diff options
| -rw-r--r-- | drivers/char/hw_random/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/char/hw_random/Makefile | 1 | ||||
| -rw-r--r-- | drivers/char/hw_random/nomadik-rng.c | 103 |
3 files changed, 116 insertions, 0 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 87060266ef91..6ea1014697d1 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -186,3 +186,15 @@ config HW_RANDOM_MXC_RNGA module will be called mxc-rnga. If unsure, say Y. + +config HW_RANDOM_NOMADIK + tristate "ST-Ericsson Nomadik Random Number Generator support" + depends on HW_RANDOM && PLAT_NOMADIK + ---help--- + This driver provides kernel-side support for the Random Number + Generator hardware found on ST-Ericsson SoCs (8815 and 8500). + + To compile this driver as a module, choose M here: the + module will be called nomadik-rng. + + If unsure, say Y. diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 5eeb1303f0d0..4273308aa1e3 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -18,3 +18,4 @@ obj-$(CONFIG_HW_RANDOM_VIRTIO) += virtio-rng.o obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o +obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c new file mode 100644 index 000000000000..a8b4c4010144 --- /dev/null +++ b/drivers/char/hw_random/nomadik-rng.c @@ -0,0 +1,103 @@ +/* + * Nomadik RNG support + * Copyright 2009 Alessandro Rubini + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/amba/bus.h> +#include <linux/hw_random.h> +#include <linux/io.h> + +static int nmk_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + void __iomem *base = (void __iomem *)rng->priv; + + /* + * The register is 32 bits and gives 16 random bits (low half). + * A subsequent read will delay the core for 400ns, so we just read + * once and accept the very unlikely very small delay, even if wait==0. + */ + *(u16 *)data = __raw_readl(base + 8) & 0xffff; + return 2; +} + +/* we have at most one RNG per machine, granted */ +static struct hwrng nmk_rng = { + .name = "nomadik", + .read = nmk_rng_read, +}; + +static int nmk_rng_probe(struct amba_device *dev, struct amba_id *id) +{ + void __iomem *base; + int ret; + + ret = amba_request_regions(dev, dev->dev.init_name); + if (ret) + return ret; + ret = -ENOMEM; + base = ioremap(dev->res.start, resource_size(&dev->res)); + if (!base) + goto out_release; + nmk_rng.priv = (unsigned long)base; + ret = hwrng_register(&nmk_rng); + if (ret) + goto out_unmap; + return 0; + +out_unmap: + iounmap(base); +out_release: + amba_release_regions(dev); + return ret; +} + +static int nmk_rng_remove(struct amba_device *dev) +{ + void __iomem *base = (void __iomem *)nmk_rng.priv; + hwrng_unregister(&nmk_rng); + iounmap(base); + amba_release_regions(dev); + return 0; +} + +static struct amba_id nmk_rng_ids[] = { + { + .id = 0x000805e1, + .mask = 0x000fffff, /* top bits are rev and cfg: accept all */ + }, + {0, 0}, +}; + +static struct amba_driver nmk_rng_driver = { + .drv = { + .owner = THIS_MODULE, + .name = "rng", + }, + .probe = nmk_rng_probe, + .remove = nmk_rng_remove, + .id_table = nmk_rng_ids, +}; + +static int __init nmk_rng_init(void) +{ + return amba_driver_register(&nmk_rng_driver); +} + +static void __devexit nmk_rng_exit(void) +{ + amba_driver_unregister(&nmk_rng_driver); +} + +module_init(nmk_rng_init); +module_exit(nmk_rng_exit); + +MODULE_LICENSE("GPL"); |