Annotation of sys/dev/ic/smc93cx6.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: smc93cx6.c,v 1.17 2003/09/25 06:43:34 fgsch Exp $ */
! 2: /* $NetBSD: smc93cx6.c,v 1.10 2003/05/02 19:12:19 dyoung Exp $ */
! 3:
! 4: /*
! 5: * Interface for the 93C66/56/46/26/06 serial eeprom parts.
! 6: *
! 7: * Copyright (c) 1995, 1996 Daniel M. Eischen
! 8: * All rights reserved.
! 9: *
! 10: * Redistribution and use in source and binary forms, with or without
! 11: * modification, are permitted provided that the following conditions
! 12: * are met:
! 13: * 1. Redistributions of source code must retain the above copyright
! 14: * notice immediately at the beginning of the file, without modification,
! 15: * this list of conditions, and the following disclaimer.
! 16: * 2. Redistributions in binary form must reproduce the above copyright
! 17: * notice, this list of conditions and the following disclaimer in the
! 18: * documentation and/or other materials provided with the distribution.
! 19: * 3. Absolutely no warranty of function or purpose is made by the author
! 20: * Daniel M. Eischen.
! 21: * 4. Modifications may be freely made to this file if the above conditions
! 22: * are met.
! 23: *
! 24: * $FreeBSD: src/sys/dev/aic7xxx/93cx6.c,v 1.5 2000/01/07 23:08:17 gibbs Exp $
! 25: */
! 26:
! 27: /*
! 28: * The instruction set of the 93C66/56/46/26/06 chips are as follows:
! 29: *
! 30: * Start OP *
! 31: * Function Bit Code Address** Data Description
! 32: * -------------------------------------------------------------------
! 33: * READ 1 10 A5 - A0 Reads data stored in memory,
! 34: * starting at specified address
! 35: * EWEN 1 00 11XXXX Write enable must precede
! 36: * all programming modes
! 37: * ERASE 1 11 A5 - A0 Erase register A5A4A3A2A1A0
! 38: * WRITE 1 01 A5 - A0 D15 - D0 Writes register
! 39: * ERAL 1 00 10XXXX Erase all registers
! 40: * WRAL 1 00 01XXXX D15 - D0 Writes to all registers
! 41: * EWDS 1 00 00XXXX Disables all programming
! 42: * instructions
! 43: * *Note: A value of X for address is a don't care condition.
! 44: * **Note: There are 8 address bits for the 93C56/66 chips unlike
! 45: * the 93C46/26/06 chips which have 6 address bits.
! 46: *
! 47: * The 93C46 has a four wire interface: clock, chip select, data in, and
! 48: * data out. In order to perform one of the above functions, you need
! 49: * to enable the chip select for a clock period (typically a minimum of
! 50: * 1 usec, with the clock high and low a minimum of 750 and 250 nsec
! 51: * respectively). While the chip select remains high, you can clock in
! 52: * the instructions (above) starting with the start bit, followed by the
! 53: * OP code, Address, and Data (if needed). For the READ instruction, the
! 54: * requested 16-bit register contents is read from the data out line but
! 55: * is preceded by an initial zero (leading 0, followed by 16-bits, MSB
! 56: * first). The clock cycling from low to high initiates the next data
! 57: * bit to be sent from the chip.
! 58: *
! 59: */
! 60:
! 61: #include <sys/param.h>
! 62: #include <sys/systm.h>
! 63: #include <machine/bus.h>
! 64: #include <dev/ic/smc93cx6var.h>
! 65:
! 66: /*
! 67: * Right now, we only have to read the SEEPROM. But we make it easier to
! 68: * add other 93Cx6 functions.
! 69: */
! 70: static struct seeprom_cmd {
! 71: unsigned char len;
! 72: unsigned char bits[3];
! 73: } seeprom_read = {3, {1, 1, 0}};
! 74:
! 75: #define CLOCK_PULSE(sd, rdy) do { \
! 76: /* \
! 77: * Wait for the SEERDY to go high; about 800 ns. \
! 78: */ \
! 79: int cpi = 1000; \
! 80: if (rdy == 0) { \
! 81: DELAY(4); /* more than long enough */ \
! 82: break; \
! 83: } \
! 84: while ((SEEPROM_STATUS_INB(sd) & rdy) == 0 && cpi-- > 0) { \
! 85: ; /* Do nothing */ \
! 86: } \
! 87: (void)SEEPROM_INB(sd); /* Clear clock */ \
! 88: } while (0)
! 89:
! 90: /*
! 91: * Read the serial EEPROM and returns 1 if successful and 0 if
! 92: * not successful.
! 93: */
! 94: int
! 95: read_seeprom(sd, buf, start_addr, count)
! 96: struct seeprom_descriptor *sd;
! 97: u_int16_t *buf;
! 98: bus_size_t start_addr;
! 99: bus_size_t count;
! 100: {
! 101: int i = 0;
! 102: u_int k = 0;
! 103: u_int16_t v;
! 104: u_int32_t temp;
! 105:
! 106: /*
! 107: * Read the requested registers of the seeprom. The loop
! 108: * will range from 0 to count-1.
! 109: */
! 110: for (k = start_addr; k < count + start_addr; k++) {
! 111: /* Send chip select for one clock cycle. */
! 112: temp = sd->sd_MS ^ sd->sd_CS;
! 113: SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
! 114: CLOCK_PULSE(sd, sd->sd_RDY);
! 115:
! 116: /*
! 117: * Now we're ready to send the read command followed by the
! 118: * address of the 16-bit register we want to read.
! 119: */
! 120: for (i = 0; i < seeprom_read.len; i++) {
! 121: if (seeprom_read.bits[i] != 0)
! 122: temp ^= sd->sd_DO;
! 123: SEEPROM_OUTB(sd, temp);
! 124: CLOCK_PULSE(sd, sd->sd_RDY);
! 125: SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
! 126: CLOCK_PULSE(sd, sd->sd_RDY);
! 127: if (seeprom_read.bits[i] != 0)
! 128: temp ^= sd->sd_DO;
! 129: }
! 130: /* Send the 6 or 8 bit address (MSB first, LSB last). */
! 131: for (i = (sd->sd_chip - 1); i >= 0; i--) {
! 132: if ((k & (1 << i)) != 0)
! 133: temp ^= sd->sd_DO;
! 134: SEEPROM_OUTB(sd, temp);
! 135: CLOCK_PULSE(sd, sd->sd_RDY);
! 136: SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
! 137: CLOCK_PULSE(sd, sd->sd_RDY);
! 138: if ((k & (1 << i)) != 0)
! 139: temp ^= sd->sd_DO;
! 140: }
! 141:
! 142: /*
! 143: * Now read the 16 bit register. An initial 0 precedes the
! 144: * register contents which begins with bit 15 (MSB) and ends
! 145: * with bit 0 (LSB). The initial 0 will be shifted off the
! 146: * top of our word as we let the loop run from 0 to 16.
! 147: */
! 148: v = 0;
! 149: for (i = 16; i >= 0; i--) {
! 150: SEEPROM_OUTB(sd, temp);
! 151: CLOCK_PULSE(sd, sd->sd_RDY);
! 152: v <<= 1;
! 153: if (SEEPROM_DATA_INB(sd) & sd->sd_DI)
! 154: v |= 1;
! 155: SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
! 156: CLOCK_PULSE(sd, sd->sd_RDY);
! 157: }
! 158:
! 159: buf[k - start_addr] = v;
! 160:
! 161: /* Reset the chip select for the next command cycle. */
! 162: temp = sd->sd_MS;
! 163: SEEPROM_OUTB(sd, temp);
! 164: CLOCK_PULSE(sd, sd->sd_RDY);
! 165: SEEPROM_OUTB(sd, temp ^ sd->sd_CK);
! 166: CLOCK_PULSE(sd, sd->sd_RDY);
! 167: SEEPROM_OUTB(sd, temp);
! 168: CLOCK_PULSE(sd, sd->sd_RDY);
! 169: }
! 170: #ifdef AHC_DUMP_EEPROM
! 171: printf("\nSerial EEPROM:\n\t");
! 172: for (k = 0; k < count; k = k + 1) {
! 173: if (((k % 8) == 0) && (k != 0)) {
! 174: printf ("\n\t");
! 175: }
! 176: printf (" 0x%x", buf[k]);
! 177: }
! 178: printf ("\n");
! 179: #endif
! 180: return (1);
! 181: }
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