[PATCH v4 4/5] platform/x86: acer-wmi: Implement proper hwmon support

[Armin Wolf <W_Armin@gmx.de>]

After looking at the ACPI AML code, it seems that the command 0x0000
used with ACER_WMID_GET_GAMING_SYS_INFO_METHODID returns a bitmap of
all supported sensor indices available through the 0x0001 command.

Those sensor indices seem to include both temperature and fan speed
sensors, with only the fan speed sensors being currently supported.

Use the output of this new command to implement reliable sensor
detection. This fixes detection of fans which do not spin during
probe, as fans are currently being ignored if their speed is 0.

Also add support for the new temperature sensor ids.

Tested-by: Rayan Margham <rayanmargham4@gmail.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/platform/x86/acer-wmi.c | 113 ++++++++++++++++++++++----------
 1 file changed, 79 insertions(+), 34 deletions(-)

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index ac4500f33b8c..aad8eb0ddae5 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -30,6 +30,7 @@
 #include <linux/input/sparse-keymap.h>
 #include <acpi/video.h>
 #include <linux/hwmon.h>
+#include <linux/units.h>
 #include <linux/bitfield.h>

 MODULE_AUTHOR("Carlos Corbacho");
@@ -71,7 +72,9 @@ MODULE_LICENSE("GPL");
 #define ACER_PREDATOR_V4_THERMAL_PROFILE_EC_OFFSET 0x54

 #define ACER_PREDATOR_V4_RETURN_STATUS_BIT_MASK GENMASK_ULL(7, 0)
-#define ACER_PREDATOR_V4_FAN_SPEED_READ_BIT_MASK GENMASK(20, 8)
+#define ACER_PREDATOR_V4_SENSOR_INDEX_BIT_MASK GENMASK_ULL(15, 8)
+#define ACER_PREDATOR_V4_SENSOR_READING_BIT_MASK GENMASK_ULL(23, 8)
+#define ACER_PREDATOR_V4_SUPPORTED_SENSORS_BIT_MASK GENMASK_ULL(39, 24)

 /*
  * Acer ACPI method GUIDs
@@ -99,9 +102,17 @@ enum acer_wmi_event_ids {
 };

 enum acer_wmi_predator_v4_sys_info_command {
-	ACER_WMID_CMD_GET_PREDATOR_V4_BAT_STATUS = 0x02,
-	ACER_WMID_CMD_GET_PREDATOR_V4_CPU_FAN_SPEED = 0x0201,
-	ACER_WMID_CMD_GET_PREDATOR_V4_GPU_FAN_SPEED = 0x0601,
+	ACER_WMID_CMD_GET_PREDATOR_V4_SUPPORTED_SENSORS = 0x0000,
+	ACER_WMID_CMD_GET_PREDATOR_V4_SENSOR_READING	= 0x0001,
+	ACER_WMID_CMD_GET_PREDATOR_V4_BAT_STATUS	= 0x0002,
+};
+
+enum acer_wmi_predator_v4_sensor_id {
+	ACER_WMID_SENSOR_CPU_TEMPERATURE	= 0x01,
+	ACER_WMID_SENSOR_CPU_FAN_SPEED		= 0x02,
+	ACER_WMID_SENSOR_EXTERNAL_TEMPERATURE_2 = 0x03,
+	ACER_WMID_SENSOR_GPU_FAN_SPEED		= 0x06,
+	ACER_WMID_SENSOR_GPU_TEMPERATURE	= 0x0A,
 };

 static const struct key_entry acer_wmi_keymap[] __initconst = {
@@ -272,6 +283,7 @@ static u16 commun_func_bitmap;
 static u8 commun_fn_key_number;
 static bool cycle_gaming_thermal_profile = true;
 static bool predator_v4;
+static u64 supported_sensors;

 module_param(mailled, int, 0444);
 module_param(brightness, int, 0444);
@@ -1779,27 +1791,6 @@ static int acer_gsensor_event(void)
 	return 0;
 }

-static int acer_get_fan_speed(int fan)
-{
-	u64 fanspeed;
-	u32 command;
-	int ret;
-
-	if (!quirks->predator_v4)
-		return -EOPNOTSUPP;
-
-	if (fan == 0)
-		command = ACER_WMID_CMD_GET_PREDATOR_V4_CPU_FAN_SPEED;
-	else
-		command = ACER_WMID_CMD_GET_PREDATOR_V4_GPU_FAN_SPEED;
-
-	ret = WMID_gaming_get_sys_info(command, &fanspeed);
-	if (ret < 0)
-		return ret;
-
-	return FIELD_GET(ACER_PREDATOR_V4_FAN_SPEED_READ_BIT_MASK, fanspeed);
-}
-
 /*
  *  Predator series turbo button
  */
@@ -2688,43 +2679,86 @@ static void __init create_debugfs(void)
 			   &interface->debug.wmid_devices);
 }

+static const enum acer_wmi_predator_v4_sensor_id acer_wmi_temp_channel_to_sensor_id[] = {
+	[0] = ACER_WMID_SENSOR_CPU_TEMPERATURE,
+	[1] = ACER_WMID_SENSOR_GPU_TEMPERATURE,
+	[2] = ACER_WMID_SENSOR_EXTERNAL_TEMPERATURE_2,
+};
+
+static const enum acer_wmi_predator_v4_sensor_id acer_wmi_fan_channel_to_sensor_id[] = {
+	[0] = ACER_WMID_SENSOR_CPU_FAN_SPEED,
+	[1] = ACER_WMID_SENSOR_GPU_FAN_SPEED,
+};
+
 static umode_t acer_wmi_hwmon_is_visible(const void *data,
 					 enum hwmon_sensor_types type, u32 attr,
 					 int channel)
 {
+	enum acer_wmi_predator_v4_sensor_id sensor_id;
+	const u64 *supported_sensors = data;
+
 	switch (type) {
+	case hwmon_temp:
+		sensor_id = acer_wmi_temp_channel_to_sensor_id[channel];
+		break;
 	case hwmon_fan:
-		if (acer_get_fan_speed(channel) >= 0)
-			return 0444;
+		sensor_id = acer_wmi_fan_channel_to_sensor_id[channel];
 		break;
 	default:
 		return 0;
 	}

+	if (*supported_sensors & BIT(sensor_id - 1))
+		return 0444;
+
 	return 0;
 }

 static int acer_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 			       u32 attr, int channel, long *val)
 {
+	u64 command = ACER_WMID_CMD_GET_PREDATOR_V4_SENSOR_READING;
+	u64 result;
 	int ret;

 	switch (type) {
+	case hwmon_temp:
+		command |= FIELD_PREP(ACER_PREDATOR_V4_SENSOR_INDEX_BIT_MASK,
+				      acer_wmi_temp_channel_to_sensor_id[channel]);
+
+		ret = WMID_gaming_get_sys_info(command, &result);
+		if (ret < 0)
+			return ret;
+
+		result = FIELD_GET(ACER_PREDATOR_V4_SENSOR_READING_BIT_MASK, result);
+		*val = result * MILLIDEGREE_PER_DEGREE;
+		return 0;
 	case hwmon_fan:
-		ret = acer_get_fan_speed(channel);
+		command |= FIELD_PREP(ACER_PREDATOR_V4_SENSOR_INDEX_BIT_MASK,
+				      acer_wmi_fan_channel_to_sensor_id[channel]);
+
+		ret = WMID_gaming_get_sys_info(command, &result);
 		if (ret < 0)
 			return ret;
-		*val = ret;
-		break;
+
+		*val = FIELD_GET(ACER_PREDATOR_V4_SENSOR_READING_BIT_MASK, result);
+		return 0;
 	default:
 		return -EOPNOTSUPP;
 	}
-
-	return 0;
 }

 static const struct hwmon_channel_info *const acer_wmi_hwmon_info[] = {
-	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT, HWMON_F_INPUT), NULL
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT
+			   ),
+	HWMON_CHANNEL_INFO(fan,
+			   HWMON_F_INPUT,
+			   HWMON_F_INPUT
+			   ),
+	NULL
 };

 static const struct hwmon_ops acer_wmi_hwmon_ops = {
@@ -2741,9 +2775,20 @@ static int acer_wmi_hwmon_init(void)
 {
 	struct device *dev = &acer_platform_device->dev;
 	struct device *hwmon;
+	u64 result;
+	int ret;
+
+	ret = WMID_gaming_get_sys_info(ACER_WMID_CMD_GET_PREDATOR_V4_SUPPORTED_SENSORS, &result);
+	if (ret < 0)
+		return ret;
+
+	/* Return early if no sensors are available */
+	supported_sensors = FIELD_GET(ACER_PREDATOR_V4_SUPPORTED_SENSORS_BIT_MASK, result);
+	if (!supported_sensors)
+		return 0;

 	hwmon = devm_hwmon_device_register_with_info(dev, "acer",
-						     &acer_platform_driver,
+						     &supported_sensors,
 						     &acer_wmi_hwmon_chip_info,
 						     NULL);

--
2.39.5