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: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Fabio Estevam
Herbert Xu
parent
a9ccb7bd0a
commit
821873abc2
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@ -59,16 +59,21 @@
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#define RNGA_STATUS_LAST_READ_STATUS 0x00000002
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#define RNGA_STATUS_SECURITY_VIOLATION 0x00000001
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static struct platform_device *rng_dev;
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struct mxc_rng {
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struct device *dev;
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struct hwrng rng;
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void __iomem *mem;
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struct clk *clk;
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};
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static int mxc_rnga_data_present(struct hwrng *rng, int wait)
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{
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void __iomem *rng_base = (void __iomem *)rng->priv;
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int i;
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struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);
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for (i = 0; i < 20; i++) {
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/* how many random numbers are in FIFO? [0-16] */
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int level = (__raw_readl(rng_base + RNGA_STATUS) &
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int level = (__raw_readl(mxc_rng->mem + RNGA_STATUS) &
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RNGA_STATUS_LEVEL_MASK) >> 8;
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if (level || !wait)
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return !!level;
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@ -81,20 +86,20 @@ static int mxc_rnga_data_read(struct hwrng *rng, u32 * data)
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{
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int err;
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u32 ctrl;
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void __iomem *rng_base = (void __iomem *)rng->priv;
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struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);
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/* retrieve a random number from FIFO */
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*data = __raw_readl(rng_base + RNGA_OUTPUT_FIFO);
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*data = __raw_readl(mxc_rng->mem + RNGA_OUTPUT_FIFO);
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/* some error while reading this random number? */
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err = __raw_readl(rng_base + RNGA_STATUS) & RNGA_STATUS_ERROR_INT;
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err = __raw_readl(mxc_rng->mem + RNGA_STATUS) & RNGA_STATUS_ERROR_INT;
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/* if error: clear error interrupt, but doesn't return random number */
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if (err) {
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dev_dbg(&rng_dev->dev, "Error while reading random number!\n");
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ctrl = __raw_readl(rng_base + RNGA_CONTROL);
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dev_dbg(mxc_rng->dev, "Error while reading random number!\n");
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ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);
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__raw_writel(ctrl | RNGA_CONTROL_CLEAR_INT,
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rng_base + RNGA_CONTROL);
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mxc_rng->mem + RNGA_CONTROL);
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return 0;
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} else
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return 4;
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@ -103,22 +108,22 @@ static int mxc_rnga_data_read(struct hwrng *rng, u32 * data)
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static int mxc_rnga_init(struct hwrng *rng)
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{
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u32 ctrl, osc;
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void __iomem *rng_base = (void __iomem *)rng->priv;
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struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);
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/* wake up */
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ctrl = __raw_readl(rng_base + RNGA_CONTROL);
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__raw_writel(ctrl & ~RNGA_CONTROL_SLEEP, rng_base + RNGA_CONTROL);
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ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);
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__raw_writel(ctrl & ~RNGA_CONTROL_SLEEP, mxc_rng->mem + RNGA_CONTROL);
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/* verify if oscillator is working */
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osc = __raw_readl(rng_base + RNGA_STATUS);
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osc = __raw_readl(mxc_rng->mem + RNGA_STATUS);
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if (osc & RNGA_STATUS_OSC_DEAD) {
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dev_err(&rng_dev->dev, "RNGA Oscillator is dead!\n");
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dev_err(mxc_rng->dev, "RNGA Oscillator is dead!\n");
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return -ENODEV;
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}
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/* go running */
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ctrl = __raw_readl(rng_base + RNGA_CONTROL);
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__raw_writel(ctrl | RNGA_CONTROL_GO, rng_base + RNGA_CONTROL);
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ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);
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__raw_writel(ctrl | RNGA_CONTROL_GO, mxc_rng->mem + RNGA_CONTROL);
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return 0;
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}
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@ -126,40 +131,40 @@ static int mxc_rnga_init(struct hwrng *rng)
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static void mxc_rnga_cleanup(struct hwrng *rng)
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{
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u32 ctrl;
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void __iomem *rng_base = (void __iomem *)rng->priv;
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struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);
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ctrl = __raw_readl(rng_base + RNGA_CONTROL);
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ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);
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/* stop rnga */
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__raw_writel(ctrl & ~RNGA_CONTROL_GO, rng_base + RNGA_CONTROL);
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__raw_writel(ctrl & ~RNGA_CONTROL_GO, mxc_rng->mem + RNGA_CONTROL);
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}
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static struct hwrng mxc_rnga = {
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.name = "mxc-rnga",
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.init = mxc_rnga_init,
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.cleanup = mxc_rnga_cleanup,
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.data_present = mxc_rnga_data_present,
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.data_read = mxc_rnga_data_read
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};
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static int __init mxc_rnga_probe(struct platform_device *pdev)
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{
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int err = -ENODEV;
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struct clk *clk;
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struct resource *res, *mem;
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void __iomem *rng_base = NULL;
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struct mxc_rng *mxc_rng;
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if (rng_dev)
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return -EBUSY;
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mxc_rng = devm_kzalloc(&pdev->dev, sizeof(struct mxc_rng),
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GFP_KERNEL);
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if (!mxc_rng)
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return -ENOMEM;
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clk = clk_get(&pdev->dev, NULL);
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if (IS_ERR(clk)) {
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mxc_rng->dev = &pdev->dev;
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mxc_rng->rng.name = "mxc-rnga";
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mxc_rng->rng.init = mxc_rnga_init;
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mxc_rng->rng.cleanup = mxc_rnga_cleanup,
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mxc_rng->rng.data_present = mxc_rnga_data_present,
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mxc_rng->rng.data_read = mxc_rnga_data_read,
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mxc_rng->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(mxc_rng->clk)) {
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dev_err(&pdev->dev, "Could not get rng_clk!\n");
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err = PTR_ERR(clk);
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err = PTR_ERR(mxc_rng->clk);
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goto out;
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}
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clk_prepare_enable(clk);
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clk_prepare_enable(mxc_rng->clk);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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@ -173,36 +178,27 @@ static int __init mxc_rnga_probe(struct platform_device *pdev)
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goto err_region;
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}
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rng_base = ioremap(res->start, resource_size(res));
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if (!rng_base) {
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mxc_rng->mem = ioremap(res->start, resource_size(res));
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if (!mxc_rng->mem) {
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err = -ENOMEM;
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goto err_ioremap;
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}
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mxc_rnga.priv = (unsigned long)rng_base;
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err = hwrng_register(&mxc_rnga);
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err = hwrng_register(&mxc_rng->rng);
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if (err) {
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dev_err(&pdev->dev, "MXC RNGA registering failed (%d)\n", err);
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goto err_register;
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goto err_ioremap;
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}
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rng_dev = pdev;
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dev_info(&pdev->dev, "MXC RNGA Registered.\n");
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return 0;
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err_register:
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iounmap(rng_base);
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rng_base = NULL;
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err_ioremap:
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release_mem_region(res->start, resource_size(res));
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err_region:
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clk_disable_unprepare(clk);
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clk_put(clk);
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clk_disable_unprepare(mxc_rng->clk);
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out:
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return err;
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@ -211,17 +207,15 @@ out:
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static int __exit mxc_rnga_remove(struct platform_device *pdev)
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{
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struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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void __iomem *rng_base = (void __iomem *)mxc_rnga.priv;
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struct clk *clk = clk_get(&pdev->dev, NULL);
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struct mxc_rng *mxc_rng = platform_get_drvdata(pdev);
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hwrng_unregister(&mxc_rnga);
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hwrng_unregister(&mxc_rng->rng);
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iounmap(rng_base);
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iounmap(mxc_rng->mem);
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release_mem_region(res->start, resource_size(res));
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clk_disable_unprepare(clk);
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clk_put(clk);
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clk_disable_unprepare(mxc_rng->clk);
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return 0;
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}
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