From patchwork Wed Mar 13 06:43:31 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: girishks2000@gmail.com X-Patchwork-Id: 2261781 Return-Path: X-Original-To: patchwork-spi-devel-general@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) by patchwork2.kernel.org (Postfix) with ESMTP id 74819DF215 for ; Wed, 13 Mar 2013 06:44:08 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-3.v29.ch3.sourceforge.com) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UFfPz-0001HU-PG; Wed, 13 Mar 2013 06:44:07 +0000 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UFfPy-0001HM-Ql for spi-devel-general@lists.sourceforge.net; Wed, 13 Mar 2013 06:44:06 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.223.177 as permitted sender) client-ip=209.85.223.177; envelope-from=girishks2000@gmail.com; helo=mail-ie0-f177.google.com; Received: from mail-ie0-f177.google.com ([209.85.223.177]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1UFfPx-00062B-Cy for spi-devel-general@lists.sourceforge.net; Wed, 13 Mar 2013 06:44:06 +0000 Received: by mail-ie0-f177.google.com with SMTP id 16so992748iea.36 for ; Tue, 12 Mar 2013 23:44:00 -0700 (PDT) X-Received: by 10.50.16.138 with SMTP id g10mr15320424igd.33.1363157040152; Tue, 12 Mar 2013 23:44:00 -0700 (PDT) Received: from localhost.localdomain ([115.113.119.130]) by mx.google.com with ESMTPS id hi4sm1406711igc.6.2013.03.12.23.43.56 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 12 Mar 2013 23:43:59 -0700 (PDT) From: Girish K S To: spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH V3 2/5] spi: s3c64xx: added support for polling mode Date: Wed, 13 Mar 2013 12:13:31 +0530 Message-Id: <1363157014-9615-3-git-send-email-ks.giri@samsung.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1363157014-9615-1-git-send-email-ks.giri@samsung.com> References: <1363157014-9615-1-git-send-email-ks.giri@samsung.com> X-Spam-Score: -1.4 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (girishks2000[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends in digit (girishks2000[at]gmail.com) -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1UFfPx-00062B-Cy Cc: t.figa@samsung.com, broonie@opensource.wolfsonmicro.com, Girish K S X-BeenThere: spi-devel-general@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Linux SPI core/device drivers discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: spi-devel-general-bounces@lists.sourceforge.net From: Girish K S The 64xx spi driver supports partial polling mode. Only the last chunk of the transfer length is transferred or recieved in polling mode. Some SoC's that adopt this controller might not have have dma interface. This patch adds support for complete polling mode and gives flexibity for the user to select poll/dma mode. Signed-off-by: Girish K S --- drivers/spi/spi-s3c64xx.c | 116 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 81 insertions(+), 35 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 4188b2f..054b8d4 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -35,6 +35,7 @@ #include #define MAX_SPI_PORTS 3 +#define S3C64XX_SPI_QUIRK_POLL (1 << 0) /* Registers and bit-fields */ @@ -126,6 +127,7 @@ #define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t) +#define is_polling(x) (x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL) #define RXBUSY (1<<2) #define TXBUSY (1<<3) @@ -154,6 +156,7 @@ struct s3c64xx_spi_port_config { int fifo_lvl_mask[MAX_SPI_PORTS]; int rx_lvl_offset; int tx_st_done; + int quirks; bool high_speed; bool clk_from_cmu; }; @@ -419,6 +422,27 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, cs = spi->controller_data; gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); + + /* Start the signals */ + writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); +} + +static u32 wait_for_timeout(struct s3c64xx_spi_driver_data *sdd, + int timeout_ms) +{ + void __iomem *regs = sdd->regs; + unsigned long val; + u32 status; + /* max fifo depth available */ + u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1; + + val = msecs_to_loops(timeout_ms); + do { + status = readl(regs + S3C64XX_SPI_STATUS); + } while (RX_FIFO_LVL(status, sdd) < max_fifo && --val); + + /* return the actual received data length */ + return RX_FIFO_LVL(status, sdd); } static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, @@ -443,20 +467,19 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, } while (RX_FIFO_LVL(status, sdd) < xfer->len && --val); } - if (!val) - return -EIO; - 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 (xfer->rx_buf == NULL) { + if (val && !xfer->rx_buf) { val = msecs_to_loops(10); status = readl(regs + S3C64XX_SPI_STATUS); while ((TX_FIFO_LVL(status, sdd) @@ -466,30 +489,53 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd, status = readl(regs + S3C64XX_SPI_STATUS); } - if (!val) - return -EIO; } + + /* 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 == NULL) { + if (!xfer->rx_buf) { sdd->state &= ~TXBUSY; return 0; } - switch (sdd->cur_bpw) { - case 32: - ioread32_rep(regs + S3C64XX_SPI_RX_DATA, - xfer->rx_buf, xfer->len / 4); - break; - case 16: - ioread16_rep(regs + S3C64XX_SPI_RX_DATA, - xfer->rx_buf, xfer->len / 2); - break; - default: - ioread8_rep(regs + S3C64XX_SPI_RX_DATA, - xfer->rx_buf, xfer->len); - break; - } + /* + * 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 = wait_for_timeout(sdd, ms); + + 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; } @@ -505,6 +551,10 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, sdd->tgl_spi = NULL; gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); + + /* Quiese the signals */ + writel(S3C64XX_SPI_SLAVE_SIG_INACT, + sdd->regs + S3C64XX_SPI_SLAVE_SEL); } static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) @@ -586,7 +636,7 @@ static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd, struct device *dev = &sdd->pdev->dev; struct spi_transfer *xfer; - if (msg->is_dma_mapped) + if (is_polling(sdd) || msg->is_dma_mapped) return 0; /* First mark all xfer unmapped */ @@ -635,7 +685,7 @@ static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd, struct device *dev = &sdd->pdev->dev; struct spi_transfer *xfer; - if (msg->is_dma_mapped) + if (is_polling(sdd) || msg->is_dma_mapped) return; list_for_each_entry(xfer, &msg->transfers, transfer_list) { @@ -713,7 +763,8 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master, } /* Polling method for xfers not bigger than FIFO capacity */ - if (xfer->len <= ((FIFO_LVL_MASK(sdd) >> 1) + 1)) + if (is_polling(sdd) || + xfer->len <= ((FIFO_LVL_MASK(sdd) >> 1) + 1)) use_dma = 0; else use_dma = 1; @@ -729,17 +780,10 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master, /* Slave Select */ enable_cs(sdd, spi); - /* Start the signals */ - writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); - spin_unlock_irqrestore(&sdd->lock, flags); status = wait_for_xfer(sdd, xfer, use_dma); - /* Quiese the signals */ - writel(S3C64XX_SPI_SLAVE_SIG_INACT, - sdd->regs + S3C64XX_SPI_SLAVE_SEL); - if (status) { dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n", xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0, @@ -795,7 +839,7 @@ static int s3c64xx_spi_prepare_transfer(struct spi_master *spi) struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi); /* Acquire DMA channels */ - while (!acquire_dma(sdd)) + while (!is_polling(sdd) && !acquire_dma(sdd)) usleep_range(10000, 11000); pm_runtime_get_sync(&sdd->pdev->dev); @@ -808,8 +852,10 @@ static int s3c64xx_spi_unprepare_transfer(struct spi_master *spi) struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi); /* Free DMA channels */ - sdd->ops->release(sdd->rx_dma.ch, &s3c64xx_spi_dma_client); - sdd->ops->release(sdd->tx_dma.ch, &s3c64xx_spi_dma_client); + if (!is_polling(sdd)) { + sdd->ops->release(sdd->rx_dma.ch, &s3c64xx_spi_dma_client); + sdd->ops->release(sdd->tx_dma.ch, &s3c64xx_spi_dma_client); + } pm_runtime_put(&sdd->pdev->dev); @@ -1217,7 +1263,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev) sdd->cur_bpw = 8; - if (!sdd->pdev->dev.of_node) { + if (!sdd->pdev->dev.of_node && !is_polling(sdd)) { res = platform_get_resource(pdev, IORESOURCE_DMA, 0); if (!res) { dev_err(&pdev->dev, "Unable to get SPI tx dma "