diff options
Diffstat (limited to 'drivers/misc/eeprom/ee1004.c')
| -rw-r--r-- | drivers/misc/eeprom/ee1004.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c index 140bcb20f091..d4aeeb2b2169 100644 --- a/drivers/misc/eeprom/ee1004.c +++ b/drivers/misc/eeprom/ee1004.c @@ -186,14 +186,31 @@ static void ee1004_probe_temp_sensor(struct i2c_client *client) struct i2c_board_info info = { .type = "jc42" }; unsigned short addr = 0x18 | (client->addr & 7); unsigned short addr_list[] = { addr, I2C_CLIENT_END }; - u8 byte14; + u8 data[2]; int ret; /* byte 14, bit 7 is set if temp sensor is present */ - ret = ee1004_eeprom_read(client, &byte14, 14, 1); - if (ret != 1 || !(byte14 & BIT(7))) + ret = ee1004_eeprom_read(client, data, 14, 1); + if (ret != 1) return; + if (!(data[0] & BIT(7))) { + /* + * If the SPD data suggests that there is no temperature + * sensor, it may still be there for SPD revision 1.0. + * See SPD Annex L, Revision 1 and 2, for details. + * Check DIMM type and SPD revision; if it is a DDR4 + * with SPD revision 1.0, check the thermal sensor address + * and instantiate the jc42 driver if a chip is found at + * that address. + * It is not necessary to check if there is a chip at the + * temperature sensor address since i2c_new_scanned_device() + * will do that and return silently if no chip is found. + */ + ret = ee1004_eeprom_read(client, data, 1, 2); + if (ret != 2 || data[0] != 0x10 || data[1] != 0x0c) + return; + } i2c_new_scanned_device(client->adapter, &info, addr_list, NULL); } |