Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751655AbdG1Gyv (ORCPT ); Fri, 28 Jul 2017 02:54:51 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:36168 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751465AbdG1GyC (ORCPT ); Fri, 28 Jul 2017 02:54:02 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C31896099A Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=varada@codeaurora.org From: Varadarajan Narayanan To: broonie@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, andy.gross@linaro.org, david.brown@linaro.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org Cc: Varadarajan Narayanan , Matthew McClintock Subject: [PATCH v6 12/14] spi: qup: allow multiple DMA transactions per spi xfer Date: Fri, 28 Jul 2017 12:22:59 +0530 Message-Id: <1501224781-19519-13-git-send-email-varada@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1501224781-19519-1-git-send-email-varada@codeaurora.org> References: <1501224781-19519-1-git-send-email-varada@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3707 Lines: 135 Much like the block mode changes, we are breaking up DMA transactions into 64K chunks so we can reset the QUP engine. Signed-off-by: Matthew McClintock Signed-off-by: Varadarajan Narayanan --- drivers/spi/spi-qup.c | 92 ++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 66 insertions(+), 26 deletions(-) diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c index 1af3b41..3c2c2c0 100644 --- a/drivers/spi/spi-qup.c +++ b/drivers/spi/spi-qup.c @@ -418,12 +418,35 @@ static void spi_qup_dma_terminate(struct spi_master *master, dmaengine_terminate_all(master->dma_rx); } +static u32 spi_qup_sgl_get_nents_len(struct scatterlist *sgl, u32 max, + u32 *nents) +{ + struct scatterlist *sg; + u32 total = 0; + + *nents = 0; + + for (sg = sgl; sg; sg = sg_next(sg)) { + unsigned int len = sg_dma_len(sg); + + /* check for overflow as well as limit */ + if (((total + len) < total) || ((total + len) > max)) + break; + + total += len; + (*nents)++; + } + + return total; +} + static int spi_qup_do_dma(struct spi_device *spi, struct spi_transfer *xfer, unsigned long timeout) { dma_async_tx_callback rx_done = NULL, tx_done = NULL; struct spi_master *master = spi->master; struct spi_qup *qup = spi_master_get_devdata(master); + struct scatterlist *tx_sgl, *rx_sgl; int ret; if (xfer->rx_buf) @@ -431,40 +454,57 @@ static int spi_qup_do_dma(struct spi_device *spi, struct spi_transfer *xfer, else if (xfer->tx_buf) tx_done = spi_qup_dma_done; - ret = spi_qup_io_config(spi, xfer); - if (ret) - return ret; + rx_sgl = xfer->rx_sg.sgl; + tx_sgl = xfer->tx_sg.sgl; - /* before issuing the descriptors, set the QUP to run */ - ret = spi_qup_set_state(qup, QUP_STATE_RUN); - if (ret) { - dev_warn(qup->dev, "%s(%d): cannot set RUN state\n", - __func__, __LINE__); - return ret; - } + do { + u32 rx_nents, tx_nents; + + if (rx_sgl) + qup->n_words = spi_qup_sgl_get_nents_len(rx_sgl, + SPI_MAX_XFER, &rx_nents) / qup->w_size; + if (tx_sgl) + qup->n_words = spi_qup_sgl_get_nents_len(tx_sgl, + SPI_MAX_XFER, &tx_nents) / qup->w_size; + if (!qup->n_words) + return -EIO; - if (xfer->rx_buf) { - ret = spi_qup_prep_sg(master, xfer->rx_sg.sgl, - xfer->rx_sg.nents, DMA_DEV_TO_MEM, - rx_done); + ret = spi_qup_io_config(spi, xfer); if (ret) return ret; - dma_async_issue_pending(master->dma_rx); - } - - if (xfer->tx_buf) { - ret = spi_qup_prep_sg(master, xfer->tx_sg.sgl, - xfer->tx_sg.nents, DMA_MEM_TO_DEV, - tx_done); - if (ret) + /* before issuing the descriptors, set the QUP to run */ + ret = spi_qup_set_state(qup, QUP_STATE_RUN); + if (ret) { + dev_warn(qup->dev, "cannot set RUN state\n"); return ret; + } + if (rx_sgl) { + ret = spi_qup_prep_sg(master, rx_sgl, rx_nents, + DMA_DEV_TO_MEM, rx_done); + if (ret) + return ret; + dma_async_issue_pending(master->dma_rx); + } - dma_async_issue_pending(master->dma_tx); - } + if (tx_sgl) { + ret = spi_qup_prep_sg(master, tx_sgl, tx_nents, + DMA_MEM_TO_DEV, tx_done); + if (ret) + return ret; + + dma_async_issue_pending(master->dma_tx); + } + + if (!wait_for_completion_timeout(&qup->done, timeout)) + return -ETIMEDOUT; + + for (; rx_sgl && rx_nents--; rx_sgl = sg_next(rx_sgl)) + ; + for (; tx_sgl && tx_nents--; tx_sgl = sg_next(tx_sgl)) + ; - if (!wait_for_completion_timeout(&qup->done, timeout)) - return -ETIMEDOUT; + } while (rx_sgl || tx_sgl); return 0; } -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation