From patchwork Wed Nov 17 10:44:05 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sekhar Nori X-Patchwork-Id: 331941 Received: from devils.ext.ti.com (devils.ext.ti.com [198.47.26.153]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id oAHAutaj013268 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 17 Nov 2010 10:57:16 GMT Received: from dlep36.itg.ti.com ([157.170.170.91]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id oAHAt5LO009982 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 17 Nov 2010 04:55:05 -0600 Received: from linux.omap.com (localhost [127.0.0.1]) by dlep36.itg.ti.com (8.13.8/8.13.8) with ESMTP id oAHAt4JE003121; Wed, 17 Nov 2010 04:55:04 -0600 (CST) Received: from linux.omap.com (localhost [127.0.0.1]) by linux.omap.com (Postfix) with ESMTP id BC6BD80636; Wed, 17 Nov 2010 04:55:04 -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 D2C2A8063F 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 oAHAiU2M021907; 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 oAHAiPFG030493; 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 oAHAiPaq030490; Wed, 17 Nov 2010 16:14:25 +0530 From: Sekhar Nori To: spi-devel-general@lists.sourceforge.net Subject: [PATCH 33/49] spi: davinci: do not use temporary buffer if no transmit data provided Date: Wed, 17 Nov 2010 16:14:05 +0530 Message-Id: <1289990661-30126-34-git-send-email-nsekhar@ti.com> X-Mailer: git-send-email 1.6.2.4 In-Reply-To: <1289990661-30126-33-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> 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 10:57:16 +0000 (UTC) diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c index a5f03dd..f512939 100644 --- a/drivers/spi/davinci_spi.c +++ b/drivers/spi/davinci_spi.c @@ -38,8 +38,6 @@ #define CS_DEFAULT 0xFF -#define SPI_BUFSIZ (SMP_CACHE_BYTES + 1) - #define SPIFMT_PHASE_MASK BIT(16) #define SPIFMT_POLARITY_MASK BIT(17) #define SPIFMT_DISTIMER_MASK BIT(18) @@ -140,7 +138,6 @@ struct davinci_spi { const void *tx; void *rx; - u8 *tmp_buf; int rcount; int wcount; struct davinci_spi_dma dma_channels; @@ -718,7 +715,7 @@ 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, temp_count; + int count; struct davinci_spi_dma *davinci_spi_dma; int data_type, ret; unsigned long tx_reg, rx_reg; @@ -750,6 +747,18 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) /* Enable SPI */ set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); + /* + * Transmit DMA setup + * + * If there is transmit data, map the transmit buffer, set it as the + * source of data and set the source B index to data size. + * If there is no transmit data, set the transmit register as the + * source of data, and set the source B index to zero. + * + * The destination is always the transmit register itself. And the + * destination never increments. + */ + if (t->tx_buf) { t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, count, DMA_TO_DEVICE); @@ -758,25 +767,15 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) " TX buffer\n", count); return -ENOMEM; } - temp_count = count; - } else { - /* We need TX clocking for RX transaction */ - t->tx_dma = dma_map_single(&spi->dev, - (void *)davinci_spi->tmp_buf, count + 1, - DMA_TO_DEVICE); - if (dma_mapping_error(&spi->dev, t->tx_dma)) { - dev_dbg(sdev, "Unable to DMA map a %d bytes" - " TX tmp buffer\n", count); - return -ENOMEM; - } - temp_count = count + 1; } edma_set_transfer_params(davinci_spi_dma->dma_tx_channel, - data_type, temp_count, 1, 0, ASYNC); + data_type, count, 1, 0, ASYNC); edma_set_dest(davinci_spi_dma->dma_tx_channel, tx_reg, INCR, W8BIT); - edma_set_src(davinci_spi_dma->dma_tx_channel, t->tx_dma, INCR, W8BIT); - edma_set_src_index(davinci_spi_dma->dma_tx_channel, data_type, 0); + edma_set_src(davinci_spi_dma->dma_tx_channel, + t->tx_buf ? t->tx_dma : tx_reg, INCR, W8BIT); + edma_set_src_index(davinci_spi_dma->dma_tx_channel, + t->tx_buf ? data_type : 0, 0); edma_set_dest_index(davinci_spi_dma->dma_tx_channel, 0, 0); if (t->rx_buf) { @@ -818,7 +817,8 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t) wait_for_completion_interruptible( &davinci_spi_dma->dma_rx_completion); - dma_unmap_single(NULL, t->tx_dma, temp_count, DMA_TO_DEVICE); + 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); @@ -906,17 +906,10 @@ static int davinci_spi_probe(struct platform_device *pdev) if (ret) goto unmap_io; - /* Allocate tmp_buf for tx_buf */ - davinci_spi->tmp_buf = kzalloc(SPI_BUFSIZ, GFP_KERNEL); - if (davinci_spi->tmp_buf == NULL) { - ret = -ENOMEM; - goto irq_free; - } - davinci_spi->bitbang.master = spi_master_get(master); if (davinci_spi->bitbang.master == NULL) { ret = -ENODEV; - goto free_tmp_buf; + goto irq_free; } davinci_spi->clk = clk_get(&pdev->dev, NULL); @@ -1027,8 +1020,6 @@ free_clk: clk_put(davinci_spi->clk); put_master: spi_master_put(master); -free_tmp_buf: - kfree(davinci_spi->tmp_buf); irq_free: free_irq(davinci_spi->irq, davinci_spi); unmap_io: @@ -1063,7 +1054,6 @@ static int __exit davinci_spi_remove(struct platform_device *pdev) clk_disable(davinci_spi->clk); clk_put(davinci_spi->clk); spi_master_put(master); - kfree(davinci_spi->tmp_buf); free_irq(davinci_spi->irq, davinci_spi); iounmap(davinci_spi->base); release_mem_region(davinci_spi->pbase, davinci_spi->region_size);