diff mbox series

[v4] ACPI: fan: Add hwmon support

Message ID 20240414174743.8575-1-W_Armin@gmx.de
State Superseded
Headers show
Series [v4] ACPI: fan: Add hwmon support | expand

Commit Message

Armin Wolf April 14, 2024, 5:47 p.m. UTC
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 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

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 | 170 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 184 insertions(+)
 create mode 100644 drivers/acpi/fan_hwmon.c

--
2.39.2

Comments

Ilpo Järvinen April 15, 2024, 3:57 p.m. UTC | #1
On Sun, 14 Apr 2024, 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 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
> 
> 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 | 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..0ae9017bdbae
> --- /dev/null
> +++ b/drivers/acpi/fan_hwmon.c
> @@ -0,0 +1,170 @@
> +// 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)
> +{
> +	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 atttribute should not be created.

attribute
diff mbox series

Patch

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..0ae9017bdbae
--- /dev/null
+++ b/drivers/acpi/fan_hwmon.c
@@ -0,0 +1,170 @@ 
+// 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)
+{
+	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 atttribute 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;
+
+			*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);
+}