forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
139 lines
3.0 KiB
139 lines
3.0 KiB
/* |
|
* RNG driver for AMD Geode RNGs |
|
* |
|
* Copyright 2005 (c) MontaVista Software, Inc. |
|
* |
|
* with the majority of the code coming from: |
|
* |
|
* Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG) |
|
* (c) Copyright 2003 Red Hat Inc <[email protected]> |
|
* |
|
* derived from |
|
* |
|
* Hardware driver for the AMD 768 Random Number Generator (RNG) |
|
* (c) Copyright 2001 Red Hat Inc |
|
* |
|
* derived from |
|
* |
|
* Hardware driver for Intel i810 Random Number Generator (RNG) |
|
* Copyright 2000,2001 Jeff Garzik <[email protected]> |
|
* Copyright 2000,2001 Philipp Rumpf <[email protected]> |
|
* |
|
* 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/delay.h> |
|
#include <linux/hw_random.h> |
|
#include <linux/io.h> |
|
#include <linux/kernel.h> |
|
#include <linux/module.h> |
|
#include <linux/pci.h> |
|
|
|
|
|
#define PFX KBUILD_MODNAME ": " |
|
|
|
#define GEODE_RNG_DATA_REG 0x50 |
|
#define GEODE_RNG_STATUS_REG 0x54 |
|
|
|
/* |
|
* Data for PCI driver interface |
|
* |
|
* This data only exists for exporting the supported |
|
* PCI ids via MODULE_DEVICE_TABLE. We do not actually |
|
* register a pci_driver, because someone else might one day |
|
* want to register another driver on the same PCI id. |
|
*/ |
|
static const struct pci_device_id pci_tbl[] = { |
|
{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), 0, }, |
|
{ 0, }, /* terminate list */ |
|
}; |
|
MODULE_DEVICE_TABLE(pci, pci_tbl); |
|
|
|
|
|
static int geode_rng_data_read(struct hwrng *rng, u32 *data) |
|
{ |
|
void __iomem *mem = (void __iomem *)rng->priv; |
|
|
|
*data = readl(mem + GEODE_RNG_DATA_REG); |
|
|
|
return 4; |
|
} |
|
|
|
static int geode_rng_data_present(struct hwrng *rng, int wait) |
|
{ |
|
void __iomem *mem = (void __iomem *)rng->priv; |
|
int data, i; |
|
|
|
for (i = 0; i < 20; i++) { |
|
data = !!(readl(mem + GEODE_RNG_STATUS_REG)); |
|
if (data || !wait) |
|
break; |
|
udelay(10); |
|
} |
|
return data; |
|
} |
|
|
|
|
|
static struct hwrng geode_rng = { |
|
.name = "geode", |
|
.data_present = geode_rng_data_present, |
|
.data_read = geode_rng_data_read, |
|
}; |
|
|
|
|
|
static int __init geode_rng_init(void) |
|
{ |
|
int err = -ENODEV; |
|
struct pci_dev *pdev = NULL; |
|
const struct pci_device_id *ent; |
|
void __iomem *mem; |
|
unsigned long rng_base; |
|
|
|
for_each_pci_dev(pdev) { |
|
ent = pci_match_id(pci_tbl, pdev); |
|
if (ent) |
|
goto found; |
|
} |
|
/* Device not found. */ |
|
goto out; |
|
|
|
found: |
|
rng_base = pci_resource_start(pdev, 0); |
|
if (rng_base == 0) |
|
goto out; |
|
err = -ENOMEM; |
|
mem = ioremap(rng_base, 0x58); |
|
if (!mem) |
|
goto out; |
|
geode_rng.priv = (unsigned long)mem; |
|
|
|
pr_info("AMD Geode RNG detected\n"); |
|
err = hwrng_register(&geode_rng); |
|
if (err) { |
|
pr_err(PFX "RNG registering failed (%d)\n", |
|
err); |
|
goto err_unmap; |
|
} |
|
out: |
|
return err; |
|
|
|
err_unmap: |
|
iounmap(mem); |
|
goto out; |
|
} |
|
|
|
static void __exit geode_rng_exit(void) |
|
{ |
|
void __iomem *mem = (void __iomem *)geode_rng.priv; |
|
|
|
hwrng_unregister(&geode_rng); |
|
iounmap(mem); |
|
} |
|
|
|
module_init(geode_rng_init); |
|
module_exit(geode_rng_exit); |
|
|
|
MODULE_DESCRIPTION("H/W RNG driver for AMD Geode LX CPUs"); |
|
MODULE_LICENSE("GPL");
|
|
|