[PATCH v3] iio: humidity: ens210: Fix missing I2C functionality checks
From: Salah Triki
Date: Tue May 05 2026 - 13:53:38 EST
The ENS210 driver uses SMBus transactions (such as byte, word, and block
data reads/writes) during the probe and measurement phases. However, the
initial functionality check only validated a subset of these capabilities,
which could lead to loading failures on adapters requiring SMBus
emulation or native-only controllers.
To ensure compatibility across a wide range of I2C adapters, modify the
functionality check to verify if the adapter supports the required native
operations or, failing that, supports the SMBus emulation layer.
Fixes: c524fbca672e ("iio: humidity: Add support for ENS210")
Signed-off-by: Salah Triki <salah.triki@xxxxxxxxx>
---
Changes since v2:
- Fixed the alignment and indentation of the I2C functionality check
per Maxime's review.
Changes since v1:
- Updated the I2C functionality test to check for both required native
operations and SMBus emulation (`I2C_FUNC_SMBUS_EMUL`) to prevent
loading issues on controllers lacking the emulation flag.
drivers/iio/humidity/ens210.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/humidity/ens210.c b/drivers/iio/humidity/ens210.c
index 77418d97f30d..07925bed2bea 100644
--- a/drivers/iio/humidity/ens210.c
+++ b/drivers/iio/humidity/ens210.c
@@ -202,9 +202,13 @@ static int ens210_probe(struct i2c_client *client)
int ret;
if (!i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
- I2C_FUNC_SMBUS_WRITE_BYTE |
- I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+ I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
+ I2C_FUNC_SMBUS_WRITE_BYTE |
+ I2C_FUNC_SMBUS_READ_BYTE_DATA |
+ I2C_FUNC_SMBUS_READ_WORD_DATA |
+ I2C_FUNC_SMBUS_READ_I2C_BLOCK) &&
+ !i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_EMUL)) {
return dev_err_probe(&client->dev, -EOPNOTSUPP,
"adapter does not support some i2c transactions\n");
}
--
2.43.0