 437177b028
			
		
	
	
		437177b028
		
	
	
	
	
		
			
			128 byte reads are much more common than 32 byte reads. The message passing + setup/teardown for a read is much more expensive, in terms of time, than the reading itself. A slightly bigger struct is well worth the time savings. This reduces read times for /dev/eeprom from 57 seconds per 4KB to 14 seconds. Additionally, make sending the page address in the eeprom driver and utility optional. This can save a little time when reading within the same page and allows support for smaller devices that don't support pages (example: chips containing EDID). Change-Id: Ie48087caee40c11fa241d1555fce9309ddd27b43
		
			
				
	
	
		
			217 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			217 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #include <minix/i2c.h>
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| #include <minix/com.h>
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| 
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| #include <sys/types.h>
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| #include <sys/stat.h>
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| 
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| #include <ctype.h>
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| #include <errno.h>
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| #include <fcntl.h>
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| #include <unistd.h>
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| 
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| #include "eepromread.h"
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| 
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| static int __eeprom_read128(int fd, i2c_addr_t addr, uint16_t memaddr,
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|     void *buf, size_t buflen, int flags);
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| static int eeprom_dump(int fd, i2c_addr_t addr, int flags);
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| 
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| #define DEFAULT_I2C_DEVICE "/dev/i2c-1"
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| #define DEFAULT_I2C_ADDRESS 0x50
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| 
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| /*
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|  * The /dev interface only supports 128 byte reads/writes and the EEPROM is
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|  * larger, so to read the whole EEPROM, the task is broken down into 128 byte
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|  * chunks in eeprom_read(). __eeprom_read128() does the actual ioctl() to do
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|  * the read.
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|  *
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|  * A future enhancement might be to add support for the /dev/eeprom interface
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|  * and if one way fails, fall back to the other. /dev/eeprom can fail if the
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|  * eeprom driver isn't running and /dev/i2c can fail if the eeprom driver
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|  * claimed the eeprom device.
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|  */
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| 
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| static int
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| __eeprom_read128(int fd, i2c_addr_t addr, uint16_t memaddr, void *buf,
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|     size_t buflen, int flags)
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| {
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| 	int r;
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| 	minix_i2c_ioctl_exec_t ioctl_exec;
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| 
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| 	if (buflen > I2C_EXEC_MAX_BUFLEN || buf == NULL
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| 	    || ((memaddr + buflen) < memaddr)) {
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| 		errno = EINVAL;
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| 		return -1;
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| 	}
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| 
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| 	memset(&ioctl_exec, '\0', sizeof(minix_i2c_ioctl_exec_t));
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| 
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| 	ioctl_exec.iie_op = I2C_OP_READ_WITH_STOP;
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| 	ioctl_exec.iie_addr = addr;
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| 
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| 	/* set the address to read from */
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| 	if ((BDEV_NOPAGE & flags) == BDEV_NOPAGE) {
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| 		/* reading within the current page */
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| 		ioctl_exec.iie_cmd[0] = (memaddr & 0xff);
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| 		ioctl_exec.iie_cmdlen = 1;
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| 	} else {
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| 		/* reading from device with multiple pages */
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| 		ioctl_exec.iie_cmd[0] = ((memaddr >> 8) & 0xff);
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| 		ioctl_exec.iie_cmd[1] = (memaddr & 0xff);
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| 		ioctl_exec.iie_cmdlen = 2;
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| 	}
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| 	ioctl_exec.iie_buflen = buflen;
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| 
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| 	r = ioctl(fd, MINIX_I2C_IOCTL_EXEC, &ioctl_exec);
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| 	if (r == -1) {
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| 		return -1;
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| 	}
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| 
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| 	/* call was good, copy results to caller's buffer */
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| 	memcpy(buf, ioctl_exec.iie_buf, buflen);
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| 
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| 	return 0;
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| }
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| 
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| int
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| eeprom_read(int fd, i2c_addr_t addr, uint16_t memaddr, void *buf,
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|     size_t buflen, int flags)
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| {
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| 	int r;
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| 	uint16_t i;
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| 
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| 	if (buf == NULL || ((memaddr + buflen) < memaddr)) {
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| 		errno = EINVAL;
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| 		return -1;
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| 	}
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| 
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| 
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| 	for (i = 0; i < buflen; i += 128) {
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| 
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| 		r = __eeprom_read128(fd, addr, memaddr + i, buf + i,
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| 		    ((buflen - i) < 128) ? (buflen - i) : 128, flags);
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| 		if (r == -1) {
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| 			return -1;
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| 		}
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| /*
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|  * Read 256 bytes and print it to the screen in HEX and ASCII.
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|  */
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| static int
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| eeprom_dump(int fd, i2c_addr_t addr, int flags)
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| {
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| 	int i, j, r;
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| 	uint8_t buf[256];
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| 
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| 	memset(buf, '\0', 256);
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| 
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| 	r = eeprom_read(fd, addr, 0x0000, buf, 256, flags);
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| 	if (r == -1) {
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| 		return r;
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| 	}
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| 
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| 	/* print table header */
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| 	for (i = 0; i < 2; i++) {
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| 		printf("   ");
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| 		for (j = 0x0; j <= 0xf; j++) {
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| 			if (i == 0) {
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| 				printf("  ");
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| 			}
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| 			printf("%x", j);
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| 		}
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| 	}
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| 	printf("\n");
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| 
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| 	/* print table data */
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| 	for (i = 0x00; i < 0xff; i += 0x10) {
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| 
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| 		/* row label */
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| 		printf("%02x:", i);
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| 
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| 		/* row data (in hex) */
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| 		for (j = 0x0; j <= 0xf; j++) {
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| 			printf(" %02x", buf[i + j]);
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| 		}
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| 
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| 		printf("   ");
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| 
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| 		/* row data (in ASCII) */
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| 		for (j = 0x0; j <= 0xf; j++) {
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| 			if (isprint(buf[i + j])) {
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| 				printf("%c", buf[i + j]);
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| 			} else {
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| 				printf(".");
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| 			}
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| 		}
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| 
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| 		printf("\n");
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| int
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| main(int argc, char *argv[])
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| {
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| 	int r, fd;
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| 	int ch, iflag = 0, read_flags = 0;
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| 	char *device = DEFAULT_I2C_DEVICE;
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| 	i2c_addr_t address = DEFAULT_I2C_ADDRESS;
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| 
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| 	setprogname(*argv);
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| 
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| 	while ((ch = getopt(argc, argv, "a:f:in")) != -1) {
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| 		switch (ch) {
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| 		case 'a':
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| 			address = strtol(optarg, NULL, 0x10);
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| 			break;
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| 		case 'f':
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| 			device = optarg;
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| 			break;
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| 		case 'i':
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| 			iflag = 1;
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| 			break;
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| 		case 'n':
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| 			read_flags |= BDEV_NOPAGE;
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| 			break;
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| 		default:
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| 			break;
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| 		}
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| 	}
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| 
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| 	fd = open(device, O_RDWR);
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| 	if (fd == -1) {
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| 		fprintf(stderr, "open(): %s\n", strerror(errno));
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| 		return 1;
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| 	}
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| 
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| 	if (iflag == 1) {
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| 		r = board_info(fd, address, read_flags);
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| 		if (r == -1) {
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| 			fprintf(stderr, "board_info(): %s\n", strerror(errno));
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| 			return 1;
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| 		}
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| 	} else {
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| 		r = eeprom_dump(fd, address, read_flags);
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| 		if (r == -1) {
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| 			fprintf(stderr, "eeprom_dump(): %s\n", strerror(errno));
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| 			return 1;
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| 		}
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| 	}
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| 
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| 	r = close(fd);
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| 	if (r == -1) {
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| 		fprintf(stderr, "close(): %s\n", strerror(errno));
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| 		return 1;
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| 	}
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| 
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| 	return 0;
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| }
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| 
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