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23cd1385 RB |
1 | /* |
2 | * Copyright (C) 2003 David Brownell | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU Lesser General Public License as published | |
6 | * by the Free Software Foundation; either version 2.1 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * Ported to U-boot by: Thomas Smits <ts.smits@gmail.com> and | |
10 | * Remy Bohmer <linux@bohmer.net> | |
11 | */ | |
12 | ||
13 | #include <common.h> | |
14 | #include <asm/errno.h> | |
15 | #include <linux/usb/ch9.h> | |
b9300531 | 16 | #include <usbdescriptors.h> |
23cd1385 RB |
17 | #include <linux/usb/gadget.h> |
18 | ||
19 | #include <asm/unaligned.h> | |
20 | ||
21 | ||
22 | static int utf8_to_utf16le(const char *s, __le16 *cp, unsigned len) | |
23 | { | |
24 | int count = 0; | |
25 | u8 c; | |
26 | u16 uchar; | |
27 | ||
6142e0ae VK |
28 | /* |
29 | * this insists on correct encodings, though not minimal ones. | |
23cd1385 RB |
30 | * BUT it currently rejects legit 4-byte UTF-8 code points, |
31 | * which need surrogate pairs. (Unicode 3.1 can use them.) | |
32 | */ | |
33 | while (len != 0 && (c = (u8) *s++) != 0) { | |
34 | if ((c & 0x80)) { | |
6142e0ae VK |
35 | /* |
36 | * 2-byte sequence: | |
37 | * 00000yyyyyxxxxxx = 110yyyyy 10xxxxxx | |
38 | */ | |
23cd1385 RB |
39 | if ((c & 0xe0) == 0xc0) { |
40 | uchar = (c & 0x1f) << 6; | |
41 | ||
42 | c = (u8) *s++; | |
43 | if ((c & 0xc0) != 0x80) | |
44 | goto fail; | |
45 | c &= 0x3f; | |
46 | uchar |= c; | |
47 | ||
6142e0ae VK |
48 | /* |
49 | * 3-byte sequence (most CJKV characters): | |
50 | * zzzzyyyyyyxxxxxx = 1110zzzz 10yyyyyy 10xxxxxx | |
51 | */ | |
23cd1385 RB |
52 | } else if ((c & 0xf0) == 0xe0) { |
53 | uchar = (c & 0x0f) << 12; | |
54 | ||
55 | c = (u8) *s++; | |
56 | if ((c & 0xc0) != 0x80) | |
57 | goto fail; | |
58 | c &= 0x3f; | |
59 | uchar |= c << 6; | |
60 | ||
61 | c = (u8) *s++; | |
62 | if ((c & 0xc0) != 0x80) | |
63 | goto fail; | |
64 | c &= 0x3f; | |
65 | uchar |= c; | |
66 | ||
67 | /* no bogus surrogates */ | |
68 | if (0xd800 <= uchar && uchar <= 0xdfff) | |
69 | goto fail; | |
70 | ||
6142e0ae VK |
71 | /* |
72 | * 4-byte sequence (surrogate pairs, currently rare): | |
73 | * 11101110wwwwzzzzyy + 110111yyyyxxxxxx | |
74 | * = 11110uuu 10uuzzzz 10yyyyyy 10xxxxxx | |
75 | * (uuuuu = wwww + 1) | |
76 | * FIXME accept the surrogate code points (only) | |
77 | */ | |
23cd1385 RB |
78 | } else |
79 | goto fail; | |
80 | } else | |
81 | uchar = c; | |
82 | put_unaligned_le16(uchar, cp++); | |
83 | count++; | |
84 | len--; | |
85 | } | |
86 | return count; | |
87 | fail: | |
88 | return -1; | |
89 | } | |
90 | ||
91 | ||
92 | /** | |
93 | * usb_gadget_get_string - fill out a string descriptor | |
94 | * @table: of c strings encoded using UTF-8 | |
95 | * @id: string id, from low byte of wValue in get string descriptor | |
96 | * @buf: at least 256 bytes | |
97 | * | |
98 | * Finds the UTF-8 string matching the ID, and converts it into a | |
99 | * string descriptor in utf16-le. | |
100 | * Returns length of descriptor (always even) or negative errno | |
101 | * | |
102 | * If your driver needs stings in multiple languages, you'll probably | |
103 | * "switch (wIndex) { ... }" in your ep0 string descriptor logic, | |
104 | * using this routine after choosing which set of UTF-8 strings to use. | |
105 | * Note that US-ASCII is a strict subset of UTF-8; any string bytes with | |
106 | * the eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1 | |
107 | * characters (which are also widely used in C strings). | |
108 | */ | |
109 | int | |
6142e0ae | 110 | usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf) |
23cd1385 RB |
111 | { |
112 | struct usb_string *s; | |
113 | int len; | |
114 | ||
115 | /* descriptor 0 has the language id */ | |
116 | if (id == 0) { | |
6142e0ae VK |
117 | buf[0] = 4; |
118 | buf[1] = USB_DT_STRING; | |
119 | buf[2] = (u8) table->language; | |
120 | buf[3] = (u8) (table->language >> 8); | |
23cd1385 RB |
121 | return 4; |
122 | } | |
123 | for (s = table->strings; s && s->s; s++) | |
124 | if (s->id == id) | |
125 | break; | |
126 | ||
127 | /* unrecognized: stall. */ | |
128 | if (!s || !s->s) | |
129 | return -EINVAL; | |
130 | ||
131 | /* string descriptors have length, tag, then UTF16-LE text */ | |
6142e0ae VK |
132 | len = min((size_t) 126, strlen(s->s)); |
133 | memset(buf + 2, 0, 2 * len); /* zero all the bytes */ | |
23cd1385 RB |
134 | len = utf8_to_utf16le(s->s, (__le16 *)&buf[2], len); |
135 | if (len < 0) | |
136 | return -EINVAL; | |
6142e0ae VK |
137 | buf[0] = (len + 1) * 2; |
138 | buf[1] = USB_DT_STRING; | |
139 | return buf[0]; | |
23cd1385 | 140 | } |