linux-toradex.git/drivers/hwmon/pmbus, branch master

hwmon: (tps53679) Fix device ID comparison and printing in tps53676_identify()

2026-03-30T17:46:53+00:00

tps53676_identify() uses strncmp() to compare the device ID buffer
against a byte sequence containing embedded non-printable bytes
(\x53\x67\x60). strncmp() is semantically wrong for binary data
comparison; use memcmp() instead.

Additionally, the buffer from i2c_smbus_read_block_data() is not
NUL-terminated, so printing it with "%s" in the error path is
undefined behavior and may read past the buffer. Use "%*ph" to
hex-dump the actual bytes returned.

Per the datasheet, the expected device ID is the 6-byte sequence
54 49 53 67 60 00 ("TI\x53\x67\x60\x00"), so compare all 6 bytes
including the trailing NUL.

Fixes: cb3d37b59012 ("hwmon: (pmbus/tps53679) Add support for TI TPS53676")
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260330155618.77403-1-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck

hwmon: (ltc4286) Add missing MODULE_IMPORT_NS("PMBUS")

2026-03-30T02:04:16+00:00

ltc4286.c uses PMBus core symbols exported in the PMBUS namespace,
such as pmbus_do_probe(), but does not declare MODULE_IMPORT_NS("PMBUS").

Add the missing namespace import to avoid modpost warnings.

Fixes: 0c459759ca97 ("hwmon: (pmbus) Add ltc4286 driver")
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260329170925.34581-5-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck

hwmon: (pxe1610) Check return value of page-select write in probe

2026-03-30T02:04:16+00:00

pxe1610_probe() writes PMBUS_PAGE to select page 0 but does not check
the return value. If the write fails, subsequent register reads operate
on an indeterminate page, leading to silent misconfiguration.

Check the return value and propagate the error using dev_err_probe(),
which also handles -EPROBE_DEFER correctly without log spam.

Fixes: 344757bac526 ("hwmon: (pmbus) Add Infineon PXE1610 VR driver")
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260329170925.34581-4-sanman.pradhan@hpe.com
[groeck: Fix "Fixes" SHA]
Signed-off-by: Guenter Roeck

hwmon: (tps53679) Fix array access with zero-length block read

2026-03-30T02:04:16+00:00

i2c_smbus_read_block_data() can return 0, indicating a zero-length
read. When this happens, tps53679_identify_chip() accesses buf[ret - 1]
which is buf[-1], reading one byte before the buffer on the stack.

Fix by changing the check from "ret < 0" to "ret <= 0", treating a
zero-length read as an error (-EIO), which prevents the out-of-bounds
array access.

Also fix a typo in the adjacent comment: "if present" instead of
duplicate "if".

Fixes: 75ca1e5875fe ("hwmon: (pmbus/tps53679) Add support for TPS53685")
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260329170925.34581-2-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck

hwmon: (pmbus/core) Protect regulator operations with mutex

2026-03-25T20:32:37+00:00

The regulator operations pmbus_regulator_get_voltage(),
pmbus_regulator_set_voltage(), and pmbus_regulator_list_voltage()
access PMBus registers and shared data but were not protected by
the update_lock mutex. This could lead to race conditions.

However, adding mutex protection directly to these functions causes
a deadlock because pmbus_regulator_notify() (which calls
regulator_notifier_call_chain()) is often called with the mutex
already held (e.g., from pmbus_fault_handler()). If a regulator
callback then calls one of the now-protected voltage functions,
it will attempt to acquire the same mutex.

Rework pmbus_regulator_notify() to utilize a worker function to
send notifications outside of the mutex protection. Events are
stored as atomics in a per-page bitmask and processed by the worker.

Initialize the worker and its associated data during regulator
registration, and ensure it is cancelled on device removal using
devm_add_action_or_reset().

While at it, remove the unnecessary include of linux/of.h.

Cc: Sanman Pradhan 
Fixes: ddbb4db4ced1b ("hwmon: (pmbus) Add regulator support")
Reviewed-by: Sanman Pradhan 
Signed-off-by: Guenter Roeck

hwmon: (pmbus) Introduce the concept of "write-only" attributes

2026-03-25T20:32:33+00:00

Attributes intended to clear sensor history are intended to be writeable
only. Reading those attributes today results in reporting more or less
random values. To avoid ABI surprises, have those attributes explicitly
return 0 when reading.

Fixes: 787c095edaa9d ("hwmon: (pmbus/core) Add support for rated attributes")
Reviewed-by: Sanman Pradhan 
Signed-off-by: Guenter Roeck

hwmon: (pmbus) Mark lowest/average/highest/rated attributes as read-only

2026-03-25T20:32:24+00:00

Writing those attributes is not supported, so mark them as read-only.

Prior to this change, attempts to write into these attributes returned
an error.

Mark boolean fields in struct pmbus_limit_attr and in struct
pmbus_sensor_attr as bit fields to reduce configuration data size.
The data is scanned only while probing, so performance is not a concern.

Fixes: 6f183d33a02e6 ("hwmon: (pmbus) Add support for peak attributes")
Reviewed-by: Sanman Pradhan 
Signed-off-by: Guenter Roeck

hwmon: (pmbus/isl68137) Add mutex protection for AVS enable sysfs attributes

2026-03-24T14:55:34+00:00

The custom avs0_enable and avs1_enable sysfs attributes access PMBus
registers through the exported API helpers (pmbus_read_byte_data,
pmbus_read_word_data, pmbus_write_word_data, pmbus_update_byte_data)
without holding the PMBus update_lock mutex. These exported helpers do
not acquire the mutex internally, unlike the core's internal callers
which hold the lock before invoking them.

The store callback is especially vulnerable: it performs a multi-step
read-modify-write sequence (read VOUT_COMMAND, write VOUT_COMMAND, then
update OPERATION) where concurrent access from another thread could
interleave and corrupt the register state.

Add pmbus_lock_interruptible()/pmbus_unlock() around both the show and
store callbacks to serialize PMBus register access with the rest of the
driver.

Fixes: 038a9c3d1e424 ("hwmon: (pmbus/isl68137) Add driver for Intersil ISL68137 PWM Controller")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260319173055.125271-3-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck

hwmon: (pmbus/ina233) Fix error handling and sign extension in shunt voltage read

2026-03-24T14:55:08+00:00

ina233_read_word_data() reads MFR_READ_VSHUNT via pmbus_read_word_data()
but has two issues:

1. The return value is not checked for errors before being used in
   arithmetic. A negative error code from a failed I2C transaction is
   passed directly to DIV_ROUND_CLOSEST(), producing garbage data.

2. MFR_READ_VSHUNT is a 16-bit two's complement value. Negative shunt
   voltages (values with bit 15 set) are treated as large positive
   values since pmbus_read_word_data() returns them zero-extended in an
   int. This leads to incorrect scaling in the VIN coefficient
   conversion.

Fix both issues by adding an error check, casting to s16 for proper
sign extension, and clamping the result to a valid non-negative range.
The clamp is necessary because read_word_data callbacks must return
non-negative values on success (negative values indicate errors to the
pmbus core).

Fixes: b64b6cb163f16 ("hwmon: Add driver for TI INA233 Current and Power Monitor")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260319173055.125271-2-sanman.pradhan@hpe.com
[groeck: Fixed clamp to avoid losing the sign bit]
Signed-off-by: Guenter Roeck

hwmon: (pmbus/isl68137) Fix unchecked return value and use sysfs_emit()

2026-03-18T20:38:55+00:00

isl68137_avs_enable_show_page() uses the return value of
pmbus_read_byte_data() without checking for errors. If the I2C transaction
fails, a negative error code is passed through bitwise operations,
producing incorrect output.

Add an error check to propagate the return value if it is negative.
Additionally, modernize the callback by replacing sprintf()
with sysfs_emit().

Fixes: 038a9c3d1e424 ("hwmon: (pmbus/isl68137) Add driver for Intersil ISL68137 PWM Controller")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260318193952.47908-2-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck