xref: /linux/drivers/ssb/sprom.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
1 /*
2  * Sonics Silicon Backplane
3  * Common SPROM support routines
4  *
5  * Copyright (C) 2005-2008 Michael Buesch <mb@bu3sch.de>
6  * Copyright (C) 2005 Martin Langer <martin-langer@gmx.de>
7  * Copyright (C) 2005 Stefano Brivio <st3@riseup.net>
8  * Copyright (C) 2005 Danny van Dyk <kugelfang@gentoo.org>
9  * Copyright (C) 2005 Andreas Jaggi <andreas.jaggi@waterwave.ch>
10  *
11  * Licensed under the GNU/GPL. See COPYING for details.
12  */
13 
14 #include "ssb_private.h"
15 
16 #include <linux/ctype.h>
17 #include <linux/slab.h>
18 
19 
20 static const struct ssb_sprom *fallback_sprom;
21 
22 
23 static int sprom2hex(const u16 *sprom, char *buf, size_t buf_len,
24 		     size_t sprom_size_words)
25 {
26 	int i, pos = 0;
27 
28 	for (i = 0; i < sprom_size_words; i++)
29 		pos += snprintf(buf + pos, buf_len - pos - 1,
30 				"%04X", swab16(sprom[i]) & 0xFFFF);
31 	pos += snprintf(buf + pos, buf_len - pos - 1, "\n");
32 
33 	return pos + 1;
34 }
35 
36 static int hex2sprom(u16 *sprom, const char *dump, size_t len,
37 		     size_t sprom_size_words)
38 {
39 	char c, tmp[5] = { 0 };
40 	int err, cnt = 0;
41 	unsigned long parsed;
42 
43 	/* Strip whitespace at the end. */
44 	while (len) {
45 		c = dump[len - 1];
46 		if (!isspace(c) && c != '\0')
47 			break;
48 		len--;
49 	}
50 	/* Length must match exactly. */
51 	if (len != sprom_size_words * 4)
52 		return -EINVAL;
53 
54 	while (cnt < sprom_size_words) {
55 		memcpy(tmp, dump, 4);
56 		dump += 4;
57 		err = strict_strtoul(tmp, 16, &parsed);
58 		if (err)
59 			return err;
60 		sprom[cnt++] = swab16((u16)parsed);
61 	}
62 
63 	return 0;
64 }
65 
66 /* Common sprom device-attribute show-handler */
67 ssize_t ssb_attr_sprom_show(struct ssb_bus *bus, char *buf,
68 			    int (*sprom_read)(struct ssb_bus *bus, u16 *sprom))
69 {
70 	u16 *sprom;
71 	int err = -ENOMEM;
72 	ssize_t count = 0;
73 	size_t sprom_size_words = bus->sprom_size;
74 
75 	sprom = kcalloc(sprom_size_words, sizeof(u16), GFP_KERNEL);
76 	if (!sprom)
77 		goto out;
78 
79 	/* Use interruptible locking, as the SPROM write might
80 	 * be holding the lock for several seconds. So allow userspace
81 	 * to cancel operation. */
82 	err = -ERESTARTSYS;
83 	if (mutex_lock_interruptible(&bus->sprom_mutex))
84 		goto out_kfree;
85 	err = sprom_read(bus, sprom);
86 	mutex_unlock(&bus->sprom_mutex);
87 
88 	if (!err)
89 		count = sprom2hex(sprom, buf, PAGE_SIZE, sprom_size_words);
90 
91 out_kfree:
92 	kfree(sprom);
93 out:
94 	return err ? err : count;
95 }
96 
97 /* Common sprom device-attribute store-handler */
98 ssize_t ssb_attr_sprom_store(struct ssb_bus *bus,
99 			     const char *buf, size_t count,
100 			     int (*sprom_check_crc)(const u16 *sprom, size_t size),
101 			     int (*sprom_write)(struct ssb_bus *bus, const u16 *sprom))
102 {
103 	u16 *sprom;
104 	int res = 0, err = -ENOMEM;
105 	size_t sprom_size_words = bus->sprom_size;
106 	struct ssb_freeze_context freeze;
107 
108 	sprom = kcalloc(bus->sprom_size, sizeof(u16), GFP_KERNEL);
109 	if (!sprom)
110 		goto out;
111 	err = hex2sprom(sprom, buf, count, sprom_size_words);
112 	if (err) {
113 		err = -EINVAL;
114 		goto out_kfree;
115 	}
116 	err = sprom_check_crc(sprom, sprom_size_words);
117 	if (err) {
118 		err = -EINVAL;
119 		goto out_kfree;
120 	}
121 
122 	/* Use interruptible locking, as the SPROM write might
123 	 * be holding the lock for several seconds. So allow userspace
124 	 * to cancel operation. */
125 	err = -ERESTARTSYS;
126 	if (mutex_lock_interruptible(&bus->sprom_mutex))
127 		goto out_kfree;
128 	err = ssb_devices_freeze(bus, &freeze);
129 	if (err) {
130 		ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze all devices\n");
131 		goto out_unlock;
132 	}
133 	res = sprom_write(bus, sprom);
134 	err = ssb_devices_thaw(&freeze);
135 	if (err)
136 		ssb_printk(KERN_ERR PFX "SPROM write: Could not thaw all devices\n");
137 out_unlock:
138 	mutex_unlock(&bus->sprom_mutex);
139 out_kfree:
140 	kfree(sprom);
141 out:
142 	if (res)
143 		return res;
144 	return err ? err : count;
145 }
146 
147 /**
148  * ssb_arch_set_fallback_sprom - Set a fallback SPROM for use if no SPROM is found.
149  *
150  * @sprom: The SPROM data structure to register.
151  *
152  * With this function the architecture implementation may register a fallback
153  * SPROM data structure. The fallback is only used for PCI based SSB devices,
154  * where no valid SPROM can be found in the shadow registers.
155  *
156  * This function is useful for weird architectures that have a half-assed SSB device
157  * hardwired to their PCI bus.
158  *
159  * Note that it does only work with PCI attached SSB devices. PCMCIA devices currently
160  * don't use this fallback.
161  * Architectures must provide the SPROM for native SSB devices anyway,
162  * so the fallback also isn't used for native devices.
163  *
164  * This function is available for architecture code, only. So it is not exported.
165  */
166 int ssb_arch_set_fallback_sprom(const struct ssb_sprom *sprom)
167 {
168 	if (fallback_sprom)
169 		return -EEXIST;
170 	fallback_sprom = sprom;
171 
172 	return 0;
173 }
174 
175 const struct ssb_sprom *ssb_get_fallback_sprom(void)
176 {
177 	return fallback_sprom;
178 }
179 
180 /* http://bcm-v4.sipsolutions.net/802.11/IsSpromAvailable */
181 bool ssb_is_sprom_available(struct ssb_bus *bus)
182 {
183 	/* status register only exists on chipcomon rev >= 11 and we need check
184 	   for >= 31 only */
185 	/* this routine differs from specs as we do not access SPROM directly
186 	   on PCMCIA */
187 	if (bus->bustype == SSB_BUSTYPE_PCI &&
188 	    bus->chipco.dev &&	/* can be unavailible! */
189 	    bus->chipco.dev->id.revision >= 31)
190 		return bus->chipco.capabilities & SSB_CHIPCO_CAP_SPROM;
191 
192 	return true;
193 }
194