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.
Signed-off-by: Armin Wolf <[email protected]>
---
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 | 173 +++++++++++++++++++++++++++++++++++++++
4 files changed, 187 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..e7e5b6a29e7f
--- /dev/null
+++ b/drivers/acpi/fan_hwmon.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * fan_hwmon.c - hwmon interface for the ACPI Fan driver
+ *
+ * Copyright (C) 2024 Armin Wolf <[email protected]>
+ */
+
+#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)
+{
+ const struct acpi_fan *fan = drvdata;
+ int i;
+
+ 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;
+ 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:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int acpi_fan_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 -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;
+ 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;
+ 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_CHANNEL_INFO(power, HWMON_P_INPUT),
+ NULL
+};
+
+static const struct hwmon_chip_info acpi_fan_chip_info = {
+ .ops = &acpi_fan_ops,
+ .info = acpi_fan_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_chip_info, NULL);
+
+ return PTR_ERR_OR_ZERO(hdev);
+}
--
2.39.2
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 <[email protected]>
> + */
..
> +#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
On Mon, 22 Apr 2024, Armin Wolf 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".
>
> Tested with a custom ACPI SSDT.
>
> Signed-off-by: Armin Wolf <[email protected]>
Reviewed-by: Ilpo J?rvinen <[email protected]>
--
i.
On Mon, Apr 22, 2024 at 9:36 AM Andy Shevchenko
<[email protected]> 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 <[email protected]>
> > + */
>
> ...
>
> > +#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!