platform/x86: system76_acpi: Report temperature and fan speed

Add a hwmon interface to report CPU/GPU temperature and fan speed.
sensors now reports an ACPI interface with the entries:

system76_acpi-acpi-0
Adapter: ACPI interface
CPU fan:        0 RPM
GPU fan:        0 RPM
CPU temp:     +47.0°C
GPU temp:      +0.0°C

Signed-off-by: Jeremy Soller <jeremy@system76.com>
Signed-off-by: Tim Crawford <tcrawford@system76.com>
Link: https://lore.kernel.org/r/20211006202202.7479-2-tcrawford@system76.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/system76_acpi.c b/drivers/platform/x86/system76_acpi.c
index c14fd22ba1968798f07ece9799b57b0f370c2636..2a78ac64d689779d035fea65d38334a57cd86bd2 100644 (file)
--- a/drivers/platform/x86/system76_acpi.c
+++ b/drivers/platform/x86/system76_acpi.c
@@ -10,6 +10,8 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/leds.h>
@@ -24,6 +26,9 @@ struct system76_data {
        enum led_brightness kb_brightness;
        enum led_brightness kb_toggle_brightness;
        int kb_color;
+       struct device *therm;
+       union acpi_object *nfan;
+       union acpi_object *ntmp;
 };
 
 static const struct acpi_device_id device_ids[] = {
@@ -63,9 +68,57 @@ static int system76_get(struct system76_data *data, char *method)
        handle = acpi_device_handle(data->acpi_dev);
        status = acpi_evaluate_integer(handle, method, NULL, &ret);
        if (ACPI_SUCCESS(status))
-               return (int)ret;
-       else
-               return -1;
+               return ret;
+       return -ENODEV;
+}
+
+// Get a System76 ACPI device value by name with index
+static int system76_get_index(struct system76_data *data, char *method, int index)
+{
+       union acpi_object obj;
+       struct acpi_object_list obj_list;
+       acpi_handle handle;
+       acpi_status status;
+       unsigned long long ret = 0;
+
+       obj.type = ACPI_TYPE_INTEGER;
+       obj.integer.value = index;
+       obj_list.count = 1;
+       obj_list.pointer = &obj;
+
+       handle = acpi_device_handle(data->acpi_dev);
+       status = acpi_evaluate_integer(handle, method, &obj_list, &ret);
+       if (ACPI_SUCCESS(status))
+               return ret;
+       return -ENODEV;
+}
+
+// Get a System76 ACPI device object by name
+static int system76_get_object(struct system76_data *data, char *method, union acpi_object **obj)
+{
+       acpi_handle handle;
+       acpi_status status;
+       struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
+
+       handle = acpi_device_handle(data->acpi_dev);
+       status = acpi_evaluate_object(handle, method, NULL, &buf);
+       if (ACPI_SUCCESS(status)) {
+               *obj = buf.pointer;
+               return 0;
+       }
+
+       return -ENODEV;
+}
+
+// Get a name from a System76 ACPI device object
+static char *system76_name(union acpi_object *obj, int index)
+{
+       if (obj && obj->type == ACPI_TYPE_PACKAGE && index <= obj->package.count) {
+               if (obj->package.elements[index].type == ACPI_TYPE_STRING)
+                       return obj->package.elements[index].string.pointer;
+       }
+
+       return NULL;
 }
 
 // Set a System76 ACPI device value by name
@@ -270,6 +323,146 @@ static void kb_led_hotkey_color(struct system76_data *data)
        kb_led_notify(data);
 }
 
+static umode_t thermal_is_visible(const void *drvdata, enum hwmon_sensor_types type,
+                                 u32 attr, int channel)
+{
+       const struct system76_data *data = drvdata;
+
+       switch (type) {
+       case hwmon_fan:
+       case hwmon_pwm:
+               if (system76_name(data->nfan, channel))
+                       return 0444;
+               break;
+
+       case hwmon_temp:
+               if (system76_name(data->ntmp, channel))
+                       return 0444;
+               break;
+
+       default:
+               return 0;
+       }
+
+       return 0;
+}
+
+static int thermal_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+                       int channel, long *val)
+{
+       struct system76_data *data = dev_get_drvdata(dev);
+       int raw;
+
+       switch (type) {
+       case hwmon_fan:
+               if (attr == hwmon_fan_input) {
+                       raw = system76_get_index(data, "GFAN", channel);
+                       if (raw < 0)
+                               return raw;
+                       *val = (raw >> 8) & 0xFFFF;
+                       return 0;
+               }
+               break;
+
+       case hwmon_pwm:
+               if (attr == hwmon_pwm_input) {
+                       raw = system76_get_index(data, "GFAN", channel);
+                       if (raw < 0)
+                               return raw;
+                       *val = raw & 0xFF;
+                       return 0;
+               }
+               break;
+
+       case hwmon_temp:
+               if (attr == hwmon_temp_input) {
+                       raw = system76_get_index(data, "GTMP", channel);
+                       if (raw < 0)
+                               return raw;
+                       *val = raw * 1000;
+                       return 0;
+               }
+               break;
+
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       return -EOPNOTSUPP;
+}
+
+static int thermal_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+                              int channel, const char **str)
+{
+       struct system76_data *data = dev_get_drvdata(dev);
+
+       switch (type) {
+       case hwmon_fan:
+               if (attr == hwmon_fan_label) {
+                       *str = system76_name(data->nfan, channel);
+                       if (*str)
+                               return 0;
+               }
+               break;
+
+       case hwmon_temp:
+               if (attr == hwmon_temp_label) {
+                       *str = system76_name(data->ntmp, channel);
+                       if (*str)
+                               return 0;
+               }
+               break;
+
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       return -EOPNOTSUPP;
+}
+
+static const struct hwmon_ops thermal_ops = {
+       .is_visible = thermal_is_visible,
+       .read = thermal_read,
+       .read_string = thermal_read_string,
+};
+
+// Allocate up to 8 fans and temperatures
+static const struct hwmon_channel_info *thermal_channel_info[] = {
+       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_CHANNEL_INFO(pwm,
+               HWMON_PWM_INPUT,
+               HWMON_PWM_INPUT,
+               HWMON_PWM_INPUT,
+               HWMON_PWM_INPUT,
+               HWMON_PWM_INPUT,
+               HWMON_PWM_INPUT,
+               HWMON_PWM_INPUT,
+               HWMON_PWM_INPUT),
+       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),
+       NULL
+};
+
+static const struct hwmon_chip_info thermal_chip_info = {
+       .ops = &thermal_ops,
+       .info = thermal_channel_info,
+};
+
 // Handle ACPI notification
 static void system76_notify(struct acpi_device *acpi_dev, u32 event)
 {
@@ -346,7 +539,26 @@ static int system76_add(struct acpi_device *acpi_dev)
                        return err;
        }
 
+       err = system76_get_object(data, "NFAN", &data->nfan);
+       if (err)
+               goto error;
+
+       err = system76_get_object(data, "NTMP", &data->ntmp);
+       if (err)
+               goto error;
+
+       data->therm = devm_hwmon_device_register_with_info(&acpi_dev->dev,
+               "system76_acpi", data, &thermal_chip_info, NULL);
+       err = PTR_ERR_OR_ZERO(data->therm);
+       if (err)
+               goto error;
+
        return 0;
+
+error:
+       kfree(data->ntmp);
+       kfree(data->nfan);
+       return err;
 }
 
 // Remove a System76 ACPI device
@@ -359,9 +571,11 @@ static int system76_remove(struct acpi_device *acpi_dev)
                device_remove_file(data->kb_led.dev, &kb_led_color_dev_attr);
 
        devm_led_classdev_unregister(&acpi_dev->dev, &data->ap_led);
-
        devm_led_classdev_unregister(&acpi_dev->dev, &data->kb_led);
 
+       kfree(data->nfan);
+       kfree(data->ntmp);
+
        system76_get(data, "FINI");
 
        return 0;