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Commit 7d254559 authored by Pramod Gurav's avatar Pramod Gurav Committed by Vinod Koul
Browse files

dmaengine: qcom-bam-dma: Add pm_runtime support 



Adds pm_runtime support for BAM DMA so that clock is enabled only
when there is a transaction going on to help save power.

Signed-off-by: default avatarPramod Gurav <pramod.gurav@linaro.org>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 1a695a90

drivers/dma/qcom/bam_dma.c

+109 −1
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ 
#include <linux/of_dma.h>

#include <linux/clk.h>

#include <linux/dmaengine.h>

#include <linux/pm_runtime.h>



#include "../dmaengine.h"

#include "../virt-dma.h"
@@ -58,6 +59,8 @@ struct bam_desc_hw { 
	__le16 flags;

};



#define BAM_DMA_AUTOSUSPEND_DELAY 100



#define DESC_FLAG_INT BIT(15)

#define DESC_FLAG_EOT BIT(14)

#define DESC_FLAG_EOB BIT(13)
@@ -527,12 +530,17 @@ static void bam_free_chan(struct dma_chan *chan) 
	struct bam_device *bdev = bchan->bdev;

	u32 val;

	unsigned long flags;

	int ret;



	ret = pm_runtime_get_sync(bdev->dev);

	if (ret < 0)

		return;



	vchan_free_chan_resources(to_virt_chan(chan));



	if (bchan->curr_txd) {

		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");

		return;

		goto err;

	}



	spin_lock_irqsave(&bchan->vc.lock, flags);
@@ -550,6 +558,10 @@ static void bam_free_chan(struct dma_chan *chan) 


	/* disable irq */

	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));



err:

	pm_runtime_mark_last_busy(bdev->dev);

	pm_runtime_put_autosuspend(bdev->dev);

}



/**
@@ -696,11 +708,18 @@ static int bam_pause(struct dma_chan *chan) 
	struct bam_chan *bchan = to_bam_chan(chan);

	struct bam_device *bdev = bchan->bdev;

	unsigned long flag;

	int ret;



	ret = pm_runtime_get_sync(bdev->dev);

	if (ret < 0)

		return ret;



	spin_lock_irqsave(&bchan->vc.lock, flag);

	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));

	bchan->paused = 1;

	spin_unlock_irqrestore(&bchan->vc.lock, flag);

	pm_runtime_mark_last_busy(bdev->dev);

	pm_runtime_put_autosuspend(bdev->dev);



	return 0;

}
@@ -715,11 +734,18 @@ static int bam_resume(struct dma_chan *chan) 
	struct bam_chan *bchan = to_bam_chan(chan);

	struct bam_device *bdev = bchan->bdev;

	unsigned long flag;

	int ret;



	ret = pm_runtime_get_sync(bdev->dev);

	if (ret < 0)

		return ret;



	spin_lock_irqsave(&bchan->vc.lock, flag);

	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));

	bchan->paused = 0;

	spin_unlock_irqrestore(&bchan->vc.lock, flag);

	pm_runtime_mark_last_busy(bdev->dev);

	pm_runtime_put_autosuspend(bdev->dev);



	return 0;

}
@@ -795,6 +821,7 @@ static irqreturn_t bam_dma_irq(int irq, void *data) 
{

	struct bam_device *bdev = data;

	u32 clr_mask = 0, srcs = 0;

	int ret;



	srcs |= process_channel_irqs(bdev);
@@ -802,6 +829,10 @@ static irqreturn_t bam_dma_irq(int irq, void *data) 
	if (srcs & P_IRQ)

		tasklet_schedule(&bdev->task);



	ret = pm_runtime_get_sync(bdev->dev);

	if (ret < 0)

		return ret;



	if (srcs & BAM_IRQ) {

		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
@@ -814,6 +845,9 @@ static irqreturn_t bam_dma_irq(int irq, void *data) 
		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));

	}



	pm_runtime_mark_last_busy(bdev->dev);

	pm_runtime_put_autosuspend(bdev->dev);



	return IRQ_HANDLED;

}
@@ -893,6 +927,7 @@ static void bam_start_dma(struct bam_chan *bchan) 
	struct bam_desc_hw *desc;

	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,

					sizeof(struct bam_desc_hw));

	int ret;



	lockdep_assert_held(&bchan->vc.lock);
@@ -904,6 +939,10 @@ static void bam_start_dma(struct bam_chan *bchan) 
	async_desc = container_of(vd, struct bam_async_desc, vd);

	bchan->curr_txd = async_desc;



	ret = pm_runtime_get_sync(bdev->dev);

	if (ret < 0)

		return;



	/* on first use, initialize the channel hardware */

	if (!bchan->initialized)

		bam_chan_init_hw(bchan, async_desc->dir);
@@ -946,6 +985,9 @@ static void bam_start_dma(struct bam_chan *bchan) 
	wmb();

	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),

			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));



	pm_runtime_mark_last_busy(bdev->dev);

	pm_runtime_put_autosuspend(bdev->dev);

}



/**
@@ -970,6 +1012,7 @@ static void dma_tasklet(unsigned long data) 
			bam_start_dma(bchan);

		spin_unlock_irqrestore(&bchan->vc.lock, flags);

	}



}



/**
@@ -1213,6 +1256,13 @@ static int bam_dma_probe(struct platform_device *pdev) 
	if (ret)

		goto err_unregister_dma;



	pm_runtime_irq_safe(&pdev->dev);

	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);

	pm_runtime_use_autosuspend(&pdev->dev);

	pm_runtime_mark_last_busy(&pdev->dev);

	pm_runtime_set_active(&pdev->dev);

	pm_runtime_enable(&pdev->dev);



	return 0;



err_unregister_dma:
@@ -1233,6 +1283,8 @@ static int bam_dma_remove(struct platform_device *pdev) 
	struct bam_device *bdev = platform_get_drvdata(pdev);

	u32 i;



	pm_runtime_force_suspend(&pdev->dev);



	of_dma_controller_free(pdev->dev.of_node);

	dma_async_device_unregister(&bdev->common);
@@ -1260,11 +1312,67 @@ static int bam_dma_remove(struct platform_device *pdev) 
	return 0;

}



static int bam_dma_runtime_suspend(struct device *dev)

{

	struct bam_device *bdev = dev_get_drvdata(dev);



	clk_disable(bdev->bamclk);



	return 0;

}



static int bam_dma_runtime_resume(struct device *dev)

{

	struct bam_device *bdev = dev_get_drvdata(dev);

	int ret;



	ret = clk_enable(bdev->bamclk);

	if (ret < 0) {

		dev_err(dev, "clk_enable failed: %d\n", ret);

		return ret;

	}



	return 0;

}

#ifdef CONFIG_PM_SLEEP

static int bam_dma_suspend(struct device *dev)

{

	struct bam_device *bdev = dev_get_drvdata(dev);



	pm_runtime_force_suspend(dev);



	clk_unprepare(bdev->bamclk);



	return 0;

}



static int bam_dma_resume(struct device *dev)

{

	struct bam_device *bdev = dev_get_drvdata(dev);

	int ret;



	ret = clk_prepare(bdev->bamclk);

	if (ret)

		return ret;



	pm_runtime_force_resume(dev);



	return 0;

}

#endif



static const struct dev_pm_ops bam_dma_pm_ops = {

	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)

	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,

				NULL)

};



static struct platform_driver bam_dma_driver = {

	.probe = bam_dma_probe,

	.remove = bam_dma_remove,

	.driver = {

		.name = "bam-dma-engine",

		.pm = &bam_dma_pm_ops,

		.of_match_table = bam_of_match,

	},

};