2024-04-08 12:37:44

by Armin Wolf

Subject: [PATCH] ACPI: fan: Add hwmon support

Currently, the driver does only supports 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".

Signed-off-by: Armin Wolf <[email protected]>
---
drivers/acpi/Makefile | 1 +
drivers/acpi/fan.h | 2 ++
drivers/acpi/fan_core.c | 7 ++++
drivers/acpi/fan_hwmon.c | 78 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 88 insertions(+)
create mode 100644 drivers/acpi/fan_hwmon.c

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index d69d5444acdb..9a2e03acc1be 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -83,6 +83,7 @@ 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-objs += 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 e7b4b4e4a55e..45c2637566da 100644
--- a/drivers/acpi/fan.h
+++ b/drivers/acpi/fan.h
@@ -56,4 +56,6 @@ 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);
+
+int devm_acpi_fan_create_hwmon(struct acpi_device *device);
#endif
diff --git a/drivers/acpi/fan_core.c b/drivers/acpi/fan_core.c
index ff72e4ef8738..6bbdbb914e95 100644
--- a/drivers/acpi/fan_core.c
+++ b/drivers/acpi/fan_core.c
@@ -7,6 +7,7 @@
* Copyright (C) 2022 Intel Corporation. All rights reserved.
*/

+#include <linux/kconfig.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
@@ -336,6 +337,12 @@ static int acpi_fan_probe(struct platform_device *pdev)
if (result)
return result;

+ if (IS_REACHABLE(CONFIG_HWMON)) {
+ 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..4f2bec8664f4
--- /dev/null
+++ b/drivers/acpi/fan_hwmon.c
@@ -0,0 +1,78 @@
+// 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 "fan.h"
+
+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_fst fst;
+ int ret;
+
+ switch (type) {
+ case hwmon_fan:
+ ret = acpi_fan_get_fst(adev, &fst);
+ if (ret < 0)
+ return ret;
+
+ switch (attr) {
+ case hwmon_fan_input:
+ if (fst.speed > LONG_MAX)
+ return -EOVERFLOW;
+
+ *val = fst.speed;
+ return 0;
+ case hwmon_fan_fault:
+ *val = (fst.speed == U32_MAX);
+ 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_FAULT),
+ 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 device *hdev;
+
+ hdev = devm_hwmon_device_register_with_info(&device->dev, "acpi_fan", device,
+ &acpi_fan_chip_info, NULL);
+
+ return PTR_ERR_OR_ZERO(hdev);
+}
--
2.39.2

2024-04-08 15:13:23

by Thomas Weißschuh

Subject: Re: [PATCH] ACPI: fan: Add hwmon support

Hi,

On 2024-04-08 14:37:18+0200, Armin Wolf wrote:
> Currently, the driver does only supports 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".
>
> Signed-off-by: Armin Wolf <[email protected]>
> ---
> drivers/acpi/Makefile | 1 +
> drivers/acpi/fan.h | 2 ++
> drivers/acpi/fan_core.c | 7 ++++
> drivers/acpi/fan_hwmon.c | 78 ++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 88 insertions(+)
> create mode 100644 drivers/acpi/fan_hwmon.c

[snip]

> +
> +int devm_acpi_fan_create_hwmon(struct acpi_device *device)
> +{
> + struct device *hdev;
> +
> + hdev = devm_hwmon_device_register_with_info(&device->dev, "acpi_fan", device,
> + &acpi_fan_chip_info, NULL);

This fails to link if CONFIG_ACPI_FAN=y and CONFIG_HWMON=n:

ld: vmlinux.o: in function `devm_acpi_fan_create_hwmon':
../drivers/acpi/fan_hwmon.c:74:(.text+0x819e65): undefined reference to `devm_hwmon_device_register_with_info'

With this fixed:

Reviewed-by: Thomas Weißschuh <[email protected]>

> +
> + return PTR_ERR_OR_ZERO(hdev);
> +}
> --
> 2.39.2
>
>

2024-04-08 15:49:08

by Ilpo Järvinen

Subject: Re: [PATCH] ACPI: fan: Add hwmon support

On Mon, 8 Apr 2024, Armin Wolf wrote:

> Currently, the driver does only supports 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".
>
> Signed-off-by: Armin Wolf <[email protected]>
> ---
> drivers/acpi/Makefile | 1 +
> drivers/acpi/fan.h | 2 ++
> drivers/acpi/fan_core.c | 7 ++++
> drivers/acpi/fan_hwmon.c | 78 ++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 88 insertions(+)
> create mode 100644 drivers/acpi/fan_hwmon.c
>
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index d69d5444acdb..9a2e03acc1be 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -83,6 +83,7 @@ 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-objs += 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 e7b4b4e4a55e..45c2637566da 100644
> --- a/drivers/acpi/fan.h
> +++ b/drivers/acpi/fan.h
> @@ -56,4 +56,6 @@ 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);
> +
> +int devm_acpi_fan_create_hwmon(struct acpi_device *device);
> #endif
> diff --git a/drivers/acpi/fan_core.c b/drivers/acpi/fan_core.c
> index ff72e4ef8738..6bbdbb914e95 100644
> --- a/drivers/acpi/fan_core.c
> +++ b/drivers/acpi/fan_core.c
> @@ -7,6 +7,7 @@
> * Copyright (C) 2022 Intel Corporation. All rights reserved.
> */
>
> +#include <linux/kconfig.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/init.h>
> @@ -336,6 +337,12 @@ static int acpi_fan_probe(struct platform_device *pdev)
> if (result)
> return result;
>
> + if (IS_REACHABLE(CONFIG_HWMON)) {
> + 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..4f2bec8664f4
> --- /dev/null
> +++ b/drivers/acpi/fan_hwmon.c
> @@ -0,0 +1,78 @@
> +// 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 "fan.h"
> +
> +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_fst fst;
> + int ret;
> +
> + switch (type) {
> + case hwmon_fan:
> + ret = acpi_fan_get_fst(adev, &fst);
> + if (ret < 0)
> + return ret;
> +
> + switch (attr) {
> + case hwmon_fan_input:
> + if (fst.speed > LONG_MAX)
> + return -EOVERFLOW;
> +
> + *val = fst.speed;
> + return 0;
> + case hwmon_fan_fault:
> + *val = (fst.speed == U32_MAX);
> + return 0;

Is it okay to return 0 in this case?

> + 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_FAULT),

One line.

--
i.


> + 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 device *hdev;
> +
> + hdev = devm_hwmon_device_register_with_info(&device->dev, "acpi_fan", device,
> + &acpi_fan_chip_info, NULL);
> +
> + return PTR_ERR_OR_ZERO(hdev);
> +}
> --
> 2.39.2
>
>

2024-04-08 17:14:22

by Armin Wolf

Subject: Re: [PATCH] ACPI: fan: Add hwmon support

Am 08.04.24 um 17:48 schrieb Ilpo Järvinen:

> On Mon, 8 Apr 2024, Armin Wolf wrote:
>
>> Currently, the driver does only supports 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".
>>
>> Signed-off-by: Armin Wolf <[email protected]>
>> ---
>> drivers/acpi/Makefile | 1 +
>> drivers/acpi/fan.h | 2 ++
>> drivers/acpi/fan_core.c | 7 ++++
>> drivers/acpi/fan_hwmon.c | 78 ++++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 88 insertions(+)
>> create mode 100644 drivers/acpi/fan_hwmon.c
>>
>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>> index d69d5444acdb..9a2e03acc1be 100644
>> --- a/drivers/acpi/Makefile
>> +++ b/drivers/acpi/Makefile
>> @@ -83,6 +83,7 @@ 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-objs += 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 e7b4b4e4a55e..45c2637566da 100644
>> --- a/drivers/acpi/fan.h
>> +++ b/drivers/acpi/fan.h
>> @@ -56,4 +56,6 @@ 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);
>> +
>> +int devm_acpi_fan_create_hwmon(struct acpi_device *device);
>> #endif
>> diff --git a/drivers/acpi/fan_core.c b/drivers/acpi/fan_core.c
>> index ff72e4ef8738..6bbdbb914e95 100644
>> --- a/drivers/acpi/fan_core.c
>> +++ b/drivers/acpi/fan_core.c
>> @@ -7,6 +7,7 @@
>> * Copyright (C) 2022 Intel Corporation. All rights reserved.
>> */
>>
>> +#include <linux/kconfig.h>
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> #include <linux/init.h>
>> @@ -336,6 +337,12 @@ static int acpi_fan_probe(struct platform_device *pdev)
>> if (result)
>> return result;
>>
>> + if (IS_REACHABLE(CONFIG_HWMON)) {
>> + 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..4f2bec8664f4
>> --- /dev/null
>> +++ b/drivers/acpi/fan_hwmon.c
>> @@ -0,0 +1,78 @@
>> +// 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 "fan.h"
>> +
>> +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_fst fst;
>> + int ret;
>> +
>> + switch (type) {
>> + case hwmon_fan:
>> + ret = acpi_fan_get_fst(adev, &fst);
>> + if (ret < 0)
>> + return ret;
>> +
>> + switch (attr) {
>> + case hwmon_fan_input:
>> + if (fst.speed > LONG_MAX)
>> + return -EOVERFLOW;
>> +
>> + *val = fst.speed;
>> + return 0;
>> + case hwmon_fan_fault:
>> + *val = (fst.speed == U32_MAX);
>> + return 0;
> Is it okay to return 0 in this case?

Hi,

i think so, since the value of the attribute (with the meaning of "is the rpm value ok?") is being
correctly stored in val. If acpi_fan_get_fst() fails, we already return a negative error code.

Thanks,
Armin Wolf

>> + 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_FAULT),
> One line.
>

2024-04-08 22:21:40

by Ilpo Järvinen

Subject: Re: [PATCH] ACPI: fan: Add hwmon support

On Mon, 8 Apr 2024, Armin Wolf wrote:
> Am 08.04.24 um 17:48 schrieb Ilpo Järvinen:
> > On Mon, 8 Apr 2024, Armin Wolf wrote:
> >
> > > Currently, the driver does only supports 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".
> > >
> > > Signed-off-by: Armin Wolf <[email protected]>
> > > ---
> > > drivers/acpi/Makefile | 1 +
> > > drivers/acpi/fan.h | 2 ++
> > > drivers/acpi/fan_core.c | 7 ++++
> > > drivers/acpi/fan_hwmon.c | 78 ++++++++++++++++++++++++++++++++++++++++
> > > 4 files changed, 88 insertions(+)
> > > create mode 100644 drivers/acpi/fan_hwmon.c
> > >
> > > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> > > index d69d5444acdb..9a2e03acc1be 100644
> > > --- a/drivers/acpi/Makefile
> > > +++ b/drivers/acpi/Makefile
> > > @@ -83,6 +83,7 @@ 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-objs += 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 e7b4b4e4a55e..45c2637566da 100644
> > > --- a/drivers/acpi/fan.h
> > > +++ b/drivers/acpi/fan.h
> > > @@ -56,4 +56,6 @@ 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);
> > > +
> > > +int devm_acpi_fan_create_hwmon(struct acpi_device *device);
> > > #endif
> > > diff --git a/drivers/acpi/fan_core.c b/drivers/acpi/fan_core.c
> > > index ff72e4ef8738..6bbdbb914e95 100644
> > > --- a/drivers/acpi/fan_core.c
> > > +++ b/drivers/acpi/fan_core.c
> > > @@ -7,6 +7,7 @@
> > > * Copyright (C) 2022 Intel Corporation. All rights reserved.
> > > */
> > >
> > > +#include <linux/kconfig.h>
> > > #include <linux/kernel.h>
> > > #include <linux/module.h>
> > > #include <linux/init.h>
> > > @@ -336,6 +337,12 @@ static int acpi_fan_probe(struct platform_device
> > > *pdev)
> > > if (result)
> > > return result;
> > >
> > > + if (IS_REACHABLE(CONFIG_HWMON)) {
> > > + 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..4f2bec8664f4
> > > --- /dev/null
> > > +++ b/drivers/acpi/fan_hwmon.c
> > > @@ -0,0 +1,78 @@
> > > +// 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 "fan.h"
> > > +
> > > +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_fst fst;
> > > + int ret;
> > > +
> > > + switch (type) {
> > > + case hwmon_fan:
> > > + ret = acpi_fan_get_fst(adev, &fst);
> > > + if (ret < 0)
> > > + return ret;
> > > +
> > > + switch (attr) {
> > > + case hwmon_fan_input:
> > > + if (fst.speed > LONG_MAX)
> > > + return -EOVERFLOW;
> > > +
> > > + *val = fst.speed;
> > > + return 0;
> > > + case hwmon_fan_fault:
> > > + *val = (fst.speed == U32_MAX);
> > > + return 0;
> > Is it okay to return 0 in this case?
>
> Hi,
>
> i think so, since the value of the attribute (with the meaning of "is the rpm
> value ok?") is being
> correctly stored in val. If acpi_fan_get_fst() fails, we already return a
> negative error code.

Ah, right. It seems fine.

--
i.

> > > + 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_FAULT),
> > One line.
> >
>