diff options
| author | Qingshuang Fu <fuqingshuang@kylinos.cn> | 2026-08-05 14:16:45 +0800 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2026-08-06 22:37:44 -0700 |
| commit | fddb5ceaf901b050ed2a1a7deeecbf97e003435a (patch) | |
| tree | e323b86f1913dfcbf1ee7b8bcf4be875d01f69b0 | |
| parent | 36c4d73ce05d1d8896c2669eb0730d35a02a2ec1 (diff) | |
hwmon: (ads7828) Fix external VREF regulator handling
The driver currently has two issues with the external VREF regulator
handling in ads7828_probe():
1. All errors from devm_regulator_get_optional() are ignored, causing the
driver to incorrectly fall back to internal VREF even for transient
errors like -EPROBE_DEFER or genuine failures like -ENOMEM.
2. The external regulator is never enabled. The driver calls
regulator_get_voltage() without first calling regulator_enable(),
so the VREF pin may remain unpowered if the regulator is not
configured as always-on.
Fix both issues by switching to devm_regulator_get_enable_read_voltage(),
which handles regulator get, enable, and voltage read in one call.
Only -ENODEV (no regulator specified in device tree) should trigger the
fallback to internal VREF. All other errors are propagated to the caller.
Fixes: a8ddfea09566 ("hwmon: (ads7828) Accept optional parameters from device tree")
Signed-off-by: Qingshuang Fu <fuqingshuang@kylinos.cn>
Link: https://lore.kernel.org/r/20260805061645.1331652-1-fffsqian@163.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
| -rw-r--r-- | drivers/hwmon/ads7828.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c index 149cfcec78dc..f8f2f621dfea 100644 --- a/drivers/hwmon/ads7828.c +++ b/drivers/hwmon/ads7828.c @@ -106,12 +106,11 @@ static int ads7828_probe(struct i2c_client *client) struct ads7828_data *data; struct device *hwmon_dev; unsigned int vref_mv = ADS7828_INT_VREF_MV; - unsigned int vref_uv; + int vref_uv; bool diff_input = false; bool ext_vref = false; unsigned int regval; enum ads7828_chips chip; - struct regulator *reg; data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL); if (!data) @@ -125,9 +124,11 @@ static int ads7828_probe(struct i2c_client *client) } else if (dev->of_node) { diff_input = of_property_read_bool(dev->of_node, "ti,differential-input"); - reg = devm_regulator_get_optional(dev, "vref"); - if (!IS_ERR(reg)) { - vref_uv = regulator_get_voltage(reg); + vref_uv = devm_regulator_get_enable_read_voltage(dev, "vref"); + if (vref_uv < 0) { + if (vref_uv != -ENODEV) + return vref_uv; + } else { vref_mv = DIV_ROUND_CLOSEST(vref_uv, 1000); if (vref_mv < ADS7828_EXT_VREF_MV_MIN || vref_mv > ADS7828_EXT_VREF_MV_MAX) |