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-rw-r--r--drivers/iio/pressure/bmp280-core.c203
1 files changed, 132 insertions, 71 deletions
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index fd1da26a62e4..5ec3e41b65f2 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -55,6 +55,28 @@ struct bmp180_calib {
s16 MD;
};
+/* See datasheet Section 4.2.2. */
+struct bmp280_calib {
+ u16 T1;
+ s16 T2;
+ s16 T3;
+ u16 P1;
+ s16 P2;
+ s16 P3;
+ s16 P4;
+ s16 P5;
+ s16 P6;
+ s16 P7;
+ s16 P8;
+ s16 P9;
+ u8 H1;
+ s16 H2;
+ u8 H3;
+ s16 H4;
+ s16 H5;
+ s8 H6;
+};
+
struct bmp280_data {
struct device *dev;
struct mutex lock;
@@ -62,7 +84,10 @@ struct bmp280_data {
struct completion done;
bool use_eoc;
const struct bmp280_chip_info *chip_info;
- struct bmp180_calib calib;
+ union {
+ struct bmp180_calib bmp180;
+ struct bmp280_calib bmp280;
+ } calib;
struct regulator *vddd;
struct regulator *vdda;
unsigned int start_up_time; /* in microseconds */
@@ -120,67 +145,121 @@ static const struct iio_chan_spec bmp280_channels[] = {
},
};
-/*
- * Returns humidity in percent, resolution is 0.01 percent. Output value of
- * "47445" represents 47445/1024 = 46.333 %RH.
- *
- * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula".
- */
-
-static u32 bmp280_compensate_humidity(struct bmp280_data *data,
- s32 adc_humidity)
+static int bmp280_read_calib(struct bmp280_data *data,
+ struct bmp280_calib *calib,
+ unsigned int chip)
{
+ int ret;
+ unsigned int tmp;
struct device *dev = data->dev;
- unsigned int H1, H3, tmp;
- int H2, H4, H5, H6, ret, var;
+ __le16 t_buf[BMP280_COMP_TEMP_REG_COUNT / 2];
+ __le16 p_buf[BMP280_COMP_PRESS_REG_COUNT / 2];
+
+ /* Read temperature calibration values. */
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
+ t_buf, BMP280_COMP_TEMP_REG_COUNT);
+ if (ret < 0) {
+ dev_err(data->dev,
+ "failed to read temperature calibration parameters\n");
+ return ret;
+ }
+
+ calib->T1 = le16_to_cpu(t_buf[T1]);
+ calib->T2 = le16_to_cpu(t_buf[T2]);
+ calib->T3 = le16_to_cpu(t_buf[T3]);
- ret = regmap_read(data->regmap, BMP280_REG_COMP_H1, &H1);
+ /* Read pressure calibration values. */
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
+ p_buf, BMP280_COMP_PRESS_REG_COUNT);
+ if (ret < 0) {
+ dev_err(data->dev,
+ "failed to read pressure calibration parameters\n");
+ return ret;
+ }
+
+ calib->P1 = le16_to_cpu(p_buf[P1]);
+ calib->P2 = le16_to_cpu(p_buf[P2]);
+ calib->P3 = le16_to_cpu(p_buf[P3]);
+ calib->P4 = le16_to_cpu(p_buf[P4]);
+ calib->P5 = le16_to_cpu(p_buf[P5]);
+ calib->P6 = le16_to_cpu(p_buf[P6]);
+ calib->P7 = le16_to_cpu(p_buf[P7]);
+ calib->P8 = le16_to_cpu(p_buf[P8]);
+ calib->P9 = le16_to_cpu(p_buf[P9]);
+
+ /*
+ * Read humidity calibration values.
+ * Due to some odd register addressing we cannot just
+ * do a big bulk read. Instead, we have to read each Hx
+ * value separately and sometimes do some bit shifting...
+ * Humidity data is only available on BME280.
+ */
+ if (chip != BME280_CHIP_ID)
+ return 0;
+
+ ret = regmap_read(data->regmap, BMP280_REG_COMP_H1, &tmp);
if (ret < 0) {
dev_err(dev, "failed to read H1 comp value\n");
return ret;
}
+ calib->H1 = tmp;
ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &tmp, 2);
if (ret < 0) {
dev_err(dev, "failed to read H2 comp value\n");
return ret;
}
- H2 = sign_extend32(le16_to_cpu(tmp), 15);
+ calib->H2 = sign_extend32(le16_to_cpu(tmp), 15);
- ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &H3);
+ ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp);
if (ret < 0) {
dev_err(dev, "failed to read H3 comp value\n");
return ret;
}
+ calib->H3 = tmp;
ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &tmp, 2);
if (ret < 0) {
dev_err(dev, "failed to read H4 comp value\n");
return ret;
}
- H4 = sign_extend32(((be16_to_cpu(tmp) >> 4) & 0xff0) |
- (be16_to_cpu(tmp) & 0xf), 11);
+ calib->H4 = sign_extend32(((be16_to_cpu(tmp) >> 4) & 0xff0) |
+ (be16_to_cpu(tmp) & 0xf), 11);
ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &tmp, 2);
if (ret < 0) {
dev_err(dev, "failed to read H5 comp value\n");
return ret;
}
- H5 = sign_extend32(((le16_to_cpu(tmp) >> 4) & 0xfff), 11);
+ calib->H5 = sign_extend32(((le16_to_cpu(tmp) >> 4) & 0xfff), 11);
ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp);
if (ret < 0) {
dev_err(dev, "failed to read H6 comp value\n");
return ret;
}
- H6 = sign_extend32(tmp, 7);
+ calib->H6 = sign_extend32(tmp, 7);
+
+ return 0;
+}
+/*
+ * Returns humidity in percent, resolution is 0.01 percent. Output value of
+ * "47445" represents 47445/1024 = 46.333 %RH.
+ *
+ * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula".
+ */
+static u32 bmp280_compensate_humidity(struct bmp280_data *data,
+ s32 adc_humidity)
+{
+ s32 var;
+ struct bmp280_calib *calib = &data->calib.bmp280;
var = ((s32)data->t_fine) - (s32)76800;
- var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var))
- + (s32)16384) >> 15) * (((((((var * H6) >> 10)
- * (((var * (s32)H3) >> 11) + (s32)32768)) >> 10)
- + (s32)2097152) * H2 + 8192) >> 14);
- var -= ((((var >> 15) * (var >> 15)) >> 7) * (s32)H1) >> 4;
+ var = ((((adc_humidity << 14) - (calib->H4 << 20) - (calib->H5 * var))
+ + (s32)16384) >> 15) * (((((((var * calib->H6) >> 10)
+ * (((var * (s32)calib->H3) >> 11) + (s32)32768)) >> 10)
+ + (s32)2097152) * calib->H2 + 8192) >> 14);
+ var -= ((((var >> 15) * (var >> 15)) >> 7) * (s32)calib->H1) >> 4;
return var >> 12;
};
@@ -195,31 +274,14 @@ static u32 bmp280_compensate_humidity(struct bmp280_data *data,
static s32 bmp280_compensate_temp(struct bmp280_data *data,
s32 adc_temp)
{
- int ret;
s32 var1, var2;
- __le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2];
+ struct bmp280_calib *calib = &data->calib.bmp280;
- ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
- buf, BMP280_COMP_TEMP_REG_COUNT);
- if (ret < 0) {
- dev_err(data->dev,
- "failed to read temperature calibration parameters\n");
- return ret;
- }
-
- /*
- * The double casts are necessary because le16_to_cpu returns an
- * unsigned 16-bit value. Casting that value directly to a
- * signed 32-bit will not do proper sign extension.
- *
- * Conversely, T1 and P1 are unsigned values, so they can be
- * cast straight to the larger type.
- */
- var1 = (((adc_temp >> 3) - ((s32)le16_to_cpu(buf[T1]) << 1)) *
- ((s32)(s16)le16_to_cpu(buf[T2]))) >> 11;
- var2 = (((((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1]))) *
- ((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) *
- ((s32)(s16)le16_to_cpu(buf[T3]))) >> 14;
+ var1 = (((adc_temp >> 3) - ((s32)calib->T1 << 1)) *
+ ((s32)calib->T2)) >> 11;
+ var2 = (((((adc_temp >> 4) - ((s32)calib->T1)) *
+ ((adc_temp >> 4) - ((s32)calib->T1))) >> 12) *
+ ((s32)calib->T3)) >> 14;
data->t_fine = var1 + var2;
return (data->t_fine * 5 + 128) >> 8;
@@ -235,34 +297,25 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data,
static u32 bmp280_compensate_press(struct bmp280_data *data,
s32 adc_press)
{
- int ret;
s64 var1, var2, p;
- __le16 buf[BMP280_COMP_PRESS_REG_COUNT / 2];
-
- ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
- buf, BMP280_COMP_PRESS_REG_COUNT);
- if (ret < 0) {
- dev_err(data->dev,
- "failed to read pressure calibration parameters\n");
- return ret;
- }
+ struct bmp280_calib *calib = &data->calib.bmp280;
var1 = ((s64)data->t_fine) - 128000;
- var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]);
- var2 += (var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17;
- var2 += ((s64)(s16)le16_to_cpu(buf[P4])) << 35;
- var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) +
- ((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12);
- var1 = ((((s64)1) << 47) + var1) * ((s64)le16_to_cpu(buf[P1])) >> 33;
+ var2 = var1 * var1 * (s64)calib->P6;
+ var2 += (var1 * (s64)calib->P5) << 17;
+ var2 += ((s64)calib->P4) << 35;
+ var1 = ((var1 * var1 * (s64)calib->P3) >> 8) +
+ ((var1 * (s64)calib->P2) << 12);
+ var1 = ((((s64)1) << 47) + var1) * ((s64)calib->P1) >> 33;
if (var1 == 0)
return 0;
p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125;
p = div64_s64(p, var1);
- var1 = (((s64)(s16)le16_to_cpu(buf[P9])) * (p >> 13) * (p >> 13)) >> 25;
- var2 = (((s64)(s16)le16_to_cpu(buf[P8])) * p) >> 19;
- p = ((p + var1 + var2) >> 8) + (((s64)(s16)le16_to_cpu(buf[P7])) << 4);
+ var1 = (((s64)calib->P9) * (p >> 13) * (p >> 13)) >> 25;
+ var2 = ((s64)(calib->P8) * p) >> 19;
+ p = ((p + var1 + var2) >> 8) + (((s64)calib->P7) << 4);
return (u32)p;
}
@@ -752,7 +805,7 @@ static int bmp180_read_calib(struct bmp280_data *data,
static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp)
{
s32 x1, x2;
- struct bmp180_calib *calib = &data->calib;
+ struct bmp180_calib *calib = &data->calib.bmp180;
x1 = ((adc_temp - calib->AC6) * calib->AC5) >> 15;
x2 = (calib->MC << 11) / (x1 + calib->MD);
@@ -814,7 +867,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
s32 b3, b6;
u32 b4, b7;
s32 oss = data->oversampling_press;
- struct bmp180_calib *calib = &data->calib;
+ struct bmp180_calib *calib = &data->calib.bmp180;
b6 = data->t_fine - 4000;
x1 = (calib->B2 * (b6 * b6 >> 12)) >> 11;
@@ -1028,11 +1081,19 @@ int bmp280_common_probe(struct device *dev,
dev_set_drvdata(dev, indio_dev);
/*
- * The BMP085 and BMP180 has calibration in an E2PROM, read it out
- * at probe time. It will not change.
+ * Some chips have calibration parameters "programmed into the devices'
+ * non-volatile memory during production". Let's read them out at probe
+ * time once. They will not change.
*/
if (chip_id == BMP180_CHIP_ID) {
- ret = bmp180_read_calib(data, &data->calib);
+ ret = bmp180_read_calib(data, &data->calib.bmp180);
+ if (ret < 0) {
+ dev_err(data->dev,
+ "failed to read calibration coefficients\n");
+ goto out_disable_vdda;
+ }
+ } else if (chip_id == BMP280_CHIP_ID || chip_id == BME280_CHIP_ID) {
+ ret = bmp280_read_calib(data, &data->calib.bmp280, chip_id);
if (ret < 0) {
dev_err(data->dev,
"failed to read calibration coefficients\n");
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-31 20:45:10 +0000