@ 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; }