From patchwork Fri Sep 22 16:20:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 13396007 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0103ECD4843 for ; Fri, 22 Sep 2023 16:21:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=/zAQwINjpSDjQ0OBEYBOcDtTWtF7q1EXgKuogjH8T60=; b=Lt8RaRfKgiSw6K EiulRWTGFhPVCyA+s3lGmWJQGS9yBEkb+xjIgFttX6aAN0Dmtal7FswEj/J4aZWLD4T3Bu0GBn2pb JhasJnzXHmGgtEbEUK+dbq9c+eOL9+2wumzyn/R4DqrwTQAIWmHIUHXeqXTG0/U795LXZCUtdRVED f9IGqAuMfJlHQNsY4ZP2H0rtix+JqGuStCVUrHWwxlgr7AeqeYRhnYuNB3j4TR3srAY0rMTIEIUrv jImnGt4GxBuPWqOg5Oro2bwK6sivDeBMKndRmtv/CIYjHsmW1tYTvIrV0vW304R4/mUCJSYmRpels F9pC3+SpmGRWIYvuSCbA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qjiu8-009OiD-1Y; Fri, 22 Sep 2023 16:21:20 +0000 Received: from relay4-d.mail.gandi.net ([2001:4b98:dc4:8::224]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qjitv-009Odd-1H for linux-arm-kernel@lists.infradead.org; Fri, 22 Sep 2023 16:21:11 +0000 Received: by mail.gandi.net (Postfix) with ESMTPSA id 1A09FE0009; Fri, 22 Sep 2023 16:21:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1695399665; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hM/G7GLoJFD2BkQOr/LMeiSdKwvxTEdiVuJVUQHGZ5k=; b=DqgLRa0e5okZfd/ObrWO96bmvQsNN1Lyn++po3TQY+w5EHCHa9+WwfA/601N/DB899xsXK WZZVeCYjmA3RONBlWbeUBP2Z3oR9ZadIkTPAlYQ39uVqfWC0uBTLLHg4piTNkhe2p0VJnv CVs019y9QYZvRXV38ZW8pPQxF4dSeke0/0JOU/pdd/5jM1R5qY4qqW5HuntdV1wNlsYZUS VO+SouYeLgdje3B4jGpxe6XgsX3lxAh+L2Ele5KWOND7Ef2lY5aEwlkl7RgoKLPWJkB6Eh EIQBVpACeEbkUOXPPxWjvwWNJzEN5MIe8JcGwYulxxpCpGXhDZSvkc8tPN1Otw== From: Miquel Raynal To: Lizhi Hou , Brian Xu , Raj Kumar Rampelli , Vinod Koul , Michal Simek Cc: dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Thomas Petazzoni , , Miquel Raynal Subject: [PATCH v2 2/2] dmaengine: xilinx: xdma: Support cyclic transfers Date: Fri, 22 Sep 2023 18:20:56 +0200 Message-Id: <20230922162056.594933-3-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230922162056.594933-1-miquel.raynal@bootlin.com> References: <20230922162056.594933-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 X-GND-Sasl: miquel.raynal@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230922_092107_726147_5FA24195 X-CRM114-Status: GOOD ( 26.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In order to use this dmaengine with sound devices, let's add cyclic transfers support. Most of the code is reused from the existing scatter-gather implementation, only the final linking between descriptors, the control fields (to trigger interrupts more often) and the interrupt handling are really different. This controller supports up to 32 adjacent descriptors, we assume this is way more than enough for the purpose of cyclic transfers and limit to 32 the number of cycled descriptors. This way, we simplify a lot the overall handling of the descriptors. Signed-off-by: Miquel Raynal --- drivers/dma/xilinx/xdma-regs.h | 2 + drivers/dma/xilinx/xdma.c | 165 +++++++++++++++++++++++++++++++-- 2 files changed, 161 insertions(+), 6 deletions(-) diff --git a/drivers/dma/xilinx/xdma-regs.h b/drivers/dma/xilinx/xdma-regs.h index dd98b4526b90..e641a5083e14 100644 --- a/drivers/dma/xilinx/xdma-regs.h +++ b/drivers/dma/xilinx/xdma-regs.h @@ -44,6 +44,8 @@ FIELD_PREP(XDMA_DESC_FLAGS_BITS, (flag))) #define XDMA_DESC_CONTROL_LAST \ XDMA_DESC_CONTROL(1, XDMA_DESC_STOPPED | XDMA_DESC_COMPLETED) +#define XDMA_DESC_CONTROL_CYCLIC \ + XDMA_DESC_CONTROL(1, XDMA_DESC_COMPLETED) /* * Descriptor for a single contiguous memory block transfer. diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c index 09ed13d6666d..bc9a6ca3353e 100644 --- a/drivers/dma/xilinx/xdma.c +++ b/drivers/dma/xilinx/xdma.c @@ -83,6 +83,9 @@ struct xdma_chan { * @dblk_num: Number of hardware descriptor blocks * @desc_num: Number of hardware descriptors * @completed_desc_num: Completed hardware descriptors + * @cyclic: Cyclic transfer vs. scatter-gather + * @periods: Number of periods in the cyclic transfer + * @period_size: Size of a period in bytes in cyclic transfers */ struct xdma_desc { struct virt_dma_desc vdesc; @@ -93,6 +96,9 @@ struct xdma_desc { u32 dblk_num; u32 desc_num; u32 completed_desc_num; + bool cyclic; + u32 periods; + u32 period_size; }; #define XDMA_DEV_STATUS_REG_DMA BIT(0) @@ -174,6 +180,25 @@ static void xdma_link_sg_desc_blocks(struct xdma_desc *sw_desc) desc->control = cpu_to_le32(XDMA_DESC_CONTROL_LAST); } +/** + * xdma_link_cyclic_desc_blocks - Link cyclic descriptor blocks for DMA transfer + * @sw_desc: Tx descriptor pointer + */ +static void xdma_link_cyclic_desc_blocks(struct xdma_desc *sw_desc) +{ + struct xdma_desc_block *block; + struct xdma_hw_desc *desc; + int i; + + block = sw_desc->desc_blocks; + for (i = 0; i < sw_desc->desc_num - 1; i++) { + desc = block->virt_addr + i * XDMA_DESC_SIZE; + desc->next_desc = cpu_to_le64(block->dma_addr + ((i + 1) * XDMA_DESC_SIZE)); + } + desc = block->virt_addr + i * XDMA_DESC_SIZE; + desc->next_desc = cpu_to_le64(block->dma_addr); +} + static inline struct xdma_chan *to_xdma_chan(struct dma_chan *chan) { return container_of(chan, struct xdma_chan, vchan.chan); @@ -233,7 +258,7 @@ static void xdma_free_desc(struct virt_dma_desc *vdesc) * @desc_num: Number of hardware descriptors */ static struct xdma_desc * -xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num) +xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num, bool cyclic) { struct xdma_desc *sw_desc; struct xdma_hw_desc *desc; @@ -249,13 +274,17 @@ xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num) sw_desc->chan = chan; sw_desc->desc_num = desc_num; + sw_desc->cyclic = cyclic; dblk_num = DIV_ROUND_UP(desc_num, XDMA_DESC_ADJACENT); sw_desc->desc_blocks = kcalloc(dblk_num, sizeof(*sw_desc->desc_blocks), GFP_NOWAIT); if (!sw_desc->desc_blocks) goto failed; - control = XDMA_DESC_CONTROL(1, 0); + if (cyclic) + control = XDMA_DESC_CONTROL_CYCLIC; + else + control = XDMA_DESC_CONTROL(1, 0); sw_desc->dblk_num = dblk_num; for (i = 0; i < sw_desc->dblk_num; i++) { @@ -269,7 +298,10 @@ xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num) desc[j].control = cpu_to_le32(control); } - xdma_link_sg_desc_blocks(sw_desc); + if (cyclic) + xdma_link_cyclic_desc_blocks(sw_desc); + else + xdma_link_sg_desc_blocks(sw_desc); return sw_desc; @@ -469,7 +501,7 @@ xdma_prep_device_sg(struct dma_chan *chan, struct scatterlist *sgl, for_each_sg(sgl, sg, sg_len, i) desc_num += DIV_ROUND_UP(sg_dma_len(sg), XDMA_DESC_BLEN_MAX); - sw_desc = xdma_alloc_desc(xdma_chan, desc_num); + sw_desc = xdma_alloc_desc(xdma_chan, desc_num, false); if (!sw_desc) return NULL; sw_desc->dir = dir; @@ -524,6 +556,81 @@ xdma_prep_device_sg(struct dma_chan *chan, struct scatterlist *sgl, return NULL; } +/** + * xdma_prep_dma_cyclic - prepare for cyclic DMA transactions + * @chan: DMA channel pointer + * @address: Device DMA address to access + * @size: Total length to transfer + * @period_size: Period size to use for each transfer + * @dir: Transfer direction + * @flags: Transfer ack flags + */ +static struct dma_async_tx_descriptor * +xdma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t address, + size_t size, size_t period_size, + enum dma_transfer_direction dir, + unsigned long flags) +{ + struct xdma_chan *xdma_chan = to_xdma_chan(chan); + struct xdma_device *xdev = xdma_chan->xdev_hdl; + unsigned int periods = size / period_size; + struct dma_async_tx_descriptor *tx_desc; + struct xdma_desc_block *dblk; + struct xdma_hw_desc *desc; + struct xdma_desc *sw_desc; + unsigned int i; + + /* + * Simplify the whole logic by preventing an abnormally high number of + * periods and periods size. + */ + if (period_size > XDMA_DESC_BLEN_MAX) { + xdma_err(xdev, "period size limited to %lu bytes\n", XDMA_DESC_BLEN_MAX); + return NULL; + } + + if (periods > XDMA_DESC_ADJACENT) { + xdma_err(xdev, "number of periods limited to %u\n", XDMA_DESC_ADJACENT); + return NULL; + } + + sw_desc = xdma_alloc_desc(xdma_chan, periods, true); + if (!sw_desc) + return NULL; + + sw_desc->periods = periods; + sw_desc->period_size = period_size; + sw_desc->dir = dir; + + dblk = sw_desc->desc_blocks; + desc = dblk->virt_addr; + + /* fill hardware descriptor */ + for (i = 0; i < periods; i++) { + desc->bytes = cpu_to_le32(period_size); + if (dir == DMA_MEM_TO_DEV) { + desc->src_addr = cpu_to_le64(address + i * period_size); + desc->dst_addr = cpu_to_le64(xdma_chan->cfg.dst_addr); + } else { + desc->src_addr = cpu_to_le64(xdma_chan->cfg.src_addr); + desc->dst_addr = cpu_to_le64(address + i * period_size); + } + + desc++; + } + + tx_desc = vchan_tx_prep(&xdma_chan->vchan, &sw_desc->vdesc, flags); + if (!tx_desc) + goto failed; + + return tx_desc; + +failed: + xdma_free_desc(&sw_desc->vdesc); + + return NULL; +} + /** * xdma_device_config - Configure the DMA channel * @chan: DMA channel @@ -583,7 +690,36 @@ static int xdma_alloc_chan_resources(struct dma_chan *chan) static enum dma_status xdma_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *state) { - return dma_cookie_status(chan, cookie, state); + struct xdma_chan *xdma_chan = to_xdma_chan(chan); + struct xdma_desc *desc = NULL; + struct virt_dma_desc *vd; + enum dma_status ret; + unsigned long flags; + unsigned int period_idx; + u32 residue = 0; + + ret = dma_cookie_status(chan, cookie, state); + if (ret == DMA_COMPLETE) + return ret; + + spin_lock_irqsave(&xdma_chan->vchan.lock, flags); + + vd = vchan_find_desc(&xdma_chan->vchan, cookie); + if (vd) + desc = to_xdma_desc(vd); + if (!desc || !desc->cyclic) { + spin_unlock_irqrestore(&xdma_chan->vchan.lock, flags); + return ret; + } + + period_idx = desc->completed_desc_num % desc->periods; + residue = (desc->periods - period_idx) * desc->period_size; + + spin_unlock_irqrestore(&xdma_chan->vchan.lock, flags); + + dma_set_residue(state, residue); + + return ret; } /** @@ -599,6 +735,7 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id) struct virt_dma_desc *vd; struct xdma_desc *desc; int ret; + u32 st; spin_lock(&xchan->vchan.lock); @@ -617,6 +754,19 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id) goto out; desc->completed_desc_num += complete_desc_num; + + if (desc->cyclic) { + ret = regmap_read(xdev->rmap, xchan->base + XDMA_CHAN_STATUS, + &st); + if (ret) + goto out; + + regmap_write(xdev->rmap, xchan->base + XDMA_CHAN_STATUS, st); + + vchan_cyclic_callback(vd); + goto out; + } + /* * if all data blocks are transferred, remove and complete the request */ @@ -630,7 +780,7 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id) complete_desc_num != XDMA_DESC_BLOCK_NUM * XDMA_DESC_ADJACENT) goto out; - /* transfer the rest of data */ + /* transfer the rest of data (SG only) */ xdma_xfer_start(xchan); out: @@ -930,8 +1080,10 @@ static int xdma_probe(struct platform_device *pdev) dma_cap_set(DMA_SLAVE, xdev->dma_dev.cap_mask); dma_cap_set(DMA_PRIVATE, xdev->dma_dev.cap_mask); + dma_cap_set(DMA_CYCLIC, xdev->dma_dev.cap_mask); xdev->dma_dev.dev = &pdev->dev; + xdev->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT; xdev->dma_dev.device_free_chan_resources = xdma_free_chan_resources; xdev->dma_dev.device_alloc_chan_resources = xdma_alloc_chan_resources; xdev->dma_dev.device_tx_status = xdma_tx_status; @@ -941,6 +1093,7 @@ static int xdma_probe(struct platform_device *pdev) xdev->dma_dev.filter.map = pdata->device_map; xdev->dma_dev.filter.mapcnt = pdata->device_map_cnt; xdev->dma_dev.filter.fn = xdma_filter_fn; + xdev->dma_dev.device_prep_dma_cyclic = xdma_prep_dma_cyclic; ret = dma_async_device_register(&xdev->dma_dev); if (ret) {