/*
Copyright (C) 2004 - 2006 rt2x00 SourceForge Project
<http://rt2x00.serialmonkey.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the
Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
Module: eeprom_93cx6
Abstract: EEPROM reader routines for 93cx6 chipsets.
Supported chipsets: 93c46 & 93c66.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/eeprom_93cx6.h>
MODULE_AUTHOR("http://rt2x00.serialmonkey.com");
MODULE_VERSION("1.0");
MODULE_DESCRIPTION("EEPROM 93cx6 chip driver");
MODULE_LICENSE("GPL");
static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom)
{
eeprom->reg_data_clock = 1;
eeprom->register_write(eeprom);
/*
* Add a short delay for the pulse to work.
* According to the specifications the "maximum minimum"
* time should be 450ns.
*/
ndelay(450);
}
static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom)
{
eeprom->reg_data_clock = 0;
eeprom->register_write(eeprom);
/*
* Add a short delay for the pulse to work.
* According to the specifications the "maximum minimum"
* time should be 450ns.
*/
ndelay(450);
}
static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom)
{
/*
* Clear all flags, and enable chip select.
*/
eeprom->register_read(eeprom);
eeprom->reg_data_in = 0;
eeprom->reg_data_out = 0;
eeprom->reg_data_clock = 0;
eeprom->reg_chip_select = 1;
eeprom->register_write(eeprom);
/*
* kick a pulse.
*/
eeprom_93cx6_pulse_high(eeprom);
eeprom_93cx6_pulse_low(eeprom);
}
static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom)
{
/*
* Clear chip_select and data_in flags.
*/
eeprom->register_read(eeprom);
eeprom->reg_data_in = 0;
eeprom->reg_chip_select = 0;
eeprom->register_write(eeprom);
/*
* kick a pulse.
*/
eeprom_93cx6_pulse_high(eeprom);
eeprom_93cx6_pulse_low(eeprom);
}
static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom,
const u16 data, const u16 count)
{
unsigned int i;
eeprom->register_read(eeprom);
/*
* Clear data flags.
*/
eeprom->reg_data_in = 0;
eeprom->reg_data_out = 0;
/*
* Start writing all bits.
*/
for (i = count; i > 0; i--) {
/*
* Check if this bit needs to be set.
*/
eeprom->reg_data_in = !!(data & (1 << (i - 1)));
/*
* Write the bit to the eeprom register.
*/
eeprom->register_write(eeprom);
/*
* Kick a pulse.
*/
eeprom_93cx6_pulse_high(eeprom);
eeprom_93cx6_pulse_low(eeprom);
}
eeprom->reg_data_in = 0;
eeprom->register_write(eeprom);
}
static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom,
u16 *data, const u16 count)
{
unsigned int i;
u16 buf = 0;
eeprom->register_read(eeprom);
/*
* Clear data flags.
*/
eeprom->reg_data_in = 0;
eeprom->reg_data_out = 0;
/*
* Start reading all bits.
*/
for (i = count; i > 0; i--) {
eeprom_93cx6_pulse_high(eeprom);
eeprom->register_read(eeprom);
/*
* Clear data_in flag.
*/
eeprom->reg_data_in = 0;
/*
* Read if the bit has been set.
*/
if (eeprom->reg_data_out)
buf |= (1 << (i - 1));
eeprom_93cx6_pulse_low(eeprom);
}
*data = buf;
}
/**
* eeprom_93cx6_read - Read multiple words from eeprom
* @eeprom: Pointer to eeprom structure
* @word: Word index from where we should start reading
* @data: target pointer where the information will have to be stored
*
* This function will read the eeprom data as host-endian word
* into the given data pointer.
*/
void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word,
u16 *data)
{
u16 command;
/*
* Initialize the eeprom register
*/
eeprom_93cx6_startup(eeprom);
/*
* Select the read opcode and the word to be read.
*/
command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word;
eeprom_93cx6_write_bits(eeprom, command,
PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
/*
* Read the requested 16 bits.
*/
eeprom_93cx6_read_bits(eeprom, data, 16);
/*
* Cleanup eeprom register.
*/
eeprom_93cx6_cleanup(eeprom);
}
EXPORT_SYMBOL_GPL(eeprom_93cx6_read);
/**
* eeprom_93cx6_multiread - Read multiple words from eeprom
* @eeprom: Pointer to eeprom structure
* @word: Word index from where we should start reading
* @data: target pointer where the information will have to be stored
* @words: Number of words that should be read.
*
* This function will read all requested words from the eeprom,
* this is done by calling eeprom_93cx6_read() multiple times.
* But with the additional change that while the eeprom_93cx6_read
* will return host ordered bytes, this method will return little
* endian words.
*/
void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word,
__le16 *data, const u16 words)
{
unsigned int i;
u16 tmp;
for (i = 0; i < words; i++) {
tmp = 0;
eeprom_93cx6_read(eeprom, word + i, &tmp);
data[i] = cpu_to_le16(tmp);
}
}
EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread);
