From patchwork Thu Jul 7 17:17:50 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Franklin Cooper X-Patchwork-Id: 9219295 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 AB32A60467 for ; Thu, 7 Jul 2016 17:20:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 98BCA28306 for ; Thu, 7 Jul 2016 17:20:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8C36028405; Thu, 7 Jul 2016 17:20:16 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9567928306 for ; Thu, 7 Jul 2016 17:20:15 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bLCwv-0004lu-8P; Thu, 07 Jul 2016 17:18:53 +0000 Received: from mail-oi0-f65.google.com ([209.85.218.65]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bLCwO-0004QG-2o for linux-arm-kernel@lists.infradead.org; Thu, 07 Jul 2016 17:18:21 +0000 Received: by mail-oi0-f65.google.com with SMTP id w141so3491142oia.0 for ; Thu, 07 Jul 2016 10:17:59 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=ZmbrlgY+GPrewRWOY5aFmu1GQ2DnoybtAbUINlNLsaU=; b=HcEnSBGpIWZwqKIt1bfMt1ncnBYj8wRw+Zhh+nZfuaxJ/gvbCaRRIr9Yn1PIfRYjTX YPmr1oxCF9AFwbKUYSmo9QfD0frIKEC5dDgGIha0Gmj2v8qSfR9W9yCf5UyjOHu70VNW 4hiy/2EVjpLOjiZCcz481VL5n7tBKk++ZuSD6K9NsMPs97+Rnc4TFjFpKq0xAaQete0H FQ5f6TUlKmG0/QrwiA7EGu7C41znALoIbjNNoA6TH2oYXmeqasB80qHGLiIyHtAHWk3l TvKMFtuAxjXknVOG2u7LO1rsMGKm9enSC2KWG3nRErsOcSEL4ONyGcZmqWmN9hqGhFIn 1O7A== X-Gm-Message-State: ALyK8tI5NNb5tBwrfrtwW1jjZsuwJrpwCS9hfBqo1jcHhQgDCIqPcGypMXvDFvXNwTxovQ== X-Received: by 10.202.229.206 with SMTP id c197mr741500oih.161.1467911878936; Thu, 07 Jul 2016 10:17:58 -0700 (PDT) Received: from beast-server.fios-router.home ([108.19.207.229]) by smtp.gmail.com with ESMTPSA id 187sm12288245oid.20.2016.07.07.10.17.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 07 Jul 2016 10:17:58 -0700 (PDT) From: Franklin S Cooper Jr To: tony@atomide.com, robh+dt@kernel.org, broonie@kernel.org, linux-omap@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, andy.shevchenko@gmail.com, robert.jarzmik@free.fr, nsekhar@ti.com Subject: [RFC] [PATCH v3 3/4] spi: omap2-mcspi: Use the SPI framework to handle DMA mapping Date: Thu, 7 Jul 2016 12:17:50 -0500 Message-Id: <1467911871-4508-4-git-send-email-fcooper@ti.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1467911871-4508-1-git-send-email-fcooper@ti.com> References: <1467911871-4508-1-git-send-email-fcooper@ti.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160707_101820_363719_9B210F7C X-CRM114-Status: GOOD ( 18.38 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Franklin S Cooper Jr MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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 --- v3 changes: Use sg_split rather than custom sg table clone function. drivers/spi/spi-omap2-mcspi.c | 132 ++++++++++++++++++------------------------ 1 file changed, 56 insertions(+), 76 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index c47f958..d5157b2 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 +446,10 @@ 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; + unsigned int count, transfer_reduction = 0; + struct scatterlist *sg_out[2]; + int nb_sizes = 0, out_mapped_nents[2], ret, x; + size_t sizes[2]; u32 l; int elements = 0; int word_len, element_count; @@ -457,7 +457,6 @@ 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 +464,7 @@ 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 +478,6 @@ 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); @@ -488,15 +486,38 @@ 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; - sg_init_table(&sg, 1); - sg_dma_address(&sg) = xfer->rx_dma; - sg_dma_len(&sg) = dma_count; + if (transfer_reduction) { + /* Split sgl into two. The second sgl won't be used. */ + sizes[0] = count - transfer_reduction; + sizes[1] = transfer_reduction; + nb_sizes = 2; + } else { + /* + * Don't bother splitting the sgl. This essentially + * clones the original sgl. + */ + sizes[0] = count; + nb_sizes = 1; + } + + ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents, + 0, nb_sizes, + sizes, + sg_out, out_mapped_nents, + GFP_KERNEL); - tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1, - DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | - DMA_CTRL_ACK); + if (ret < 0) { + dev_err(&spi->dev, "sg_split failed\n"); + return 0; + } + + tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, + sg_out[0], + out_mapped_nents[0], + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (tx) { tx->callback = omap2_mcspi_rx_callback; tx->callback_param = spi; @@ -510,8 +531,9 @@ 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); + + for (x = 0; x < nb_sizes; x++) + kfree(sg_out[x]); if (mcspi->fifo_depth > 0) return count; @@ -628,8 +650,6 @@ 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; @@ -1087,8 +1107,9 @@ static void omap2_mcspi_cleanup(struct spi_device *spi) gpio_free(spi->cs_gpio); } -static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi, - struct spi_device *spi, struct spi_transfer *t) +static int omap2_mcspi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *t) { /* We only enable one channel at a time -- the one whose message is @@ -1098,7 +1119,7 @@ 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 +1127,7 @@ 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 +1187,8 @@ 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 +1199,8 @@ 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 +1269,11 @@ 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 +1353,7 @@ 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;