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lrwxrwxrwx root     root              2021-01-01 00:21 driver -> ../../../bus/w1/drivers/w1_slave_driver
-rw-rw-rw- root     root          128 2021-01-01 00:21 eeprom
-r--r--r-- root     root         4096 2021-01-01 00:21 id
-r--r--r-- root     root         4096 2021-01-01 00:21 name
lrwxrwxrwx root     root              2021-01-01 00:21 subsystem -> ../../../bus/w1
-rw-r--r-- root     root         4096 2021-01-01 00:21 uevent

cat eeprom 

/system/bin/sh: cat: eeprom: I/O error

static int w1_f0d_write(struct w1_slave *sl, int addr, int len, const u8 *data)
{
	int tries = W1_F0D_READ_RETRIES;
	u8 wrbuf[3];
	u8 rdbuf[W1_F0D_SCRATCH_SIZE];
	u8 cs;
	if ((addr & 1) || (len != 2)) {
		dev_err(&sl->dev, "%s: bad addr/len -  addr=%#x len=%d\n",
		    __func__, addr, len);
		return -1;
	}
retry:
	if (w1_reset_select_slave(sl)) {
		if (--tries)
			goto retry;
	}
	wrbuf[0] = W1_F0D_WRITE_EEPROM;
	wrbuf[1] = addr & 0xff;
	wrbuf[2] = 0xff; 
	w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
	w1_write_block(sl->master, data, len);
	w1_read_block(sl->master, rdbuf, sizeof(rdbuf));

	if ((rdbuf[0] != data[0]) || (rdbuf[1] != data[1])) {
		if (--tries)
			goto retry;
		dev_err(&sl->dev,
			"could not write to eeprom, scratchpad compare failed %d times\n",
			W1_F0D_READ_RETRIES);
		pr_info("%s: rdbuf = %#x %#x data = %#x %#x\n",
		    __func__, rdbuf[0], rdbuf[1], data[0], data[1]);
		return -1;
	}

	w1_write_8(sl->master, W1_F0D_RELEASE);
	msleep(W1_F0D_TPROG_MS);
	cs = w1_read_8(sl->master);
	if (cs != W1_F0D_CS_OK) {
		if (--tries)
			goto retry;
		dev_err(&sl->dev, "save to eeprom failed = CS=%#x\n", cs);
		return -1;
	}
	return 0;
}

static ssize_t w1_f0d_write_bin(struct file *filp, struct kobject *kobj,
				struct bin_attribute *bin_attr,
				char *buf, loff_t off, size_t count)
{
	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	int addr, len;
	int copy;
	count = w1_f0d_fix_count(off, count, W1_F0D_EEPROM_SIZE);
	if (count == 0)
		return 0;
	mutex_lock(&sl->master->mutex);
	addr = off;
	len = count;
	while (len > 0) {
		if (len < W1_F0D_SCRATCH_SIZE || addr & W1_F0D_SCRATCH_MASK) {
			char tmp[W1_F0D_SCRATCH_SIZE];
			if (w1_f0d_readblock(sl, addr & ~W1_F0D_SCRATCH_MASK,
					W1_F0D_SCRATCH_SIZE, tmp)) {
				count = -EIO;
				goto out_up;
			}
			copy = W1_F0D_SCRATCH_SIZE -
				(addr & W1_F0D_SCRATCH_MASK);
			if (copy > len)
				copy = len;
			memcpy(&tmp[addr & W1_F0D_SCRATCH_MASK], buf, copy);
			if (w1_f0d_write(sl, addr & ~W1_F0D_SCRATCH_MASK,
					W1_F0D_SCRATCH_SIZE, tmp) < 0) {
				count = -EIO;
				goto out_up;
			}
		} else {
			copy = W1_F0D_SCRATCH_SIZE;
			if (w1_f0d_write(sl, addr, copy, buf) < 0) {
				count = -EIO;
				goto out_up;
			}
		}
		buf += copy;
		addr += copy;
		len -= copy;
	}
out_up:
	mutex_unlock(&sl->master->mutex);
	return count;
}