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Commit 48bc73ba authored by Pierre-Yves MORDRET's avatar Pierre-Yves MORDRET Committed by Vinod Koul
Browse files

dmaengine: stm32-dma: Add PM Runtime support 



Use pm_runtime engine for clock management purpose.

Signed-off-by: default avatarPierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent ca4c72c0

drivers/dma/stm32-dma.c

+51 −7
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/of_device.h>

#include <linux/of_dma.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/reset.h>

#include <linux/sched.h>

#include <linux/slab.h>
@@ -1115,15 +1116,14 @@ static int stm32_dma_alloc_chan_resources(struct dma_chan *c) 
	int ret;



	chan->config_init = false;

	ret = clk_prepare_enable(dmadev->clk);

	if (ret < 0) {

		dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);



	ret = pm_runtime_get_sync(dmadev->ddev.dev);

	if (ret < 0)

		return ret;

	}



	ret = stm32_dma_disable_chan(chan);

	if (ret < 0)

		clk_disable_unprepare(dmadev->clk);

		pm_runtime_put(dmadev->ddev.dev);



	return ret;

}
@@ -1143,7 +1143,7 @@ static void stm32_dma_free_chan_resources(struct dma_chan *c) 
		spin_unlock_irqrestore(&chan->vchan.lock, flags);

	}



	clk_disable_unprepare(dmadev->clk);

	pm_runtime_put(dmadev->ddev.dev);



	vchan_free_chan_resources(to_virt_chan(c));

}
@@ -1243,6 +1243,12 @@ static int stm32_dma_probe(struct platform_device *pdev) 
		return PTR_ERR(dmadev->clk);

	}



	ret = clk_prepare_enable(dmadev->clk);

	if (ret < 0) {

		dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);

		return ret;

	}



	dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,

						"st,mem2mem");
@@ -1292,7 +1298,7 @@ static int stm32_dma_probe(struct platform_device *pdev) 


	ret = dma_async_device_register(dd);

	if (ret)

		return ret;

		goto clk_free;



	for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {

		chan = &dmadev->chan[i];
@@ -1324,20 +1330,58 @@ static int stm32_dma_probe(struct platform_device *pdev) 


	platform_set_drvdata(pdev, dmadev);



	pm_runtime_set_active(&pdev->dev);

	pm_runtime_enable(&pdev->dev);

	pm_runtime_get_noresume(&pdev->dev);

	pm_runtime_put(&pdev->dev);



	dev_info(&pdev->dev, "STM32 DMA driver registered\n");



	return 0;



err_unregister:

	dma_async_device_unregister(dd);

clk_free:

	clk_disable_unprepare(dmadev->clk);



	return ret;

}



#ifdef CONFIG_PM

static int stm32_dma_runtime_suspend(struct device *dev)

{

	struct stm32_dma_device *dmadev = dev_get_drvdata(dev);



	clk_disable_unprepare(dmadev->clk);



	return 0;

}



static int stm32_dma_runtime_resume(struct device *dev)

{

	struct stm32_dma_device *dmadev = dev_get_drvdata(dev);

	int ret;



	ret = clk_prepare_enable(dmadev->clk);

	if (ret) {

		dev_err(dev, "failed to prepare_enable clock\n");

		return ret;

	}



	return 0;

}

#endif



static const struct dev_pm_ops stm32_dma_pm_ops = {

	SET_RUNTIME_PM_OPS(stm32_dma_runtime_suspend,

			   stm32_dma_runtime_resume, NULL)

};



static struct platform_driver stm32_dma_driver = {

	.driver = {

		.name = "stm32-dma",

		.of_match_table = stm32_dma_of_match,

		.pm = &stm32_dma_pm_ops,

	},

};