1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * ipmi_si_pci.c
4 *
5 * Handling for IPMI devices on the PCI bus.
6 */
7
8#define pr_fmt(fmt) "ipmi_pci: " fmt
9
10#include <linux/module.h>
11#include <linux/pci.h>
12#include "ipmi_si.h"
13
14static bool pci_registered;
15
16static bool si_trypci = true;
17
18module_param_named(trypci, si_trypci, bool, 0);
19MODULE_PARM_DESC(trypci,
20		 "Setting this to zero will disable the default scan of the interfaces identified via pci");
21
22#define PCI_DEVICE_ID_HP_MMC 0x121A
23
24static int ipmi_pci_probe_regspacing(struct si_sm_io *io)
25{
26	if (io->si_type == SI_KCS) {
27		unsigned char	status;
28		int		regspacing;
29
30		io->regsize = DEFAULT_REGSIZE;
31		io->regshift = 0;
32
33		/* detect 1, 4, 16byte spacing */
34		for (regspacing = DEFAULT_REGSPACING; regspacing <= 16;) {
35			io->regspacing = regspacing;
36			if (io->io_setup(io)) {
37				dev_err(io->dev, "Could not setup I/O space\n");
38				return DEFAULT_REGSPACING;
39			}
40			/* write invalid cmd */
41			io->outputb(io, 1, 0x10);
42			/* read status back */
43			status = io->inputb(io, 1);
44			io->io_cleanup(io);
45			if (status)
46				return regspacing;
47			regspacing *= 4;
48		}
49	}
50	return DEFAULT_REGSPACING;
51}
52
53static struct pci_device_id ipmi_pci_blacklist[] = {
54	/*
55	 * This is a "Virtual IPMI device", whatever that is.  It appears
56	 * as a KCS device by the class, but it is not one.
57	 */
58	{ PCI_VDEVICE(REALTEK, 0x816c) },
59	{ 0, }
60};
61
62static int ipmi_pci_probe(struct pci_dev *pdev,
63				    const struct pci_device_id *ent)
64{
65	int rv;
66	struct si_sm_io io;
67
68	if (pci_match_id(ipmi_pci_blacklist, pdev))
69		return -ENODEV;
70
71	memset(&io, 0, sizeof(io));
72	io.addr_source = SI_PCI;
73	dev_info(&pdev->dev, "probing via PCI");
74
75	switch (pdev->class) {
76	case PCI_CLASS_SERIAL_IPMI_SMIC:
77		io.si_type = SI_SMIC;
78		break;
79
80	case PCI_CLASS_SERIAL_IPMI_KCS:
81		io.si_type = SI_KCS;
82		break;
83
84	case PCI_CLASS_SERIAL_IPMI_BT:
85		io.si_type = SI_BT;
86		break;
87
88	default:
89		dev_info(&pdev->dev, "Unknown IPMI class: %x\n", pdev->class);
90		return -ENOMEM;
91	}
92
93	rv = pcim_enable_device(pdev);
94	if (rv) {
95		dev_err(&pdev->dev, "couldn't enable PCI device\n");
96		return rv;
97	}
98
99	if (pci_resource_flags(pdev, 0) & IORESOURCE_IO) {
100		io.addr_space = IPMI_IO_ADDR_SPACE;
101		io.io_setup = ipmi_si_port_setup;
102	} else {
103		io.addr_space = IPMI_MEM_ADDR_SPACE;
104		io.io_setup = ipmi_si_mem_setup;
105	}
106	io.addr_data = pci_resource_start(pdev, 0);
107
108	io.dev = &pdev->dev;
109
110	io.regspacing = ipmi_pci_probe_regspacing(&io);
111	io.regsize = DEFAULT_REGSIZE;
112	io.regshift = 0;
113
114	io.irq = pdev->irq;
115	if (io.irq)
116		io.irq_setup = ipmi_std_irq_setup;
117
118	dev_info(&pdev->dev, "%pR regsize %d spacing %d irq %d\n",
119		 &pdev->resource[0], io.regsize, io.regspacing, io.irq);
120
121	return ipmi_si_add_smi(&io);
122}
123
124static void ipmi_pci_remove(struct pci_dev *pdev)
125{
126	ipmi_si_remove_by_dev(&pdev->dev);
127}
128
129static const struct pci_device_id ipmi_pci_devices[] = {
130	{ PCI_VDEVICE(HP, PCI_DEVICE_ID_HP_MMC) },
131	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_SMIC, ~0) },
132	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_KCS, ~0) },
133	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_BT, ~0) },
134	{ 0, }
135};
136MODULE_DEVICE_TABLE(pci, ipmi_pci_devices);
137
138static struct pci_driver ipmi_pci_driver = {
139	.name =         SI_DEVICE_NAME,
140	.id_table =     ipmi_pci_devices,
141	.probe =        ipmi_pci_probe,
142	.remove =       ipmi_pci_remove,
143};
144
145void ipmi_si_pci_init(void)
146{
147	if (si_trypci) {
148		int rv = pci_register_driver(&ipmi_pci_driver);
149		if (rv)
150			pr_err("Unable to register PCI driver: %d\n", rv);
151		else
152			pci_registered = true;
153	}
154}
155
156void ipmi_si_pci_shutdown(void)
157{
158	if (pci_registered)
159		pci_unregister_driver(&ipmi_pci_driver);
160}
161