373 строки
8.4 KiB
C
373 строки
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2004 - 2006 rt2x00 SourceForge Project
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* <http://rt2x00.serialmonkey.com>
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*
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* Module: eeprom_93cx6
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* Abstract: EEPROM reader routines for 93cx6 chipsets.
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* Supported chipsets: 93c46 & 93c66.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/eeprom_93cx6.h>
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MODULE_AUTHOR("http://rt2x00.serialmonkey.com");
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MODULE_VERSION("1.0");
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MODULE_DESCRIPTION("EEPROM 93cx6 chip driver");
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MODULE_LICENSE("GPL");
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static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom)
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{
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eeprom->reg_data_clock = 1;
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eeprom->register_write(eeprom);
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/*
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* Add a short delay for the pulse to work.
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* According to the specifications the "maximum minimum"
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* time should be 450ns.
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*/
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ndelay(450);
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}
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static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom)
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{
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eeprom->reg_data_clock = 0;
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eeprom->register_write(eeprom);
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/*
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* Add a short delay for the pulse to work.
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* According to the specifications the "maximum minimum"
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* time should be 450ns.
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*/
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ndelay(450);
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}
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static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom)
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{
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/*
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* Clear all flags, and enable chip select.
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*/
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eeprom->register_read(eeprom);
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eeprom->reg_data_in = 0;
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eeprom->reg_data_out = 0;
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eeprom->reg_data_clock = 0;
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eeprom->reg_chip_select = 1;
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eeprom->drive_data = 1;
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eeprom->register_write(eeprom);
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/*
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* kick a pulse.
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*/
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eeprom_93cx6_pulse_high(eeprom);
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eeprom_93cx6_pulse_low(eeprom);
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}
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static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom)
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{
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/*
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* Clear chip_select and data_in flags.
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*/
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eeprom->register_read(eeprom);
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eeprom->reg_data_in = 0;
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eeprom->reg_chip_select = 0;
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eeprom->register_write(eeprom);
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/*
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* kick a pulse.
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*/
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eeprom_93cx6_pulse_high(eeprom);
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eeprom_93cx6_pulse_low(eeprom);
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}
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static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom,
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const u16 data, const u16 count)
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{
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unsigned int i;
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eeprom->register_read(eeprom);
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/*
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* Clear data flags.
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*/
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eeprom->reg_data_in = 0;
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eeprom->reg_data_out = 0;
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eeprom->drive_data = 1;
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/*
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* Start writing all bits.
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*/
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for (i = count; i > 0; i--) {
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/*
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* Check if this bit needs to be set.
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*/
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eeprom->reg_data_in = !!(data & (1 << (i - 1)));
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/*
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* Write the bit to the eeprom register.
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*/
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eeprom->register_write(eeprom);
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/*
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* Kick a pulse.
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*/
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eeprom_93cx6_pulse_high(eeprom);
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eeprom_93cx6_pulse_low(eeprom);
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}
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eeprom->reg_data_in = 0;
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eeprom->register_write(eeprom);
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}
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static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom,
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u16 *data, const u16 count)
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{
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unsigned int i;
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u16 buf = 0;
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eeprom->register_read(eeprom);
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/*
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* Clear data flags.
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*/
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eeprom->reg_data_in = 0;
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eeprom->reg_data_out = 0;
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eeprom->drive_data = 0;
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/*
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* Start reading all bits.
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*/
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for (i = count; i > 0; i--) {
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eeprom_93cx6_pulse_high(eeprom);
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eeprom->register_read(eeprom);
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/*
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* Clear data_in flag.
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*/
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eeprom->reg_data_in = 0;
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/*
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* Read if the bit has been set.
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*/
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if (eeprom->reg_data_out)
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buf |= (1 << (i - 1));
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eeprom_93cx6_pulse_low(eeprom);
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}
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*data = buf;
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}
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/**
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* eeprom_93cx6_read - Read a word from eeprom
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* @eeprom: Pointer to eeprom structure
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* @word: Word index from where we should start reading
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* @data: target pointer where the information will have to be stored
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*
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* This function will read the eeprom data as host-endian word
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* into the given data pointer.
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*/
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void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word,
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u16 *data)
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{
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u16 command;
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/*
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* Initialize the eeprom register
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*/
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eeprom_93cx6_startup(eeprom);
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/*
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* Select the read opcode and the word to be read.
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*/
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command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word;
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eeprom_93cx6_write_bits(eeprom, command,
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PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
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/*
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* Read the requested 16 bits.
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*/
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eeprom_93cx6_read_bits(eeprom, data, 16);
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/*
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* Cleanup eeprom register.
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*/
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eeprom_93cx6_cleanup(eeprom);
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}
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EXPORT_SYMBOL_GPL(eeprom_93cx6_read);
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/**
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* eeprom_93cx6_multiread - Read multiple words from eeprom
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* @eeprom: Pointer to eeprom structure
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* @word: Word index from where we should start reading
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* @data: target pointer where the information will have to be stored
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* @words: Number of words that should be read.
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*
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* This function will read all requested words from the eeprom,
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* this is done by calling eeprom_93cx6_read() multiple times.
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* But with the additional change that while the eeprom_93cx6_read
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* will return host ordered bytes, this method will return little
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* endian words.
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*/
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void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word,
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__le16 *data, const u16 words)
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{
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unsigned int i;
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u16 tmp;
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for (i = 0; i < words; i++) {
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tmp = 0;
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eeprom_93cx6_read(eeprom, word + i, &tmp);
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data[i] = cpu_to_le16(tmp);
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}
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}
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EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread);
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/**
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* eeprom_93cx6_readb - Read a byte from eeprom
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* @eeprom: Pointer to eeprom structure
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* @word: Byte index from where we should start reading
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* @data: target pointer where the information will have to be stored
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*
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* This function will read a byte of the eeprom data
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* into the given data pointer.
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*/
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void eeprom_93cx6_readb(struct eeprom_93cx6 *eeprom, const u8 byte,
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u8 *data)
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{
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u16 command;
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u16 tmp;
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/*
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* Initialize the eeprom register
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*/
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eeprom_93cx6_startup(eeprom);
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/*
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* Select the read opcode and the byte to be read.
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*/
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command = (PCI_EEPROM_READ_OPCODE << (eeprom->width + 1)) | byte;
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eeprom_93cx6_write_bits(eeprom, command,
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PCI_EEPROM_WIDTH_OPCODE + eeprom->width + 1);
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/*
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* Read the requested 8 bits.
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*/
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eeprom_93cx6_read_bits(eeprom, &tmp, 8);
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*data = tmp & 0xff;
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/*
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* Cleanup eeprom register.
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*/
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eeprom_93cx6_cleanup(eeprom);
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}
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EXPORT_SYMBOL_GPL(eeprom_93cx6_readb);
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/**
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* eeprom_93cx6_multireadb - Read multiple bytes from eeprom
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* @eeprom: Pointer to eeprom structure
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* @byte: Index from where we should start reading
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* @data: target pointer where the information will have to be stored
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* @words: Number of bytes that should be read.
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*
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* This function will read all requested bytes from the eeprom,
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* this is done by calling eeprom_93cx6_readb() multiple times.
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*/
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void eeprom_93cx6_multireadb(struct eeprom_93cx6 *eeprom, const u8 byte,
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u8 *data, const u16 bytes)
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{
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unsigned int i;
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for (i = 0; i < bytes; i++)
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eeprom_93cx6_readb(eeprom, byte + i, &data[i]);
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}
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EXPORT_SYMBOL_GPL(eeprom_93cx6_multireadb);
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/**
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* eeprom_93cx6_wren - set the write enable state
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* @eeprom: Pointer to eeprom structure
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* @enable: true to enable writes, otherwise disable writes
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*
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* Set the EEPROM write enable state to either allow or deny
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* writes depending on the @enable value.
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*/
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void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable)
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{
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u16 command;
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/* start the command */
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eeprom_93cx6_startup(eeprom);
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/* create command to enable/disable */
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command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE;
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command <<= (eeprom->width - 2);
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eeprom_93cx6_write_bits(eeprom, command,
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PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
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eeprom_93cx6_cleanup(eeprom);
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}
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EXPORT_SYMBOL_GPL(eeprom_93cx6_wren);
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/**
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* eeprom_93cx6_write - write data to the EEPROM
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* @eeprom: Pointer to eeprom structure
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* @addr: Address to write data to.
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* @data: The data to write to address @addr.
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*
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* Write the @data to the specified @addr in the EEPROM and
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* waiting for the device to finish writing.
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*
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* Note, since we do not expect large number of write operations
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* we delay in between parts of the operation to avoid using excessive
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* amounts of CPU time busy waiting.
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*/
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void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data)
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{
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int timeout = 100;
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u16 command;
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/* start the command */
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eeprom_93cx6_startup(eeprom);
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command = PCI_EEPROM_WRITE_OPCODE << eeprom->width;
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command |= addr;
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/* send write command */
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eeprom_93cx6_write_bits(eeprom, command,
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PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
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/* send data */
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eeprom_93cx6_write_bits(eeprom, data, 16);
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/* get ready to check for busy */
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eeprom->drive_data = 0;
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eeprom->reg_chip_select = 1;
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eeprom->register_write(eeprom);
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/* wait at-least 250ns to get DO to be the busy signal */
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usleep_range(1000, 2000);
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/* wait for DO to go high to signify finish */
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while (true) {
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eeprom->register_read(eeprom);
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if (eeprom->reg_data_out)
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break;
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usleep_range(1000, 2000);
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if (--timeout <= 0) {
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printk(KERN_ERR "%s: timeout\n", __func__);
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break;
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}
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}
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eeprom_93cx6_cleanup(eeprom);
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}
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EXPORT_SYMBOL_GPL(eeprom_93cx6_write);
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