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, "Setting this to zero will disable the"
 20		 " default scan of the interfaces identified via pci");
 21
 22#define PCI_DEVICE_ID_HP_MMC 0x121A
 23
 24static void ipmi_pci_cleanup(struct si_sm_io *io)
 25{
 26	struct pci_dev *pdev = io->addr_source_data;
 27
 28	pci_disable_device(pdev);
 29}
 30
 31static int ipmi_pci_probe_regspacing(struct si_sm_io *io)
 32{
 33	if (io->si_type == SI_KCS) {
 34		unsigned char	status;
 35		int		regspacing;
 36
 37		io->regsize = DEFAULT_REGSIZE;
 38		io->regshift = 0;
 39
 40		/* detect 1, 4, 16byte spacing */
 41		for (regspacing = DEFAULT_REGSPACING; regspacing <= 16;) {
 42			io->regspacing = regspacing;
 43			if (io->io_setup(io)) {
 44				dev_err(io->dev, "Could not setup I/O space\n");
 45				return DEFAULT_REGSPACING;
 46			}
 47			/* write invalid cmd */
 48			io->outputb(io, 1, 0x10);
 49			/* read status back */
 50			status = io->inputb(io, 1);
 51			io->io_cleanup(io);
 52			if (status)
 53				return regspacing;
 54			regspacing *= 4;
 55		}
 56	}
 57	return DEFAULT_REGSPACING;
 58}
 59
 60static struct pci_device_id ipmi_pci_blacklist[] = {
 61	/*
 62	 * This is a "Virtual IPMI device", whatever that is.  It appears
 63	 * as a KCS device by the class, but it is not one.
 64	 */
 65	{ PCI_VDEVICE(REALTEK, 0x816c) },
 66	{ 0, }
 67};
 68
 69static int ipmi_pci_probe(struct pci_dev *pdev,
 70				    const struct pci_device_id *ent)
 71{
 72	int rv;
 73	struct si_sm_io io;
 74
 75	if (pci_match_id(ipmi_pci_blacklist, pdev))
 76		return -ENODEV;
 77
 78	memset(&io, 0, sizeof(io));
 79	io.addr_source = SI_PCI;
 80	dev_info(&pdev->dev, "probing via PCI");
 81
 82	switch (pdev->class) {
 83	case PCI_CLASS_SERIAL_IPMI_SMIC:
 84		io.si_type = SI_SMIC;
 85		break;
 86
 87	case PCI_CLASS_SERIAL_IPMI_KCS:
 88		io.si_type = SI_KCS;
 89		break;
 90
 91	case PCI_CLASS_SERIAL_IPMI_BT:
 92		io.si_type = SI_BT;
 93		break;
 94
 95	default:
 96		dev_info(&pdev->dev, "Unknown IPMI class: %x\n", pdev->class);
 97		return -ENOMEM;
 98	}
 99
100	rv = pci_enable_device(pdev);
101	if (rv) {
102		dev_err(&pdev->dev, "couldn't enable PCI device\n");
103		return rv;
104	}
105
106	io.addr_source_cleanup = ipmi_pci_cleanup;
107	io.addr_source_data = pdev;
108
109	if (pci_resource_flags(pdev, 0) & IORESOURCE_IO) {
110		io.addr_space = IPMI_IO_ADDR_SPACE;
111		io.io_setup = ipmi_si_port_setup;
112	} else {
113		io.addr_space = IPMI_MEM_ADDR_SPACE;
114		io.io_setup = ipmi_si_mem_setup;
115	}
116	io.addr_data = pci_resource_start(pdev, 0);
117
118	io.dev = &pdev->dev;
119
120	io.regspacing = ipmi_pci_probe_regspacing(&io);
121	io.regsize = DEFAULT_REGSIZE;
122	io.regshift = 0;
123
124	io.irq = pdev->irq;
125	if (io.irq)
126		io.irq_setup = ipmi_std_irq_setup;
127
128	dev_info(&pdev->dev, "%pR regsize %d spacing %d irq %d\n",
129		 &pdev->resource[0], io.regsize, io.regspacing, io.irq);
130
131	rv = ipmi_si_add_smi(&io);
132	if (rv)
133		pci_disable_device(pdev);
134
135	return rv;
136}
137
138static void ipmi_pci_remove(struct pci_dev *pdev)
139{
140	ipmi_si_remove_by_dev(&pdev->dev);
141}
142
143static const struct pci_device_id ipmi_pci_devices[] = {
144	{ PCI_VDEVICE(HP, PCI_DEVICE_ID_HP_MMC) },
145	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_SMIC, ~0) },
146	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_KCS, ~0) },
147	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_BT, ~0) },
148	{ 0, }
149};
150MODULE_DEVICE_TABLE(pci, ipmi_pci_devices);
151
152static struct pci_driver ipmi_pci_driver = {
153	.name =         SI_DEVICE_NAME,
154	.id_table =     ipmi_pci_devices,
155	.probe =        ipmi_pci_probe,
156	.remove =       ipmi_pci_remove,
157};
158
159void ipmi_si_pci_init(void)
160{
161	if (si_trypci) {
162		int rv = pci_register_driver(&ipmi_pci_driver);
163		if (rv)
164			pr_err("Unable to register PCI driver: %d\n", rv);
165		else
166			pci_registered = true;
167	}
168}
169
170void ipmi_si_pci_shutdown(void)
171{
172	if (pci_registered)
173		pci_unregister_driver(&ipmi_pci_driver);
174}