xref: /openbmc/linux/drivers/pnp/system.c (revision f3539c12)
1 /*
2  * system.c - a driver for reserving pnp system resources
3  *
4  * Some code is based on pnpbios_core.c
5  * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
6  * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
7  *	Bjorn Helgaas <bjorn.helgaas@hp.com>
8  */
9 
10 #include <linux/pnp.h>
11 #include <linux/device.h>
12 #include <linux/init.h>
13 #include <linux/slab.h>
14 #include <linux/kernel.h>
15 #include <linux/ioport.h>
16 
17 static const struct pnp_device_id pnp_dev_table[] = {
18 	/* General ID for reserving resources */
19 	{"PNP0c02", 0},
20 	/* memory controller */
21 	{"PNP0c01", 0},
22 	{"", 0}
23 };
24 
25 static void reserve_range(struct pnp_dev *dev, struct resource *r, int port)
26 {
27 	char *regionid;
28 	const char *pnpid = dev_name(&dev->dev);
29 	resource_size_t start = r->start, end = r->end;
30 	struct resource *res;
31 
32 	regionid = kmalloc(16, GFP_KERNEL);
33 	if (!regionid)
34 		return;
35 
36 	snprintf(regionid, 16, "pnp %s", pnpid);
37 	if (port)
38 		res = request_region(start, end - start + 1, regionid);
39 	else
40 		res = request_mem_region(start, end - start + 1, regionid);
41 	if (res)
42 		res->flags &= ~IORESOURCE_BUSY;
43 	else
44 		kfree(regionid);
45 
46 	/*
47 	 * Failures at this point are usually harmless. pci quirks for
48 	 * example do reserve stuff they know about too, so we may well
49 	 * have double reservations.
50 	 */
51 	dev_info(&dev->dev, "%pR %s reserved\n", r,
52 		 res ? "has been" : "could not be");
53 }
54 
55 static void reserve_resources_of_dev(struct pnp_dev *dev)
56 {
57 	struct resource *res;
58 	int i;
59 
60 	for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) {
61 		if (res->flags & IORESOURCE_DISABLED)
62 			continue;
63 		if (res->start == 0)
64 			continue;	/* disabled */
65 		if (res->start < 0x100)
66 			/*
67 			 * Below 0x100 is only standard PC hardware
68 			 * (pics, kbd, timer, dma, ...)
69 			 * We should not get resource conflicts there,
70 			 * and the kernel reserves these anyway
71 			 * (see arch/i386/kernel/setup.c).
72 			 * So, do nothing
73 			 */
74 			continue;
75 		if (res->end < res->start)
76 			continue;	/* invalid */
77 
78 		reserve_range(dev, res, 1);
79 	}
80 
81 	for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) {
82 		if (res->flags & IORESOURCE_DISABLED)
83 			continue;
84 
85 		reserve_range(dev, res, 0);
86 	}
87 }
88 
89 static int system_pnp_probe(struct pnp_dev *dev,
90 			    const struct pnp_device_id *dev_id)
91 {
92 	reserve_resources_of_dev(dev);
93 	return 0;
94 }
95 
96 static struct pnp_driver system_pnp_driver = {
97 	.name     = "system",
98 	.id_table = pnp_dev_table,
99 	.flags    = PNP_DRIVER_RES_DO_NOT_CHANGE,
100 	.probe    = system_pnp_probe,
101 };
102 
103 static int __init pnp_system_init(void)
104 {
105 	return pnp_register_driver(&system_pnp_driver);
106 }
107 
108 /**
109  * Reserve motherboard resources after PCI claim BARs,
110  * but before PCI assign resources for uninitialized PCI devices
111  */
112 fs_initcall(pnp_system_init);
113