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/*
* 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, this list of conditions, and the following disclaimer,
* without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL").
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: //depot/aic7xxx/aic7xxx/aic7xxx_93cx6.c#10 $
*
* $FreeBSD: src/sys/dev/aic7xxx/aic7xxx_93cx6.c,v 1.9 2000/11/10 20:13:41 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 precede
* 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 "aic7xxx_osm.h"
#include "aic7xxx_inline.h"
#include "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 {
uint8_t len;
uint8_t 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;
uint16_t *buf;
u_int start_addr;
u_int count;
{
int i = 0;
u_int k = 0;
uint16_t v;
uint8_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 AHC_DUMP_EEPROM
printf("\nSerial EEPROM:\n\t");
for (k = 0; k < count; k = k + 1) {
if (((k % 8) == 0) && (k != 0)) {
printf ("\n\t");
}
printf (" 0x%x", buf[k]);
}
printf ("\n");
#endif
return (1);
}
int
verify_cksum(struct seeprom_config *sc)
{
int i;
int maxaddr;
uint32_t checksum;
uint16_t *scarray;
maxaddr = (sizeof(*sc)/2) - 1;
checksum = 0;
scarray = (uint16_t *)sc;
for (i = 0; i < maxaddr; i++)
checksum = checksum + scarray[i];
if (checksum == 0
|| (checksum & 0xFFFF) != sc->checksum) {
return (0);
} else {
return(1);
}
}
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