From 871480933a1c28f8a9fed4c4d34d06c439a7a422 Mon Sep 17 00:00:00 2001 From: Srikant Patnaik Date: Sun, 11 Jan 2015 12:28:04 +0530 Subject: Moved, renamed, and deleted files The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure. --- drivers/char/hw_random/nomadik-rng.c | 112 +++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 drivers/char/hw_random/nomadik-rng.c (limited to 'drivers/char/hw_random/nomadik-rng.c') diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c new file mode 100644 index 00000000..96de0249 --- /dev/null +++ b/drivers/char/hw_random/nomadik-rng.c @@ -0,0 +1,112 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +static struct clk *rng_clk; + +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, const struct amba_id *id) +{ + void __iomem *base; + int ret; + + rng_clk = clk_get(&dev->dev, NULL); + if (IS_ERR(rng_clk)) { + dev_err(&dev->dev, "could not get rng clock\n"); + ret = PTR_ERR(rng_clk); + return ret; + } + + clk_enable(rng_clk); + + ret = amba_request_regions(dev, dev->dev.init_name); + if (ret) + goto out_clk; + 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); +out_clk: + clk_disable(rng_clk); + clk_put(rng_clk); + 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); + clk_disable(rng_clk); + clk_put(rng_clk); + return 0; +} + +static struct amba_id nmk_rng_ids[] = { + { + .id = 0x000805e1, + .mask = 0x000fffff, /* top bits are rev and cfg: accept all */ + }, + {0, 0}, +}; + +MODULE_DEVICE_TABLE(amba, nmk_rng_ids); + +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, +}; + +module_amba_driver(nmk_rng_driver); + +MODULE_LICENSE("GPL"); -- cgit