1/*
2 * Sonics Silicon Backplane
3 * Common SPROM support routines
4 *
5 * Copyright (C) 2005-2008 Michael Buesch <m@bues.ch>
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
20static int(*get_fallback_sprom)(struct ssb_bus *dev, struct ssb_sprom *out);
21
22
23static 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
36static 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 = kstrtoul(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 */
67ssize_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
91out_kfree:
92 kfree(sprom);
93out:
94 return err ? err : count;
95}
96
97/* Common sprom device-attribute store-handler */
98ssize_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 pr_err("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 pr_err("SPROM write: Could not thaw all devices\n");
137out_unlock:
138 mutex_unlock(&bus->sprom_mutex);
139out_kfree:
140 kfree(sprom);
141out:
142 if (res)
143 return res;
144 return err ? err : count;
145}
146
147/**
148 * ssb_arch_register_fallback_sprom - Registers a method providing a
149 * fallback SPROM if no SPROM is found.
150 *
151 * @sprom_callback: The callback function.
152 *
153 * With this function the architecture implementation may register a
154 * callback handler which fills the SPROM data structure. The fallback is
155 * only used for PCI based SSB devices, where no valid SPROM can be found
156 * in the shadow registers.
157 *
158 * This function is useful for weird architectures that have a half-assed
159 * SSB device hardwired to their PCI bus.
160 *
161 * Note that it does only work with PCI attached SSB devices. PCMCIA
162 * devices currently don't use this fallback.
163 * Architectures must provide the SPROM for native SSB devices anyway, so
164 * the fallback also isn't used for native devices.
165 *
166 * This function is available for architecture code, only. So it is not
167 * exported.
168 */
169int ssb_arch_register_fallback_sprom(int (*sprom_callback)(struct ssb_bus *bus,
170 struct ssb_sprom *out))
171{
172 if (get_fallback_sprom)
173 return -EEXIST;
174 get_fallback_sprom = sprom_callback;
175
176 return 0;
177}
178
179int ssb_fill_sprom_with_fallback(struct ssb_bus *bus, struct ssb_sprom *out)
180{
181 if (!get_fallback_sprom)
182 return -ENOENT;
183
184 return get_fallback_sprom(bus, out);
185}
186
187/* http://bcm-v4.sipsolutions.net/802.11/IsSpromAvailable */
188bool ssb_is_sprom_available(struct ssb_bus *bus)
189{
190 /* status register only exists on chipcomon rev >= 11 and we need check
191 for >= 31 only */
192 /* this routine differs from specs as we do not access SPROM directly
193 on PCMCIA */
194 if (bus->bustype == SSB_BUSTYPE_PCI &&
195 bus->chipco.dev && /* can be unavailable! */
196 bus->chipco.dev->id.revision >= 31)
197 return bus->chipco.capabilities & SSB_CHIPCO_CAP_SPROM;
198
199 return true;
200}
201