1/*
 2 * Hardware Random Number Generator support for Cavium, Inc.
 3 * Thunder processor family.
 4 *
 5 * This file is subject to the terms and conditions of the GNU General Public
 6 * License.  See the file "COPYING" in the main directory of this archive
 7 * for more details.
 8 *
 9 * Copyright (C) 2016 Cavium, Inc.
10 */
11
12#include <linux/hw_random.h>
13#include <linux/io.h>
14#include <linux/module.h>
15#include <linux/pci.h>
16#include <linux/pci_ids.h>
17
18struct cavium_rng {
19	struct hwrng ops;
20	void __iomem *result;
21};
22
23/* Read data from the RNG unit */
24static int cavium_rng_read(struct hwrng *rng, void *dat, size_t max, bool wait)
25{
26	struct cavium_rng *p = container_of(rng, struct cavium_rng, ops);
27	unsigned int size = max;
28
29	while (size >= 8) {
30		*((u64 *)dat) = readq(p->result);
31		size -= 8;
32		dat += 8;
33	}
34	while (size > 0) {
35		*((u8 *)dat) = readb(p->result);
36		size--;
37		dat++;
38	}
39	return max;
40}
41
42/* Map Cavium RNG to an HWRNG object */
43static int cavium_rng_probe_vf(struct	pci_dev		*pdev,
44			 const struct	pci_device_id	*id)
45{
46	struct	cavium_rng *rng;
47	int	ret;
48
49	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
50	if (!rng)
51		return -ENOMEM;
52
53	/* Map the RNG result */
54	rng->result = pcim_iomap(pdev, 0, 0);
55	if (!rng->result) {
56		dev_err(&pdev->dev, "Error iomap failed retrieving result.\n");
57		return -ENOMEM;
58	}
59
60	rng->ops.name    = "cavium rng";
61	rng->ops.read    = cavium_rng_read;
62	rng->ops.quality = 1000;
63
64	pci_set_drvdata(pdev, rng);
65
66	ret = hwrng_register(&rng->ops);
67	if (ret) {
68		dev_err(&pdev->dev, "Error registering device as HWRNG.\n");
69		return ret;
70	}
71
72	return 0;
73}
74
75/* Remove the VF */
76void  cavium_rng_remove_vf(struct pci_dev *pdev)
77{
78	struct cavium_rng *rng;
79
80	rng = pci_get_drvdata(pdev);
81	hwrng_unregister(&rng->ops);
82}
83
84static const struct pci_device_id cavium_rng_vf_id_table[] = {
85	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa033), 0, 0, 0},
86	{0,},
87};
88MODULE_DEVICE_TABLE(pci, cavium_rng_vf_id_table);
89
90static struct pci_driver cavium_rng_vf_driver = {
91	.name		= "cavium_rng_vf",
92	.id_table	= cavium_rng_vf_id_table,
93	.probe		= cavium_rng_probe_vf,
94	.remove		= cavium_rng_remove_vf,
95};
96module_pci_driver(cavium_rng_vf_driver);
97
98MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
99MODULE_LICENSE("GPL");