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1/*
2 * Sonics Silicon Backplane
3 * Common SPROM support routines
4 *
5 * Copyright (C) 2005-2008 Michael Buesch <[email protected]>
6 * Copyright (C) 2005 Martin Langer <[email protected]>
7 * Copyright (C) 2005 Stefano Brivio <[email protected]>
8 * Copyright (C) 2005 Danny van Dyk <[email protected]>
9 * Copyright (C) 2005 Andreas Jaggi <[email protected]>
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 += scnprintf(buf + pos, buf_len - pos - 1,
30 "%04X", swab16(sprom[i]) & 0xFFFF);
31 pos += scnprintf(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 */
83 err = -ERESTARTSYS;
84 if (mutex_lock_interruptible(&bus->sprom_mutex))
85 goto out_kfree;
86 err = sprom_read(bus, sprom);
87 mutex_unlock(&bus->sprom_mutex);
88
89 if (!err)
90 count = sprom2hex(sprom, buf, PAGE_SIZE, sprom_size_words);
91
92out_kfree:
93 kfree(sprom);
94out:
95 return err ? err : count;
96}
97
98/* Common sprom device-attribute store-handler */
99ssize_t ssb_attr_sprom_store(struct ssb_bus *bus,
100 const char *buf, size_t count,
101 int (*sprom_check_crc)(const u16 *sprom, size_t size),
102 int (*sprom_write)(struct ssb_bus *bus, const u16 *sprom))
103{
104 u16 *sprom;
105 int res = 0, err = -ENOMEM;
106 size_t sprom_size_words = bus->sprom_size;
107 struct ssb_freeze_context freeze;
108
109 sprom = kcalloc(bus->sprom_size, sizeof(u16), GFP_KERNEL);
110 if (!sprom)
111 goto out;
112 err = hex2sprom(sprom, buf, count, sprom_size_words);
113 if (err) {
114 err = -EINVAL;
115 goto out_kfree;
116 }
117 err = sprom_check_crc(sprom, sprom_size_words);
118 if (err) {
119 err = -EINVAL;
120 goto out_kfree;
121 }
122
123 /* Use interruptible locking, as the SPROM write might
124 * be holding the lock for several seconds. So allow userspace
125 * to cancel operation.
126 */
127 err = -ERESTARTSYS;
128 if (mutex_lock_interruptible(&bus->sprom_mutex))
129 goto out_kfree;
130 err = ssb_devices_freeze(bus, &freeze);
131 if (err) {
132 pr_err("SPROM write: Could not freeze all devices\n");
133 goto out_unlock;
134 }
135 res = sprom_write(bus, sprom);
136 err = ssb_devices_thaw(&freeze);
137 if (err)
138 pr_err("SPROM write: Could not thaw all devices\n");
139out_unlock:
140 mutex_unlock(&bus->sprom_mutex);
141out_kfree:
142 kfree(sprom);
143out:
144 if (res)
145 return res;
146 return err ? err : count;
147}
148
149/**
150 * ssb_arch_register_fallback_sprom - Registers a method providing a
151 * fallback SPROM if no SPROM is found.
152 *
153 * @sprom_callback: The callback function.
154 *
155 * With this function the architecture implementation may register a
156 * callback handler which fills the SPROM data structure. The fallback is
157 * only used for PCI based SSB devices, where no valid SPROM can be found
158 * in the shadow registers.
159 *
160 * This function is useful for weird architectures that have a half-assed
161 * SSB device hardwired to their PCI bus.
162 *
163 * Note that it does only work with PCI attached SSB devices. PCMCIA
164 * devices currently don't use this fallback.
165 * Architectures must provide the SPROM for native SSB devices anyway, so
166 * the fallback also isn't used for native devices.
167 *
168 * This function is available for architecture code, only. So it is not
169 * exported.
170 */
171int ssb_arch_register_fallback_sprom(int (*sprom_callback)(struct ssb_bus *bus,
172 struct ssb_sprom *out))
173{
174 if (get_fallback_sprom)
175 return -EEXIST;
176 get_fallback_sprom = sprom_callback;
177
178 return 0;
179}
180
181int ssb_fill_sprom_with_fallback(struct ssb_bus *bus, struct ssb_sprom *out)
182{
183 if (!get_fallback_sprom)
184 return -ENOENT;
185
186 return get_fallback_sprom(bus, out);
187}
188
189/* https://bcm-v4.sipsolutions.net/802.11/IsSpromAvailable */
190bool ssb_is_sprom_available(struct ssb_bus *bus)
191{
192 /* status register only exists on chipcomon rev >= 11 and we need check
193 * for >= 31 only
194 */
195 /* this routine differs from specs as we do not access SPROM directly
196 * on PCMCIA
197 */
198 if (bus->bustype == SSB_BUSTYPE_PCI &&
199 bus->chipco.dev && /* can be unavailable! */
200 bus->chipco.dev->id.revision >= 31)
201 return bus->chipco.capabilities & SSB_CHIPCO_CAP_SPROM;
202
203 return true;
204}