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bu27034: ROHM BU27034ANUC correct lux calculation
The ROHM BU27034NUC was cancelled and BU27034ANUC is replacing this sensor. The lux computation based on the data from a BU27034ANUC is different from the computation for the data from an old BU27034NUC. Fix the lux computation. Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> Link: https://patch.msgid.link/b7bea76b54b28eb354dc523771a0e0a8b6f26095.1720176341.git.mazziesaccount@gmail.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Matti Vaittinen
Jonathan Cameron
parent
bb1059815f
commit
eb13959e2d
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@ -573,102 +573,21 @@ static int bu27034_set_scale(struct bu27034_data *data, int chan,
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}
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/*
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* for (D1/D0 < 0.87):
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* lx = 0.004521097 * D1 - 0.002663996 * D0 +
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* 0.00012213 * D1 * D1 / D0
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* for (D1/D0 < 1.5):
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* lx = (0.001193 * D0 + (-0.0000747) * D1) * ((D1/D0 – 1.5) * (0.25) + 1)
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*
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* => 115.7400832 * ch1 / gain1 / mt -
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* 68.1982976 * ch0 / gain0 / mt +
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* 0.00012213 * 25600 * (ch1 / gain1 / mt) * 25600 *
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* (ch1 /gain1 / mt) / (25600 * ch0 / gain0 / mt)
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* => -0.000745625 * D0 + 0.0002515625 * D1 + -0.000018675 * D1 * D1 / D0
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*
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* A = 0.00012213 * 25600 * (ch1 /gain1 / mt) * 25600 *
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* (ch1 /gain1 / mt) / (25600 * ch0 / gain0 / mt)
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* => 0.00012213 * 25600 * (ch1 /gain1 / mt) *
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* (ch1 /gain1 / mt) / (ch0 / gain0 / mt)
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* => 0.00012213 * 25600 * (ch1 / gain1) * (ch1 /gain1 / mt) /
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* (ch0 / gain0)
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* => 0.00012213 * 25600 * (ch1 / gain1) * (ch1 /gain1 / mt) *
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* gain0 / ch0
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* => 3.126528 * ch1 * ch1 * gain0 / gain1 / gain1 / mt /ch0
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* => (6.44 * ch1 / gain1 + 19.088 * ch0 / gain0 -
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* 0.47808 * ch1 * ch1 * gain0 / gain1 / gain1 / ch0) /
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* mt
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*
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* lx = (115.7400832 * ch1 / gain1 - 68.1982976 * ch0 / gain0) /
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* mt + A
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* => (115.7400832 * ch1 / gain1 - 68.1982976 * ch0 / gain0) /
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* mt + 3.126528 * ch1 * ch1 * gain0 / gain1 / gain1 / mt /
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* ch0
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* Else
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* lx = 0.001193 * D0 - 0.0000747 * D1
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*
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* => (115.7400832 * ch1 / gain1 - 68.1982976 * ch0 / gain0 +
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* 3.126528 * ch1 * ch1 * gain0 / gain1 / gain1 / ch0) /
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* mt
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*
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* For (0.87 <= D1/D0 < 1.00)
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* lx = (0.001331* D0 + 0.0000354 * D1) * ((D1/D0 – 0.87) * (0.385) + 1)
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* => (0.001331 * 256 * 100 * ch0 / gain0 / mt + 0.0000354 * 256 *
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* 100 * ch1 / gain1 / mt) * ((D1/D0 - 0.87) * (0.385) + 1)
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* => (34.0736 * ch0 / gain0 / mt + 0.90624 * ch1 / gain1 / mt) *
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* ((D1/D0 - 0.87) * (0.385) + 1)
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* => (34.0736 * ch0 / gain0 / mt + 0.90624 * ch1 / gain1 / mt) *
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* (0.385 * D1/D0 - 0.66505)
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* => (34.0736 * ch0 / gain0 / mt + 0.90624 * ch1 / gain1 / mt) *
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* (0.385 * 256 * 100 * ch1 / gain1 / mt / (256 * 100 * ch0 / gain0 / mt) - 0.66505)
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* => (34.0736 * ch0 / gain0 / mt + 0.90624 * ch1 / gain1 / mt) *
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* (9856 * ch1 / gain1 / mt / (25600 * ch0 / gain0 / mt) + 0.66505)
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* => 13.118336 * ch1 / (gain1 * mt)
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* + 22.66064768 * ch0 / (gain0 * mt)
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* + 8931.90144 * ch1 * ch1 * gain0 /
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* (25600 * ch0 * gain1 * gain1 * mt)
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* + 0.602694912 * ch1 / (gain1 * mt)
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*
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* => [0.3489024 * ch1 * ch1 * gain0 / (ch0 * gain1 * gain1)
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* + 22.66064768 * ch0 / gain0
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* + 13.721030912 * ch1 / gain1
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* ] / mt
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*
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* For (D1/D0 >= 1.00)
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*
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* lx = (0.001331* D0 + 0.0000354 * D1) * ((D1/D0 – 2.0) * (-0.05) + 1)
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* => (0.001331* D0 + 0.0000354 * D1) * (-0.05D1/D0 + 1.1)
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* => (0.001331 * 256 * 100 * ch0 / gain0 / mt + 0.0000354 * 256 *
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* 100 * ch1 / gain1 / mt) * (-0.05D1/D0 + 1.1)
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* => (34.0736 * ch0 / gain0 / mt + 0.90624 * ch1 / gain1 / mt) *
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* (-0.05 * 256 * 100 * ch1 / gain1 / mt / (256 * 100 * ch0 / gain0 / mt) + 1.1)
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* => (34.0736 * ch0 / gain0 / mt + 0.90624 * ch1 / gain1 / mt) *
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* (-1280 * ch1 / (gain1 * mt * 25600 * ch0 / gain0 / mt) + 1.1)
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* => (34.0736 * ch0 * -1280 * ch1 * gain0 * mt /( gain0 * mt * gain1 * mt * 25600 * ch0)
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* + 34.0736 * 1.1 * ch0 / (gain0 * mt)
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* + 0.90624 * ch1 * -1280 * ch1 *gain0 * mt / (gain1 * mt *gain1 * mt * 25600 * ch0)
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* + 1.1 * 0.90624 * ch1 / (gain1 * mt)
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* => -43614.208 * ch1 / (gain1 * mt * 25600)
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* + 37.48096 ch0 / (gain0 * mt)
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* - 1159.9872 * ch1 * ch1 * gain0 / (gain1 * gain1 * mt * 25600 * ch0)
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* + 0.996864 ch1 / (gain1 * mt)
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* => [
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* - 0.045312 * ch1 * ch1 * gain0 / (gain1 * gain1 * ch0)
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* - 0.706816 * ch1 / gain1
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* + 37.48096 ch0 /gain0
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* ] * mt
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*
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*
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* So, the first case (D1/D0 < 0.87) can be computed to a form:
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*
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* lx = (3.126528 * ch1 * ch1 * gain0 / (ch0 * gain1 * gain1) +
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* 115.7400832 * ch1 / gain1 +
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* -68.1982976 * ch0 / gain0
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* / mt
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*
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* Second case (0.87 <= D1/D0 < 1.00) goes to form:
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*
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* => [0.3489024 * ch1 * ch1 * gain0 / (ch0 * gain1 * gain1) +
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* 13.721030912 * ch1 / gain1 +
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* 22.66064768 * ch0 / gain0
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* ] / mt
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*
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* Third case (D1/D0 >= 1.00) goes to form:
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* => [-0.045312 * ch1 * ch1 * gain0 / (ch0 * gain1 * gain1) +
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* -0.706816 * ch1 / gain1 +
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* 37.48096 ch0 /(gain0
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* ] / mt
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* => (1.91232 * ch1 / gain1 + 30.5408 * ch0 / gain0 +
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* [0 * ch1 * ch1 * gain0 / gain1 / gain1 / ch0] ) /
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* mt
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*
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* This can be unified to format:
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* lx = [
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@ -678,19 +597,14 @@ static int bu27034_set_scale(struct bu27034_data *data, int chan,
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* ] / mt
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*
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* For case 1:
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* A = 3.126528,
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* B = 115.7400832
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* C = -68.1982976
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* A = -0.47808,
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* B = 6.44,
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* C = 19.088
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*
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* For case 2:
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* A = 0.3489024
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* B = 13.721030912
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* C = 22.66064768
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*
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* For case 3:
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* A = -0.045312
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* B = -0.706816
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* C = 37.48096
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* A = 0
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* B = 1.91232
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* C = 30.5408
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*/
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struct bu27034_lx_coeff {
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@ -795,21 +709,16 @@ static int bu27034_fixp_calc_lx(unsigned int ch0, unsigned int ch1,
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{
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static const struct bu27034_lx_coeff coeff[] = {
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{
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.A = 31265280, /* 3.126528 */
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.B = 1157400832, /*115.7400832 */
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.C = 681982976, /* -68.1982976 */
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.is_neg = {false, false, true},
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.A = 4780800, /* -0.47808 */
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.B = 64400000, /* 6.44 */
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.C = 190880000, /* 19.088 */
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.is_neg = { true, false, false },
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}, {
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.A = 3489024, /* 0.3489024 */
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.B = 137210309, /* 13.721030912 */
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.C = 226606476, /* 22.66064768 */
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.A = 0, /* 0 */
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.B = 19123200, /* 1.91232 */
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.C = 305408000, /* 30.5408 */
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/* All terms positive */
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}, {
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.A = 453120, /* -0.045312 */
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.B = 7068160, /* -0.706816 */
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.C = 374809600, /* 37.48096 */
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.is_neg = {true, true, false},
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}
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},
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};
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const struct bu27034_lx_coeff *c = &coeff[coeff_idx];
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u64 res = 0, terms[3];
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@ -972,12 +881,10 @@ static int bu27034_get_single_result(struct bu27034_data *data, int chan,
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* D1 = data1/ch1_gain/meas_time_ms * 25600
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*
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* Then:
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* if (D1/D0 < 0.87)
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* lx = (0.001331 * D0 + 0.0000354 * D1) * ((D1 / D0 - 0.87) * 3.45 + 1)
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* else if (D1/D0 < 1)
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* lx = (0.001331 * D0 + 0.0000354 * D1) * ((D1 / D0 - 0.87) * 0.385 + 1)
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* else
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* lx = (0.001331 * D0 + 0.0000354 * D1) * ((D1 / D0 - 2) * -0.05 + 1)
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* If (D1/D0 < 1.5)
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* lx = (0.001193 * D0 + (-0.0000747) * D1) * ((D1 / D0 – 1.5) * 0.25 + 1)
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* Else
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* lx = (0.001193 * D0 + (-0.0000747) * D1)
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*
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* We use it here. Users who have for example some colored lens
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* need to modify the calculation but I hope this gives a starting point for
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@ -1028,12 +935,10 @@ static int bu27034_calc_mlux(struct bu27034_data *data, __le16 *res, int *val)
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d1_d0_ratio_scaled /= ch0 * gain1;
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}
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if (d1_d0_ratio_scaled < 87)
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if (d1_d0_ratio_scaled < 150)
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ret = bu27034_fixp_calc_lx(ch0, ch1, gain0, gain1, meastime, 0);
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else if (d1_d0_ratio_scaled < 100)
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ret = bu27034_fixp_calc_lx(ch0, ch1, gain0, gain1, meastime, 1);
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else
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ret = bu27034_fixp_calc_lx(ch0, ch1, gain0, gain1, meastime, 2);
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ret = bu27034_fixp_calc_lx(ch0, ch1, gain0, gain1, meastime, 1);
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if (ret < 0)
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return ret;
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