xref: /openbmc/linux/drivers/pnp/support.c (revision 22246614)
1 /*
2  * support.c - standard functions for the use of pnp protocol drivers
3  *
4  * Copyright 2003 Adam Belay <ambx1@neo.rr.com>
5  */
6 
7 #include <linux/module.h>
8 #include <linux/ctype.h>
9 #include <linux/pnp.h>
10 #include "base.h"
11 
12 /**
13  * pnp_is_active - Determines if a device is active based on its current
14  *	resources
15  * @dev: pointer to the desired PnP device
16  */
17 int pnp_is_active(struct pnp_dev *dev)
18 {
19 	if (!pnp_port_start(dev, 0) && pnp_port_len(dev, 0) <= 1 &&
20 	    !pnp_mem_start(dev, 0) && pnp_mem_len(dev, 0) <= 1 &&
21 	    pnp_irq(dev, 0) == -1 && pnp_dma(dev, 0) == -1)
22 		return 0;
23 	else
24 		return 1;
25 }
26 
27 EXPORT_SYMBOL(pnp_is_active);
28 
29 /*
30  * Functionally similar to acpi_ex_eisa_id_to_string(), but that's
31  * buried in the ACPI CA, and we can't depend on it being present.
32  */
33 void pnp_eisa_id_to_string(u32 id, char *str)
34 {
35 	id = be32_to_cpu(id);
36 
37 	/*
38 	 * According to the specs, the first three characters are five-bit
39 	 * compressed ASCII, and the left-over high order bit should be zero.
40 	 * However, the Linux ISAPNP code historically used six bits for the
41 	 * first character, and there seem to be IDs that depend on that,
42 	 * e.g., "nEC8241" in the Linux 8250_pnp serial driver and the
43 	 * FreeBSD sys/pc98/cbus/sio_cbus.c driver.
44 	 */
45 	str[0] = 'A' + ((id >> 26) & 0x3f) - 1;
46 	str[1] = 'A' + ((id >> 21) & 0x1f) - 1;
47 	str[2] = 'A' + ((id >> 16) & 0x1f) - 1;
48 	str[3] = hex_asc((id >> 12) & 0xf);
49 	str[4] = hex_asc((id >>  8) & 0xf);
50 	str[5] = hex_asc((id >>  4) & 0xf);
51 	str[6] = hex_asc((id >>  0) & 0xf);
52 	str[7] = '\0';
53 }
54 
55 void dbg_pnp_show_resources(struct pnp_dev *dev, char *desc)
56 {
57 #ifdef DEBUG
58 	struct resource *res;
59 	int i;
60 
61 	dev_dbg(&dev->dev, "current resources: %s\n", desc);
62 
63 	for (i = 0; i < PNP_MAX_IRQ; i++) {
64 		res = pnp_get_resource(dev, IORESOURCE_IRQ, i);
65 		if (res && !(res->flags & IORESOURCE_UNSET))
66 			dev_dbg(&dev->dev, "  irq %lld flags %#lx\n",
67 				(unsigned long long) res->start, res->flags);
68 	}
69 	for (i = 0; i < PNP_MAX_DMA; i++) {
70 		res = pnp_get_resource(dev, IORESOURCE_DMA, i);
71 		if (res && !(res->flags & IORESOURCE_UNSET))
72 			dev_dbg(&dev->dev, "  dma %lld flags %#lx\n",
73 				(unsigned long long) res->start, res->flags);
74 	}
75 	for (i = 0; i < PNP_MAX_PORT; i++) {
76 		res = pnp_get_resource(dev, IORESOURCE_IO, i);
77 		if (res && !(res->flags & IORESOURCE_UNSET))
78 			dev_dbg(&dev->dev, "  io  %#llx-%#llx flags %#lx\n",
79 				(unsigned long long) res->start,
80 				(unsigned long long) res->end, res->flags);
81 	}
82 	for (i = 0; i < PNP_MAX_MEM; i++) {
83 		res = pnp_get_resource(dev, IORESOURCE_MEM, i);
84 		if (res && !(res->flags & IORESOURCE_UNSET))
85 			dev_dbg(&dev->dev, "  mem %#llx-%#llx flags %#lx\n",
86 				(unsigned long long) res->start,
87 				(unsigned long long) res->end, res->flags);
88 	}
89 #endif
90 }
91