diff options
Diffstat (limited to 'drivers/misc/eeprom/eeprom_93cx6.c')
-rw-r--r-- | drivers/misc/eeprom/eeprom_93cx6.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/misc/eeprom/eeprom_93cx6.c b/drivers/misc/eeprom/eeprom_93cx6.c new file mode 100644 index 000000000000..15b1780025c8 --- /dev/null +++ b/drivers/misc/eeprom/eeprom_93cx6.c | |||
@@ -0,0 +1,240 @@ | |||
1 | /* | ||
2 | Copyright (C) 2004 - 2006 rt2x00 SourceForge Project | ||
3 | <http://rt2x00.serialmonkey.com> | ||
4 | |||
5 | This program is free software; you can redistribute it and/or modify | ||
6 | it under the terms of the GNU General Public License as published by | ||
7 | the Free Software Foundation; either version 2 of the License, or | ||
8 | (at your option) any later version. | ||
9 | |||
10 | This program is distributed in the hope that it will be useful, | ||
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
13 | GNU General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU General Public License | ||
16 | along with this program; if not, write to the | ||
17 | Free Software Foundation, Inc., | ||
18 | 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | ||
19 | */ | ||
20 | |||
21 | /* | ||
22 | Module: eeprom_93cx6 | ||
23 | Abstract: EEPROM reader routines for 93cx6 chipsets. | ||
24 | Supported chipsets: 93c46 & 93c66. | ||
25 | */ | ||
26 | |||
27 | #include <linux/kernel.h> | ||
28 | #include <linux/module.h> | ||
29 | #include <linux/delay.h> | ||
30 | #include <linux/eeprom_93cx6.h> | ||
31 | |||
32 | MODULE_AUTHOR("http://rt2x00.serialmonkey.com"); | ||
33 | MODULE_VERSION("1.0"); | ||
34 | MODULE_DESCRIPTION("EEPROM 93cx6 chip driver"); | ||
35 | MODULE_LICENSE("GPL"); | ||
36 | |||
37 | static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom) | ||
38 | { | ||
39 | eeprom->reg_data_clock = 1; | ||
40 | eeprom->register_write(eeprom); | ||
41 | |||
42 | /* | ||
43 | * Add a short delay for the pulse to work. | ||
44 | * According to the specifications the "maximum minimum" | ||
45 | * time should be 450ns. | ||
46 | */ | ||
47 | ndelay(450); | ||
48 | } | ||
49 | |||
50 | static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom) | ||
51 | { | ||
52 | eeprom->reg_data_clock = 0; | ||
53 | eeprom->register_write(eeprom); | ||
54 | |||
55 | /* | ||
56 | * Add a short delay for the pulse to work. | ||
57 | * According to the specifications the "maximum minimum" | ||
58 | * time should be 450ns. | ||
59 | */ | ||
60 | ndelay(450); | ||
61 | } | ||
62 | |||
63 | static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom) | ||
64 | { | ||
65 | /* | ||
66 | * Clear all flags, and enable chip select. | ||
67 | */ | ||
68 | eeprom->register_read(eeprom); | ||
69 | eeprom->reg_data_in = 0; | ||
70 | eeprom->reg_data_out = 0; | ||
71 | eeprom->reg_data_clock = 0; | ||
72 | eeprom->reg_chip_select = 1; | ||
73 | eeprom->register_write(eeprom); | ||
74 | |||
75 | /* | ||
76 | * kick a pulse. | ||
77 | */ | ||
78 | eeprom_93cx6_pulse_high(eeprom); | ||
79 | eeprom_93cx6_pulse_low(eeprom); | ||
80 | } | ||
81 | |||
82 | static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom) | ||
83 | { | ||
84 | /* | ||
85 | * Clear chip_select and data_in flags. | ||
86 | */ | ||
87 | eeprom->register_read(eeprom); | ||
88 | eeprom->reg_data_in = 0; | ||
89 | eeprom->reg_chip_select = 0; | ||
90 | eeprom->register_write(eeprom); | ||
91 | |||
92 | /* | ||
93 | * kick a pulse. | ||
94 | */ | ||
95 | eeprom_93cx6_pulse_high(eeprom); | ||
96 | eeprom_93cx6_pulse_low(eeprom); | ||
97 | } | ||
98 | |||
99 | static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom, | ||
100 | const u16 data, const u16 count) | ||
101 | { | ||
102 | unsigned int i; | ||
103 | |||
104 | eeprom->register_read(eeprom); | ||
105 | |||
106 | /* | ||
107 | * Clear data flags. | ||
108 | */ | ||
109 | eeprom->reg_data_in = 0; | ||
110 | eeprom->reg_data_out = 0; | ||
111 | |||
112 | /* | ||
113 | * Start writing all bits. | ||
114 | */ | ||
115 | for (i = count; i > 0; i--) { | ||
116 | /* | ||
117 | * Check if this bit needs to be set. | ||
118 | */ | ||
119 | eeprom->reg_data_in = !!(data & (1 << (i - 1))); | ||
120 | |||
121 | /* | ||
122 | * Write the bit to the eeprom register. | ||
123 | */ | ||
124 | eeprom->register_write(eeprom); | ||
125 | |||
126 | /* | ||
127 | * Kick a pulse. | ||
128 | */ | ||
129 | eeprom_93cx6_pulse_high(eeprom); | ||
130 | eeprom_93cx6_pulse_low(eeprom); | ||
131 | } | ||
132 | |||
133 | eeprom->reg_data_in = 0; | ||
134 | eeprom->register_write(eeprom); | ||
135 | } | ||
136 | |||
137 | static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom, | ||
138 | u16 *data, const u16 count) | ||
139 | { | ||
140 | unsigned int i; | ||
141 | u16 buf = 0; | ||
142 | |||
143 | eeprom->register_read(eeprom); | ||
144 | |||
145 | /* | ||
146 | * Clear data flags. | ||
147 | */ | ||
148 | eeprom->reg_data_in = 0; | ||
149 | eeprom->reg_data_out = 0; | ||
150 | |||
151 | /* | ||
152 | * Start reading all bits. | ||
153 | */ | ||
154 | for (i = count; i > 0; i--) { | ||
155 | eeprom_93cx6_pulse_high(eeprom); | ||
156 | |||
157 | eeprom->register_read(eeprom); | ||
158 | |||
159 | /* | ||
160 | * Clear data_in flag. | ||
161 | */ | ||
162 | eeprom->reg_data_in = 0; | ||
163 | |||
164 | /* | ||
165 | * Read if the bit has been set. | ||
166 | */ | ||
167 | if (eeprom->reg_data_out) | ||
168 | buf |= (1 << (i - 1)); | ||
169 | |||
170 | eeprom_93cx6_pulse_low(eeprom); | ||
171 | } | ||
172 | |||
173 | *data = buf; | ||
174 | } | ||
175 | |||
176 | /** | ||
177 | * eeprom_93cx6_read - Read multiple words from eeprom | ||
178 | * @eeprom: Pointer to eeprom structure | ||
179 | * @word: Word index from where we should start reading | ||
180 | * @data: target pointer where the information will have to be stored | ||
181 | * | ||
182 | * This function will read the eeprom data as host-endian word | ||
183 | * into the given data pointer. | ||
184 | */ | ||
185 | void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word, | ||
186 | u16 *data) | ||
187 | { | ||
188 | u16 command; | ||
189 | |||
190 | /* | ||
191 | * Initialize the eeprom register | ||
192 | */ | ||
193 | eeprom_93cx6_startup(eeprom); | ||
194 | |||
195 | /* | ||
196 | * Select the read opcode and the word to be read. | ||
197 | */ | ||
198 | command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word; | ||
199 | eeprom_93cx6_write_bits(eeprom, command, | ||
200 | PCI_EEPROM_WIDTH_OPCODE + eeprom->width); | ||
201 | |||
202 | /* | ||
203 | * Read the requested 16 bits. | ||
204 | */ | ||
205 | eeprom_93cx6_read_bits(eeprom, data, 16); | ||
206 | |||
207 | /* | ||
208 | * Cleanup eeprom register. | ||
209 | */ | ||
210 | eeprom_93cx6_cleanup(eeprom); | ||
211 | } | ||
212 | EXPORT_SYMBOL_GPL(eeprom_93cx6_read); | ||
213 | |||
214 | /** | ||
215 | * eeprom_93cx6_multiread - Read multiple words from eeprom | ||
216 | * @eeprom: Pointer to eeprom structure | ||
217 | * @word: Word index from where we should start reading | ||
218 | * @data: target pointer where the information will have to be stored | ||
219 | * @words: Number of words that should be read. | ||
220 | * | ||
221 | * This function will read all requested words from the eeprom, | ||
222 | * this is done by calling eeprom_93cx6_read() multiple times. | ||
223 | * But with the additional change that while the eeprom_93cx6_read | ||
224 | * will return host ordered bytes, this method will return little | ||
225 | * endian words. | ||
226 | */ | ||
227 | void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word, | ||
228 | __le16 *data, const u16 words) | ||
229 | { | ||
230 | unsigned int i; | ||
231 | u16 tmp; | ||
232 | |||
233 | for (i = 0; i < words; i++) { | ||
234 | tmp = 0; | ||
235 | eeprom_93cx6_read(eeprom, word + i, &tmp); | ||
236 | data[i] = cpu_to_le16(tmp); | ||
237 | } | ||
238 | } | ||
239 | EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread); | ||
240 | |||