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[211.36.80.164]) by mx.google.com with ESMTPS id t6sm85719744paz.11.2013.02.13.11.26.50 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 13 Feb 2013 11:26:50 -0800 (PST) From: Girish K S To: spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: [PATCH V2 2/5] spi: s3c64xx: added support for polling mode Date: Wed, 13 Feb 2013 11:25:28 -0800 Message-Id: <1360783531-32654-3-git-send-email-ks.giri@samsung.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1360783531-32654-1-git-send-email-ks.giri@samsung.com> References: <1360783531-32654-1-git-send-email-ks.giri@samsung.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130213_142653_433016_AEC0A550 X-CRM114-Status: GOOD ( 26.03 ) X-Spam-Score: -2.5 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.5 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.210.47 listed in list.dnswl.org] 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) -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -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 Cc: grant.likely@secretlab.ca, t.figa@samsung.com, broonie@opensource.wolfsonmicro.com, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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 --- changes in v2: Added quirk to force polling mode. Modified the wait_for_zfer function, to handle the polling mode support. Before reading the data from the Rx fifo, no. of iterations to loop are calculated. And Rx fifo is read in the loop till all the data is read to memory drivers/spi/spi-s3c64xx.c | 128 +++++++++++++++++++++++++++++++-------------- 1 file changed, 88 insertions(+), 40 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 6eba24e..45bad5d 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) @@ -155,6 +157,7 @@ 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; }; @@ -421,6 +424,27 @@ 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, @@ -445,20 +469,19 @@ 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) @@ -468,30 +491,53 @@ 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; } @@ -507,6 +553,10 @@ 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) @@ -588,7 +638,7 @@ 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 */ @@ -637,7 +687,7 @@ 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) { @@ -715,7 +765,8 @@ 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; @@ -731,17 +782,10 @@ 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, @@ -797,7 +841,7 @@ 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); @@ -810,8 +854,10 @@ 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); @@ -1261,13 +1307,15 @@ static int s3c64xx_spi_probe(struct platform_device *pdev) sdd->cur_bpw = 8; - ret = s3c64xx_spi_get_dmares(sdd, true); - if (ret) - goto err0; + if (!is_polling(sdd)) { + ret = s3c64xx_spi_get_dmares(sdd, true); + if (ret) + goto err0; - ret = s3c64xx_spi_get_dmares(sdd, false); - if (ret) - goto err0; + ret = s3c64xx_spi_get_dmares(sdd, false); + if (ret) + goto err0; + } master->dev.of_node = pdev->dev.of_node; master->bus_num = sdd->port_id;