Re: [PATCH v2] platform/x86/tuxedo: Implement TUXEDO TUXI ACPI TFAN via hwmon

From: Werner Sembach
Date: Thu Mar 13 2025 - 17:53:13 EST


Hi Ilpo,

Am 13.03.25 um 14:47 schrieb Ilpo Järvinen:
On Thu, 6 Mar 2025, Werner Sembach wrote:

The TUXEDO Sirius 16 Gen1 & Gen2 have the custom TUXEDO Interface (TUXI)
ACPI interface which currently consists of the TFAN device. This has ACPI
functions to control the built in fans and monitor fan speeds and CPU and
GPU temprature.
temperature
thx for spotting

This driver implements this TFAN device via the hwmon subsystem with an
added temprature check that ensure a minimum fanspeed at certain
temperature
thx for spotting

temperatures. This allows userspace controlled, but hardware safe, custom
fan curves.

Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
---
MAINTAINERS | 6 +
drivers/platform/x86/Kconfig | 2 +
drivers/platform/x86/Makefile | 3 +
drivers/platform/x86/tuxedo/Kbuild | 6 +
drivers/platform/x86/tuxedo/Kconfig | 6 +
drivers/platform/x86/tuxedo/nbxx/Kbuild | 7 +
drivers/platform/x86/tuxedo/nbxx/Kconfig | 13 +
drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.c | 578 +++++++++++++++++++
8 files changed, 621 insertions(+)
create mode 100644 drivers/platform/x86/tuxedo/Kbuild
create mode 100644 drivers/platform/x86/tuxedo/Kconfig
create mode 100644 drivers/platform/x86/tuxedo/nbxx/Kbuild
create mode 100644 drivers/platform/x86/tuxedo/nbxx/Kconfig
create mode 100644 drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 8e0736dc2ee0e..7139c32e96dc7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -24190,6 +24190,12 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux.git turbostat
F: tools/power/x86/turbostat/
F: tools/testing/selftests/turbostat/
+TUXEDO DRIVERS
+M: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
+L: platform-driver-x86@xxxxxxxxxxxxxxx
+S: Supported
+F: drivers/platform/x86/tuxedo/
+
TW5864 VIDEO4LINUX DRIVER
M: Bluecherry Maintainers <maintainers@xxxxxxxxxxxxxxxxx>
M: Andrey Utkin <andrey.utkin@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 0258dd879d64b..58b258cde4fdb 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1186,6 +1186,8 @@ config SEL3350_PLATFORM
To compile this driver as a module, choose M here: the module
will be called sel3350-platform.
+source "drivers/platform/x86/tuxedo/Kconfig"
+
endif # X86_PLATFORM_DEVICES
config P2SB
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index e1b1429470674..1562dcd7ad9a5 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -153,3 +153,6 @@ obj-$(CONFIG_WINMATE_FM07_KEYS) += winmate-fm07-keys.o
# SEL
obj-$(CONFIG_SEL3350_PLATFORM) += sel3350-platform.o
+
+# TUXEDO
+obj-y += tuxedo/
diff --git a/drivers/platform/x86/tuxedo/Kbuild b/drivers/platform/x86/tuxedo/Kbuild
new file mode 100644
index 0000000000000..0de6c7871db95
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/Kbuild
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# TUXEDO X86 Platform Specific Drivers
+#
+
+obj-y += nbxx/
diff --git a/drivers/platform/x86/tuxedo/Kconfig b/drivers/platform/x86/tuxedo/Kconfig
new file mode 100644
index 0000000000000..34aa2e89f00ba
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/Kconfig
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# TUXEDO X86 Platform Specific Drivers
+#
+
+source "drivers/platform/x86/tuxedo/nbxx/Kconfig"
diff --git a/drivers/platform/x86/tuxedo/nbxx/Kbuild b/drivers/platform/x86/tuxedo/nbxx/Kbuild
new file mode 100644
index 0000000000000..10ddef3564d84
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/nbxx/Kbuild
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# TUXEDO X86 Platform Specific Drivers
+#
+
+tuxedo_nbxx_acpi_tuxi-y := acpi_tuxi.o
+obj-$(CONFIG_TUXEDO_NBXX_ACPI_TUXI) += tuxedo_nbxx_acpi_tuxi.o
diff --git a/drivers/platform/x86/tuxedo/nbxx/Kconfig b/drivers/platform/x86/tuxedo/nbxx/Kconfig
new file mode 100644
index 0000000000000..827c65c410fb2
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/nbxx/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# TUXEDO X86 Platform Specific Drivers
+#
+
+config TUXEDO_NBXX_ACPI_TUXI
+ tristate "TUXEDO NBxx ACPI TUXI Platform Driver"
+ help
+ This driver implements the ACPI TUXI device found on some TUXEDO
+ Notebooks. Currently this consists only of the TFAN subdevice which is
+ implemented via hwmon.
+
+ When compiled as a module it will be called tuxedo_nbxx_acpi_tuxi
diff --git a/drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.c b/drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.c
new file mode 100644
index 0000000000000..f42311f119956
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/nbxx/acpi_tuxi.c
@@ -0,0 +1,578 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024-2025 Werner Sembach wse@xxxxxxxxxxxxxxxxxxx
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/hwmon.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/units.h>
+#include <linux/workqueue.h>
+
+#define TUXI_SAFEGUARD_PERIOD 1000 // 1s
+#define TUXI_PWM_FAN_ON_MIN_SPEED 0x40 // ~25%
+#define TUXI_TEMP_LEVEL_HYSTERESIS 1500 // 1.5°C
+#define TUXI_FW_TEMP_OFFSET 2730 // Kelvin to Celsius
+#define TUXI_MAX_FAN_COUNT 16 /* If this is increased, new lines must
+ * be added to hwmcinfo below.
+ */
Please use static_assert() to actually enforce what the comment says.

I actually struggle to come up with how to do this for the array length because of the macro and the pointer

`static_assert(TUXI_MAX_FAN_COUNT <= ARRAY_SIZE(hwmcinfo[0]->config));` doesn't work


+
+static const struct acpi_device_id acpi_device_ids[] = {
+ {"TUXI0000", 0},
+ {"", 0}
+};
+MODULE_DEVICE_TABLE(acpi, acpi_device_ids);
+
+struct tuxi_driver_data_t {
+ acpi_handle tfan_handle;
+ struct device *hwmdev;
+};
+
+struct tuxi_hwmon_driver_data_t {
+ struct delayed_work work;
+ struct device *hwmdev;
+ u8 fan_count;
+ const char *fan_types[TUXI_MAX_FAN_COUNT];
+ u8 temp_level[TUXI_MAX_FAN_COUNT];
+ u8 curr_speed[TUXI_MAX_FAN_COUNT];
+ u8 want_speed[TUXI_MAX_FAN_COUNT];
+ u8 pwm_enabled;
+};
+
+struct tuxi_temp_high_config_t {
+ long temp;
+ u8 min_speed;
+};
+
+/* Speed values in this table must be >= TUXI_PWM_FAN_ON_MIN_SPEED to avoid
+ * undefined behaviour.
+ */
+static const struct tuxi_temp_high_config_t temp_levels[] = {
+ { 80000, 0x4d }, // ~30%
+ { 90000, 0x66 }, // ~40%
+ { 100000, 0xff }, // 100%
+ { }
+};
+
+/*
+ * Set fan speed target
+ *
+ * Set a specific fan speed (needs manual mode)
+ *
+ * Arg0: Fan index
+ * Arg1: Fan speed as a fraction of maximum speed (0-255)
+ */
+#define TUXI_TFAN_METHOD_SET_FAN_SPEED "SSPD"
+
+/*
+ * Get fan speed target
+ *
+ * Arg0: Fan index
+ * Returns: Current fan speed target a fraction of maximum speed (0-255)
+ */
+#define TUXI_TFAN_METHOD_GET_FAN_SPEED "GSPD"
+
+/*
+ * Get fans count
+ *
+ * Returns: Number of individually controllable fans
+ */
+#define TUXI_TFAN_METHOD_GET_FAN_COUNT "GCNT"
+
+/*
+ * Set fans mode
+ *
+ * Arg0: 0 = auto, 1 = manual
+ */
+#define TUXI_TFAN_METHOD_SET_FAN_MODE "SMOD"
+
+/*
+ * Get fans mode
+ *
+ * Returns: 0 = auto, 1 = manual
+ */
+#define TUXI_TFAN_METHOD_GET_FAN_MODE "GMOD"
+
+/*
+ * Get fan type/what the fan is pointed at
+ *
+ * Arg0: Fan index
+ * Returns: 0 = general, 1 = CPU, 2 = GPU
+ */
+#define TUXI_TFAN_METHOD_GET_FAN_TYPE "GTYP"
+
+static const char * const tuxi_fan_type_labels[] = {
+ "general",
+ "cpu",
+ "gpu"
+};
+
+/*
+ * Get fan temperature/temperature of what the fan is pointed at
+ *
+ * Arg0: Fan index
+ * Returns: Temperature sensor value in 10ths of degrees kelvin
+ */
+#define TUXI_TFAN_METHOD_GET_FAN_TEMPERATURE "GTMP"
+
+/*
+ * Get actual fan speed in RPM
+ *
+ * Arg0: Fan index
+ * Returns: Speed sensor value in revolutions per minute
+ */
+#define TUXI_TFAN_METHOD_GET_FAN_RPM "GRPM"
+
+static int tuxi_tfan_method(struct acpi_device *device, acpi_string method,
+ unsigned long long *params, u32 pcount,
+ unsigned long long *retval)
+{
+ struct tuxi_driver_data_t *driver_data = dev_get_drvdata(&device->dev);
+ acpi_handle handle = driver_data->tfan_handle;
+ union acpi_object *obj __free(kfree) = NULL;
Please add linux/cleanup.h include.
ack

+ struct acpi_object_list arguments;
+ unsigned long long data;
+ acpi_status status;
+ unsigned int i;
+
+ if (pcount > 0) {
+ obj = kcalloc(pcount, sizeof(*arguments.pointer), GFP_KERNEL);
+
+ arguments.count = pcount;
+ arguments.pointer = obj;
+ for (i = 0; i < pcount; ++i) {
+ arguments.pointer[i].type = ACPI_TYPE_INTEGER;
+ arguments.pointer[i].integer.value = params[i];
+ }
+ }
+ status = acpi_evaluate_integer(handle, method,
+ pcount ? &arguments : NULL, &data);
+ if (ACPI_FAILURE(status))
+ return_ACPI_STATUS(status);
+
+ if (retval)
+ *retval = data;
+
+ return 0;
+}
+
+static umode_t hwm_is_visible(const void *data, enum hwmon_sensor_types type,
+ u32 __always_unused attr, int channel)
+{
+ struct tuxi_hwmon_driver_data_t const *driver_data = data;
+
+ if (channel >= driver_data->fan_count)
+ return 0;
+
+ switch (type) {
+ case hwmon_fan:
+ return 0444;
+ case hwmon_pwm:
+ return 0644;
+ case hwmon_temp:
+ return 0444;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int hwm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int channel, long *val)
+{
+ struct tuxi_hwmon_driver_data_t *driver_data = dev_get_drvdata(dev);
+ struct acpi_device *pdev = to_acpi_device(dev->parent);
+ unsigned long long params[2], retval;
+ int ret;
+
+ switch (type) {
+ case hwmon_fan:
+ params[0] = channel;
+ ret = tuxi_tfan_method(pdev,
+ TUXI_TFAN_METHOD_GET_FAN_RPM,
These fit to same line.
ack

+ params, 1, &retval);
+ *val = retval > S32_MAX ? S32_MAX : retval;
+ return ret;
+ case hwmon_pwm:
+ switch (attr) {
+ case hwmon_pwm_input:
+ if (driver_data->pwm_enabled) {
+ *val = driver_data->curr_speed[channel];
+ return 0;
+ }
+ params[0] = channel;
+ ret = tuxi_tfan_method(pdev,
+ TUXI_TFAN_METHOD_GET_FAN_SPEED,
+ params, 1, &retval);
+ *val = retval > S32_MAX ? S32_MAX : retval;
+ return ret;
+ case hwmon_pwm_enable:
+ *val = driver_data->pwm_enabled;
+ return ret;
+ }
+ break;
+ case hwmon_temp:
+ params[0] = channel;
+ ret = tuxi_tfan_method(pdev,
+ TUXI_TFAN_METHOD_GET_FAN_TEMPERATURE,
+ params, 1, &retval);
+ *val = retval > S32_MAX / 100 ?
Add linux/limits.h include.

ack

It is included in kernel.h, so I read from this that kernel.h should not be used but the parts of it directly?


+ S32_MAX : (retval - TUXI_FW_TEMP_OFFSET) * 100;
Is the math wrong, as you do retval - TUXI_FW_TEMP_OFFSET before
multiplying?
No, retval is in 10th of °K (but the last number is always 0) so is TUXI_FW_TEMP_OFFSET which is there to convert it to 10th of °C, the * 100 is then to bring it in line with hwmon wanting to output milli degrees
Shouldn't it be like this:

retval -= TUXI_FW_TEMP_OFFSET;
*val = min(retval * 100, (unsigned long long)S32_MAX);
As retval is unsigned this would not work with (theoretical) negative °C.

+ add include for min().

And for max() used elsewere in the code -> ack


+ return ret;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int hwm_read_string(struct device *dev,
+ enum hwmon_sensor_types __always_unused type,
+ u32 __always_unused attr, int channel,
+ const char **str)
+{
+ struct tuxi_hwmon_driver_data_t *driver_data = dev_get_drvdata(dev);
+
+ *str = driver_data->fan_types[channel];
+
+ return 0;
+}
+
+static int write_speed(struct device *dev, int channel, u8 val, bool force)
+{
+ struct tuxi_hwmon_driver_data_t *driver_data = dev_get_drvdata(dev);
+ struct acpi_device *pdev = to_acpi_device(dev->parent);
+ unsigned long long params[2];
+ u8 temp_level;
+ int ret;
+
+ params[0] = channel;
+
+ /* The heatpipe across the DRMs is shared between both fans and the DRMs
In multi-line comments:

/*
* Text starts here...
Ack

What are DRMs? I guess it's neither Digital Rights Managements nor Direct
Rendering Managers :-).
Sorry brainfail, wanted to write VRMs. Good that I failed twice xD.

+ * are the most likely to go up in smoke. So it's better to apply the
+ * minimum fan speed to all fans if either CPU or GPU is working hard.
+ */
+ temp_level = max_array(driver_data->temp_level, driver_data->fan_count);
+ if (temp_level)
+ params[1] = max_t(u8, val,
+ temp_levels[temp_level - 1].min_speed);
Both are already u8 so why you need max_t(), max() should be sufficient
when types are already right.

Include is missing.

+ else if (val < TUXI_PWM_FAN_ON_MIN_SPEED / 2)
+ params[1] = 0;
+ else if (val < TUXI_PWM_FAN_ON_MIN_SPEED)
+ params[1] = TUXI_PWM_FAN_ON_MIN_SPEED;
+ else
+ params[1] = val;
+
+ if (force || params[1] != driver_data->curr_speed[channel])
+ ret = tuxi_tfan_method(pdev, TUXI_TFAN_METHOD_SET_FAN_SPEED,
+ params, 2, NULL);
+ if (ret)
+ return ret;
Please indent this to the correct level.
ack

+
+ driver_data->curr_speed[channel] = params[1];
The use of params[1] obfuscates meaning, please use local variable with a
proper name and only assign it into params[1] for the tuxi_tfan_method call.
ack

+
+ return 0;
+}
+
+static int hwm_write(struct device *dev,
+ enum hwmon_sensor_types __always_unused type, u32 attr,
+ int channel, long val)
+{
+ struct tuxi_hwmon_driver_data_t *driver_data = dev_get_drvdata(dev);
+ struct acpi_device *pdev = to_acpi_device(dev->parent);
+ unsigned long long params[2];
+ unsigned int i;
+ int ret;
+
+ switch (attr) {
+ case hwmon_pwm_input:
+ if (val > U8_MAX || val < 0)
+ return -EINVAL;
+
+ if (driver_data->pwm_enabled) {
+ driver_data->want_speed[channel] = val;
+ return write_speed(dev, channel, val, false);
+ }
+
+ return 0;
+ case hwmon_pwm_enable:
+ params[0] = val ? 1 : 0;
Can those two literals be named with defines?
ack

+ ret = tuxi_tfan_method(pdev, TUXI_TFAN_METHOD_SET_FAN_MODE,
+ params, 1, NULL);
+ if (ret)
+ return ret;
+
+ driver_data->pwm_enabled = val;
+
+ /* Activating PWM sets speed to 0. Alternative design decision
+ * could be to keep the current value. This would require proper
+ * setting of driver_data->curr_speed for example.
+ */
+ if (val)
Consider:
if (!val)
return 0;

So you can deindent the loop by one level.
Imho it makes the logic harder to follow and considering the only short code lines following after, I don't really see the benefit.

+ for (i = 0; i < driver_data->fan_count; ++i) {
+ ret = write_speed(dev, i, 0, true);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static const struct hwmon_ops hwmops = {
+ .is_visible = hwm_is_visible,
+ .read = hwm_read,
+ .read_string = hwm_read_string,
+ .write = hwm_write,
+};
+
+static const struct hwmon_channel_info * const hwmcinfo[] = {
+ HWMON_CHANNEL_INFO(fan,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL,
+ HWMON_F_INPUT | HWMON_F_LABEL),
+ HWMON_CHANNEL_INFO(pwm,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL),
+ NULL
+};
+
+static const struct hwmon_chip_info hwminfo = {
+ .ops = &hwmops,
+ .info = hwmcinfo
+};
+
+static u8 tuxi_get_temp_level(struct tuxi_hwmon_driver_data_t *driver_data,
+ u8 fan_id, long temp)
+{
+ long temp_low, temp_high;
+ unsigned int i;
+ int ret;
+
+ ret = driver_data->temp_level[fan_id];
+
+ for (i = 0; temp_levels[i].temp; ++i) {
+ temp_low = i == 0 ? S32_MIN : temp_levels[i - 1].temp;
+ temp_high = temp_levels[i].temp;
+ if (ret > i)
+ temp_high -= TUXI_TEMP_LEVEL_HYSTERESIS;
+
+ if (temp >= temp_low && temp < temp_high)
+ ret = i;
Why you cannot return i; immediately here?

leftover from when the loop wasn't it's own function

ack


+ }
+ if (temp >= temp_high)
+ ret = i;
+
+ return ret;
+}
+
+static void tuxi_periodic_hw_safeguard(struct work_struct *work)
+{
+ struct tuxi_hwmon_driver_data_t *driver_data = container_of(work,
+ struct tuxi_hwmon_driver_data_t,
+ work.work);
+ struct device *dev = driver_data->hwmdev;
+ struct acpi_device *pdev = to_acpi_device(dev->parent);
+ unsigned long long params[2], retval;
+ unsigned int i;
+ long temp;
+ int ret;
+
+ for (i = 0; i < driver_data->fan_count; ++i) {
+ params[0] = i;
+ ret = tuxi_tfan_method(pdev,
+ TUXI_TFAN_METHOD_GET_FAN_TEMPERATURE,
+ params, 1, &retval);
+ /* If reading the temprature fails, default to a high value to
temperature
thx for spotting

+ * be on the safe side in the worst case.
+ */
+ if (ret)
+ retval = 2720 + 1200;
TUXI_FW_TEMP_OFFSET + 1200 ?

Why it doesn't match to that define??
Typo and from before the define existed, fixed.

+
+ temp = retval > S32_MAX / 100 ?
+ S32_MAX : (retval - TUXI_FW_TEMP_OFFSET) * 100;
Same math issue comment as above.

Why is the read+conversion code duplicated into two places?
because here it is with special error handling and didn't thought about an own function for a defacto 2 liner

+
+ driver_data->temp_level[i] = tuxi_get_temp_level(driver_data, i,
+ temp);
+ }
+
+ // Reapply want_speeds to respect eventual new temp_levels
+ for (i = 0; i < driver_data->fan_count; ++i)
+ write_speed(dev, i, driver_data->want_speed[i], false);
+
+ schedule_delayed_work(&driver_data->work, TUXI_SAFEGUARD_PERIOD);
+}
+
+static int tuxi_hwmon_add_devices(struct acpi_device *pdev, struct device **hwmdev)
+{
+ struct tuxi_hwmon_driver_data_t *driver_data;
+ unsigned long long params[2], retval;
+ unsigned int i;
+ int ret;
+
+ /* The first version of TUXI TFAN didn't have the Get Fan Temperature
+ * method which is integral to this driver. So probe for existence and
+ * abort otherwise.
+ *
+ * The Get Fan Speed method is also missing in that version, but was
+ * added in the same version so it doesn't have to be probe separately.
+ */
+ params[0] = 0;
+ ret = tuxi_tfan_method(pdev, TUXI_TFAN_METHOD_GET_FAN_TEMPERATURE,
+ params, 1, &retval);
+ if (ret)
+ return ret;
+
+ driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data), GFP_KERNEL);
+ if (!driver_data)
+ return -ENOMEM;
+
+ /* Loading this module sets the fan mode to auto. Alternative design
+ * decision could be to keep the current value. This would require
+ * proper initialization of driver_data->curr_speed for example.
+ */
+ params[0] = 0;
Is this 0 ..._MODE_AUTO? Please use a named define if that's the case.
ack

+ ret = tuxi_tfan_method(pdev, TUXI_TFAN_METHOD_SET_FAN_MODE, params, 1,
+ NULL);
+ if (ret)
+ return ret;
+
+ ret = tuxi_tfan_method(pdev, TUXI_TFAN_METHOD_GET_FAN_COUNT, NULL, 0,
+ &retval);
+ if (ret)
+ return ret;
+ if (retval > TUXI_MAX_FAN_COUNT)
+ return -EINVAL;
+ driver_data->fan_count = retval;
+
+ for (i = 0; i < driver_data->fan_count; ++i) {
+ params[0] = i;
+ ret = tuxi_tfan_method(pdev, TUXI_TFAN_METHOD_GET_FAN_TYPE,
+ params, 1, &retval);
+ if (ret)
+ return ret;
+ else if (retval >= ARRAY_SIZE(tuxi_fan_type_labels))
No need for else as there's return.
ack

+ return -EOPNOTSUPP;
+ driver_data->fan_types[i] = tuxi_fan_type_labels[retval];
+ }
+
+ *hwmdev = devm_hwmon_device_register_with_info(&pdev->dev,
+ "tuxedo_nbxx_acpi_tuxi",
+ driver_data, &hwminfo,
+ NULL);
+ ret = PTR_ERR_OR_ZERO(*hwmdev);
+ if (ret)
This obfuscates what you're doing here as you do not actually use 0 at
all. Please use this instead:

if (IS_ERR(*hwmdev))
return PTR_ERR(*hwmdev);
ack

+ return ret;
+
+ driver_data->hwmdev = *hwmdev;
+
+ INIT_DELAYED_WORK(&driver_data->work, tuxi_periodic_hw_safeguard);
+ schedule_delayed_work(&driver_data->work, TUXI_SAFEGUARD_PERIOD);
+
+ return 0;
+}
+
+static void tuxi_hwmon_remove_devices(struct device *hwmdev)
+{
+ struct tuxi_hwmon_driver_data_t *driver_data = dev_get_drvdata(hwmdev);
+ struct acpi_device *pdev = to_acpi_device(hwmdev->parent);
+ unsigned long long params[2];
+
+ cancel_delayed_work_sync(&driver_data->work);
+
+ params[0] = 0;
Use a named define?
ack

+ tuxi_tfan_method(pdev, TUXI_TFAN_METHOD_SET_FAN_MODE, params, 1, NULL);
+}
+
+static int tuxi_add(struct acpi_device *device)
+{
+ struct tuxi_driver_data_t *driver_data;
+ acpi_status status;
+
+ driver_data = devm_kzalloc(&device->dev, sizeof(*driver_data),
+ GFP_KERNEL);
+ if (!driver_data)
+ return -ENOMEM;
+
+ // Find subdevices
+ status = acpi_get_handle(device->handle, "TFAN",
+ &driver_data->tfan_handle);
+ if (ACPI_FAILURE(status))
+ return_ACPI_STATUS(status);
+
+ dev_set_drvdata(&device->dev, driver_data);
+
+ return tuxi_hwmon_add_devices(device, &driver_data->hwmdev);
+}
+
+static void tuxi_remove(struct acpi_device *device)
+{
+ struct tuxi_driver_data_t *driver_data = dev_get_drvdata(&device->dev);
+
+ tuxi_hwmon_remove_devices(driver_data->hwmdev);
+}
+
+static struct acpi_driver acpi_driver = {
+ .name = "tuxedo_nbxx_acpi_tuxi",
+ .ids = acpi_device_ids,
+ .ops = {
+ .add = tuxi_add,
+ .remove = tuxi_remove,
+ },
+};
+
+module_acpi_driver(acpi_driver);
+
+MODULE_DESCRIPTION("TUXEDO TUXI");
Perhaps this could be made a more specific to the actual functionality?
yes overlooked this, was still a placeholder from the very beginning of writing this code.

+MODULE_AUTHOR("Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");

v3 incomming

Best regards,

Werner