1 /* $NetBSD: smc93cx6.c,v 1.15 2009/03/14 15:36:17 dsl Exp $ */
2
3 /*
4 * Interface for the 93C66/56/46/26/06 serial eeprom parts.
5 *
6 * Copyright (c) 1995, 1996 Daniel M. Eischen
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice immediately at the beginning of the file, without modification,
14 * this list of conditions, and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Absolutely no warranty of function or purpose is made by the author
19 * Daniel M. Eischen.
20 * 4. Modifications may be freely made to this file if the above conditions
21 * are met.
22 *
23 * $FreeBSD: src/sys/dev/aic7xxx/93cx6.c,v 1.5 2000/01/07 23:08:17 gibbs Exp $
24 */
25
26 /*
27 * The instruction set of the 93C66/56/46/26/06 chips are as follows:
28 *
29 * Start OP *
30 * Function Bit Code Address** Data Description
31 * -------------------------------------------------------------------
32 * READ 1 10 A5 - A0 Reads data stored in memory,
33 * starting at specified address
34 * EWEN 1 00 11XXXX Write enable must precede
35 * all programming modes
36 * ERASE 1 11 A5 - A0 Erase register A5A4A3A2A1A0
37 * WRITE 1 01 A5 - A0 D15 - D0 Writes register
38 * ERAL 1 00 10XXXX Erase all registers
39 * WRAL 1 00 01XXXX D15 - D0 Writes to all registers
40 * EWDS 1 00 00XXXX Disables all programming
41 * instructions
42 * *Note: A value of X for address is a don't care condition.
43 * **Note: There are 8 address bits for the 93C56/66 chips unlike
44 * the 93C46/26/06 chips which have 6 address bits.
45 *
46 * The 93C46 has a four wire interface: clock, chip select, data in, and
47 * data out. In order to perform one of the above functions, you need
48 * to enable the chip select for a clock period (typically a minimum of
49 * 1 usec, with the clock high and low a minimum of 750 and 250 nsec
50 * respectively). While the chip select remains high, you can clock in
51 * the instructions (above) starting with the start bit, followed by the
52 * OP code, Address, and Data (if needed). For the READ instruction, the
53 * requested 16-bit register contents is read from the data out line but
54 * is preceded by an initial zero (leading 0, followed by 16-bits, MSB
55 * first). The clock cycling from low to high initiates the next data
56 * bit to be sent from the chip.
57 *
58 */
59
60 #include <sys/cdefs.h>
61 __KERNEL_RCSID(0, "$NetBSD: smc93cx6.c,v 1.15 2009/03/14 15:36:17 dsl Exp $");
62
63 #ifndef __NetBSD__
64 #include "opt_aic7xxx.h"
65 #endif
66
67 #include <sys/param.h>
68 #include <sys/systm.h>
69 #include <sys/bus.h>
70 #ifdef __NetBSD__
71 #include <dev/ic/smc93cx6var.h>
72 #else
73 #include <machine/bus_memio.h>
74 #include <machine/bus_pio.h>
75 #include <dev/aic7xxx/93cx6.h>
76 #endif
77
78 /*
79 * Right now, we only have to read the SEEPROM. But we make it easier to
80 * add other 93Cx6 functions.
81 */
82 static struct seeprom_cmd {
83 unsigned char len;
84 unsigned char bits[3];
85 } seeprom_read = {3, {1, 1, 0}};
86
87 /* XXX bus barriers */
88 #define CLOCK_PULSE(sd, rdy) do { \
89 /* \
90 * Wait for the SEERDY to go high; about 800 ns. \
91 */ \
92 int cpi = 1000; \
93 if (rdy == 0) { \
94 DELAY(4); /* more than long enough */ \
95 break; \
96 } \
97 while ((SEEPROM_STATUS_INB(sd) & rdy) == 0 && cpi-- > 0) { \
98 ; /* Do nothing */ \
99 } \
100 (void)SEEPROM_INB(sd); /* Clear clock */ \
101 } while (0)
102
103 /*
104 * Read the serial EEPROM and returns 1 if successful and 0 if
105 * not successful.
106 */
107 int
read_seeprom(struct seeprom_descriptor * sd,u_int16_t * buf,bus_size_t start_addr,bus_size_t count)108 read_seeprom(struct seeprom_descriptor *sd, u_int16_t *buf, bus_size_t start_addr, bus_size_t count)
109 {
110 int i = 0;
111 u_int k = 0;
112 u_int16_t v;
113 u_int32_t temp;
114
115 /*
116 * Read the requested registers of the seeprom. The loop
117 * will range from 0 to count-1.
118 */
119 for (k = start_addr; k < count + start_addr; k++) {
120 /* Send chip select for one clock cycle. */
121 temp = sd->sd_MS ^ sd->sd_CS;
122 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
123 CLOCK_PULSE(sd, sd->sd_RDY);
124
125 /*
126 * Now we're ready to send the read command followed by the
127 * address of the 16-bit register we want to read.
128 */
129 for (i = 0; i < seeprom_read.len; i++) {
130 if (seeprom_read.bits[i] != 0)
131 temp ^= sd->sd_DO;
132 SEEPROM_OUTB(sd, temp);
133 CLOCK_PULSE(sd, sd->sd_RDY);
134 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
135 CLOCK_PULSE(sd, sd->sd_RDY);
136 if (seeprom_read.bits[i] != 0)
137 temp ^= sd->sd_DO;
138 }
139 /* Send the 6 or 8 bit address (MSB first, LSB last). */
140 for (i = (sd->sd_chip - 1); i >= 0; i--) {
141 if ((k & (1 << i)) != 0)
142 temp ^= sd->sd_DO;
143 SEEPROM_OUTB(sd, temp);
144 CLOCK_PULSE(sd, sd->sd_RDY);
145 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
146 CLOCK_PULSE(sd, sd->sd_RDY);
147 if ((k & (1 << i)) != 0)
148 temp ^= sd->sd_DO;
149 }
150
151 /*
152 * Now read the 16 bit register. An initial 0 precedes the
153 * register contents which begins with bit 15 (MSB) and ends
154 * with bit 0 (LSB). The initial 0 will be shifted off the
155 * top of our word as we let the loop run from 0 to 16.
156 */
157 v = 0;
158 for (i = 16; i >= 0; i--) {
159 SEEPROM_OUTB(sd, temp);
160 CLOCK_PULSE(sd, sd->sd_RDY);
161 v <<= 1;
162 if (SEEPROM_DATA_INB(sd) & sd->sd_DI)
163 v |= 1;
164 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
165 CLOCK_PULSE(sd, sd->sd_RDY);
166 }
167
168 buf[k - start_addr] = v;
169
170 /* Reset the chip select for the next command cycle. */
171 temp = sd->sd_MS;
172 SEEPROM_OUTB(sd, temp);
173 CLOCK_PULSE(sd, sd->sd_RDY);
174 SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
175 CLOCK_PULSE(sd, sd->sd_RDY);
176 SEEPROM_OUTB(sd, temp);
177 CLOCK_PULSE(sd, sd->sd_RDY);
178 }
179 #ifdef AHC_DUMP_EEPROM
180 printf("\nSerial EEPROM:\n\t");
181 for (k = 0; k < count; k = k + 1) {
182 if (((k % 8) == 0) && (k != 0)) {
183 printf ("\n\t");
184 }
185 printf (" 0x%x", buf[k]);
186 }
187 printf ("\n");
188 #endif
189 return (1);
190 }
191