373 lines
8.4 KiB
C
373 lines
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (C) 2004 - 2006 rt2x00 SourceForge Project
|
|
* <http://rt2x00.serialmonkey.com>
|
|
*
|
|
* 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->drive_data = 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;
|
|
eeprom->drive_data = 1;
|
|
|
|
/*
|
|
* 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;
|
|
eeprom->drive_data = 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 a word 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);
|
|
|
|
/**
|
|
* eeprom_93cx6_readb - Read a byte from eeprom
|
|
* @eeprom: Pointer to eeprom structure
|
|
* @byte: Byte index from where we should start reading
|
|
* @data: target pointer where the information will have to be stored
|
|
*
|
|
* This function will read a byte of the eeprom data
|
|
* into the given data pointer.
|
|
*/
|
|
void eeprom_93cx6_readb(struct eeprom_93cx6 *eeprom, const u8 byte,
|
|
u8 *data)
|
|
{
|
|
u16 command;
|
|
u16 tmp;
|
|
|
|
/*
|
|
* Initialize the eeprom register
|
|
*/
|
|
eeprom_93cx6_startup(eeprom);
|
|
|
|
/*
|
|
* Select the read opcode and the byte to be read.
|
|
*/
|
|
command = (PCI_EEPROM_READ_OPCODE << (eeprom->width + 1)) | byte;
|
|
eeprom_93cx6_write_bits(eeprom, command,
|
|
PCI_EEPROM_WIDTH_OPCODE + eeprom->width + 1);
|
|
|
|
/*
|
|
* Read the requested 8 bits.
|
|
*/
|
|
eeprom_93cx6_read_bits(eeprom, &tmp, 8);
|
|
*data = tmp & 0xff;
|
|
|
|
/*
|
|
* Cleanup eeprom register.
|
|
*/
|
|
eeprom_93cx6_cleanup(eeprom);
|
|
}
|
|
EXPORT_SYMBOL_GPL(eeprom_93cx6_readb);
|
|
|
|
/**
|
|
* eeprom_93cx6_multireadb - Read multiple bytes from eeprom
|
|
* @eeprom: Pointer to eeprom structure
|
|
* @byte: Index from where we should start reading
|
|
* @data: target pointer where the information will have to be stored
|
|
* @bytes: Number of bytes that should be read.
|
|
*
|
|
* This function will read all requested bytes from the eeprom,
|
|
* this is done by calling eeprom_93cx6_readb() multiple times.
|
|
*/
|
|
void eeprom_93cx6_multireadb(struct eeprom_93cx6 *eeprom, const u8 byte,
|
|
u8 *data, const u16 bytes)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < bytes; i++)
|
|
eeprom_93cx6_readb(eeprom, byte + i, &data[i]);
|
|
}
|
|
EXPORT_SYMBOL_GPL(eeprom_93cx6_multireadb);
|
|
|
|
/**
|
|
* eeprom_93cx6_wren - set the write enable state
|
|
* @eeprom: Pointer to eeprom structure
|
|
* @enable: true to enable writes, otherwise disable writes
|
|
*
|
|
* Set the EEPROM write enable state to either allow or deny
|
|
* writes depending on the @enable value.
|
|
*/
|
|
void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable)
|
|
{
|
|
u16 command;
|
|
|
|
/* start the command */
|
|
eeprom_93cx6_startup(eeprom);
|
|
|
|
/* create command to enable/disable */
|
|
|
|
command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE;
|
|
command <<= (eeprom->width - 2);
|
|
|
|
eeprom_93cx6_write_bits(eeprom, command,
|
|
PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
|
|
|
|
eeprom_93cx6_cleanup(eeprom);
|
|
}
|
|
EXPORT_SYMBOL_GPL(eeprom_93cx6_wren);
|
|
|
|
/**
|
|
* eeprom_93cx6_write - write data to the EEPROM
|
|
* @eeprom: Pointer to eeprom structure
|
|
* @addr: Address to write data to.
|
|
* @data: The data to write to address @addr.
|
|
*
|
|
* Write the @data to the specified @addr in the EEPROM and
|
|
* waiting for the device to finish writing.
|
|
*
|
|
* Note, since we do not expect large number of write operations
|
|
* we delay in between parts of the operation to avoid using excessive
|
|
* amounts of CPU time busy waiting.
|
|
*/
|
|
void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data)
|
|
{
|
|
int timeout = 100;
|
|
u16 command;
|
|
|
|
/* start the command */
|
|
eeprom_93cx6_startup(eeprom);
|
|
|
|
command = PCI_EEPROM_WRITE_OPCODE << eeprom->width;
|
|
command |= addr;
|
|
|
|
/* send write command */
|
|
eeprom_93cx6_write_bits(eeprom, command,
|
|
PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
|
|
|
|
/* send data */
|
|
eeprom_93cx6_write_bits(eeprom, data, 16);
|
|
|
|
/* get ready to check for busy */
|
|
eeprom->drive_data = 0;
|
|
eeprom->reg_chip_select = 1;
|
|
eeprom->register_write(eeprom);
|
|
|
|
/* wait at-least 250ns to get DO to be the busy signal */
|
|
usleep_range(1000, 2000);
|
|
|
|
/* wait for DO to go high to signify finish */
|
|
|
|
while (true) {
|
|
eeprom->register_read(eeprom);
|
|
|
|
if (eeprom->reg_data_out)
|
|
break;
|
|
|
|
usleep_range(1000, 2000);
|
|
|
|
if (--timeout <= 0) {
|
|
printk(KERN_ERR "%s: timeout\n", __func__);
|
|
break;
|
|
}
|
|
}
|
|
|
|
eeprom_93cx6_cleanup(eeprom);
|
|
}
|
|
EXPORT_SYMBOL_GPL(eeprom_93cx6_write);
|