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Commit 81d2b345 authored by Sean Wang's avatar Sean Wang Committed by Herbert Xu
Browse files

hwrng: mtk - add runtime PM support 



Add runtime PM support.  There will be the benefit on SoCs where the
clock to the RNG used can be shutdown.

Signed-off-by: default avatarSean Wang <sean.wang@mediatek.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 34194913

drivers/char/hw_random/mtk-rng.c

+42 −0
Original line number Original line Diff line number Diff line
@@ -25,6 +25,10 @@ 
#include <linux/module.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>



/* Runtime PM autosuspend timeout: */

#define RNG_AUTOSUSPEND_TIMEOUT		100





#define USEC_POLL			2

#define USEC_POLL			2

#define TIMEOUT_POLL			20

#define TIMEOUT_POLL			20
@@ -90,6 +94,8 @@ static int mtk_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) 
	struct mtk_rng *priv = to_mtk_rng(rng);

	struct mtk_rng *priv = to_mtk_rng(rng);

	int retval = 0;

	int retval = 0;





	pm_runtime_get_sync((struct device *)priv->rng.priv);



	while (max >= sizeof(u32)) {

	while (max >= sizeof(u32)) {

		if (!mtk_rng_wait_ready(rng, wait))

		if (!mtk_rng_wait_ready(rng, wait))

			break;

			break;
@@ -100,6 +106,9 @@ static int mtk_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) 
		max -= sizeof(u32);

		max -= sizeof(u32);

	}

	}





	pm_runtime_mark_last_busy((struct device *)priv->rng.priv);

	pm_runtime_put_sync_autosuspend((struct device *)priv->rng.priv);



	return retval || !wait ? retval : -EIO;

	return retval || !wait ? retval : -EIO;

}

}
@@ -120,9 +129,12 @@ static int mtk_rng_probe(struct platform_device *pdev) 
		return -ENOMEM;

		return -ENOMEM;





	priv->rng.name = pdev->name;

	priv->rng.name = pdev->name;

#ifndef CONFIG_PM

	priv->rng.init = mtk_rng_init;

	priv->rng.init = mtk_rng_init;

	priv->rng.cleanup = mtk_rng_cleanup;

	priv->rng.cleanup = mtk_rng_cleanup;

#endif

	priv->rng.read = mtk_rng_read;

	priv->rng.read = mtk_rng_read;

	priv->rng.priv = (unsigned long)&pdev->dev;





	priv->clk = devm_clk_get(&pdev->dev, "rng");

	priv->clk = devm_clk_get(&pdev->dev, "rng");

	if (IS_ERR(priv->clk)) {

	if (IS_ERR(priv->clk)) {
@@ -142,11 +154,40 @@ static int mtk_rng_probe(struct platform_device *pdev) 
		return ret;

		return ret;

	}

	}





	dev_set_drvdata(&pdev->dev, priv);

	pm_runtime_set_autosuspend_delay(&pdev->dev, RNG_AUTOSUSPEND_TIMEOUT);

	pm_runtime_use_autosuspend(&pdev->dev);

	pm_runtime_enable(&pdev->dev);



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

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





	return 0;

	return 0;

}

}





#ifdef CONFIG_PM

static int mtk_rng_runtime_suspend(struct device *dev)

{

	struct mtk_rng *priv = dev_get_drvdata(dev);



	mtk_rng_cleanup(&priv->rng);



	return 0;

}



static int mtk_rng_runtime_resume(struct device *dev)

{

	struct mtk_rng *priv = dev_get_drvdata(dev);



	return mtk_rng_init(&priv->rng);

}



static UNIVERSAL_DEV_PM_OPS(mtk_rng_pm_ops, mtk_rng_runtime_suspend,

			    mtk_rng_runtime_resume, NULL);

#define MTK_RNG_PM_OPS (&mtk_rng_pm_ops)

#else	/* CONFIG_PM */

#define MTK_RNG_PM_OPS NULL

#endif	/* CONFIG_PM */



static const struct of_device_id mtk_rng_match[] = {

static const struct of_device_id mtk_rng_match[] = {

	{ .compatible = "mediatek,mt7623-rng" },

	{ .compatible = "mediatek,mt7623-rng" },

	{},

	{},
@@ -157,6 +198,7 @@ static struct platform_driver mtk_rng_driver = { 
	.probe          = mtk_rng_probe,

	.probe          = mtk_rng_probe,

	.driver = {

	.driver = {

		.name = MTK_RNG_DEV,

		.name = MTK_RNG_DEV,

		.pm = MTK_RNG_PM_OPS,

		.of_match_table = mtk_rng_match,

		.of_match_table = mtk_rng_match,

	},

	},

};

};