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Commit 821873ab authored by Fabio Estevam's avatar Fabio Estevam Committed by Herbert Xu
Browse files

hwrng: mxc-rnga - Access data via structure 



In current driver, everytime we need to access the rng clock
,ie to enable or disable it, a call to clk_get is done.

This is not correct and the preferred way is to provide a rng data structure
that could be used for accessing rng resources.

Acked-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: default avatarFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent a9ccb7bd

drivers/char/hw_random/mxc-rnga.c

+51 −57
Original line number Diff line number Diff line
@@ -59,16 +59,21 @@ 
#define RNGA_STATUS_LAST_READ_STATUS	0x00000002

#define RNGA_STATUS_SECURITY_VIOLATION	0x00000001



static struct platform_device *rng_dev;

struct mxc_rng {

	struct device *dev;

	struct hwrng rng;

	void __iomem *mem;

	struct clk *clk;

};



static int mxc_rnga_data_present(struct hwrng *rng, int wait)

{

	void __iomem *rng_base = (void __iomem *)rng->priv;

	int i;

	struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);



	for (i = 0; i < 20; i++) {

		/* how many random numbers are in FIFO? [0-16] */

		int level = (__raw_readl(rng_base + RNGA_STATUS) &

		int level = (__raw_readl(mxc_rng->mem + RNGA_STATUS) &

				RNGA_STATUS_LEVEL_MASK) >> 8;

		if (level || !wait)

			return !!level;
@@ -81,20 +86,20 @@ static int mxc_rnga_data_read(struct hwrng *rng, u32 * data) 
{

	int err;

	u32 ctrl;

	void __iomem *rng_base = (void __iomem *)rng->priv;

	struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);



	/* retrieve a random number from FIFO */

	*data = __raw_readl(rng_base + RNGA_OUTPUT_FIFO);

	*data = __raw_readl(mxc_rng->mem + RNGA_OUTPUT_FIFO);



	/* some error while reading this random number? */

	err = __raw_readl(rng_base + RNGA_STATUS) & RNGA_STATUS_ERROR_INT;

	err = __raw_readl(mxc_rng->mem + RNGA_STATUS) & RNGA_STATUS_ERROR_INT;



	/* if error: clear error interrupt, but doesn't return random number */

	if (err) {

		dev_dbg(&rng_dev->dev, "Error while reading random number!\n");

		ctrl = __raw_readl(rng_base + RNGA_CONTROL);

		dev_dbg(mxc_rng->dev, "Error while reading random number!\n");

		ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);

		__raw_writel(ctrl | RNGA_CONTROL_CLEAR_INT,

					rng_base + RNGA_CONTROL);

					mxc_rng->mem + RNGA_CONTROL);

		return 0;

	} else

		return 4;
@@ -103,22 +108,22 @@ static int mxc_rnga_data_read(struct hwrng *rng, u32 * data) 
static int mxc_rnga_init(struct hwrng *rng)

{

	u32 ctrl, osc;

	void __iomem *rng_base = (void __iomem *)rng->priv;

	struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);



	/* wake up */

	ctrl = __raw_readl(rng_base + RNGA_CONTROL);

	__raw_writel(ctrl & ~RNGA_CONTROL_SLEEP, rng_base + RNGA_CONTROL);

	ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);

	__raw_writel(ctrl & ~RNGA_CONTROL_SLEEP, mxc_rng->mem + RNGA_CONTROL);



	/* verify if oscillator is working */

	osc = __raw_readl(rng_base + RNGA_STATUS);

	osc = __raw_readl(mxc_rng->mem + RNGA_STATUS);

	if (osc & RNGA_STATUS_OSC_DEAD) {

		dev_err(&rng_dev->dev, "RNGA Oscillator is dead!\n");

		dev_err(mxc_rng->dev, "RNGA Oscillator is dead!\n");

		return -ENODEV;

	}



	/* go running */

	ctrl = __raw_readl(rng_base + RNGA_CONTROL);

	__raw_writel(ctrl | RNGA_CONTROL_GO, rng_base + RNGA_CONTROL);

	ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);

	__raw_writel(ctrl | RNGA_CONTROL_GO, mxc_rng->mem + RNGA_CONTROL);



	return 0;

}
@@ -126,40 +131,40 @@ static int mxc_rnga_init(struct hwrng *rng) 
static void mxc_rnga_cleanup(struct hwrng *rng)

{

	u32 ctrl;

	void __iomem *rng_base = (void __iomem *)rng->priv;

	struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);



	ctrl = __raw_readl(rng_base + RNGA_CONTROL);

	ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);



	/* stop rnga */

	__raw_writel(ctrl & ~RNGA_CONTROL_GO, rng_base + RNGA_CONTROL);

	__raw_writel(ctrl & ~RNGA_CONTROL_GO, mxc_rng->mem + RNGA_CONTROL);

}



static struct hwrng mxc_rnga = {

	.name = "mxc-rnga",

	.init = mxc_rnga_init,

	.cleanup = mxc_rnga_cleanup,

	.data_present = mxc_rnga_data_present,

	.data_read = mxc_rnga_data_read

};



static int __init mxc_rnga_probe(struct platform_device *pdev)

{

	int err = -ENODEV;

	struct clk *clk;

	struct resource *res, *mem;

	void __iomem *rng_base = NULL;



	if (rng_dev)

		return -EBUSY;



	clk = clk_get(&pdev->dev, NULL);

	if (IS_ERR(clk)) {

	struct mxc_rng *mxc_rng;



	mxc_rng = devm_kzalloc(&pdev->dev, sizeof(struct mxc_rng),

					GFP_KERNEL);

	if (!mxc_rng)

		return -ENOMEM;



	mxc_rng->dev = &pdev->dev;

	mxc_rng->rng.name = "mxc-rnga";

	mxc_rng->rng.init = mxc_rnga_init;

	mxc_rng->rng.cleanup = mxc_rnga_cleanup,

	mxc_rng->rng.data_present = mxc_rnga_data_present,

	mxc_rng->rng.data_read = mxc_rnga_data_read,



	mxc_rng->clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(mxc_rng->clk)) {

		dev_err(&pdev->dev, "Could not get rng_clk!\n");

		err = PTR_ERR(clk);

		err = PTR_ERR(mxc_rng->clk);

		goto out;

	}



	clk_prepare_enable(clk);

	clk_prepare_enable(mxc_rng->clk);



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!res) {
@@ -173,36 +178,27 @@ static int __init mxc_rnga_probe(struct platform_device *pdev) 
		goto err_region;

	}



	rng_base = ioremap(res->start, resource_size(res));

	if (!rng_base) {

	mxc_rng->mem = ioremap(res->start, resource_size(res));

	if (!mxc_rng->mem) {

		err = -ENOMEM;

		goto err_ioremap;

	}



	mxc_rnga.priv = (unsigned long)rng_base;



	err = hwrng_register(&mxc_rnga);

	err = hwrng_register(&mxc_rng->rng);

	if (err) {

		dev_err(&pdev->dev, "MXC RNGA registering failed (%d)\n", err);

		goto err_register;

		goto err_ioremap;

	}



	rng_dev = pdev;



	dev_info(&pdev->dev, "MXC RNGA Registered.\n");



	return 0;



err_register:

	iounmap(rng_base);

	rng_base = NULL;



err_ioremap:

	release_mem_region(res->start, resource_size(res));



err_region:

	clk_disable_unprepare(clk);

	clk_put(clk);

	clk_disable_unprepare(mxc_rng->clk);



out:

	return err;
@@ -211,17 +207,15 @@ static int __init mxc_rnga_probe(struct platform_device *pdev) 
static int __exit mxc_rnga_remove(struct platform_device *pdev)

{

	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	void __iomem *rng_base = (void __iomem *)mxc_rnga.priv;

	struct clk *clk = clk_get(&pdev->dev, NULL);

	struct mxc_rng *mxc_rng = platform_get_drvdata(pdev);



	hwrng_unregister(&mxc_rnga);

	hwrng_unregister(&mxc_rng->rng);



	iounmap(rng_base);

	iounmap(mxc_rng->mem);



	release_mem_region(res->start, resource_size(res));



	clk_disable_unprepare(clk);

	clk_put(clk);

	clk_disable_unprepare(mxc_rng->clk);



	return 0;

}