Orange Pi5 kernel

/*
 * 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
 *
 * 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/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 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;
 
<------>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 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");