diff options
| -rw-r--r-- | drivers/char/hw_random/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/char/hw_random/Makefile | 1 | ||||
| -rw-r--r-- | drivers/char/hw_random/atmel-rng.c | 158 |
3 files changed, 172 insertions, 0 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 1d2ebc7a494..e0135873ba9 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -60,6 +60,19 @@ config HW_RANDOM_AMD If unsure, say Y. +config HW_RANDOM_ATMEL + tristate "Atmel Random Number Generator support" + depends on HW_RANDOM && ARCH_AT91SAM9G45 + default HW_RANDOM + ---help--- + This driver provides kernel-side support for the Random Number + Generator hardware found on Atmel AT91 devices. + + To compile this driver as a module, choose M here: the + module will be called atmel-rng. + + If unsure, say Y. + config HW_RANDOM_GEODE tristate "AMD Geode HW Random Number Generator support" depends on HW_RANDOM && X86_32 && PCI diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index c88f244c8a7..b2ff5265a99 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -7,6 +7,7 @@ rng-core-y := core.o obj-$(CONFIG_HW_RANDOM_TIMERIOMEM) += timeriomem-rng.o obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o +obj-$(CONFIG_HW_RANDOM_ATMEL) += atmel-rng.o obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o n2-rng-y := n2-drv.o n2-asm.o diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c new file mode 100644 index 00000000000..241df2e76ab --- /dev/null +++ b/drivers/char/hw_random/atmel-rng.c @@ -0,0 +1,158 @@ +/* + * Copyright (c) 2011 Peter Korsgaard <jacmet@sunsite.dk> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/hw_random.h> +#include <linux/platform_device.h> + +#define TRNG_CR 0x00 +#define TRNG_ISR 0x1c +#define TRNG_ODATA 0x50 + +#define TRNG_KEY 0x524e4700 /* RNG */ + +struct atmel_trng { + struct clk *clk; + void __iomem *base; + struct hwrng rng; +}; + +static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max, + bool wait) +{ + struct atmel_trng *trng = container_of(rng, struct atmel_trng, rng); + u32 *data = buf; + + /* data ready? */ + if (readl(trng->base + TRNG_ODATA) & 1) { + *data = readl(trng->base + TRNG_ODATA); + return 4; + } else + return 0; +} + +static int atmel_trng_probe(struct platform_device *pdev) +{ + struct atmel_trng *trng; + struct resource *res; + int ret; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -EINVAL; + + trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL); + if (!trng) + return -ENOMEM; + + if (!devm_request_mem_region(&pdev->dev, res->start, + resource_size(res), pdev->name)) + return -EBUSY; + + trng->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); + if (!trng->base) + return -EBUSY; + + trng->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(trng->clk)) + return PTR_ERR(trng->clk); + + ret = clk_enable(trng->clk); + if (ret) + goto err_enable; + + writel(TRNG_KEY | 1, trng->base + TRNG_CR); + trng->rng.name = pdev->name; + trng->rng.read = atmel_trng_read; + + ret = hwrng_register(&trng->rng); + if (ret) + goto err_register; + + platform_set_drvdata(pdev, trng); + + return 0; + +err_register: + clk_disable(trng->clk); +err_enable: + clk_put(trng->clk); + + return ret; +} + +static int __devexit atmel_trng_remove(struct platform_device *pdev) +{ + struct atmel_trng *trng = platform_get_drvdata(pdev); + + hwrng_unregister(&trng->rng); + + writel(TRNG_KEY, trng->base + TRNG_CR); + clk_disable(trng->clk); + clk_put(trng->clk); + + platform_set_drvdata(pdev, NULL); + + return 0; +} + +#ifdef CONFIG_PM +static int atmel_trng_suspend(struct device *dev) +{ + struct atmel_trng *trng = dev_get_drvdata(dev); + + clk_disable(trng->clk); + + return 0; +} + +static int atmel_trng_resume(struct device *dev) +{ + struct atmel_trng *trng = dev_get_drvdata(dev); + + return clk_enable(trng->clk); +} + +static const struct dev_pm_ops atmel_trng_pm_ops = { + .suspend = atmel_trng_suspend, + .resume = atmel_trng_resume, +}; +#endif /* CONFIG_PM */ + +static struct platform_driver atmel_trng_driver = { + .probe = atmel_trng_probe, + .remove = __devexit_p(atmel_trng_remove), + .driver = { + .name = "atmel-trng", + .owner = THIS_MODULE, +#ifdef CONFIG_PM + .pm = &atmel_trng_pm_ops, +#endif /* CONFIG_PM */ + }, +}; + +static int __init atmel_trng_init(void) +{ + return platform_driver_register(&atmel_trng_driver); +} +module_init(atmel_trng_init); + +static void __exit atmel_trng_exit(void) +{ + platform_driver_unregister(&atmel_trng_driver); +} +module_exit(atmel_trng_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>"); +MODULE_DESCRIPTION("Atmel true random number generator driver"); |