diff options
Diffstat (limited to 'drivers/char/hw_random/mxc-rnga.c')
| -rw-r--r-- | drivers/char/hw_random/mxc-rnga.c | 163 |
1 files changed, 67 insertions, 96 deletions
diff --git a/drivers/char/hw_random/mxc-rnga.c b/drivers/char/hw_random/mxc-rnga.c index 187c6be80f4..6a86b6f56af 100644 --- a/drivers/char/hw_random/mxc-rnga.c +++ b/drivers/char/hw_random/mxc-rnga.c @@ -24,6 +24,7 @@ #include <linux/ioport.h> #include <linux/platform_device.h> #include <linux/hw_random.h> +#include <linux/delay.h> #include <linux/io.h> /* RNGA Registers */ @@ -58,38 +59,47 @@ #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) +static int mxc_rnga_data_present(struct hwrng *rng, int wait) { - int level; - void __iomem *rng_base = (void __iomem *)rng->priv; - - /* how many random numbers is in FIFO? [0-16] */ - level = ((__raw_readl(rng_base + RNGA_STATUS) & - RNGA_STATUS_LEVEL_MASK) >> 8); - - return level > 0 ? 1 : 0; + 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(mxc_rng->mem + RNGA_STATUS) & + RNGA_STATUS_LEVEL_MASK) >> 8; + if (level || !wait) + return !!level; + udelay(10); + } + return 0; } 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; @@ -98,22 +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; } @@ -121,83 +131,62 @@ 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, "rng"); - if (IS_ERR(clk)) { + struct resource *res; + 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_enable(clk); + err = clk_prepare_enable(mxc_rng->clk); + if (err) + goto out; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) { - err = -ENOENT; - goto err_region; - } - - mem = request_mem_region(res->start, resource_size(res), pdev->name); - if (mem == NULL) { - err = -EBUSY; - goto err_region; - } - - rng_base = ioremap(res->start, resource_size(res)); - if (!rng_base) { - err = -ENOMEM; + mxc_rng->mem = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(mxc_rng->mem)) { + err = PTR_ERR(mxc_rng->mem); 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(clk); - clk_put(clk); + clk_disable_unprepare(mxc_rng->clk); out: return err; @@ -205,18 +194,11 @@ out: 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, "rng"); - - hwrng_unregister(&mxc_rnga); + struct mxc_rng *mxc_rng = platform_get_drvdata(pdev); - iounmap(rng_base); + hwrng_unregister(&mxc_rng->rng); - release_mem_region(res->start, resource_size(res)); - - clk_disable(clk); - clk_put(clk); + clk_disable_unprepare(mxc_rng->clk); return 0; } @@ -229,18 +211,7 @@ static struct platform_driver mxc_rnga_driver = { .remove = __exit_p(mxc_rnga_remove), }; -static int __init mod_init(void) -{ - return platform_driver_probe(&mxc_rnga_driver, mxc_rnga_probe); -} - -static void __exit mod_exit(void) -{ - platform_driver_unregister(&mxc_rnga_driver); -} - -module_init(mod_init); -module_exit(mod_exit); +module_platform_driver_probe(mxc_rnga_driver, mxc_rnga_probe); MODULE_AUTHOR("Freescale Semiconductor, Inc."); MODULE_DESCRIPTION("H/W RNGA driver for i.MX"); |
