From: Chu Lin <linchuyuan@xxxxxxxxxx> [ Upstream commit 6d1d41c075a1a54ba03370e268171fec20e06563 ] Issue: When PEC is enabled, binding adm1272 to the adm1275 would fail due to PEC error. See below: adm1275: probe of xxxx failed with error -74 Diagnosis: Per the datasheet of adm1272, adm1278, adm1293 and amd1294, PMON_CONFIG (0xd4) is 16bits wide. On the other hand, PMON_CONFIG (0xd4) for adm1275 is 8bits wide. The driver should not assume everything is 8bits wide and read only 8bits from it. Solution: If it is adm1272, adm1278, adm1293 and adm1294, use i2c_read_word. Else, use i2c_read_byte Testing: Binding adm1272 to the driver. The change is only tested on adm1272. Signed-off-by: Chu Lin <linchuyuan@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200709040612.3977094-1-linchuyuan@xxxxxxxxxx Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/hwmon/pmbus/adm1275.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c index e25f541227dae..19317575d1c6a 100644 --- a/drivers/hwmon/pmbus/adm1275.c +++ b/drivers/hwmon/pmbus/adm1275.c @@ -465,6 +465,7 @@ MODULE_DEVICE_TABLE(i2c, adm1275_id); static int adm1275_probe(struct i2c_client *client, const struct i2c_device_id *id) { + s32 (*config_read_fn)(const struct i2c_client *client, u8 reg); u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1]; int config, device_config; int ret; @@ -510,11 +511,16 @@ static int adm1275_probe(struct i2c_client *client, "Device mismatch: Configured %s, detected %s\n", id->name, mid->name); - config = i2c_smbus_read_byte_data(client, ADM1275_PMON_CONFIG); + if (mid->driver_data == adm1272 || mid->driver_data == adm1278 || + mid->driver_data == adm1293 || mid->driver_data == adm1294) + config_read_fn = i2c_smbus_read_word_data; + else + config_read_fn = i2c_smbus_read_byte_data; + config = config_read_fn(client, ADM1275_PMON_CONFIG); if (config < 0) return config; - device_config = i2c_smbus_read_byte_data(client, ADM1275_DEVICE_CONFIG); + device_config = config_read_fn(client, ADM1275_DEVICE_CONFIG); if (device_config < 0) return device_config; -- 2.25.1
