From patchwork Fri Jun 17 22:45:13 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Franklin Cooper X-Patchwork-Id: 9185095 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D6C3C6075F for ; Fri, 17 Jun 2016 22:46:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C6345280B0 for ; Fri, 17 Jun 2016 22:46:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BA99D282EE; Fri, 17 Jun 2016 22:46:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1405328236 for ; Fri, 17 Jun 2016 22:46:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932801AbcFQWpo (ORCPT ); Fri, 17 Jun 2016 18:45:44 -0400 Received: from arroyo.ext.ti.com ([198.47.19.12]:60398 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932430AbcFQWpn (ORCPT ); Fri, 17 Jun 2016 18:45:43 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id u5HMjdt8015077; Fri, 17 Jun 2016 17:45:39 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id u5HMjdWj019185; Fri, 17 Jun 2016 17:45:39 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.3.294.0; Fri, 17 Jun 2016 17:45:38 -0500 Received: from dbdmail01.india.ti.com (dbdmail01.india.ti.com [172.24.162.206]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id u5HMjbTp022193; Fri, 17 Jun 2016 17:45:38 -0500 Received: from udb0273011.am.dhcp.ti.com (udb0273011.am.dhcp.ti.com [128.247.83.33]) by dbdmail01.india.ti.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id u5HMjN1O006459; Sat, 18 Jun 2016 04:15:34 +0530 From: Franklin S Cooper Jr To: , , , , , , , CC: Franklin S Cooper Jr Subject: [RFC] [PATCH 3/3] spi: omap2-mcspi: Use the SPI framework to handle DMA mapping Date: Fri, 17 Jun 2016 17:45:13 -0500 Message-ID: <1466203513-4771-4-git-send-email-fcooper@ti.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1466203513-4771-1-git-send-email-fcooper@ti.com> References: <1466203513-4771-1-git-send-email-fcooper@ti.com> MIME-Version: 1.0 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently, the driver handles mapping buffers to be used by the DMA. However, there are times that the current mapping implementation will fail for certain buffers. Fortunately, the SPI framework can detect and map buffers so its usable by the DMA. Update the driver to utilize the SPI framework for buffer mapping instead. Also incorporate hooks that the framework uses to determine if the DMA can or can not be used. This will result in the original omap2_mcspi_transfer_one function being deleted and omap2_mcspi_work_one being renamed to omap2_mcspi_transfer_one. Previously transfer_one was only responsible for mapping and work_one handled the transfer. But now only transferring needs to be handled by the driver. Signed-off-by: Franklin S Cooper Jr --- drivers/spi/spi-omap2-mcspi.c | 109 ++++++++++++++---------------------------- 1 file changed, 36 insertions(+), 73 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index c47f958..84ba671 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -419,16 +419,13 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi, if (mcspi_dma->dma_tx) { struct dma_async_tx_descriptor *tx; - struct scatterlist sg; dmaengine_slave_config(mcspi_dma->dma_tx, &cfg); - sg_init_table(&sg, 1); - sg_dma_address(&sg) = xfer->tx_dma; - sg_dma_len(&sg) = xfer->len; - - tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1, - DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl, + xfer->tx_sg.nents, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (tx) { tx->callback = omap2_mcspi_tx_callback; tx->callback_param = spi; @@ -449,7 +446,8 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, { struct omap2_mcspi *mcspi; struct omap2_mcspi_dma *mcspi_dma; - unsigned int count, dma_count; + struct sg_table *cloned_table = NULL; + unsigned int count, transfer_reduction = 0; u32 l; int elements = 0; int word_len, element_count; @@ -457,7 +455,6 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, mcspi = spi_master_get_devdata(spi->master); mcspi_dma = &mcspi->dma_channels[spi->chip_select]; count = xfer->len; - dma_count = xfer->len; /* * In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM @@ -465,7 +462,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, * normal mode. */ if (mcspi->fifo_depth == 0) - dma_count -= es; + transfer_reduction = es; word_len = cs->word_len; l = mcspi_cached_chconf0(spi); @@ -479,7 +476,6 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, if (mcspi_dma->dma_rx) { struct dma_async_tx_descriptor *tx; - struct scatterlist sg; dmaengine_slave_config(mcspi_dma->dma_rx, &cfg); @@ -488,13 +484,22 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, * configured in turbo mode. */ if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0) - dma_count -= es; + transfer_reduction += es; + + /* + * Get a cloned copy of the rx sg_table whose transfer count + * has been reduced by transfer_reduction. + */ + cloned_table = sg_table_clone(&xfer->rx_sg, + count - transfer_reduction, + GFP_KERNEL); - sg_init_table(&sg, 1); - sg_dma_address(&sg) = xfer->rx_dma; - sg_dma_len(&sg) = dma_count; + if (IS_ERR(cloned_table)) + return 0; - tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1, + tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, + cloned_table->sgl, + cloned_table->nents, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (tx) { @@ -510,8 +515,9 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, omap2_mcspi_set_dma_req(spi, 1, 1); wait_for_completion(&mcspi_dma->dma_rx_completion); - dma_unmap_single(mcspi->dev, xfer->rx_dma, count, - DMA_FROM_DEVICE); + + kfree(cloned_table->sgl); + kfree(cloned_table); if (mcspi->fifo_depth > 0) return count; @@ -628,8 +634,6 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) if (tx != NULL) { wait_for_completion(&mcspi_dma->dma_tx_completion); - dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len, - DMA_TO_DEVICE); if (mcspi->fifo_depth > 0) { irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS; @@ -1087,7 +1091,7 @@ static void omap2_mcspi_cleanup(struct spi_device *spi) gpio_free(spi->cs_gpio); } -static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi, +static int omap2_mcspi_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *t) { @@ -1098,7 +1102,7 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi, * chipselect with the FORCE bit ... CS != channel enable. */ - struct spi_master *master; + struct omap2_mcspi *mcspi; struct omap2_mcspi_dma *mcspi_dma; struct omap2_mcspi_cs *cs; struct omap2_mcspi_device_config *cd; @@ -1106,7 +1110,7 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi, int status = 0; u32 chconf; - master = spi->master; + mcspi = spi_master_get_devdata(master); mcspi_dma = mcspi->dma_channels + spi->chip_select; cs = spi->controller_state; cd = spi->controller_data; @@ -1166,7 +1170,8 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi, unsigned count; if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) && - (t->len >= DMA_MIN_BYTES)) + master->cur_msg_mapped && + master->can_dma(master, spi, t)) omap2_mcspi_set_fifo(spi, t, 1); omap2_mcspi_set_enable(spi, 1); @@ -1177,7 +1182,8 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi, + OMAP2_MCSPI_TX0); if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) && - (t->len >= DMA_MIN_BYTES)) + master->cur_msg_mapped && + master->can_dma(master, spi, t)) count = omap2_mcspi_txrx_dma(spi, t); else count = omap2_mcspi_txrx_pio(spi, t); @@ -1246,55 +1252,11 @@ static int omap2_mcspi_prepare_message(struct spi_master *master, return 0; } -static int omap2_mcspi_transfer_one(struct spi_master *master, - struct spi_device *spi, struct spi_transfer *t) +static bool omap2_mcspi_can_dma(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *xfer) { - struct omap2_mcspi *mcspi; - struct omap2_mcspi_dma *mcspi_dma; - const void *tx_buf = t->tx_buf; - void *rx_buf = t->rx_buf; - unsigned len = t->len; - - mcspi = spi_master_get_devdata(master); - mcspi_dma = mcspi->dma_channels + spi->chip_select; - - if ((len && !(rx_buf || tx_buf))) { - dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n", - t->speed_hz, - len, - tx_buf ? "tx" : "", - rx_buf ? "rx" : "", - t->bits_per_word); - return -EINVAL; - } - - if (len < DMA_MIN_BYTES) - goto skip_dma_map; - - if (mcspi_dma->dma_tx && tx_buf != NULL) { - t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf, - len, DMA_TO_DEVICE); - if (dma_mapping_error(mcspi->dev, t->tx_dma)) { - dev_dbg(mcspi->dev, "dma %cX %d bytes error\n", - 'T', len); - return -EINVAL; - } - } - if (mcspi_dma->dma_rx && rx_buf != NULL) { - t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len, - DMA_FROM_DEVICE); - if (dma_mapping_error(mcspi->dev, t->rx_dma)) { - dev_dbg(mcspi->dev, "dma %cX %d bytes error\n", - 'R', len); - if (tx_buf != NULL) - dma_unmap_single(mcspi->dev, t->tx_dma, - len, DMA_TO_DEVICE); - return -EINVAL; - } - } - -skip_dma_map: - return omap2_mcspi_work_one(mcspi, spi, t); + return (xfer->len >= DMA_MIN_BYTES); } static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi) @@ -1374,6 +1336,7 @@ static int omap2_mcspi_probe(struct platform_device *pdev) master->setup = omap2_mcspi_setup; master->auto_runtime_pm = true; master->prepare_message = omap2_mcspi_prepare_message; + master->can_dma = omap2_mcspi_can_dma; master->transfer_one = omap2_mcspi_transfer_one; master->set_cs = omap2_mcspi_set_cs; master->cleanup = omap2_mcspi_cleanup;