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@xxxxxx> --- 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@xxxxxx> + */ + +#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
