From patchwork Fri Jan 24 20:06:14 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 3535871 Return-Path: X-Original-To: patchwork-linux-spi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 5E6AC9F1C3 for ; Fri, 24 Jan 2014 20:06:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id ED55A20179 for ; Fri, 24 Jan 2014 20:06:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 261F22013D for ; Fri, 24 Jan 2014 20:06:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751735AbaAXUGX (ORCPT ); Fri, 24 Jan 2014 15:06:23 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:59191 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751686AbaAXUGX (ORCPT ); Fri, 24 Jan 2014 15:06:23 -0500 Received: from cpc11-sgyl31-2-0-cust68.sgyl.cable.virginm.net ([94.175.92.69] helo=debutante.sirena.org.uk) by mezzanine.sirena.org.uk with esmtpsa (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1W6n1A-000693-4O; Fri, 24 Jan 2014 20:06:21 +0000 Received: from broonie by debutante.sirena.org.uk with local (Exim 4.82) (envelope-from ) id 1W6n15-0007Vi-9q; Fri, 24 Jan 2014 20:06:15 +0000 From: Mark Brown To: linux-spi@vger.kernel.org Cc: linaro-kernel@lists.linaro.org, linux-samsung-soc@vger.kernel.org, Mark Brown Date: Fri, 24 Jan 2014 20:06:14 +0000 Message-Id: <1390593974-28837-1-git-send-email-broonie@kernel.org> X-Mailer: git-send-email 1.8.5.3 X-SA-Exim-Connect-IP: 94.175.92.69 X-SA-Exim-Mail-From: broonie@sirena.org.uk X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Subject: [PATCH] spi/s3c64xx: Split wait_for_xfer() into PIO and DMA versions X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) 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 From: Mark Brown There is no meaningful code sharing between the PIO and DMA variants (just the timeout calculation) so in order to make the code easier to work with split the two cases. Looking at the code it is not clear how the PIO version works for large transmits, greater than FIFO size is only handled for RX. Signed-off-by: Mark Brown --- drivers/spi/spi-s3c64xx.c | 166 +++++++++++++++++++++++++--------------------- 1 file changed, 89 insertions(+), 77 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 19113538f5c6..b9ba7a3e7741 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -677,101 +677,110 @@ static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd, return RX_FIFO_LVL(status, sdd); } -static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, - struct spi_transfer *xfer, int dma_mode) +static int wait_for_dma(struct s3c64xx_spi_driver_data *sdd, + struct spi_transfer *xfer) { void __iomem *regs = sdd->regs; unsigned long val; + u32 status; int ms; /* millisecs to xfer 'len' bytes @ 'cur_speed' */ ms = xfer->len * 8 * 1000 / sdd->cur_speed; ms += 10; /* some tolerance */ - if (dma_mode) { - val = msecs_to_jiffies(ms) + 10; - val = wait_for_completion_timeout(&sdd->xfer_completion, val); - } else { - u32 status; - val = msecs_to_loops(ms); - do { + val = msecs_to_jiffies(ms) + 10; + val = wait_for_completion_timeout(&sdd->xfer_completion, val); + + /* + * If the previous xfer was completed within timeout, then + * proceed further else return -EIO. + * DmaTx returns after simply writing data in the FIFO, + * w/o waiting for real transmission on the bus to finish. + * DmaRx returns only after Dma read data from FIFO which + * needs bus transmission to finish, so we don't worry if + * Xfer involved Rx(with or without Tx). + */ + if (val && !xfer->rx_buf) { + val = msecs_to_loops(10); + status = readl(regs + S3C64XX_SPI_STATUS); + while ((TX_FIFO_LVL(status, sdd) + || !S3C64XX_SPI_ST_TX_DONE(status, sdd)) + && --val) { + cpu_relax(); status = readl(regs + S3C64XX_SPI_STATUS); - } while (RX_FIFO_LVL(status, sdd) < xfer->len && --val); + } + } - if (dma_mode) { - u32 status; - - /* - * If the previous xfer was completed within timeout, then - * proceed further else return -EIO. - * DmaTx returns after simply writing data in the FIFO, - * w/o waiting for real transmission on the bus to finish. - * DmaRx returns only after Dma read data from FIFO which - * needs bus transmission to finish, so we don't worry if - * Xfer involved Rx(with or without Tx). - */ - if (val && !xfer->rx_buf) { - val = msecs_to_loops(10); - status = readl(regs + S3C64XX_SPI_STATUS); - while ((TX_FIFO_LVL(status, sdd) - || !S3C64XX_SPI_ST_TX_DONE(status, sdd)) - && --val) { - cpu_relax(); - status = readl(regs + S3C64XX_SPI_STATUS); - } + /* If timed out while checking rx/tx status return error */ + if (!val) + return -EIO; - } + return 0; +} - /* If timed out while checking rx/tx status return error */ - if (!val) - return -EIO; - } else { - int loops; - u32 cpy_len; - u8 *buf; - - /* If it was only Tx */ - if (!xfer->rx_buf) { - sdd->state &= ~TXBUSY; - return 0; - } +static int wait_for_pio(struct s3c64xx_spi_driver_data *sdd, + struct spi_transfer *xfer) +{ + void __iomem *regs = sdd->regs; + unsigned long val; + u32 status; + int loops; + u32 cpy_len; + u8 *buf; + int ms; - /* - * If the receive length is bigger than the controller fifo - * size, calculate the loops and read the fifo as many times. - * loops = length / max fifo size (calculated by using the - * fifo mask). - * For any size less than the fifo size the below code is - * executed atleast once. - */ - loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1); - buf = xfer->rx_buf; - do { - /* wait for data to be received in the fifo */ - cpy_len = s3c64xx_spi_wait_for_timeout(sdd, - (loops ? ms : 0)); + /* millisecs to xfer 'len' bytes @ 'cur_speed' */ + ms = xfer->len * 8 * 1000 / sdd->cur_speed; + ms += 10; /* some tolerance */ - switch (sdd->cur_bpw) { - case 32: - ioread32_rep(regs + S3C64XX_SPI_RX_DATA, - buf, cpy_len / 4); - break; - case 16: - ioread16_rep(regs + S3C64XX_SPI_RX_DATA, - buf, cpy_len / 2); - break; - default: - ioread8_rep(regs + S3C64XX_SPI_RX_DATA, - buf, cpy_len); - break; - } + val = msecs_to_loops(ms); + do { + status = readl(regs + S3C64XX_SPI_STATUS); + } while (RX_FIFO_LVL(status, sdd) < xfer->len && --val); - buf = buf + cpy_len; - } while (loops--); - sdd->state &= ~RXBUSY; + + /* If it was only Tx */ + if (!xfer->rx_buf) { + sdd->state &= ~TXBUSY; + return 0; } + /* + * If the receive length is bigger than the controller fifo + * size, calculate the loops and read the fifo as many times. + * loops = length / max fifo size (calculated by using the + * fifo mask). + * For any size less than the fifo size the below code is + * executed atleast once. + */ + loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1); + buf = xfer->rx_buf; + do { + /* wait for data to be received in the fifo */ + cpy_len = s3c64xx_spi_wait_for_timeout(sdd, + (loops ? ms : 0)); + + switch (sdd->cur_bpw) { + case 32: + ioread32_rep(regs + S3C64XX_SPI_RX_DATA, + buf, cpy_len / 4); + break; + case 16: + ioread16_rep(regs + S3C64XX_SPI_RX_DATA, + buf, cpy_len / 2); + break; + default: + ioread8_rep(regs + S3C64XX_SPI_RX_DATA, + buf, cpy_len); + break; + } + + buf = buf + cpy_len; + } while (loops--); + sdd->state &= ~RXBUSY; + return 0; } @@ -928,7 +937,10 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master, spin_unlock_irqrestore(&sdd->lock, flags); - status = wait_for_xfer(sdd, xfer, use_dma); + if (use_dma) + status = wait_for_dma(sdd, xfer); + else + status = wait_for_pio(sdd, xfer); if (status) { dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",