linux-sg2042/drivers/char/hw_random/cavium-rng.c

95 lines
2.2 KiB
C

/*
* Hardware Random Number Generator support for Cavium Inc.
* Thunder processor family.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2016 Cavium, Inc.
*/
#include <linux/hw_random.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#define THUNDERX_RNM_ENT_EN 0x1
#define THUNDERX_RNM_RNG_EN 0x2
struct cavium_rng_pf {
void __iomem *control_status;
};
/* Enable the RNG hardware and activate the VF */
static int cavium_rng_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
struct cavium_rng_pf *rng;
int iov_err;
rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
if (!rng)
return -ENOMEM;
/*Map the RNG control */
rng->control_status = pcim_iomap(pdev, 0, 0);
if (!rng->control_status) {
dev_err(&pdev->dev,
"Error iomap failed retrieving control_status.\n");
return -ENOMEM;
}
/* Enable the RNG hardware and entropy source */
writeq(THUNDERX_RNM_RNG_EN | THUNDERX_RNM_ENT_EN,
rng->control_status);
pci_set_drvdata(pdev, rng);
/* Enable the Cavium RNG as a VF */
iov_err = pci_enable_sriov(pdev, 1);
if (iov_err != 0) {
/* Disable the RNG hardware and entropy source */
writeq(0, rng->control_status);
dev_err(&pdev->dev,
"Error initializing RNG virtual function,(%i).\n",
iov_err);
return iov_err;
}
return 0;
}
/* Disable VF and RNG Hardware */
static void cavium_rng_remove(struct pci_dev *pdev)
{
struct cavium_rng_pf *rng;
rng = pci_get_drvdata(pdev);
/* Remove the VF */
pci_disable_sriov(pdev);
/* Disable the RNG hardware and entropy source */
writeq(0, rng->control_status);
}
static const struct pci_device_id cavium_rng_pf_id_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa018), 0, 0, 0}, /* Thunder RNM */
{0,},
};
MODULE_DEVICE_TABLE(pci, cavium_rng_pf_id_table);
static struct pci_driver cavium_rng_pf_driver = {
.name = "cavium_rng_pf",
.id_table = cavium_rng_pf_id_table,
.probe = cavium_rng_probe,
.remove = cavium_rng_remove,
};
module_pci_driver(cavium_rng_pf_driver);
MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
MODULE_LICENSE("GPL");