From patchwork Fri Jan 23 16:08:36 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ricardo Ribalda Delgado X-Patchwork-Id: 5695931 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id BC60E9F358 for ; Fri, 23 Jan 2015 16:19:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D11D7202AE for ; Fri, 23 Jan 2015 16:19:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EE85E201F4 for ; Fri, 23 Jan 2015 16:19:39 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YEguh-0001lS-8t; Fri, 23 Jan 2015 16:16:51 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YEgnc-0003I3-BX for linux-arm-kernel@bombadil.infradead.org; Fri, 23 Jan 2015 16:09:32 +0000 Received: from mail-la0-x234.google.com ([2a00:1450:4010:c03::234]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YEgnW-00014V-AD for linux-arm-kernel@lists.infradead.org; Fri, 23 Jan 2015 16:09:27 +0000 Received: by mail-la0-f52.google.com with SMTP id ge10so3949368lab.11 for ; Fri, 23 Jan 2015 08:09:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=XvAy6fNXs+EdUy5VBRi7HEZSu6TnLJv50KOQmVkXRgc=; b=WtLgnF5xotrBWMRjZybMCYkLUW9wyjGBKSg/zFyqh2gq8qkiv/iMN0uG6RnhrkThvN VxwhPfq/0/NjBsEHu+I5jFtgd5qrIcI59WH9HzN5sLY8oDXZAZEmHRiDj7sYltwmX1Qv 9Jw/ja2ERqNYlS1je29+19OZ+POYaVaRV/kycdwBZZDeHqN4Ib4Yhp8mL1kkv8p9lzpP 3cXKMCU9Mtb6hTwPJ+u1thg/n65grghCCHFefXOs+ph+P+3fHBzo31axDcnqJDoI5RqT WIr8xVhTIlpA+5sXmwtN6NcphsY9WUQ/+k8lgurGT7ga7b4ACOdB8VZgGlhaB5YXSogq +tFQ== X-Received: by 10.152.42.164 with SMTP id p4mr313005lal.45.1422029340322; Fri, 23 Jan 2015 08:09:00 -0800 (PST) Received: from neopili.qtec.com (cpe.xe-3-0-1-778.vbrnqe10.dk.customer.tdc.net. [80.197.57.18]) by mx.google.com with ESMTPSA id h7sm542990lbl.41.2015.01.23.08.08.58 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 23 Jan 2015 08:08:58 -0800 (PST) From: Ricardo Ribalda Delgado To: Mark Brown , Michal Simek , =?UTF-8?q?S=C3=B6ren=20Brinkmann?= , linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 04/18] spi-xilinx: Simplify spi_fill_tx_fifo Date: Fri, 23 Jan 2015 17:08:36 +0100 Message-Id: <1422029330-10971-5-git-send-email-ricardo.ribalda@gmail.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1422029330-10971-1-git-send-email-ricardo.ribalda@gmail.com> References: <1422029330-10971-1-git-send-email-ricardo.ribalda@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150123_110926_515438_12955662 X-CRM114-Status: GOOD ( 16.60 ) X-Spam-Score: -2.7 (--) Cc: Ricardo Ribalda Delgado X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Instead of checking the TX_FULL flag for every transaction, find out the size of the buffer at probe time and use it. Signed-off-by: Ricardo Ribalda Delgado --- drivers/spi/spi-xilinx.c | 39 ++++++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 13 deletions(-) diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c index 416b227..17480a2 100644 --- a/drivers/spi/spi-xilinx.c +++ b/drivers/spi/spi-xilinx.c @@ -88,6 +88,7 @@ struct xilinx_spi { const u8 *tx_ptr; /* pointer in the Rx buffer */ int remaining_bytes; /* the number of bytes left to transfer */ u8 bits_per_word; + int buffer_size; /* buffer size in words */ unsigned int (*read_fn)(void __iomem *); void (*write_fn)(u32, void __iomem *); void (*tx_fn)(struct xilinx_spi *); @@ -221,24 +222,16 @@ static int xilinx_spi_setup_transfer(struct spi_device *spi, return 0; } -static int xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi) +static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi, int n_words) { - u8 sr; - int n_words = 0; + xspi->remaining_bytes -= n_words * xspi->bits_per_word / 8; - /* Fill the Tx FIFO with as many bytes as possible */ - sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); - while ((sr & XSPI_SR_TX_FULL_MASK) == 0 && xspi->remaining_bytes > 0) { + while (n_words--) if (xspi->tx_ptr) xspi->tx_fn(xspi); else xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET); - xspi->remaining_bytes -= xspi->bits_per_word / 8; - sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); - n_words++; - } - - return n_words; + return; } static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) @@ -265,7 +258,10 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) u16 cr; int n_words; - n_words = xilinx_spi_fill_tx_fifo(xspi); + n_words = (xspi->remaining_bytes * 8) / xspi->bits_per_word; + n_words = min(n_words, xspi->buffer_size); + + xilinx_spi_fill_tx_fifo(xspi, n_words); /* Start the transfer by not inhibiting the transmitter any * longer @@ -322,6 +318,21 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id) return IRQ_HANDLED; } +static int xilinx_spi_find_buffer_size(struct xilinx_spi *xspi) +{ + u8 sr; + int n_words = 0; + + /* Fill the Tx FIFO with as many words as possible */ + do { + xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET); + sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); + n_words++; + } while (!(sr & XSPI_SR_TX_FULL_MASK)); + + return n_words; +} + static const struct of_device_id xilinx_spi_of_match[] = { { .compatible = "xlnx,xps-spi-2.00.a", }, { .compatible = "xlnx,xps-spi-2.00.b", }, @@ -413,6 +424,8 @@ static int xilinx_spi_probe(struct platform_device *pdev) goto put_master; } + xspi->buffer_size = xilinx_spi_find_buffer_size(xspi); + /* SPI controller initializations */ xspi_init_hw(xspi);