[PATCHv2] hw_random: add driver for atmel true hardware random number generator
Nicolas Ferre
nicolas.ferre at atmel.com
Fri Oct 7 05:53:25 EDT 2011
On 10/06/2011 07:56 PM, Peter Korsgaard :
> For the IP block on 9g45/9g46/9m10/9m11.
>
> Signed-off-by: Peter Korsgaard <jacmet at sunsite.dk>
Thanks, I am delighted to see this driver!
Acked-by: Nicolas Ferre <nicolas.ferre at atmel.com>
Herbert,
I will handle the board specific part but should the driver part go
through the Crypto API tree?
Will you expect that I resend the patch with Jamie's and my signatures?
> ---
> Changes since v1:
> - Embed struct hwrng in struct atmel_trng as suggested by Jamie Iles.
>
> drivers/char/hw_random/Kconfig | 13 +++
> drivers/char/hw_random/Makefile | 1 +
> drivers/char/hw_random/atmel-rng.c | 158 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 172 insertions(+), 0 deletions(-)
> create mode 100644 drivers/char/hw_random/atmel-rng.c
>
> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> index 1d2ebc7..e013587 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 c88f244..b2ff526 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 0000000..241df2e
> --- /dev/null
> +++ b/drivers/char/hw_random/atmel-rng.c
> @@ -0,0 +1,158 @@
> +/*
> + * Copyright (c) 2011 Peter Korsgaard <jacmet at 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 at sunsite.dk>");
> +MODULE_DESCRIPTION("Atmel true random number generator driver");
Best regards,
--
Nicolas Ferre
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