xref: /openbmc/linux/drivers/char/ipmi/ipmi_si_pci.c (revision 96de2506)
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 #include <linux/module.h>
8 #include <linux/pci.h>
9 #include "ipmi_si.h"
10 
11 #define PFX "ipmi_pci: "
12 
13 static bool pci_registered;
14 
15 static bool si_trypci = true;
16 
17 module_param_named(trypci, si_trypci, bool, 0);
18 MODULE_PARM_DESC(trypci, "Setting this to zero will disable the"
19 		 " default scan of the interfaces identified via pci");
20 
21 #define PCI_CLASS_SERIAL_IPMI		0x0c07
22 #define PCI_CLASS_SERIAL_IPMI_SMIC	0x0c0700
23 #define PCI_CLASS_SERIAL_IPMI_KCS	0x0c0701
24 #define PCI_CLASS_SERIAL_IPMI_BT	0x0c0702
25 
26 #define PCI_DEVICE_ID_HP_MMC 0x121A
27 
28 static void ipmi_pci_cleanup(struct si_sm_io *io)
29 {
30 	struct pci_dev *pdev = io->addr_source_data;
31 
32 	pci_disable_device(pdev);
33 }
34 
35 static int ipmi_pci_probe_regspacing(struct si_sm_io *io)
36 {
37 	if (io->si_type == SI_KCS) {
38 		unsigned char	status;
39 		int		regspacing;
40 
41 		io->regsize = DEFAULT_REGSIZE;
42 		io->regshift = 0;
43 
44 		/* detect 1, 4, 16byte spacing */
45 		for (regspacing = DEFAULT_REGSPACING; regspacing <= 16;) {
46 			io->regspacing = regspacing;
47 			if (io->io_setup(io)) {
48 				dev_err(io->dev,
49 					"Could not setup I/O space\n");
50 				return DEFAULT_REGSPACING;
51 			}
52 			/* write invalid cmd */
53 			io->outputb(io, 1, 0x10);
54 			/* read status back */
55 			status = io->inputb(io, 1);
56 			io->io_cleanup(io);
57 			if (status)
58 				return regspacing;
59 			regspacing *= 4;
60 		}
61 	}
62 	return DEFAULT_REGSPACING;
63 }
64 
65 static struct pci_device_id ipmi_pci_blacklist[] = {
66 	/*
67 	 * This is a "Virtual IPMI device", whatever that is.  It appears
68 	 * as a KCS device by the class, but it is not one.
69 	 */
70 	{ PCI_VDEVICE(REALTEK, 0x816c) },
71 	{ 0, }
72 };
73 
74 static int ipmi_pci_probe(struct pci_dev *pdev,
75 				    const struct pci_device_id *ent)
76 {
77 	int rv;
78 	struct si_sm_io io;
79 
80 	if (pci_match_id(ipmi_pci_blacklist, pdev))
81 		return -ENODEV;
82 
83 	memset(&io, 0, sizeof(io));
84 	io.addr_source = SI_PCI;
85 	dev_info(&pdev->dev, "probing via PCI");
86 
87 	switch (pdev->class) {
88 	case PCI_CLASS_SERIAL_IPMI_SMIC:
89 		io.si_type = SI_SMIC;
90 		break;
91 
92 	case PCI_CLASS_SERIAL_IPMI_KCS:
93 		io.si_type = SI_KCS;
94 		break;
95 
96 	case PCI_CLASS_SERIAL_IPMI_BT:
97 		io.si_type = SI_BT;
98 		break;
99 
100 	default:
101 		dev_info(&pdev->dev, "Unknown IPMI class: %x\n", pdev->class);
102 		return -ENOMEM;
103 	}
104 
105 	rv = pci_enable_device(pdev);
106 	if (rv) {
107 		dev_err(&pdev->dev, "couldn't enable PCI device\n");
108 		return rv;
109 	}
110 
111 	io.addr_source_cleanup = ipmi_pci_cleanup;
112 	io.addr_source_data = pdev;
113 
114 	if (pci_resource_flags(pdev, 0) & IORESOURCE_IO) {
115 		io.addr_type = IPMI_IO_ADDR_SPACE;
116 		io.io_setup = ipmi_si_port_setup;
117 	} else {
118 		io.addr_type = IPMI_MEM_ADDR_SPACE;
119 		io.io_setup = ipmi_si_mem_setup;
120 	}
121 	io.addr_data = pci_resource_start(pdev, 0);
122 
123 	io.regspacing = ipmi_pci_probe_regspacing(&io);
124 	io.regsize = DEFAULT_REGSIZE;
125 	io.regshift = 0;
126 
127 	io.irq = pdev->irq;
128 	if (io.irq)
129 		io.irq_setup = ipmi_std_irq_setup;
130 
131 	io.dev = &pdev->dev;
132 
133 	dev_info(&pdev->dev, "%pR regsize %d spacing %d irq %d\n",
134 		&pdev->resource[0], io.regsize, io.regspacing, io.irq);
135 
136 	rv = ipmi_si_add_smi(&io);
137 	if (rv)
138 		pci_disable_device(pdev);
139 
140 	return rv;
141 }
142 
143 static void ipmi_pci_remove(struct pci_dev *pdev)
144 {
145 	ipmi_si_remove_by_dev(&pdev->dev);
146 }
147 
148 static const struct pci_device_id ipmi_pci_devices[] = {
149 	{ PCI_VDEVICE(HP, PCI_DEVICE_ID_HP_MMC) },
150 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_SMIC, ~0) },
151 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_KCS, ~0) },
152 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_BT, ~0) },
153 	{ 0, }
154 };
155 MODULE_DEVICE_TABLE(pci, ipmi_pci_devices);
156 
157 static struct pci_driver ipmi_pci_driver = {
158 	.name =         DEVICE_NAME,
159 	.id_table =     ipmi_pci_devices,
160 	.probe =        ipmi_pci_probe,
161 	.remove =       ipmi_pci_remove,
162 };
163 
164 void ipmi_si_pci_init(void)
165 {
166 	if (si_trypci) {
167 		int rv = pci_register_driver(&ipmi_pci_driver);
168 		if (rv)
169 			pr_err(PFX "Unable to register PCI driver: %d\n", rv);
170 		else
171 			pci_registered = true;
172 	}
173 }
174 
175 void ipmi_si_pci_shutdown(void)
176 {
177 	if (pci_registered)
178 		pci_unregister_driver(&ipmi_pci_driver);
179 }
180