xref: /linux/drivers/char/ipmi/ipmi_si_pci.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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,
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 
24 static 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 
53 static 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 
62 static 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 		if (!IS_ENABLED(CONFIG_HAS_IOPORT))
101 			return -ENXIO;
102 
103 		io.addr_space = IPMI_IO_ADDR_SPACE;
104 		io.io_setup = ipmi_si_port_setup;
105 	} else {
106 		io.addr_space = IPMI_MEM_ADDR_SPACE;
107 		io.io_setup = ipmi_si_mem_setup;
108 	}
109 	io.addr_data = pci_resource_start(pdev, 0);
110 
111 	io.dev = &pdev->dev;
112 
113 	io.regspacing = ipmi_pci_probe_regspacing(&io);
114 	io.regsize = DEFAULT_REGSIZE;
115 	io.regshift = 0;
116 
117 	io.irq = pdev->irq;
118 	if (io.irq)
119 		io.irq_setup = ipmi_std_irq_setup;
120 
121 	dev_info(&pdev->dev, "%pR regsize %d spacing %d irq %d\n",
122 		 &pdev->resource[0], io.regsize, io.regspacing, io.irq);
123 
124 	return ipmi_si_add_smi(&io);
125 }
126 
127 static void ipmi_pci_remove(struct pci_dev *pdev)
128 {
129 	ipmi_si_remove_by_dev(&pdev->dev);
130 }
131 
132 static const struct pci_device_id ipmi_pci_devices[] = {
133 	{ PCI_VDEVICE(HP, PCI_DEVICE_ID_HP_MMC) },
134 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_SMIC, ~0) },
135 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_KCS, ~0) },
136 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_IPMI_BT, ~0) },
137 	{ 0, }
138 };
139 MODULE_DEVICE_TABLE(pci, ipmi_pci_devices);
140 
141 static struct pci_driver ipmi_pci_driver = {
142 	.name =         SI_DEVICE_NAME,
143 	.id_table =     ipmi_pci_devices,
144 	.probe =        ipmi_pci_probe,
145 	.remove =       ipmi_pci_remove,
146 };
147 
148 void ipmi_si_pci_init(void)
149 {
150 	if (si_trypci) {
151 		int rv = pci_register_driver(&ipmi_pci_driver);
152 		if (rv)
153 			pr_err("Unable to register PCI driver: %d\n", rv);
154 		else
155 			pci_registered = true;
156 	}
157 }
158 
159 void ipmi_si_pci_shutdown(void)
160 {
161 	if (pci_registered)
162 		pci_unregister_driver(&ipmi_pci_driver);
163 }
164