2 * Interface for the 93C66/56/46/26/06 serial eeprom parts.
4 * Copyright (c) 1995, 1996 Daniel M. Eischen
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice immediately at the beginning of the file, without modification,
12 * this list of conditions, and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Absolutely no warranty of function or purpose is made by the author
18 * 4. Modifications may be freely made to this file if the above conditions
25 * The instruction set of the 93C66/56/46/26/06 chips are as follows:
28 * Function Bit Code Address** Data Description
29 * -------------------------------------------------------------------
30 * READ 1 10 A5 - A0 Reads data stored in memory,
31 * starting at specified address
32 * EWEN 1 00 11XXXX Write enable must preceed
33 * all programming modes
34 * ERASE 1 11 A5 - A0 Erase register A5A4A3A2A1A0
35 * WRITE 1 01 A5 - A0 D15 - D0 Writes register
36 * ERAL 1 00 10XXXX Erase all registers
37 * WRAL 1 00 01XXXX D15 - D0 Writes to all registers
38 * EWDS 1 00 00XXXX Disables all programming
40 * *Note: A value of X for address is a don't care condition.
41 * **Note: There are 8 address bits for the 93C56/66 chips unlike
42 * the 93C46/26/06 chips which have 6 address bits.
44 * The 93C46 has a four wire interface: clock, chip select, data in, and
45 * data out. In order to perform one of the above functions, you need
46 * to enable the chip select for a clock period (typically a minimum of
47 * 1 usec, with the clock high and low a minimum of 750 and 250 nsec
48 * respectively). While the chip select remains high, you can clock in
49 * the instructions (above) starting with the start bit, followed by the
50 * OP code, Address, and Data (if needed). For the READ instruction, the
51 * requested 16-bit register contents is read from the data out line but
52 * is preceded by an initial zero (leading 0, followed by 16-bits, MSB
53 * first). The clock cycling from low to high initiates the next data
54 * bit to be sent from the chip.
58 #include "opt_aic7xxx.h"
60 #include <sys/param.h>
61 #include <sys/systm.h>
62 #include <machine/bus_memio.h>
63 #include <machine/bus_pio.h>
64 #include <machine/bus.h>
65 #include <dev/aic7xxx/93cx6.h>
68 * Right now, we only have to read the SEEPROM. But we make it easier to
69 * add other 93Cx6 functions.
71 static struct seeprom_cmd {
73 unsigned char bits[3];
74 } seeprom_read = {3, {1, 1, 0}};
77 * Wait for the SEERDY to go high; about 800 ns.
79 #define CLOCK_PULSE(sd, rdy) \
80 while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) { \
83 (void)SEEPROM_INB(sd); /* Clear clock */
86 * Read the serial EEPROM and returns 1 if successful and 0 if
90 read_seeprom(sd, buf, start_addr, count)
91 struct seeprom_descriptor *sd;
93 bus_size_t start_addr;
102 * Read the requested registers of the seeprom. The loop
103 * will range from 0 to count-1.
105 for (k = start_addr; k < count + start_addr; k++) {
106 /* Send chip select for one clock cycle. */
107 temp = sd->sd_MS ^ sd->sd_CS;
108 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
109 CLOCK_PULSE(sd, sd->sd_RDY);
112 * Now we're ready to send the read command followed by the
113 * address of the 16-bit register we want to read.
115 for (i = 0; i < seeprom_read.len; i++) {
116 if (seeprom_read.bits[i] != 0)
118 SEEPROM_OUTB(sd, temp);
119 CLOCK_PULSE(sd, sd->sd_RDY);
120 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
121 CLOCK_PULSE(sd, sd->sd_RDY);
122 if (seeprom_read.bits[i] != 0)
125 /* Send the 6 or 8 bit address (MSB first, LSB last). */
126 for (i = (sd->sd_chip - 1); i >= 0; i--) {
127 if ((k & (1 << i)) != 0)
129 SEEPROM_OUTB(sd, temp);
130 CLOCK_PULSE(sd, sd->sd_RDY);
131 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
132 CLOCK_PULSE(sd, sd->sd_RDY);
133 if ((k & (1 << i)) != 0)
138 * Now read the 16 bit register. An initial 0 precedes the
139 * register contents which begins with bit 15 (MSB) and ends
140 * with bit 0 (LSB). The initial 0 will be shifted off the
141 * top of our word as we let the loop run from 0 to 16.
144 for (i = 16; i >= 0; i--) {
145 SEEPROM_OUTB(sd, temp);
146 CLOCK_PULSE(sd, sd->sd_RDY);
148 if (SEEPROM_DATA_INB(sd) & sd->sd_DI)
150 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
151 CLOCK_PULSE(sd, sd->sd_RDY);
154 buf[k - start_addr] = v;
156 /* Reset the chip select for the next command cycle. */
158 SEEPROM_OUTB(sd, temp);
159 CLOCK_PULSE(sd, sd->sd_RDY);
160 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
161 CLOCK_PULSE(sd, sd->sd_RDY);
162 SEEPROM_OUTB(sd, temp);
163 CLOCK_PULSE(sd, sd->sd_RDY);
165 #ifdef AHC_DUMP_EEPROM
166 printf("\nSerial EEPROM:\n\t");
167 for (k = 0; k < count; k = k + 1) {
168 if (((k % 8) == 0) && (k != 0)) {
171 printf (" 0x%x", buf[k]);