linux-toradex.git/drivers/hwmon/ltc2992.c, branch v7.2-rc5

hwmon: Use named initializers for arrays of i2c_device_data

2026-06-09T15:22:59+00:00

While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.

The mentioned robustness is relevant for a planned change to struct
i2c_device_id that replaces .driver_data by an anonymous union.

While touching all these arrays, unify indention and usage of commas.

This patch doesn't modify the compiled arrays, only their representation
in source form benefits. The former was confirmed with x86 and arm64
builds.

Signed-off-by: Uwe Kleine-König (The Capable Hub) 
Link: https://lore.kernel.org/r/65b77bcd452752c36d866069cc5790b26d2bf8dc.1778688803.git.u.kleine-koenig@baylibre.com
Signed-off-by: Guenter Roeck

hwmon: (ltc2992) Fix u32 overflow in power read path

2026-04-30T17:23:59+00:00

ltc2992_get_power() computes the divisor for mul_u64_u32_div() as
r_sense_uohm * 1000. This multiplication overflows u32 when
r_sense_uohm exceeds about 4.29 ohms (4294967 micro-ohms), producing
a truncated divisor and an incorrect power reading.

Cancel the factor of 1000 from both the numerator
(VADC_UV_LSB * IADC_NANOV_LSB = 312500000) and the divisor
(r_sense_uohm * 1000), giving (VADC_UV_LSB / 1000) * IADC_NANOV_LSB
= 312500 as the numerator and plain r_sense_uohm as the divisor.
The cancellation is exact because LTC2992_VADC_UV_LSB (25000) is
divisible by 1000.

This is the read-path counterpart of the write-path fix applied in
the preceding patch.

Fixes: b0bd407e94b03 ("hwmon: (ltc2992) Add support")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260416215904.101969-3-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck

hwmon: (ltc2992) Clamp threshold writes to hardware range

2026-04-30T17:22:48+00:00

ltc2992_set_voltage(), ltc2992_set_current(), and ltc2992_set_power()
do not validate the user-supplied value before converting it to a
register value. This can result in:

1. Negative input values wrapping to large positive register values.
   For power, the negative long is implicitly cast to u64 in
   mul_u64_u32_div(), producing an incorrect value. For voltage and
   current, the negative converted value wraps when passed to
   ltc2992_write_reg() as a u32.

2. Intermediate arithmetic exceeding the range representable in u64 on
   64-bit platforms. In ltc2992_set_voltage(), (u64)val * 1000 can
   exceed U64_MAX when val is a large positive long. In
   ltc2992_set_current(), (u64)val * r_sense_uohm can overflow
   similarly. In ltc2992_set_power(), the computed value may not fit
   in u64.

3. Register values exceeding the hardware field width. Voltage and
   current threshold registers are 12-bit (stored left-justified in
   16 bits), and power threshold registers are 24-bit. Without
   clamping, bits above the field width are truncated in
   ltc2992_write_reg().

Fix by clamping negative values to zero, clamping positive values to
the rounded hardware-representable maximum (the value returned by the
read path for a full-scale register) to prevent intermediate overflow,
and clamping the converted register value to the hardware field width
before writing. The existing conversion formula and rounding behavior
are preserved.

In the power write path, cancel the factor of 1000 from both the
numerator (r_sense_uohm * 1000) and the denominator
(VADC_UV_LSB * IADC_NANOV_LSB) to also eliminate a u32 overflow of
r_sense_uohm * 1000 when r_sense_uohm exceeds about 4.29 ohms.

Fixes: b0bd407e94b03 ("hwmon: (ltc2992) Add support")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan 
Link: https://lore.kernel.org/r/20260416215904.101969-2-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck

treewide: rename GPIO set callbacks back to their original names

2025-08-07T08:07:06+00:00

The conversion of all GPIO drivers to using the .set_rv() and
.set_multiple_rv() callbacks from struct gpio_chip (which - unlike their
predecessors - return an integer and allow the controller drivers to
indicate failures to users) is now complete and the legacy ones have
been removed. Rename the new callbacks back to their original names in
one sweeping change.

Signed-off-by: Bartosz Golaszewski

hwmon: (ltc2992) Use new GPIO line value setter callbacks

2025-04-23T14:18:27+00:00

struct gpio_chip now has callbacks for setting line values that return
an integer, allowing to indicate failures. Convert the driver to using
them.

Signed-off-by: Bartosz Golaszewski 
Link: https://lore.kernel.org/r/20250407-gpiochip-set-rv-hwmon-v1-1-1fa38f34dc07@linaro.org
Reviewed-by: Linus Walleij 
[groeck: Fixed multi-line alignment issue]
Signed-off-by: Guenter Roeck

hwmon: (ltc2992) use device_for_each_child_node_scoped() to access child nodes

2024-07-31T17:43:52+00:00

The iterated nodes are direct children of the device node, and the
`device_for_each_child_node()` macro accounts for child node
availability.

`fwnode_for_each_available_child_node()` is meant to access the child
nodes of an fwnode, and therefore not direct child nodes of the device
node.

In this case, the child nodes are not required outside the loop, and
the scoped version of the macro can be used to remove the repetitive
`goto put` pattern.

Use `device_for_each_child_node_scoped_scoped()` to indicate device's
direct child nodes.

Reviewed-by: Jonathan Cameron 
Signed-off-by: Javier Carrasco 
Link: https://lore.kernel.org/r/20240721-device_for_each_child_node-available-v2-2-f33748fd8b2d@gmail.com
Signed-off-by: Guenter Roeck

hwmon: (ltc2992) Fix memory leak in ltc2992_parse_dt()

2024-05-29T22:34:46+00:00

A new error path was added to the fwnode_for_each_available_node() loop
in ltc2992_parse_dt(), which leads to an early return that requires a
call to fwnode_handle_put() to avoid a memory leak in that case.

Add the missing fwnode_handle_put() in the error path from a zero value
shunt resistor.

Cc: stable@vger.kernel.org
Fixes: 10b029020487 ("hwmon: (ltc2992) Avoid division by zero")
Signed-off-by: Javier Carrasco 
Link: https://lore.kernel.org/r/20240523-fwnode_for_each_available_child_node_scoped-v2-1-701f3a03f2fb@gmail.com
Signed-off-by: Guenter Roeck

hwmon: Drop explicit initialization of struct i2c_device_id::driver_data to 0

2024-05-01T14:47:49+00:00

These drivers don't use the driver_data member of struct i2c_device_id,
so don't explicitly initialize this member.

This prepares putting driver_data in an anonymous union which requires
either no initialization or named designators. But it's also a nice
cleanup on its own.

Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20240430085654.1028864-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Guenter Roeck

hwmon: (ltc2992) Avoid division by zero

2023-10-28T16:21:36+00:00

Do not allow setting shunt resistor to 0. This results in a division by
zero when performing current value computations based on input voltages
and connected resistor values.

Signed-off-by: Antoniu Miclaus 
Link: https://lore.kernel.org/r/20231011135754.13508-1-antoniu.miclaus@analog.com
Signed-off-by: Guenter Roeck

hwmon: Switch i2c drivers back to use .probe()

2023-06-08T13:41:17+00:00

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20230505131718.1210071-1-u.kleine-koenig@pengutronix.de
[groeck: Added missing change in pmbus/acbel-fsg032.c]
Signed-off-by: Guenter Roeck