[][Refactor MT7986 thermal temperature formula]
[Description]
Refactor MT7986 thermal temperature calculation formula to
prevent loss of floating-point accuracy.
[Release-log]
N/A
Change-Id: I65d76d2f4d389d2ee127429a0835acd91726fcce
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/4769470
diff --git a/target/linux/mediatek/files-5.4/drivers/thermal/mtk_thermal.c b/target/linux/mediatek/files-5.4/drivers/thermal/mtk_thermal.c
index f73682d..e1886bb 100644
--- a/target/linux/mediatek/files-5.4/drivers/thermal/mtk_thermal.c
+++ b/target/linux/mediatek/files-5.4/drivers/thermal/mtk_thermal.c
@@ -672,27 +672,18 @@
static int raw_to_mcelsius_v3(struct mtk_thermal *mt, int sensno, s32 raw)
{
- s32 format_1;
- s32 g_oe;
- s32 g_gain;
- s32 g_x_roomt;
s32 tmp;
if (raw == 0)
return 0;
raw &= 0xfff;
- g_gain = 1 + ((mt->adc_ge - 512) >> 12);
- g_oe = mt->adc_oe - 512;
- format_1 = mt->vts[sensno] + 2900 - g_oe;
- g_x_roomt = format_1 / (g_gain << 12);
-
- tmp = (((raw - g_oe) >> 12) / g_gain) - g_x_roomt;
- tmp = tmp * 15 / 18;
- tmp = (tmp * 100000) / 149;
- tmp = (mt->degc_cali >> 1) - tmp;
+ tmp = 100000 * 15 / 16 * 10000;
+ tmp /= 4096 - 512 + mt->adc_ge;
+ tmp /= 1490;
+ tmp *= raw - mt->vts[sensno] - 2900;
- return tmp * 100;
+ return mt->degc_cali * 500 - tmp;
}
/**