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From: Amelie Delaunay <amelie.delaunay@foss.st.com>
To: Vinod Koul <vkoul@kernel.org>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof
 Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley
	<conor+dt@kernel.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre
 Torgue <alexandre.torgue@foss.st.com>
CC: <dmaengine@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        <linux-hardening@vger.kernel.org>,
        Amelie Delaunay
	<amelie.delaunay@foss.st.com>
Subject: [PATCH 08/12] dmaengine: stm32-dma3: add device_pause and device_resume ops
Date: Tue, 23 Apr 2024 14:32:58 +0200
Message-ID: <20240423123302.1550592-9-amelie.delaunay@foss.st.com>
In-Reply-To: <20240423123302.1550592-1-amelie.delaunay@foss.st.com>
References: <20240423123302.1550592-1-amelie.delaunay@foss.st.com>
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STM32 DMA3 controller is able to suspend an ongoing transfer (the transfer
is suspended after the ongoing burst is flushed to the destination) and
resume it from the point it was suspended. No need to reconfigure any
register.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 drivers/dma/stm32/stm32-dma3.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c
index 73e856a5aeab..3d827c33150e 100644
--- a/drivers/dma/stm32/stm32-dma3.c
+++ b/drivers/dma/stm32/stm32-dma3.c
@@ -1240,6 +1240,35 @@ static int stm32_dma3_config(struct dma_chan *c, struct dma_slave_config *config
 	return 0;
 }
 
+static int stm32_dma3_pause(struct dma_chan *c)
+{
+	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
+	int ret;
+
+	ret = stm32_dma3_chan_suspend(chan, true);
+	if (ret)
+		return ret;
+
+	chan->dma_status = DMA_PAUSED;
+
+	dev_dbg(chan2dev(chan), "vchan %pK: paused\n", &chan->vchan);
+
+	return 0;
+}
+
+static int stm32_dma3_resume(struct dma_chan *c)
+{
+	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
+
+	stm32_dma3_chan_suspend(chan, false);
+
+	chan->dma_status = DMA_IN_PROGRESS;
+
+	dev_dbg(chan2dev(chan), "vchan %pK: resumed\n", &chan->vchan);
+
+	return 0;
+}
+
 static int stm32_dma3_terminate_all(struct dma_chan *c)
 {
 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
@@ -1476,6 +1505,8 @@ static int stm32_dma3_probe(struct platform_device *pdev)
 	dma_dev->device_prep_dma_cyclic = stm32_dma3_prep_dma_cyclic;
 	dma_dev->device_caps = stm32_dma3_caps;
 	dma_dev->device_config = stm32_dma3_config;
+	dma_dev->device_pause = stm32_dma3_pause;
+	dma_dev->device_resume = stm32_dma3_resume;
 	dma_dev->device_terminate_all = stm32_dma3_terminate_all;
 	dma_dev->device_synchronize = stm32_dma3_synchronize;
 	dma_dev->device_tx_status = dma_cookie_status;
-- 
2.25.1