1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Hardware Random Number Generator support.
4 * Cavium Thunder, Marvell OcteonTx/Tx2 processor families.
5 *
6 * Copyright (C) 2016 Cavium, Inc.
7 */
8
9#include <linux/hw_random.h>
10#include <linux/io.h>
11#include <linux/module.h>
12#include <linux/pci.h>
13#include <linux/pci_ids.h>
14
15#define THUNDERX_RNM_ENT_EN     0x1
16#define THUNDERX_RNM_RNG_EN     0x2
17
18struct cavium_rng_pf {
19	void __iomem *control_status;
20};
21
22/* Enable the RNG hardware and activate the VF */
23static int cavium_rng_probe(struct pci_dev *pdev,
24			const struct pci_device_id *id)
25{
26	struct	cavium_rng_pf *rng;
27	int	iov_err;
28
29	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
30	if (!rng)
31		return -ENOMEM;
32
33	/*Map the RNG control */
34	rng->control_status = pcim_iomap(pdev, 0, 0);
35	if (!rng->control_status) {
36		dev_err(&pdev->dev,
37			"Error iomap failed retrieving control_status.\n");
38		return -ENOMEM;
39	}
40
41	/* Enable the RNG hardware and entropy source */
42	writeq(THUNDERX_RNM_RNG_EN | THUNDERX_RNM_ENT_EN,
43		rng->control_status);
44
45	pci_set_drvdata(pdev, rng);
46
47	/* Enable the Cavium RNG as a VF */
48	iov_err = pci_enable_sriov(pdev, 1);
49	if (iov_err != 0) {
50		/* Disable the RNG hardware and entropy source */
51		writeq(0, rng->control_status);
52		dev_err(&pdev->dev,
53			"Error initializing RNG virtual function,(%i).\n",
54			iov_err);
55		return iov_err;
56	}
57
58	return 0;
59}
60
61/* Disable VF and RNG Hardware */
62static void cavium_rng_remove(struct pci_dev *pdev)
63{
64	struct cavium_rng_pf *rng;
65
66	rng = pci_get_drvdata(pdev);
67
68	/* Remove the VF */
69	pci_disable_sriov(pdev);
70
71	/* Disable the RNG hardware and entropy source */
72	writeq(0, rng->control_status);
73}
74
75static const struct pci_device_id cavium_rng_pf_id_table[] = {
76	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa018), 0, 0, 0}, /* Thunder RNM */
77	{0,},
78};
79
80MODULE_DEVICE_TABLE(pci, cavium_rng_pf_id_table);
81
82static struct pci_driver cavium_rng_pf_driver = {
83	.name		= "cavium_rng_pf",
84	.id_table	= cavium_rng_pf_id_table,
85	.probe		= cavium_rng_probe,
86	.remove		= cavium_rng_remove,
87};
88
89module_pci_driver(cavium_rng_pf_driver);
90MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
91MODULE_LICENSE("GPL v2");
92