1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Hardware Random Number Generator support.
4*4882a593Smuzhiyun * Cavium Thunder, Marvell OcteonTx/Tx2 processor families.
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Copyright (C) 2016 Cavium, Inc.
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/hw_random.h>
10*4882a593Smuzhiyun #include <linux/io.h>
11*4882a593Smuzhiyun #include <linux/module.h>
12*4882a593Smuzhiyun #include <linux/pci.h>
13*4882a593Smuzhiyun #include <linux/pci_ids.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #define THUNDERX_RNM_ENT_EN 0x1
16*4882a593Smuzhiyun #define THUNDERX_RNM_RNG_EN 0x2
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun struct cavium_rng_pf {
19*4882a593Smuzhiyun void __iomem *control_status;
20*4882a593Smuzhiyun };
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun /* Enable the RNG hardware and activate the VF */
cavium_rng_probe(struct pci_dev * pdev,const struct pci_device_id * id)23*4882a593Smuzhiyun static int cavium_rng_probe(struct pci_dev *pdev,
24*4882a593Smuzhiyun const struct pci_device_id *id)
25*4882a593Smuzhiyun {
26*4882a593Smuzhiyun struct cavium_rng_pf *rng;
27*4882a593Smuzhiyun int iov_err;
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
30*4882a593Smuzhiyun if (!rng)
31*4882a593Smuzhiyun return -ENOMEM;
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun /*Map the RNG control */
34*4882a593Smuzhiyun rng->control_status = pcim_iomap(pdev, 0, 0);
35*4882a593Smuzhiyun if (!rng->control_status) {
36*4882a593Smuzhiyun dev_err(&pdev->dev,
37*4882a593Smuzhiyun "Error iomap failed retrieving control_status.\n");
38*4882a593Smuzhiyun return -ENOMEM;
39*4882a593Smuzhiyun }
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun /* Enable the RNG hardware and entropy source */
42*4882a593Smuzhiyun writeq(THUNDERX_RNM_RNG_EN | THUNDERX_RNM_ENT_EN,
43*4882a593Smuzhiyun rng->control_status);
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun pci_set_drvdata(pdev, rng);
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun /* Enable the Cavium RNG as a VF */
48*4882a593Smuzhiyun iov_err = pci_enable_sriov(pdev, 1);
49*4882a593Smuzhiyun if (iov_err != 0) {
50*4882a593Smuzhiyun /* Disable the RNG hardware and entropy source */
51*4882a593Smuzhiyun writeq(0, rng->control_status);
52*4882a593Smuzhiyun dev_err(&pdev->dev,
53*4882a593Smuzhiyun "Error initializing RNG virtual function,(%i).\n",
54*4882a593Smuzhiyun iov_err);
55*4882a593Smuzhiyun return iov_err;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun return 0;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun /* Disable VF and RNG Hardware */
cavium_rng_remove(struct pci_dev * pdev)62*4882a593Smuzhiyun static void cavium_rng_remove(struct pci_dev *pdev)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun struct cavium_rng_pf *rng;
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun rng = pci_get_drvdata(pdev);
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun /* Remove the VF */
69*4882a593Smuzhiyun pci_disable_sriov(pdev);
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun /* Disable the RNG hardware and entropy source */
72*4882a593Smuzhiyun writeq(0, rng->control_status);
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun static const struct pci_device_id cavium_rng_pf_id_table[] = {
76*4882a593Smuzhiyun { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa018), 0, 0, 0}, /* Thunder RNM */
77*4882a593Smuzhiyun {0,},
78*4882a593Smuzhiyun };
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun MODULE_DEVICE_TABLE(pci, cavium_rng_pf_id_table);
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun static struct pci_driver cavium_rng_pf_driver = {
83*4882a593Smuzhiyun .name = "cavium_rng_pf",
84*4882a593Smuzhiyun .id_table = cavium_rng_pf_id_table,
85*4882a593Smuzhiyun .probe = cavium_rng_probe,
86*4882a593Smuzhiyun .remove = cavium_rng_remove,
87*4882a593Smuzhiyun };
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun module_pci_driver(cavium_rng_pf_driver);
90*4882a593Smuzhiyun MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
91*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
92