eeprom: at24: fix reading from 24MAC402/24MAC602

Chip datasheet mentions that word addresses other than the actual
start position of the MAC delivers undefined results. So fix this.
Current implementation doesn't work due to this wrong offset.

Cc: stable@vger.kernel.org
Fixes: 0b813658c115 ("eeprom: at24: add support for at24mac series")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 783244b485ccdce70c197026e633370712b5178c..8ca6772b3baf386ca235f31c3559c3f28904d2b2 100644 (file)
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -425,7 +425,8 @@ static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf,
        memset(msg, 0, sizeof(msg));
        msg[0].addr = client->addr;
        msg[0].buf = addrbuf;
-       addrbuf[0] = 0x90 + offset;
+       /* EUI-48 starts from 0x9a, EUI-64 from 0x98 */
+       addrbuf[0] = 0xa0 - at24->chip.byte_len + offset;
        msg[0].len = 1;
        msg[1].addr = client->addr;
        msg[1].flags = I2C_M_RD;