Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 12 Apr 2024 22:27:56 +0200 | Subject | Re: [PATCH v3 2/2] ACPI: fan: Add hwmon support | From | Armin Wolf <> |
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Am 12.04.24 um 18:41 schrieb Guenter Roeck:
> On Fri, Apr 12, 2024 at 06:08:57PM +0200, Armin Wolf wrote: >> Currently, the driver does only support a custom sysfs >> 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". >> >> Compile-tested only. >> >> Signed-off-by: Armin Wolf <W_Armin@gmx.de> >> --- >> 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 >> >> The changes will be tested by Mikael Lund Jepsen from Danelec and >> should be merged only after those tests. >> --- >> drivers/acpi/Makefile | 1 + >> drivers/acpi/fan.h | 9 +++ >> drivers/acpi/fan_core.c | 4 ++ >> drivers/acpi/fan_hwmon.c | 148 +++++++++++++++++++++++++++++++++++++++ >> 4 files changed, 162 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..57216ba872db >> --- /dev/null >> +++ b/drivers/acpi/fan_hwmon.c >> @@ -0,0 +1,148 @@ >> +// SPDX-License-Identifier: GPL-2.0-or-later >> +/* >> + * fan_hwmon.c - hwmon interface for the ACPI Fan driver >> + * >> + * Copyright (C) 2024 Armin Wolf <W_Armin@gmx.de> >> + */ >> + >> +#include <linux/acpi.h> >> +#include <linux/hwmon.h> >> +#include <linux/limits.h> >> +#include <linux/units.h> >> + >> +#include "fan.h" >> + >> +/* Returned when the ACPI fan does not support speed reporting */ >> +#define FAN_SPEED_UNAVAILABLE 0xffffffff >> +#define FAN_POWER_UNAVAILABLE 0xffffffff >> + >> +static struct acpi_fan_fps *acpi_fan_get_current_fps(struct acpi_fan *fan, u64 control) >> +{ >> + 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_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr, >> + int channel) >> +{ >> + return 0444; >> +} >> + >> +static int acpi_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, >> + long *val) >> +{ >> + struct acpi_device *adev = dev_get_drvdata(dev); >> + struct acpi_fan *fan = acpi_driver_data(adev); >> + 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 -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; >> + >> + *val = fps->speed; >> + return 0; >> + case hwmon_fan_fault: >> + *val = (fst.speed == FAN_SPEED_UNAVAILABLE); > Is it documented that this is indeed a fault (broken fan) ? > Hi,
it actually means that the fan does not support speed reporting.
>> + return 0; >> + default: >> + break; >> + } >> + break; >> + case hwmon_power: >> + fps = acpi_fan_get_current_fps(fan, fst.control); >> + if (!fps) >> + return -ENODATA; >> + >> + switch (attr) { >> + case hwmon_power_input: >> + 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; >> + case hwmon_power_fault: >> + *val = (fps->power == FAN_POWER_UNAVAILABLE); > Is it documented that this is indeed a power supply failure ? > What if the value is simply not reported ? "UNAVAILABLE" is not > commonly associated with a "fault". > > Guenter > FAN_POWER_UNAVAILABLE signals that the power value is not supported. Would it be more suitable to drop the fault attributes and just return -ENODATA in such a case?
Thanks, Armin Wolf
>> + return 0; >> + default: >> + break; >> + } >> + break; >> + default: >> + break; >> + } >> + >> + return -EOPNOTSUPP; >> +} >> + >> +static const struct hwmon_ops acpi_fan_ops = { >> + .is_visible = acpi_fan_is_visible, >> + .read = acpi_fan_read, >> +}; >> + >> +static const struct hwmon_channel_info * const acpi_fan_info[] = { >> + HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT), >> + HWMON_CHANNEL_INFO(power, HWMON_P_INPUT | HWMON_P_FAULT), >> + NULL >> +}; >> + >> +static const struct hwmon_chip_info acpi_fan_chip_info = { >> + .ops = &acpi_fan_ops, >> + .info = acpi_fan_info, >> +}; >> + >> +static const struct hwmon_channel_info * const acpi_fan_fine_grain_info[] = { >> + HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_FAULT), >> + NULL >> +}; >> + >> +static const struct hwmon_chip_info acpi_fan_fine_grain_chip_info = { >> + .ops = &acpi_fan_ops, >> + .info = acpi_fan_fine_grain_info, >> +}; >> + >> +int devm_acpi_fan_create_hwmon(struct acpi_device *device) >> +{ >> + struct acpi_fan *fan = acpi_driver_data(device); >> + const struct hwmon_chip_info *info; >> + struct device *hdev; >> + >> + /* When in fine grain control mode, not every fan control value >> + * has an associated fan performance state. >> + */ >> + if (fan->fif.fine_grain_ctrl) >> + info = &acpi_fan_fine_grain_chip_info; >> + else >> + info = &acpi_fan_chip_info; >> + >> + hdev = devm_hwmon_device_register_with_info(&device->dev, "acpi_fan", device, info, NULL); >> + >> + return PTR_ERR_OR_ZERO(hdev); >> +} >> -- >> 2.39.2 >>
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