On Fri, May 10, 2024 at 10:13 PM Armin Wolf <W_Armin@xxxxxx> wrote: > > 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". > > Reviewed-by: Andy Shevchenko <andy@xxxxxxxxxx> > Signed-off-by: Armin Wolf <W_Armin@xxxxxx> > --- > Tested witha custom ACPI SSDT, available here: > https://github.com/Wer-Wolf/acpi-fan-ssdt > > Changes since v7: > - add Reviewed-by tag > - spelling fixes > - add missing types.h include > > Changes since v6: > - add "hwmon" to the names of functions and variables > related to hwmon > - replace -ENODATA with -EIO/-ENODEV > > Changes since v5: > - fix coding style issues > - replace double break with return > - add missing includes > > Changes since v4: > - fix spelling issues > - check power values for overflow condition too > > Changes since v3: > - drop fault attrs > - rework initialization > > Changes since v2: > - add support for fanX_target and power attrs > > Changes since v1: > - fix undefined reference error > - fix fan speed validation > - coding style fixes > - clarify that the changes are compile-tested only > - add hwmon maintainers to cc list > --- > drivers/acpi/Makefile | 1 + > drivers/acpi/fan.h | 9 +++ > drivers/acpi/fan_core.c | 4 + > drivers/acpi/fan_hwmon.c | 170 +++++++++++++++++++++++++++++++++++++++ > 4 files changed, 184 insertions(+) > create mode 100644 drivers/acpi/fan_hwmon.c > > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index 39ea5cfa8326..61ca4afe83dc 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -77,6 +77,7 @@ obj-$(CONFIG_ACPI_TINY_POWER_BUTTON) += tiny-power-button.o > obj-$(CONFIG_ACPI_FAN) += fan.o > fan-objs := fan_core.o > fan-objs += fan_attr.o > +fan-$(CONFIG_HWMON) += fan_hwmon.o > > obj-$(CONFIG_ACPI_VIDEO) += video.o > obj-$(CONFIG_ACPI_TAD) += acpi_tad.o > diff --git a/drivers/acpi/fan.h b/drivers/acpi/fan.h > index f89d19c922dc..db25a3898af7 100644 > --- a/drivers/acpi/fan.h > +++ b/drivers/acpi/fan.h > @@ -10,6 +10,8 @@ > #ifndef _ACPI_FAN_H_ > #define _ACPI_FAN_H_ > > +#include <linux/kconfig.h> > + > #define ACPI_FAN_DEVICE_IDS \ > {"INT3404", }, /* Fan */ \ > {"INTC1044", }, /* Fan for Tiger Lake generation */ \ > @@ -57,4 +59,11 @@ struct acpi_fan { > int acpi_fan_get_fst(struct acpi_device *device, struct acpi_fan_fst *fst); > int acpi_fan_create_attributes(struct acpi_device *device); > void acpi_fan_delete_attributes(struct acpi_device *device); > + > +#if IS_REACHABLE(CONFIG_HWMON) > +int devm_acpi_fan_create_hwmon(struct acpi_device *device); > +#else > +static inline int devm_acpi_fan_create_hwmon(struct acpi_device *device) { return 0; }; > +#endif > + > #endif > diff --git a/drivers/acpi/fan_core.c b/drivers/acpi/fan_core.c > index ff72e4ef8738..7cea4495f19b 100644 > --- a/drivers/acpi/fan_core.c > +++ b/drivers/acpi/fan_core.c > @@ -336,6 +336,10 @@ static int acpi_fan_probe(struct platform_device *pdev) > if (result) > return result; > > + result = devm_acpi_fan_create_hwmon(device); > + if (result) > + return result; > + > result = acpi_fan_create_attributes(device); > if (result) > return result; > diff --git a/drivers/acpi/fan_hwmon.c b/drivers/acpi/fan_hwmon.c > new file mode 100644 > index 000000000000..bd0d31a398fa > --- /dev/null > +++ b/drivers/acpi/fan_hwmon.c > @@ -0,0 +1,170 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * hwmon interface for the ACPI Fan driver. > + * > + * Copyright (C) 2024 Armin Wolf <W_Armin@xxxxxx> > + */ > + > +#include <linux/acpi.h> > +#include <linux/device.h> > +#include <linux/err.h> > +#include <linux/hwmon.h> > +#include <linux/limits.h> > +#include <linux/types.h> > +#include <linux/units.h> > + > +#include "fan.h" > + > +/* Returned when the ACPI fan does not support speed reporting */ > +#define FAN_SPEED_UNAVAILABLE U32_MAX > +#define FAN_POWER_UNAVAILABLE U32_MAX > + > +static struct acpi_fan_fps *acpi_fan_get_current_fps(struct acpi_fan *fan, u64 control) > +{ > + unsigned int i; > + > + 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_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + const struct acpi_fan *fan = drvdata; > + unsigned int i; AFAICS, the code below can be rewritten as follows: if (fan->fif.fine_grain_ctrl) return 0; switch (type) { case hwmon_fan: if (attr == hwmon_fan_input || attr == hwmon_fan_target) return 0444; return 0; case hwmon_power: if (attr == hwmon_power_input) { for (i = 0; i < fan->fps_count; i++) { if (fan->fps[i].power != FAN_POWER_UNAVAILABLE) return 0444; } } fallthrough; default: return 0; } without changing functionality, which is both less duplication and fewer lines of code. > + > + 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: > + return 0; > + } > + 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. > + */ > + 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: > + return 0; > + } > + default: > + return 0; > + } > +} > + > +static int acpi_fan_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, > + int channel, long *val) > +{ > + struct acpi_device *adev = to_acpi_device(dev->parent); > + struct acpi_fan *fan = dev_get_drvdata(dev); > + struct acpi_fan_fps *fps; > + struct acpi_fan_fst fst; > + int ret; > + > + ret = acpi_fan_get_fst(adev, &fst); > + if (ret < 0) > + return ret; > + > + switch (type) { > + case hwmon_fan: > + switch (attr) { > + case hwmon_fan_input: > + if (fst.speed == FAN_SPEED_UNAVAILABLE) > + return -ENODEV; > + > + 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 -EIO; > + > + if (fps->speed > LONG_MAX) > + return -EOVERFLOW; > + > + *val = fps->speed; > + return 0; > + default: > + return -EOPNOTSUPP; > + } > + case hwmon_power: > + switch (attr) { > + case hwmon_power_input: > + fps = acpi_fan_get_current_fps(fan, fst.control); > + if (!fps) > + return -EIO; > + > + if (fps->power == FAN_POWER_UNAVAILABLE) > + return -ENODEV; > + > + if (fps->power > LONG_MAX / MICROWATT_PER_MILLIWATT) > + return -EOVERFLOW; > + > + *val = fps->power * MICROWATT_PER_MILLIWATT; > + return 0; > + default: > + return -EOPNOTSUPP; > + } > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static const struct hwmon_ops acpi_fan_hwmon_ops = { > + .is_visible = acpi_fan_hwmon_is_visible, > + .read = acpi_fan_hwmon_read, > +}; > + > +static const struct hwmon_channel_info * const acpi_fan_hwmon_info[] = { > + HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET), > + HWMON_CHANNEL_INFO(power, HWMON_P_INPUT), > + NULL > +}; > + > +static const struct hwmon_chip_info acpi_fan_hwmon_chip_info = { > + .ops = &acpi_fan_hwmon_ops, > + .info = acpi_fan_hwmon_info, > +}; > + > +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_hwmon_chip_info, NULL); > + return PTR_ERR_OR_ZERO(hdev); > +} > -- > 2.39.2 > >
