On Mon, Apr 22, 2024 at 9:36 AM Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > > 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. I agree here, but for a different reason. If all of the other cases return from the function, the default one should return either unless there is a specific reason not to. IIUC, there's no such reason in this 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. > */ Yes, please. Thanks!