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path: root/drivers/iio/temperature/mlx90632.c
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Diffstat (limited to 'drivers/iio/temperature/mlx90632.c')
-rw-r--r--drivers/iio/temperature/mlx90632.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
index 51b812bcff2e..c3de10ba5b1e 100644
--- a/drivers/iio/temperature/mlx90632.c
+++ b/drivers/iio/temperature/mlx90632.c
@@ -374,11 +374,11 @@ static s32 mlx90632_calc_temp_ambient(s16 ambient_new_raw, s16 ambient_old_raw,
}
static s32 mlx90632_calc_temp_object_iteration(s32 prev_object_temp, s64 object,
- s64 TAdut, s32 Fa, s32 Fb,
+ s64 TAdut, s64 TAdut4, s32 Fa, s32 Fb,
s32 Ga, s16 Ha, s16 Hb,
u16 emissivity)
{
- s64 calcedKsTO, calcedKsTA, ir_Alpha, TAdut4, Alpha_corr;
+ s64 calcedKsTO, calcedKsTA, ir_Alpha, Alpha_corr;
s64 Ha_customer, Hb_customer;
Ha_customer = ((s64)Ha * 1000000LL) >> 14ULL;
@@ -393,30 +393,35 @@ static s32 mlx90632_calc_temp_object_iteration(s32 prev_object_temp, s64 object,
Alpha_corr = emissivity * div64_s64(Alpha_corr, 100000LL);
Alpha_corr = div64_s64(Alpha_corr, 1000LL);
ir_Alpha = div64_s64((s64)object * 10000000LL, Alpha_corr);
- TAdut4 = (div64_s64(TAdut, 10000LL) + 27315) *
- (div64_s64(TAdut, 10000LL) + 27315) *
- (div64_s64(TAdut, 10000LL) + 27315) *
- (div64_s64(TAdut, 10000LL) + 27315);
return (int_sqrt64(int_sqrt64(ir_Alpha * 1000000000000LL + TAdut4))
- 27315 - Hb_customer) * 10;
}
+static s64 mlx90632_calc_ta4(s64 TAdut, s64 scale)
+{
+ return (div64_s64(TAdut, scale) + 27315) *
+ (div64_s64(TAdut, scale) + 27315) *
+ (div64_s64(TAdut, scale) + 27315) *
+ (div64_s64(TAdut, scale) + 27315);
+}
+
static s32 mlx90632_calc_temp_object(s64 object, s64 ambient, s32 Ea, s32 Eb,
s32 Fa, s32 Fb, s32 Ga, s16 Ha, s16 Hb,
u16 tmp_emi)
{
- s64 kTA, kTA0, TAdut;
+ s64 kTA, kTA0, TAdut, TAdut4;
s64 temp = 25000;
s8 i;
kTA = (Ea * 1000LL) >> 16LL;
kTA0 = (Eb * 1000LL) >> 8LL;
TAdut = div64_s64(((ambient - kTA0) * 1000000LL), kTA) + 25 * 1000000LL;
+ TAdut4 = mlx90632_calc_ta4(TAdut, 10000LL);
/* Iterations of calculation as described in datasheet */
for (i = 0; i < 5; ++i) {
- temp = mlx90632_calc_temp_object_iteration(temp, object, TAdut,
+ temp = mlx90632_calc_temp_object_iteration(temp, object, TAdut, TAdut4,
Fa, Fb, Ga, Ha, Hb,
tmp_emi);
}