1 /* 2 * Interface for the 93C66/56/46/26/06 serial eeprom parts. 3 * 4 * Copyright (c) 1995, 1996 Daniel M. Eischen 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions, and the following disclaimer, 12 * without modification. 13 * 2. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * Alternatively, this software may be distributed under the terms of the 17 * GNU Public License ("GPL"). 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 23 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $Id: //depot/src/aic7xxx/aic7xxx_93cx6.c#4 $ 32 * 33 * $FreeBSD$ 34 */ 35 36 /* 37 * The instruction set of the 93C66/56/46/26/06 chips are as follows: 38 * 39 * Start OP * 40 * Function Bit Code Address** Data Description 41 * ------------------------------------------------------------------- 42 * READ 1 10 A5 - A0 Reads data stored in memory, 43 * starting at specified address 44 * EWEN 1 00 11XXXX Write enable must preceed 45 * all programming modes 46 * ERASE 1 11 A5 - A0 Erase register A5A4A3A2A1A0 47 * WRITE 1 01 A5 - A0 D15 - D0 Writes register 48 * ERAL 1 00 10XXXX Erase all registers 49 * WRAL 1 00 01XXXX D15 - D0 Writes to all registers 50 * EWDS 1 00 00XXXX Disables all programming 51 * instructions 52 * *Note: A value of X for address is a don't care condition. 53 * **Note: There are 8 address bits for the 93C56/66 chips unlike 54 * the 93C46/26/06 chips which have 6 address bits. 55 * 56 * The 93C46 has a four wire interface: clock, chip select, data in, and 57 * data out. In order to perform one of the above functions, you need 58 * to enable the chip select for a clock period (typically a minimum of 59 * 1 usec, with the clock high and low a minimum of 750 and 250 nsec 60 * respectively). While the chip select remains high, you can clock in 61 * the instructions (above) starting with the start bit, followed by the 62 * OP code, Address, and Data (if needed). For the READ instruction, the 63 * requested 16-bit register contents is read from the data out line but 64 * is preceded by an initial zero (leading 0, followed by 16-bits, MSB 65 * first). The clock cycling from low to high initiates the next data 66 * bit to be sent from the chip. 67 * 68 */ 69 70 #ifdef __linux__ 71 #include "aic7xxx_linux.h" 72 #include "aic7xxx_inline.h" 73 #include "aic7xxx_93cx6.h" 74 #endif 75 76 #ifdef __FreeBSD__ 77 #include <dev/aic7xxx/aic7xxx_freebsd.h> 78 #include <dev/aic7xxx/aic7xxx_inline.h> 79 #include <dev/aic7xxx/aic7xxx_93cx6.h> 80 #endif 81 82 /* 83 * Right now, we only have to read the SEEPROM. But we make it easier to 84 * add other 93Cx6 functions. 85 */ 86 static struct seeprom_cmd { 87 uint8_t len; 88 uint8_t bits[3]; 89 } seeprom_read = {3, {1, 1, 0}}; 90 91 /* 92 * Wait for the SEERDY to go high; about 800 ns. 93 */ 94 #define CLOCK_PULSE(sd, rdy) \ 95 while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) { \ 96 ; /* Do nothing */ \ 97 } \ 98 (void)SEEPROM_INB(sd); /* Clear clock */ 99 100 /* 101 * Read the serial EEPROM and returns 1 if successful and 0 if 102 * not successful. 103 */ 104 int 105 read_seeprom(sd, buf, start_addr, count) 106 struct seeprom_descriptor *sd; 107 uint16_t *buf; 108 u_int start_addr; 109 u_int count; 110 { 111 int i = 0; 112 u_int k = 0; 113 uint16_t v; 114 uint8_t temp; 115 116 /* 117 * Read the requested registers of the seeprom. The loop 118 * will range from 0 to count-1. 119 */ 120 for (k = start_addr; k < count + start_addr; k++) { 121 /* Send chip select for one clock cycle. */ 122 temp = sd->sd_MS ^ sd->sd_CS; 123 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 124 CLOCK_PULSE(sd, sd->sd_RDY); 125 126 /* 127 * Now we're ready to send the read command followed by the 128 * address of the 16-bit register we want to read. 129 */ 130 for (i = 0; i < seeprom_read.len; i++) { 131 if (seeprom_read.bits[i] != 0) 132 temp ^= sd->sd_DO; 133 SEEPROM_OUTB(sd, temp); 134 CLOCK_PULSE(sd, sd->sd_RDY); 135 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 136 CLOCK_PULSE(sd, sd->sd_RDY); 137 if (seeprom_read.bits[i] != 0) 138 temp ^= sd->sd_DO; 139 } 140 /* Send the 6 or 8 bit address (MSB first, LSB last). */ 141 for (i = (sd->sd_chip - 1); i >= 0; i--) { 142 if ((k & (1 << i)) != 0) 143 temp ^= sd->sd_DO; 144 SEEPROM_OUTB(sd, temp); 145 CLOCK_PULSE(sd, sd->sd_RDY); 146 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 147 CLOCK_PULSE(sd, sd->sd_RDY); 148 if ((k & (1 << i)) != 0) 149 temp ^= sd->sd_DO; 150 } 151 152 /* 153 * Now read the 16 bit register. An initial 0 precedes the 154 * register contents which begins with bit 15 (MSB) and ends 155 * with bit 0 (LSB). The initial 0 will be shifted off the 156 * top of our word as we let the loop run from 0 to 16. 157 */ 158 v = 0; 159 for (i = 16; i >= 0; i--) { 160 SEEPROM_OUTB(sd, temp); 161 CLOCK_PULSE(sd, sd->sd_RDY); 162 v <<= 1; 163 if (SEEPROM_DATA_INB(sd) & sd->sd_DI) 164 v |= 1; 165 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 166 CLOCK_PULSE(sd, sd->sd_RDY); 167 } 168 169 buf[k - start_addr] = v; 170 171 /* Reset the chip select for the next command cycle. */ 172 temp = sd->sd_MS; 173 SEEPROM_OUTB(sd, temp); 174 CLOCK_PULSE(sd, sd->sd_RDY); 175 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 176 CLOCK_PULSE(sd, sd->sd_RDY); 177 SEEPROM_OUTB(sd, temp); 178 CLOCK_PULSE(sd, sd->sd_RDY); 179 } 180 #ifdef AHC_DUMP_EEPROM 181 printf("\nSerial EEPROM:\n\t"); 182 for (k = 0; k < count; k = k + 1) { 183 if (((k % 8) == 0) && (k != 0)) { 184 printf ("\n\t"); 185 } 186 printf (" 0x%x", buf[k]); 187 } 188 printf ("\n"); 189 #endif 190 return (1); 191 } 192 193 int 194 verify_cksum(struct seeprom_config *sc) 195 { 196 int i; 197 int maxaddr; 198 uint32_t checksum; 199 uint16_t *scarray; 200 201 maxaddr = (sizeof(*sc)/2) - 1; 202 checksum = 0; 203 scarray = (uint16_t *)sc; 204 205 for (i = 0; i < maxaddr; i++) 206 checksum = checksum + scarray[i]; 207 if (checksum == 0 208 || (checksum & 0xFFFF) != sc->checksum) { 209 return (0); 210 } else { 211 return(1); 212 } 213 } 214