perf tools: Don't clone maps from parent when synthesizing forks
[linux/fpc-iii.git] / drivers / misc / eeprom / eeprom_93cx6.c
blob0cf2c9d676be839cb9040ba0500fe247b406286b
1 /*
2 * Copyright (C) 2004 - 2006 rt2x00 SourceForge Project
3 * <http://rt2x00.serialmonkey.com>
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.
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.
15 * Module: eeprom_93cx6
16 * Abstract: EEPROM reader routines for 93cx6 chipsets.
17 * Supported chipsets: 93c46 & 93c66.
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/delay.h>
23 #include <linux/eeprom_93cx6.h>
25 MODULE_AUTHOR("http://rt2x00.serialmonkey.com");
26 MODULE_VERSION("1.0");
27 MODULE_DESCRIPTION("EEPROM 93cx6 chip driver");
28 MODULE_LICENSE("GPL");
30 static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom)
32 eeprom->reg_data_clock = 1;
33 eeprom->register_write(eeprom);
36 * Add a short delay for the pulse to work.
37 * According to the specifications the "maximum minimum"
38 * time should be 450ns.
40 ndelay(450);
43 static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom)
45 eeprom->reg_data_clock = 0;
46 eeprom->register_write(eeprom);
49 * Add a short delay for the pulse to work.
50 * According to the specifications the "maximum minimum"
51 * time should be 450ns.
53 ndelay(450);
56 static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom)
59 * Clear all flags, and enable chip select.
61 eeprom->register_read(eeprom);
62 eeprom->reg_data_in = 0;
63 eeprom->reg_data_out = 0;
64 eeprom->reg_data_clock = 0;
65 eeprom->reg_chip_select = 1;
66 eeprom->drive_data = 1;
67 eeprom->register_write(eeprom);
70 * kick a pulse.
72 eeprom_93cx6_pulse_high(eeprom);
73 eeprom_93cx6_pulse_low(eeprom);
76 static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom)
79 * Clear chip_select and data_in flags.
81 eeprom->register_read(eeprom);
82 eeprom->reg_data_in = 0;
83 eeprom->reg_chip_select = 0;
84 eeprom->register_write(eeprom);
87 * kick a pulse.
89 eeprom_93cx6_pulse_high(eeprom);
90 eeprom_93cx6_pulse_low(eeprom);
93 static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom,
94 const u16 data, const u16 count)
96 unsigned int i;
98 eeprom->register_read(eeprom);
101 * Clear data flags.
103 eeprom->reg_data_in = 0;
104 eeprom->reg_data_out = 0;
105 eeprom->drive_data = 1;
108 * Start writing all bits.
110 for (i = count; i > 0; i--) {
112 * Check if this bit needs to be set.
114 eeprom->reg_data_in = !!(data & (1 << (i - 1)));
117 * Write the bit to the eeprom register.
119 eeprom->register_write(eeprom);
122 * Kick a pulse.
124 eeprom_93cx6_pulse_high(eeprom);
125 eeprom_93cx6_pulse_low(eeprom);
128 eeprom->reg_data_in = 0;
129 eeprom->register_write(eeprom);
132 static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom,
133 u16 *data, const u16 count)
135 unsigned int i;
136 u16 buf = 0;
138 eeprom->register_read(eeprom);
141 * Clear data flags.
143 eeprom->reg_data_in = 0;
144 eeprom->reg_data_out = 0;
145 eeprom->drive_data = 0;
148 * Start reading all bits.
150 for (i = count; i > 0; i--) {
151 eeprom_93cx6_pulse_high(eeprom);
153 eeprom->register_read(eeprom);
156 * Clear data_in flag.
158 eeprom->reg_data_in = 0;
161 * Read if the bit has been set.
163 if (eeprom->reg_data_out)
164 buf |= (1 << (i - 1));
166 eeprom_93cx6_pulse_low(eeprom);
169 *data = buf;
173 * eeprom_93cx6_read - Read a word from eeprom
174 * @eeprom: Pointer to eeprom structure
175 * @word: Word index from where we should start reading
176 * @data: target pointer where the information will have to be stored
178 * This function will read the eeprom data as host-endian word
179 * into the given data pointer.
181 void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word,
182 u16 *data)
184 u16 command;
187 * Initialize the eeprom register
189 eeprom_93cx6_startup(eeprom);
192 * Select the read opcode and the word to be read.
194 command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word;
195 eeprom_93cx6_write_bits(eeprom, command,
196 PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
199 * Read the requested 16 bits.
201 eeprom_93cx6_read_bits(eeprom, data, 16);
204 * Cleanup eeprom register.
206 eeprom_93cx6_cleanup(eeprom);
208 EXPORT_SYMBOL_GPL(eeprom_93cx6_read);
211 * eeprom_93cx6_multiread - Read multiple words from eeprom
212 * @eeprom: Pointer to eeprom structure
213 * @word: Word index from where we should start reading
214 * @data: target pointer where the information will have to be stored
215 * @words: Number of words that should be read.
217 * This function will read all requested words from the eeprom,
218 * this is done by calling eeprom_93cx6_read() multiple times.
219 * But with the additional change that while the eeprom_93cx6_read
220 * will return host ordered bytes, this method will return little
221 * endian words.
223 void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word,
224 __le16 *data, const u16 words)
226 unsigned int i;
227 u16 tmp;
229 for (i = 0; i < words; i++) {
230 tmp = 0;
231 eeprom_93cx6_read(eeprom, word + i, &tmp);
232 data[i] = cpu_to_le16(tmp);
235 EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread);
238 * eeprom_93cx6_readb - Read a byte from eeprom
239 * @eeprom: Pointer to eeprom structure
240 * @word: Byte index from where we should start reading
241 * @data: target pointer where the information will have to be stored
243 * This function will read a byte of the eeprom data
244 * into the given data pointer.
246 void eeprom_93cx6_readb(struct eeprom_93cx6 *eeprom, const u8 byte,
247 u8 *data)
249 u16 command;
250 u16 tmp;
253 * Initialize the eeprom register
255 eeprom_93cx6_startup(eeprom);
258 * Select the read opcode and the byte to be read.
260 command = (PCI_EEPROM_READ_OPCODE << (eeprom->width + 1)) | byte;
261 eeprom_93cx6_write_bits(eeprom, command,
262 PCI_EEPROM_WIDTH_OPCODE + eeprom->width + 1);
265 * Read the requested 8 bits.
267 eeprom_93cx6_read_bits(eeprom, &tmp, 8);
268 *data = tmp & 0xff;
271 * Cleanup eeprom register.
273 eeprom_93cx6_cleanup(eeprom);
275 EXPORT_SYMBOL_GPL(eeprom_93cx6_readb);
278 * eeprom_93cx6_multireadb - Read multiple bytes from eeprom
279 * @eeprom: Pointer to eeprom structure
280 * @byte: Index from where we should start reading
281 * @data: target pointer where the information will have to be stored
282 * @words: Number of bytes that should be read.
284 * This function will read all requested bytes from the eeprom,
285 * this is done by calling eeprom_93cx6_readb() multiple times.
287 void eeprom_93cx6_multireadb(struct eeprom_93cx6 *eeprom, const u8 byte,
288 u8 *data, const u16 bytes)
290 unsigned int i;
292 for (i = 0; i < bytes; i++)
293 eeprom_93cx6_readb(eeprom, byte + i, &data[i]);
295 EXPORT_SYMBOL_GPL(eeprom_93cx6_multireadb);
298 * eeprom_93cx6_wren - set the write enable state
299 * @eeprom: Pointer to eeprom structure
300 * @enable: true to enable writes, otherwise disable writes
302 * Set the EEPROM write enable state to either allow or deny
303 * writes depending on the @enable value.
305 void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable)
307 u16 command;
309 /* start the command */
310 eeprom_93cx6_startup(eeprom);
312 /* create command to enable/disable */
314 command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE;
315 command <<= (eeprom->width - 2);
317 eeprom_93cx6_write_bits(eeprom, command,
318 PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
320 eeprom_93cx6_cleanup(eeprom);
322 EXPORT_SYMBOL_GPL(eeprom_93cx6_wren);
325 * eeprom_93cx6_write - write data to the EEPROM
326 * @eeprom: Pointer to eeprom structure
327 * @addr: Address to write data to.
328 * @data: The data to write to address @addr.
330 * Write the @data to the specified @addr in the EEPROM and
331 * waiting for the device to finish writing.
333 * Note, since we do not expect large number of write operations
334 * we delay in between parts of the operation to avoid using excessive
335 * amounts of CPU time busy waiting.
337 void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data)
339 int timeout = 100;
340 u16 command;
342 /* start the command */
343 eeprom_93cx6_startup(eeprom);
345 command = PCI_EEPROM_WRITE_OPCODE << eeprom->width;
346 command |= addr;
348 /* send write command */
349 eeprom_93cx6_write_bits(eeprom, command,
350 PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
352 /* send data */
353 eeprom_93cx6_write_bits(eeprom, data, 16);
355 /* get ready to check for busy */
356 eeprom->drive_data = 0;
357 eeprom->reg_chip_select = 1;
358 eeprom->register_write(eeprom);
360 /* wait at-least 250ns to get DO to be the busy signal */
361 usleep_range(1000, 2000);
363 /* wait for DO to go high to signify finish */
365 while (true) {
366 eeprom->register_read(eeprom);
368 if (eeprom->reg_data_out)
369 break;
371 usleep_range(1000, 2000);
373 if (--timeout <= 0) {
374 printk(KERN_ERR "%s: timeout\n", __func__);
375 break;
379 eeprom_93cx6_cleanup(eeprom);
381 EXPORT_SYMBOL_GPL(eeprom_93cx6_write);