IBASE SMARC-EVK1 - Manual (Page 74)

48 SMARC Evaluation Kit
vmask = strtol(maskp, &end, 0);
if (*end || vmask == 0) {
fprintf(stderr, "Error: Data value mask invalid!\n");
help();
}
if (((size == I2C_SMBUS_BYTE || size == I2C_SMBUS_BYTE_DATA)
&& vmask > 0xff) || vmask > 0xffff) {
fprintf(stderr, "Error: Data value mask out of range!\n");
help();
}
}
file = open_i2c_dev(i2cbus, filename, sizeof(filename), 0);
if (file < 0
|| check_funcs(file, size, pec)
|| set_slave_addr(file, address, force))
exit(1);
if (!yes && !confirm(filename, address, size, daddress,
value, vmask, block, len, pec))
exit(0);
if (vmask) {
int oldvalue;
switch (size) {
case I2C_SMBUS_BYTE:
oldvalue = i2c_smbus_read_byte(file);
break;
case I2C_SMBUS_WORD_DATA:
oldvalue = i2c_smbus_read_word_data(file, daddress);
break;
default:
oldvalue = i2c_smbus_read_byte_data(file, daddress);
}
if (oldvalue < 0) {
fprintf(stderr, "Error: Failed to read old value\n");
exit(1);
}
value = (value & vmask) | (oldvalue & ~vmask);
if (!yes) {
fprintf(stderr, "Old value 0x%0*x, write mask "
"0x%0*x: Will write 0x%0*x to register "
"0x%02x\n",
size == I2C_SMBUS_WORD_DATA ? 4 : 2, oldvalue,
size == I2C_SMBUS_WORD_DATA ? 4 : 2, vmask,
size == I2C_SMBUS_WORD_DATA ? 4 : 2, value,
daddress);
fprintf(stderr, "Continue? [Y/n] ");
fflush(stderr);
if (!user_ack(1)) {
fprintf(stderr, "Aborting on user request.\n");
exit(0);
}
}
}
if (pec && ioctl(file, I2C_PEC, 1) < 0) {
fprintf(stderr, "Error: Could not set PEC: %s\n",
strerror(errno));
close(file);
exit(1);
}
switch (size) {
case I2C_SMBUS_BYTE:
res = i2c_smbus_write_byte(file, daddress);