175 lines
5.8 KiB
C
175 lines
5.8 KiB
C
/*
|
|
* Interface for the 93C66/56/46/26/06 serial eeprom parts.
|
|
*
|
|
* Copyright (c) 1995, 1996 Daniel M. Eischen
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice immediately at the beginning of the file, without modification,
|
|
* this list of conditions, and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Absolutely no warranty of function or purpose is made by the author
|
|
* Daniel M. Eischen.
|
|
* 4. Modifications may be freely made to this file if the above conditions
|
|
* are met.
|
|
*
|
|
* $Id: 93cx6.c,v 1.1 1998/09/15 07:24:16 gibbs Exp $
|
|
*/
|
|
|
|
/*
|
|
* The instruction set of the 93C66/56/46/26/06 chips are as follows:
|
|
*
|
|
* Start OP *
|
|
* Function Bit Code Address** Data Description
|
|
* -------------------------------------------------------------------
|
|
* READ 1 10 A5 - A0 Reads data stored in memory,
|
|
* starting at specified address
|
|
* EWEN 1 00 11XXXX Write enable must preceed
|
|
* all programming modes
|
|
* ERASE 1 11 A5 - A0 Erase register A5A4A3A2A1A0
|
|
* WRITE 1 01 A5 - A0 D15 - D0 Writes register
|
|
* ERAL 1 00 10XXXX Erase all registers
|
|
* WRAL 1 00 01XXXX D15 - D0 Writes to all registers
|
|
* EWDS 1 00 00XXXX Disables all programming
|
|
* instructions
|
|
* *Note: A value of X for address is a don't care condition.
|
|
* **Note: There are 8 address bits for the 93C56/66 chips unlike
|
|
* the 93C46/26/06 chips which have 6 address bits.
|
|
*
|
|
* The 93C46 has a four wire interface: clock, chip select, data in, and
|
|
* data out. In order to perform one of the above functions, you need
|
|
* to enable the chip select for a clock period (typically a minimum of
|
|
* 1 usec, with the clock high and low a minimum of 750 and 250 nsec
|
|
* respectively). While the chip select remains high, you can clock in
|
|
* the instructions (above) starting with the start bit, followed by the
|
|
* OP code, Address, and Data (if needed). For the READ instruction, the
|
|
* requested 16-bit register contents is read from the data out line but
|
|
* is preceded by an initial zero (leading 0, followed by 16-bits, MSB
|
|
* first). The clock cycling from low to high initiates the next data
|
|
* bit to be sent from the chip.
|
|
*
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <machine/bus_memio.h>
|
|
#include <machine/bus_pio.h>
|
|
#include <machine/bus.h>
|
|
#include <dev/aic7xxx/93cx6.h>
|
|
|
|
/*
|
|
* Right now, we only have to read the SEEPROM. But we make it easier to
|
|
* add other 93Cx6 functions.
|
|
*/
|
|
static struct seeprom_cmd {
|
|
unsigned char len;
|
|
unsigned char bits[3];
|
|
} seeprom_read = {3, {1, 1, 0}};
|
|
|
|
/*
|
|
* Wait for the SEERDY to go high; about 800 ns.
|
|
*/
|
|
#define CLOCK_PULSE(sd, rdy) \
|
|
while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) { \
|
|
; /* Do nothing */ \
|
|
} \
|
|
(void)SEEPROM_INB(sd); /* Clear clock */
|
|
|
|
/*
|
|
* Read the serial EEPROM and returns 1 if successful and 0 if
|
|
* not successful.
|
|
*/
|
|
int
|
|
read_seeprom(sd, buf, start_addr, count)
|
|
struct seeprom_descriptor *sd;
|
|
u_int16_t *buf;
|
|
bus_size_t start_addr;
|
|
bus_size_t count;
|
|
{
|
|
int i = 0;
|
|
u_int k = 0;
|
|
u_int16_t v;
|
|
u_int8_t temp;
|
|
|
|
/*
|
|
* Read the requested registers of the seeprom. The loop
|
|
* will range from 0 to count-1.
|
|
*/
|
|
for (k = start_addr; k < count + start_addr; k++) {
|
|
/* Send chip select for one clock cycle. */
|
|
temp = sd->sd_MS ^ sd->sd_CS;
|
|
SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
|
|
/*
|
|
* Now we're ready to send the read command followed by the
|
|
* address of the 16-bit register we want to read.
|
|
*/
|
|
for (i = 0; i < seeprom_read.len; i++) {
|
|
if (seeprom_read.bits[i] != 0)
|
|
temp ^= sd->sd_DO;
|
|
SEEPROM_OUTB(sd, temp);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
if (seeprom_read.bits[i] != 0)
|
|
temp ^= sd->sd_DO;
|
|
}
|
|
/* Send the 6 or 8 bit address (MSB first, LSB last). */
|
|
for (i = (sd->sd_chip - 1); i >= 0; i--) {
|
|
if ((k & (1 << i)) != 0)
|
|
temp ^= sd->sd_DO;
|
|
SEEPROM_OUTB(sd, temp);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
if ((k & (1 << i)) != 0)
|
|
temp ^= sd->sd_DO;
|
|
}
|
|
|
|
/*
|
|
* Now read the 16 bit register. An initial 0 precedes the
|
|
* register contents which begins with bit 15 (MSB) and ends
|
|
* with bit 0 (LSB). The initial 0 will be shifted off the
|
|
* top of our word as we let the loop run from 0 to 16.
|
|
*/
|
|
v = 0;
|
|
for (i = 16; i >= 0; i--) {
|
|
SEEPROM_OUTB(sd, temp);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
v <<= 1;
|
|
if (SEEPROM_DATA_INB(sd) & sd->sd_DI)
|
|
v |= 1;
|
|
SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
}
|
|
|
|
buf[k - start_addr] = v;
|
|
|
|
/* Reset the chip select for the next command cycle. */
|
|
temp = sd->sd_MS;
|
|
SEEPROM_OUTB(sd, temp);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
SEEPROM_OUTB(sd, temp);
|
|
CLOCK_PULSE(sd, sd->sd_RDY);
|
|
}
|
|
#ifdef DUMP_93CX6_EEPROM
|
|
printf("\nSerial EEPROM:");
|
|
for (k = 0; k < count; k = k + 1) {
|
|
if (((k % 8) == 0) && (k != 0)) {
|
|
printf ("\n ");
|
|
}
|
|
printf (" 0x%x", buf[k]);
|
|
}
|
|
printf ("\n");
|
|
#endif
|
|
return (1);
|
|
}
|