Mon, Apr 22, 2024 at 08:08:35AM +0200, Armin Wolf kirjoitti:
> Currently, the driver does only support a custom sysfs
> interface to allow userspace to read the fan speed.
> Add support for the standard hwmon interface so users
> can read the fan speed with standard tools like "sensors".
>
> Tested with a custom ACPI SSDT.
...
> +/*
> + * fan_hwmon.c - hwmon interface for the ACPI Fan driver
No file name in the file, it makes an unneeded burden if file is going to be
renamed.
> + *
> + * Copyright (C) 2024 Armin Wolf <W_Armin@xxxxxx>
> + */
...
> +#include <linux/acpi.h>
> +#include <linux/hwmon.h>
Please, follow IWYU pronciple, e.g., missing err.h here.
> +#include <linux/limits.h>
> +#include <linux/units.h>
...
> +/* Returned when the ACPI fan does not support speed reporting */
> +#define FAN_SPEED_UNAVAILABLE 0xffffffff
> +#define FAN_POWER_UNAVAILABLE 0xffffffff
Shouldn't these be rather as ~0 of the respective types or _MAX (from limits.h)
or something like that?
...
> +static struct acpi_fan_fps *acpi_fan_get_current_fps(struct acpi_fan *fan, u64 control)
> +{
> + int i;
unsigned
> + for (i = 0; i < fan->fps_count; i++) {
> + if (fan->fps[i].control == control)
> + return &fan->fps[i];
> + }
> +
> + return NULL;
> +}
...
> +static umode_t acpi_fan_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
> + int channel)
> +{
> + const struct acpi_fan *fan = drvdata;
> + int i;
unsigned
> + switch (type) {
> + case hwmon_fan:
> + switch (attr) {
> + case hwmon_fan_input:
> + return 0444;
> + case hwmon_fan_target:
> + /* When in fine grain control mode, not every fan control value
> + * has an associated fan performance state.
> + */
> + if (fan->fif.fine_grain_ctrl)
> + return 0;
> +
> + return 0444;
> + default:
> + break;
> + }
> + break;
Instead of two breaks, just return 0 from 'default' case.
> + case hwmon_power:
> + switch (attr) {
> + case hwmon_power_input:
> + /* When in fine grain control mode, not every fan control value
> + * has an associated fan performance state.
> + */
/*
* Use correct style for multi-line
* comment blocks. As in this example.
*/
> + if (fan->fif.fine_grain_ctrl)
> + return 0;
> +
> + /* When all fan performance states contain no valid power data,
> + * when the associated attribute should not be created.
> + */
> + for (i = 0; i < fan->fps_count; i++) {
> + if (fan->fps[i].power != FAN_POWER_UNAVAILABLE)
> + return 0444;
> + }
> +
> + return 0;
> + default:
> + break;
> + }
> + break;
Ditto.
> + default:
> + break;
> + }
> +
> + return 0;
Return from the default.
With the above we got rid of 2 LoCs for free.
> +}
...
> + switch (type) {
> + case hwmon_fan:
> + switch (attr) {
> + case hwmon_fan_input:
> + if (fst.speed == FAN_SPEED_UNAVAILABLE)
> + return -ENODATA;
> +
> + if (fst.speed > LONG_MAX)
> + return -EOVERFLOW;
> +
> + *val = fst.speed;
> + return 0;
> + case hwmon_fan_target:
> + fps = acpi_fan_get_current_fps(fan, fst.control);
> + if (!fps)
> + return -ENODATA;
> +
> + if (fps->speed > LONG_MAX)
> + return -EOVERFLOW;
> +
> + *val = fps->speed;
> + return 0;
> + default:
> + break;
> + }
> + break;
As per above.
> + case hwmon_power:
> + switch (attr) {
> + case hwmon_power_input:
> + fps = acpi_fan_get_current_fps(fan, fst.control);
> + if (!fps)
> + return -ENODATA;
> +
> + if (fps->power == FAN_POWER_UNAVAILABLE)
> + return -ENODATA;
> +
> + if (fps->power > LONG_MAX / MICROWATT_PER_MILLIWATT)
> + return -EOVERFLOW;
> +
> + *val = fps->power * MICROWATT_PER_MILLIWATT;
> + return 0;
> + default:
> + break;
> + }
> + break;
Ditto.
> + default:
> + break;
> + }
> +
> + return -EOPNOTSUPP;
Ditto.
Again, 2 LoCs less here.
> +}
...
> +int devm_acpi_fan_create_hwmon(struct acpi_device *device)
> +{
> + struct acpi_fan *fan = acpi_driver_data(device);
> + struct device *hdev;
> +
> + hdev = devm_hwmon_device_register_with_info(&device->dev, "acpi_fan", fan,
> + &acpi_fan_chip_info, NULL);
> +
Redundant blank line.
> + return PTR_ERR_OR_ZERO(hdev);
> +}
--
With Best Regards,
Andy Shevchenko
