/* $OpenBSD: smc93cx6.c,v 1.19 2021/03/07 06:21:38 jsg Exp $ */ /* $NetBSD: smc93cx6.c,v 1.10 2003/05/02 19:12:19 dyoung Exp $ */ /* * Interface for the 93C66/56/46/26/06 serial eeprom parts. * * Copyright (c) 1995, 1996 Daniel M. Eischen * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice immediately at the beginning of the file, without modification, * this list of conditions, and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Absolutely no warranty of function or purpose is made by the author * Daniel M. Eischen. * 4. Modifications may be freely made to this file if the above conditions * are met. * * $FreeBSD: src/sys/dev/aic7xxx/93cx6.c,v 1.5 2000/01/07 23:08:17 gibbs Exp $ */ /* * The instruction set of the 93C66/56/46/26/06 chips are as follows: * * Start OP * * Function Bit Code Address** Data Description * ------------------------------------------------------------------- * READ 1 10 A5 - A0 Reads data stored in memory, * starting at specified address * EWEN 1 00 11XXXX Write enable must precede * all programming modes * ERASE 1 11 A5 - A0 Erase register A5A4A3A2A1A0 * WRITE 1 01 A5 - A0 D15 - D0 Writes register * ERAL 1 00 10XXXX Erase all registers * WRAL 1 00 01XXXX D15 - D0 Writes to all registers * EWDS 1 00 00XXXX Disables all programming * instructions * *Note: A value of X for address is a don't care condition. * **Note: There are 8 address bits for the 93C56/66 chips unlike * the 93C46/26/06 chips which have 6 address bits. * * The 93C46 has a four wire interface: clock, chip select, data in, and * data out. In order to perform one of the above functions, you need * to enable the chip select for a clock period (typically a minimum of * 1 usec, with the clock high and low a minimum of 750 and 250 nsec * respectively). While the chip select remains high, you can clock in * the instructions (above) starting with the start bit, followed by the * OP code, Address, and Data (if needed). For the READ instruction, the * requested 16-bit register contents is read from the data out line but * is preceded by an initial zero (leading 0, followed by 16-bits, MSB * first). The clock cycling from low to high initiates the next data * bit to be sent from the chip. * */ #include <sys/param.h> #include <sys/systm.h> #include <machine/bus.h> #include <dev/ic/smc93cx6var.h> /* * Right now, we only have to read the SEEPROM. But we make it easier to * add other 93Cx6 functions. */ static struct seeprom_cmd { unsigned char len; unsigned char bits[3]; } seeprom_read = {3, {1, 1, 0}}; #define CLOCK_PULSE(sd, rdy) do { \ /* \ * Wait for the SEERDY to go high; about 800 ns. \ */ \ int cpi = 1000; \ if (rdy == 0) { \ DELAY(4); /* more than long enough */ \ break; \ } \ while ((SEEPROM_STATUS_INB(sd) & rdy) == 0 && cpi-- > 0) { \ ; /* Do nothing */ \ } \ (void)SEEPROM_INB(sd); /* Clear clock */ \ } while (0) /* * Read the serial EEPROM and returns 1 if successful and 0 if * not successful. */ int read_seeprom(struct seeprom_descriptor *sd, u_int16_t *buf, bus_size_t start_addr, bus_size_t count) { int i = 0; u_int k = 0; u_int16_t v; u_int32_t temp; /* * Read the requested registers of the seeprom. The loop * will range from 0 to count-1. */ for (k = start_addr; k < count + start_addr; k++) { /* Send chip select for one clock cycle. */ temp = sd->sd_MS ^ sd->sd_CS; SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); /* * Now we're ready to send the read command followed by the * address of the 16-bit register we want to read. */ for (i = 0; i < seeprom_read.len; i++) { if (seeprom_read.bits[i] != 0) temp ^= sd->sd_DO; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); if (seeprom_read.bits[i] != 0) temp ^= sd->sd_DO; } /* Send the 6 or 8 bit address (MSB first, LSB last). */ for (i = (sd->sd_chip - 1); i >= 0; i--) { if ((k & (1 << i)) != 0) temp ^= sd->sd_DO; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); if ((k & (1 << i)) != 0) temp ^= sd->sd_DO; } /* * Now read the 16 bit register. An initial 0 precedes the * register contents which begins with bit 15 (MSB) and ends * with bit 0 (LSB). The initial 0 will be shifted off the * top of our word as we let the loop run from 0 to 16. */ v = 0; for (i = 16; i >= 0; i--) { SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); v <<= 1; if (SEEPROM_DATA_INB(sd) & sd->sd_DI) v |= 1; SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); } buf[k - start_addr] = v; /* Reset the chip select for the next command cycle. */ temp = sd->sd_MS; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); } #ifdef AHC_DUMP_EEPROM printf("\nSerial EEPROM:\n\t"); for (k = 0; k < count; k = k + 1) { if (((k % 8) == 0) && (k != 0)) { printf ("\n\t"); } printf (" 0x%04x", buf[k]); } printf ("\n"); #endif return (1); }
