linux/drivers/char/hw_random/nomadik-rng.c
Linus Torvalds 59ecc26004 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "Here is the crypto update for 3.15:
   - Added 3DES driver for OMAP4/AM43xx
   - Added AVX2 acceleration for SHA
   - Added hash-only AEAD algorithms in caam
   - Removed tegra driver as it is not functioning and the hardware is
     too slow
   - Allow blkcipher walks over AEAD (needed for ARM)
   - Fixed unprotected FPU/SSE access in ghash-clmulni-intel
   - Fixed highmem crash in omap-sham
   - Add (zero entropy) randomness when initialising hardware RNGs
   - Fixed unaligned ahash comletion functions
   - Added soft module depedency for crc32c for initrds that use crc32c"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (60 commits)
  crypto: ghash-clmulni-intel - use C implementation for setkey()
  crypto: x86/sha1 - reduce size of the AVX2 asm implementation
  crypto: x86/sha1 - fix stack alignment of AVX2 variant
  crypto: x86/sha1 - re-enable the AVX variant
  crypto: sha - SHA1 transform x86_64 AVX2
  crypto: crypto_wq - Fix late crypto work queue initialization
  crypto: caam - add missing key_dma unmap
  crypto: caam - add support for aead null encryption
  crypto: testmgr - add aead null encryption test vectors
  crypto: export NULL algorithms defines
  crypto: caam - remove error propagation handling
  crypto: hash - Simplify the ahash_finup implementation
  crypto: hash - Pull out the functions to save/restore request
  crypto: hash - Fix the pointer voodoo in unaligned ahash
  crypto: caam - Fix first parameter to caam_init_rng
  crypto: omap-sham - Map SG pages if they are HIGHMEM before accessing
  crypto: caam - Dynamic memory allocation for caam_rng_ctx object
  crypto: allow blkcipher walks over AEAD data
  crypto: remove direct blkcipher_walk dependency on transform
  hwrng: add randomness to system from rng sources
  ...
2014-04-03 09:28:16 -07:00

107 lines
2.3 KiB
C

/*
* 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/device.h>
#include <linux/amba/bus.h>
#include <linux/hw_random.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
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 = devm_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_prepare_enable(rng_clk);
ret = amba_request_regions(dev, dev->dev.init_name);
if (ret)
goto out_clk;
ret = -ENOMEM;
base = devm_ioremap(&dev->dev, 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_release;
return 0;
out_release:
amba_release_regions(dev);
out_clk:
clk_disable(rng_clk);
return ret;
}
static int nmk_rng_remove(struct amba_device *dev)
{
hwrng_unregister(&nmk_rng);
amba_release_regions(dev);
clk_disable(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");