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#8 $ 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 precede 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 #include <dev/aic7xxx/aic7xxx_freebsd.h> 71 #include <dev/aic7xxx/aic7xxx_inline.h> 72 #include <dev/aic7xxx/aic7xxx_93cx6.h> 73 74 /* 75 * Right now, we only have to read the SEEPROM. But we make it easier to 76 * add other 93Cx6 functions. 77 */ 78 static struct seeprom_cmd { 79 uint8_t len; 80 uint8_t bits[3]; 81 } seeprom_read = {3, {1, 1, 0}}; 82 83 /* 84 * Wait for the SEERDY to go high; about 800 ns. 85 */ 86 #define CLOCK_PULSE(sd, rdy) \ 87 while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) { \ 88 ; /* Do nothing */ \ 89 } \ 90 (void)SEEPROM_INB(sd); /* Clear clock */ 91 92 /* 93 * Read the serial EEPROM and returns 1 if successful and 0 if 94 * not successful. 95 */ 96 int 97 read_seeprom(sd, buf, start_addr, count) 98 struct seeprom_descriptor *sd; 99 uint16_t *buf; 100 u_int start_addr; 101 u_int count; 102 { 103 int i = 0; 104 u_int k = 0; 105 uint16_t v; 106 uint8_t temp; 107 108 /* 109 * Read the requested registers of the seeprom. The loop 110 * will range from 0 to count-1. 111 */ 112 for (k = start_addr; k < count + start_addr; k++) { 113 /* Send chip select for one clock cycle. */ 114 temp = sd->sd_MS ^ sd->sd_CS; 115 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 116 CLOCK_PULSE(sd, sd->sd_RDY); 117 118 /* 119 * Now we're ready to send the read command followed by the 120 * address of the 16-bit register we want to read. 121 */ 122 for (i = 0; i < seeprom_read.len; i++) { 123 if (seeprom_read.bits[i] != 0) 124 temp ^= sd->sd_DO; 125 SEEPROM_OUTB(sd, temp); 126 CLOCK_PULSE(sd, sd->sd_RDY); 127 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 128 CLOCK_PULSE(sd, sd->sd_RDY); 129 if (seeprom_read.bits[i] != 0) 130 temp ^= sd->sd_DO; 131 } 132 /* Send the 6 or 8 bit address (MSB first, LSB last). */ 133 for (i = (sd->sd_chip - 1); i >= 0; i--) { 134 if ((k & (1 << i)) != 0) 135 temp ^= sd->sd_DO; 136 SEEPROM_OUTB(sd, temp); 137 CLOCK_PULSE(sd, sd->sd_RDY); 138 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 139 CLOCK_PULSE(sd, sd->sd_RDY); 140 if ((k & (1 << i)) != 0) 141 temp ^= sd->sd_DO; 142 } 143 144 /* 145 * Now read the 16 bit register. An initial 0 precedes the 146 * register contents which begins with bit 15 (MSB) and ends 147 * with bit 0 (LSB). The initial 0 will be shifted off the 148 * top of our word as we let the loop run from 0 to 16. 149 */ 150 v = 0; 151 for (i = 16; i >= 0; i--) { 152 SEEPROM_OUTB(sd, temp); 153 CLOCK_PULSE(sd, sd->sd_RDY); 154 v <<= 1; 155 if (SEEPROM_DATA_INB(sd) & sd->sd_DI) 156 v |= 1; 157 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 158 CLOCK_PULSE(sd, sd->sd_RDY); 159 } 160 161 buf[k - start_addr] = v; 162 163 /* Reset the chip select for the next command cycle. */ 164 temp = sd->sd_MS; 165 SEEPROM_OUTB(sd, temp); 166 CLOCK_PULSE(sd, sd->sd_RDY); 167 SEEPROM_OUTB(sd, temp ^ sd->sd_CK); 168 CLOCK_PULSE(sd, sd->sd_RDY); 169 SEEPROM_OUTB(sd, temp); 170 CLOCK_PULSE(sd, sd->sd_RDY); 171 } 172 #ifdef AHC_DUMP_EEPROM 173 printf("\nSerial EEPROM:\n\t"); 174 for (k = 0; k < count; k = k + 1) { 175 if (((k % 8) == 0) && (k != 0)) { 176 printf ("\n\t"); 177 } 178 printf (" 0x%x", buf[k]); 179 } 180 printf ("\n"); 181 #endif 182 return (1); 183 } 184 185 int 186 verify_cksum(struct seeprom_config *sc) 187 { 188 int i; 189 int maxaddr; 190 uint32_t checksum; 191 uint16_t *scarray; 192 193 maxaddr = (sizeof(*sc)/2) - 1; 194 checksum = 0; 195 scarray = (uint16_t *)sc; 196 197 for (i = 0; i < maxaddr; i++) 198 checksum = checksum + scarray[i]; 199 if (checksum == 0 200 || (checksum & 0xFFFF) != sc->checksum) { 201 return (0); 202 } else { 203 return(1); 204 } 205 } 206