From patchwork Mon Jan 10 10:37:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alain Volmat X-Patchwork-Id: 12708560 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54D6CC433EF for ; Mon, 10 Jan 2022 10:38:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244065AbiAJKir (ORCPT ); Mon, 10 Jan 2022 05:38:47 -0500 Received: from mx07-00178001.pphosted.com ([185.132.182.106]:44980 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244063AbiAJKiE (ORCPT ); Mon, 10 Jan 2022 05:38:04 -0500 Received: from pps.filterd (m0241204.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 20A9V4IQ030680; Mon, 10 Jan 2022 11:37:42 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=selector1; bh=ltuKY3JbZ9a8gnDMbB/xLmLbXhMhu4XfcFmrhNwLzSU=; b=puEdB7FwTo5ZqfbW9w6h8VvccFHdyT7TqxDMeKo8OWELlPslVpd/OcpdjmcDrHTi9/yt X3nKp4jkAK8ZgZj79voIn9XBnsumcaJ/a0kOQOZFxy5xluMeV/LSpP1HmHndwlHIJhq+ Kb9ha/tS7d33SGyHIh8gAze9WjZEiUoTtjymq5JCjwHO07tDvr9qESvqmAvSvDDZB8ow dwxPzdcWpEErcqH/k71R4FU9bU0bz60UHUakVhUwlCKDYicKXMDd0WahiMLnzro8zNB+ 0B7AjqAgGJXNVkpSdCDymvgV10JFf/vxnlDWYqaEyljYOsS0FYnlIZGiW7cPqQasLMG7 TA== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3dgj85rakv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 10 Jan 2022 11:37:42 +0100 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 3896D10002A; Mon, 10 Jan 2022 11:37:40 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 2AFE9235F0F; Mon, 10 Jan 2022 11:37:40 +0100 (CET) Received: from localhost (10.75.127.48) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Mon, 10 Jan 2022 11:37:39 +0100 From: Alain Volmat To: , CC: , , , , , , Subject: [PATCH] media: stm32: dcmi: create a dma scatterlist based on DMA max_sg_burst value Date: Mon, 10 Jan 2022 11:37:39 +0100 Message-ID: <20220110103739.118426-1-alain.volmat@foss.st.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.75.127.48] X-ClientProxiedBy: SFHDAG2NODE1.st.com (10.75.127.4) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2022-01-10_04,2022-01-10_01,2021-12-02_01 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Prior to submitting a transfer to the DMA, the client should first check the capabilities of the DMA channel in term of maximum of each segment. This is given by the max_sg_burst value reported by dma_get_slave_caps API. Based on that, if the transfer is larger than what can be handled by the DMA channel, we split the transfer into several scatterlist elements. Signed-off-by: Alain Volmat --- drivers/media/platform/stm32/stm32-dcmi.c | 47 ++++++++++++++++++----- 1 file changed, 37 insertions(+), 10 deletions(-) diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index e1b17c05229c..ee170e999a88 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -113,7 +113,7 @@ struct dcmi_framesize { struct dcmi_buf { struct vb2_v4l2_buffer vb; bool prepared; - dma_addr_t paddr; + struct sg_table sgt; size_t size; struct list_head list; }; @@ -157,6 +157,7 @@ struct stm32_dcmi { enum state state; struct dma_chan *dma_chan; dma_cookie_t dma_cookie; + u32 dma_max_burst; u32 misr; int errors_count; int overrun_count; @@ -326,13 +327,11 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi, mutex_lock(&dcmi->dma_lock); /* Prepare a DMA transaction */ - desc = dmaengine_prep_slave_single(dcmi->dma_chan, buf->paddr, - buf->size, + desc = dmaengine_prep_slave_sg(dcmi->dma_chan, buf->sgt.sgl, buf->sgt.nents, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!desc) { - dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_single failed for buffer phy=%pad size=%zu\n", - __func__, &buf->paddr, buf->size); + dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_sg failed\n", __func__); mutex_unlock(&dcmi->dma_lock); return -EINVAL; } @@ -524,6 +523,10 @@ static int dcmi_buf_prepare(struct vb2_buffer *vb) struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); struct dcmi_buf *buf = container_of(vbuf, struct dcmi_buf, vb); unsigned long size; + unsigned int num_sgs = 1; + dma_addr_t dma_buf; + struct scatterlist *sg; + int i, ret; size = dcmi->fmt.fmt.pix.sizeimage; @@ -537,15 +540,33 @@ static int dcmi_buf_prepare(struct vb2_buffer *vb) if (!buf->prepared) { /* Get memory addresses */ - buf->paddr = - vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0); buf->size = vb2_plane_size(&buf->vb.vb2_buf, 0); - buf->prepared = true; + if (buf->size > dcmi->dma_max_burst) + num_sgs = DIV_ROUND_UP(buf->size, dcmi->dma_max_burst); - vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->size); + ret = sg_alloc_table(&buf->sgt, num_sgs, GFP_ATOMIC); + if (ret) { + dev_err(dcmi->dev, "sg table alloc failed\n"); + return ret; + } + + dma_buf = vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0); dev_dbg(dcmi->dev, "buffer[%d] phy=%pad size=%zu\n", - vb->index, &buf->paddr, buf->size); + vb->index, &dma_buf, buf->size); + + for_each_sg(buf->sgt.sgl, sg, num_sgs, i) { + size_t bytes = min_t(size_t, size, dcmi->dma_max_burst); + + sg_dma_address(sg) = dma_buf; + sg_dma_len(sg) = bytes; + dma_buf += bytes; + size -= bytes; + } + + buf->prepared = true; + + vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->size); } return 0; @@ -1866,6 +1887,7 @@ static int dcmi_probe(struct platform_device *pdev) struct stm32_dcmi *dcmi; struct vb2_queue *q; struct dma_chan *chan; + struct dma_slave_caps caps; struct clk *mclk; int irq; int ret = 0; @@ -1953,6 +1975,11 @@ static int dcmi_probe(struct platform_device *pdev) return ret; } + dcmi->dma_max_burst = UINT_MAX; + ret = dma_get_slave_caps(chan, &caps); + if (!ret && caps.max_sg_burst) + dcmi->dma_max_burst = caps.max_sg_burst * DMA_SLAVE_BUSWIDTH_4_BYTES; + spin_lock_init(&dcmi->irqlock); mutex_init(&dcmi->lock); mutex_init(&dcmi->dma_lock);