/* * 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 <jgarzik@redhat.com> * * derived from * * Hardware driver for the AMD 768 Random Number Generator (RNG) * (c) Copyright 2001 Red Hat Inc <alan@redhat.com> * * derived from * * Hardware driver for Intel i810 Random Number Generator (RNG) * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com> * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com> * * 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/module.h>#include <linux/kernel.h>#include <linux/pci.h>#include <linux/hw_random.h>#include <asm/io.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_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES,	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 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){	void __iomem *mem = (void __iomem *)rng->priv;	return !!(readl(mem + GEODE_RNG_STATUS_REG));}static struct hwrng geode_rng = {	.name		= "geode",	.data_present	= geode_rng_data_present,	.data_read	= geode_rng_data_read,};static int __init mod_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;	printk(KERN_INFO "AMD Geode RNG detected\n");	err = hwrng_register(&geode_rng);	if (err) {		printk(KERN_ERR PFX "RNG registering failed (%d)\n",		       err);		goto err_unmap;	}out:	return err;err_unmap:	iounmap(mem);	goto out;}static void __exit mod_exit(void){	void __iomem *mem = (void __iomem *)geode_rng.priv;	hwrng_unregister(&geode_rng);	iounmap(mem);}module_init(mod_init);module_exit(mod_exit);MODULE_DESCRIPTION("H/W RNG driver for AMD Geode LX CPUs");MODULE_LICENSE("GPL");