xref: /openbmc/linux/drivers/char/ipmi/ipmi_si_pci.c (revision dd5b2498)
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 
14 static bool pci_registered;
15 
16 static bool si_trypci = true;
17 
18 module_param_named(trypci, si_trypci, bool, 0);
19 MODULE_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 
24 static 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 
31 static 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 
60 static 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 
69 static 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 
138 static void ipmi_pci_remove(struct pci_dev *pdev)
139 {
140 	ipmi_si_remove_by_dev(&pdev->dev);
141 }
142 
143 static 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 };
150 MODULE_DEVICE_TABLE(pci, ipmi_pci_devices);
151 
152 static struct pci_driver ipmi_pci_driver = {
153 	.name =         DEVICE_NAME,
154 	.id_table =     ipmi_pci_devices,
155 	.probe =        ipmi_pci_probe,
156 	.remove =       ipmi_pci_remove,
157 };
158 
159 void 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 
170 void ipmi_si_pci_shutdown(void)
171 {
172 	if (pci_registered)
173 		pci_unregister_driver(&ipmi_pci_driver);
174 }
175