[PATCH v3 5/9] thermal/drivers/mediatek/lvts: Add lvts_temp_to_raw variant

[Laura Nao]

MT8196/MT6991 require a different version of lvts_temp_to_raw(),
specifically the multiplicative inverse of the existing implementation.
Introduce a variant of the function with inverted calculation logic to
match this requirement.

This ensures accurate raw value generation for temperature
thresholds, avoiding spurious thermal interrupts or unintended hardware
resets on MT8196/MT6991.

Reviewed-by: Chen-Yu Tsai <wenst at chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
Reviewed-by: Fei Shao <fshao at chromium.org>
Signed-off-by: Laura Nao <laura.nao at collabora.com>
---
 drivers/thermal/mediatek/lvts_thermal.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c
index 47124d33ca2e..e29664f1316a 100644
--- a/drivers/thermal/mediatek/lvts_thermal.c
+++ b/drivers/thermal/mediatek/lvts_thermal.c
@@ -300,6 +300,18 @@ static u32 lvts_temp_to_raw(int temperature, int temp_factor)
 	return div_s64(raw_temp, -temp_factor);
 }
 
+static u32 lvts_temp_to_raw_v2(int temperature, int temp_factor)
+{
+	u32 raw_temp;
+
+	if (temp_factor == 0)
+		return temperature;
+
+	raw_temp = temperature - golden_temp_offset;
+
+	return div_s64((s64)temp_factor << 14, raw_temp);
+}
+
 static int lvts_get_temp(struct thermal_zone_device *tz, int *temp)
 {
 	struct lvts_sensor *lvts_sensor = thermal_zone_device_priv(tz);
-- 
2.39.5