xref: /openbmc/linux/drivers/ssb/sprom.c (revision 367b8112)
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 
17 static int sprom2hex(const u16 *sprom, char *buf, size_t buf_len,
18 		     size_t sprom_size_words)
19 {
20 	int i, pos = 0;
21 
22 	for (i = 0; i < sprom_size_words; i++)
23 		pos += snprintf(buf + pos, buf_len - pos - 1,
24 				"%04X", swab16(sprom[i]) & 0xFFFF);
25 	pos += snprintf(buf + pos, buf_len - pos - 1, "\n");
26 
27 	return pos + 1;
28 }
29 
30 static int hex2sprom(u16 *sprom, const char *dump, size_t len,
31 		     size_t sprom_size_words)
32 {
33 	char tmp[5] = { 0 };
34 	int cnt = 0;
35 	unsigned long parsed;
36 
37 	if (len < sprom_size_words * 2)
38 		return -EINVAL;
39 
40 	while (cnt < sprom_size_words) {
41 		memcpy(tmp, dump, 4);
42 		dump += 4;
43 		parsed = simple_strtoul(tmp, NULL, 16);
44 		sprom[cnt++] = swab16((u16)parsed);
45 	}
46 
47 	return 0;
48 }
49 
50 /* Common sprom device-attribute show-handler */
51 ssize_t ssb_attr_sprom_show(struct ssb_bus *bus, char *buf,
52 			    int (*sprom_read)(struct ssb_bus *bus, u16 *sprom))
53 {
54 	u16 *sprom;
55 	int err = -ENOMEM;
56 	ssize_t count = 0;
57 	size_t sprom_size_words = bus->sprom_size;
58 
59 	sprom = kcalloc(sprom_size_words, sizeof(u16), GFP_KERNEL);
60 	if (!sprom)
61 		goto out;
62 
63 	/* Use interruptible locking, as the SPROM write might
64 	 * be holding the lock for several seconds. So allow userspace
65 	 * to cancel operation. */
66 	err = -ERESTARTSYS;
67 	if (mutex_lock_interruptible(&bus->sprom_mutex))
68 		goto out_kfree;
69 	err = sprom_read(bus, sprom);
70 	mutex_unlock(&bus->sprom_mutex);
71 
72 	if (!err)
73 		count = sprom2hex(sprom, buf, PAGE_SIZE, sprom_size_words);
74 
75 out_kfree:
76 	kfree(sprom);
77 out:
78 	return err ? err : count;
79 }
80 
81 /* Common sprom device-attribute store-handler */
82 ssize_t ssb_attr_sprom_store(struct ssb_bus *bus,
83 			     const char *buf, size_t count,
84 			     int (*sprom_check_crc)(const u16 *sprom, size_t size),
85 			     int (*sprom_write)(struct ssb_bus *bus, const u16 *sprom))
86 {
87 	u16 *sprom;
88 	int res = 0, err = -ENOMEM;
89 	size_t sprom_size_words = bus->sprom_size;
90 
91 	sprom = kcalloc(bus->sprom_size, sizeof(u16), GFP_KERNEL);
92 	if (!sprom)
93 		goto out;
94 	err = hex2sprom(sprom, buf, count, sprom_size_words);
95 	if (err) {
96 		err = -EINVAL;
97 		goto out_kfree;
98 	}
99 	err = sprom_check_crc(sprom, sprom_size_words);
100 	if (err) {
101 		err = -EINVAL;
102 		goto out_kfree;
103 	}
104 
105 	/* Use interruptible locking, as the SPROM write might
106 	 * be holding the lock for several seconds. So allow userspace
107 	 * to cancel operation. */
108 	err = -ERESTARTSYS;
109 	if (mutex_lock_interruptible(&bus->sprom_mutex))
110 		goto out_kfree;
111 	err = ssb_devices_freeze(bus);
112 	if (err == -EOPNOTSUPP) {
113 		ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze devices. "
114 			   "No suspend support. Is CONFIG_PM enabled?\n");
115 		goto out_unlock;
116 	}
117 	if (err) {
118 		ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze all devices\n");
119 		goto out_unlock;
120 	}
121 	res = sprom_write(bus, sprom);
122 	err = ssb_devices_thaw(bus);
123 	if (err)
124 		ssb_printk(KERN_ERR PFX "SPROM write: Could not thaw all devices\n");
125 out_unlock:
126 	mutex_unlock(&bus->sprom_mutex);
127 out_kfree:
128 	kfree(sprom);
129 out:
130 	if (res)
131 		return res;
132 	return err ? err : count;
133 }
134