From mboxrd@z Thu Jan 1 00:00:00 1970 From: nicolas.ferre@atmel.com (Nicolas Ferre) Date: Fri, 07 Oct 2011 11:53:25 +0200 Subject: [PATCHv2] hw_random: add driver for atmel true hardware random number generator In-Reply-To: <1317923791-31200-1-git-send-email-jacmet@sunsite.dk> References: <1317923791-31200-1-git-send-email-jacmet@sunsite.dk> Message-ID: <4E8ECC15.10704@atmel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/06/2011 07:56 PM, Peter Korsgaard : > For the IP block on 9g45/9g46/9m10/9m11. > > Signed-off-by: Peter Korsgaard Thanks, I am delighted to see this driver! Acked-by: Nicolas Ferre 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 > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#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 "); > +MODULE_DESCRIPTION("Atmel true random number generator driver"); Best regards, -- Nicolas Ferre