From: Chu Lin linchuyuan@google.com
[ 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@google.com Link: https://lore.kernel.org/r/20200709040612.3977094-1-linchuyuan@google.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5caa37fbfc187..66b12e5ccbc65 100644 --- a/drivers/hwmon/pmbus/adm1275.c +++ b/drivers/hwmon/pmbus/adm1275.c @@ -454,6 +454,7 @@ 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; @@ -499,11 +500,16 @@ 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;