From patchwork Wed Nov 17 10:44:06 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sekhar Nori X-Patchwork-Id: 331811 Received: from bear.ext.ti.com (bear.ext.ti.com [192.94.94.41]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id oAHAu3lk012787 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 17 Nov 2010 10:56:23 GMT Received: from dlep34.itg.ti.com ([157.170.170.115]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id oAHArj65017145 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 17 Nov 2010 04:53:45 -0600 Received: from linux.omap.com (localhost [127.0.0.1]) by dlep34.itg.ti.com (8.13.7/8.13.7) with ESMTP id oAHArj8n011314; Wed, 17 Nov 2010 04:53:45 -0600 (CST) Received: from linux.omap.com (localhost [127.0.0.1]) by linux.omap.com (Postfix) with ESMTP id D2E8C80632; Wed, 17 Nov 2010 04:53:44 -0600 (CST) X-Original-To: davinci-linux-open-source@linux.davincidsp.com Delivered-To: davinci-linux-open-source@linux.davincidsp.com Received: from dbdp31.itg.ti.com (dbdp31.itg.ti.com [172.24.170.98]) by linux.omap.com (Postfix) with ESMTP id 824B780637 for ; Wed, 17 Nov 2010 04:44:32 -0600 (CST) Received: from psplinux051.india.ti.com (localhost [127.0.0.1]) by dbdp31.itg.ti.com (8.13.8/8.13.8) with ESMTP id oAHAiUiJ021910; Wed, 17 Nov 2010 16:14:30 +0530 (IST) Received: from psplinux051.india.ti.com (localhost [127.0.0.1]) by psplinux051.india.ti.com (8.13.1/8.13.1) with ESMTP id oAHAiPIB030500; Wed, 17 Nov 2010 16:14:25 +0530 Received: (from a0875516@localhost) by psplinux051.india.ti.com (8.13.1/8.13.1/Submit) id oAHAiPcU030497; Wed, 17 Nov 2010 16:14:25 +0530 From: Sekhar Nori To: spi-devel-general@lists.sourceforge.net Subject: [PATCH 34/49] spi: davinci: always start receive DMA Date: Wed, 17 Nov 2010 16:14:06 +0530 Message-Id: <1289990661-30126-35-git-send-email-nsekhar@ti.com> X-Mailer: git-send-email 1.6.2.4 In-Reply-To: <1289990661-30126-34-git-send-email-nsekhar@ti.com> References: <1289990661-30126-1-git-send-email-nsekhar@ti.com> <1289990661-30126-2-git-send-email-nsekhar@ti.com> <1289990661-30126-3-git-send-email-nsekhar@ti.com> <1289990661-30126-4-git-send-email-nsekhar@ti.com> <1289990661-30126-5-git-send-email-nsekhar@ti.com> <1289990661-30126-6-git-send-email-nsekhar@ti.com> <1289990661-30126-7-git-send-email-nsekhar@ti.com> <1289990661-30126-8-git-send-email-nsekhar@ti.com> <1289990661-30126-9-git-send-email-nsekhar@ti.com> <1289990661-30126-10-git-send-email-nsekhar@ti.com> <1289990661-30126-11-git-send-email-nsekhar@ti.com> <1289990661-30126-12-git-send-email-nsekhar@ti.com> <1289990661-30126-13-git-send-email-nsekhar@ti.com> <1289990661-30126-14-git-send-email-nsekhar@ti.com> <1289990661-30126-15-git-send-email-nsekhar@ti.com> <1289990661-30126-16-git-send-email-nsekhar@ti.com> <1289990661-30126-17-git-send-email-nsekhar@ti.com> <1289990661-30126-18-git-send-email-nsekhar@ti.com> <1289990661-30126-19-git-send-email-nsekhar@ti.com> <1289990661-30126-20-git-send-email-nsekhar@ti.com> <1289990661-30126-21-git-send-email-nsekhar@ti.com> <1289990661-30126-22-git-send-email-nsekhar@ti.com> <1289990661-30126-23-git-send-email-nsekhar@ti.com> <1289990661-30126-24-git-send-email-nsekhar@ti.com> <1289990661-30126-25-git-send-email-nsekhar@ti.com> <1289990661-30126-26-git-send-email-nsekhar@ti.com> <1289990661-30126-27-git-send-email-nsekhar@ti.com> <1289990661-30126-28-git-send-email-nsekhar@ti.com> <1289990661-30126-29-git-send-email-nsekhar@ti.com> <1289990661-30126-30-git-send-email-nsekhar@ti.com> <1289990661-30126-31-git-send-email-nsekhar@ti.com> <1289990661-30126-32-git-send-email-nsekhar@ti.com> <1289990661-30126-33-git-send-email-nsekhar@ti.com> <1289990661-30126-34-git-send-email-nsekhar@ti.com> Cc: Grant Likely , davinci-linux-open-source@linux.davincidsp.com, David Brownell X-BeenThere: davinci-linux-open-source@linux.davincidsp.com X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: davinci-linux-open-source-bounces@linux.davincidsp.com Errors-To: davinci-linux-open-source-bounces@linux.davincidsp.com X-Greylist: Sender succeeded STARTTLS authentication, not delayed by milter-greylist-4.2.3 (demeter1.kernel.org [140.211.167.41]); Wed, 17 Nov 2010 10:56:23 +0000 (UTC) diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c index f512939..705d006 100644 --- a/drivers/spi/davinci_spi.c +++ b/drivers/spi/davinci_spi.c @@ -138,6 +138,8 @@ struct davinci_spi { const void *tx; void *rx; +#define SPI_TMP_BUFSZ (SMP_CACHE_BYTES + 1) + u8 rx_tmp_buf[SPI_TMP_BUFSZ]; int rcount; int wcount; struct davinci_spi_dma dma_channels; @@ -716,10 +718,12 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) struct davinci_spi *davinci_spi; int int_status = 0; int count; + unsigned rx_buf_count; struct davinci_spi_dma *davinci_spi_dma; int data_type, ret; unsigned long tx_reg, rx_reg; struct davinci_spi_platform_data *pdata; + void *rx_buf; struct device *sdev; davinci_spi = spi_master_get_devdata(spi->master); @@ -778,50 +782,60 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) t->tx_buf ? data_type : 0, 0); edma_set_dest_index(davinci_spi_dma->dma_tx_channel, 0, 0); + /* + * Receive DMA setup + * + * If there is receive buffer, use it to receive data. If there + * is none provided, use a temporary receive buffer. Set the + * destination B index to 0 so effectively only one byte is used + * in the temporary buffer (address does not increment). + * + * The source of receive data is the receive data register. The + * source address never increments. + */ + if (t->rx_buf) { - t->rx_dma = dma_map_single(&spi->dev, (void *)t->rx_buf, count, - DMA_FROM_DEVICE); - if (dma_mapping_error(&spi->dev, t->rx_dma)) { - dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n", - count); - if (t->tx_buf != NULL) - dma_unmap_single(NULL, t->tx_dma, - count, DMA_TO_DEVICE); - return -ENOMEM; - } - edma_set_transfer_params(davinci_spi_dma->dma_rx_channel, - data_type, count, 1, 0, ASYNC); - edma_set_src(davinci_spi_dma->dma_rx_channel, - rx_reg, INCR, W8BIT); - edma_set_dest(davinci_spi_dma->dma_rx_channel, - t->rx_dma, INCR, W8BIT); - edma_set_src_index(davinci_spi_dma->dma_rx_channel, 0, 0); - edma_set_dest_index(davinci_spi_dma->dma_rx_channel, - data_type, 0); + rx_buf = t->rx_buf; + rx_buf_count = count; + } else { + rx_buf = davinci_spi->rx_tmp_buf; + rx_buf_count = sizeof(davinci_spi->rx_tmp_buf); + } + + t->rx_dma = dma_map_single(&spi->dev, rx_buf, rx_buf_count, + DMA_FROM_DEVICE); + if (dma_mapping_error(&spi->dev, t->rx_dma)) { + dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n", + rx_buf_count); + if (t->tx_buf) + dma_unmap_single(NULL, t->tx_dma, count, DMA_TO_DEVICE); + return -ENOMEM; } + edma_set_transfer_params(davinci_spi_dma->dma_rx_channel, data_type, + count, 1, 0, ASYNC); + edma_set_src(davinci_spi_dma->dma_rx_channel, rx_reg, INCR, W8BIT); + edma_set_dest(davinci_spi_dma->dma_rx_channel, t->rx_dma, INCR, W8BIT); + edma_set_src_index(davinci_spi_dma->dma_rx_channel, 0, 0); + edma_set_dest_index(davinci_spi_dma->dma_rx_channel, + t->rx_buf ? data_type : 0, 0); + if (pdata->cshold_bug) { u16 spidat1 = ioread16(davinci_spi->base + SPIDAT1 + 2); iowrite16(spidat1, davinci_spi->base + SPIDAT1 + 2); } - if (t->rx_buf) - edma_start(davinci_spi_dma->dma_rx_channel); - + edma_start(davinci_spi_dma->dma_rx_channel); edma_start(davinci_spi_dma->dma_tx_channel); davinci_spi_set_dma_req(spi, 1); wait_for_completion_interruptible(&davinci_spi_dma->dma_tx_completion); - - if (t->rx_buf) - wait_for_completion_interruptible( - &davinci_spi_dma->dma_rx_completion); + wait_for_completion_interruptible(&davinci_spi_dma->dma_rx_completion); if (t->tx_buf) dma_unmap_single(NULL, t->tx_dma, count, DMA_TO_DEVICE); - if (t->rx_buf) - dma_unmap_single(NULL, t->rx_dma, count, DMA_FROM_DEVICE); + dma_unmap_single(NULL, t->rx_dma, rx_buf_count, DMA_FROM_DEVICE); /* * Check for bit error, desync error,parity error,timeout error and