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-rw-r--r--drivers/iio/humidity/hdc3020.c325
1 files changed, 249 insertions, 76 deletions
diff --git a/drivers/iio/humidity/hdc3020.c b/drivers/iio/humidity/hdc3020.c
index 1e5d0d4797..1e702fcc48 100644
--- a/drivers/iio/humidity/hdc3020.c
+++ b/drivers/iio/humidity/hdc3020.c
@@ -18,6 +18,7 @@
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
+#include <linux/math64.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/units.h>
@@ -63,8 +64,10 @@
#define HDC3020_CRC8_POLYNOMIAL 0x31
-#define HDC3020_MIN_TEMP -40
-#define HDC3020_MAX_TEMP 125
+#define HDC3020_MIN_TEMP_MICRO -39872968
+#define HDC3020_MAX_TEMP_MICRO 124875639
+#define HDC3020_MAX_TEMP_HYST_MICRO 164748607
+#define HDC3020_MAX_HUM_MICRO 99220264
struct hdc3020_data {
struct i2c_client *client;
@@ -363,6 +366,105 @@ static int hdc3020_write_raw(struct iio_dev *indio_dev,
return -EINVAL;
}
+static int hdc3020_thresh_get_temp(u16 thresh)
+{
+ int temp;
+
+ /*
+ * Get the temperature threshold from 9 LSBs, shift them to get
+ * the truncated temperature threshold representation and
+ * calculate the threshold according to the formula in the
+ * datasheet. Result is degree celsius scaled by 65535.
+ */
+ temp = FIELD_GET(HDC3020_THRESH_TEMP_MASK, thresh) <<
+ HDC3020_THRESH_TEMP_TRUNC_SHIFT;
+
+ return -2949075 + (175 * temp);
+}
+
+static int hdc3020_thresh_get_hum(u16 thresh)
+{
+ int hum;
+
+ /*
+ * Get the humidity threshold from 7 MSBs, shift them to get the
+ * truncated humidity threshold representation and calculate the
+ * threshold according to the formula in the datasheet. Result is
+ * percent scaled by 65535.
+ */
+ hum = FIELD_GET(HDC3020_THRESH_HUM_MASK, thresh) <<
+ HDC3020_THRESH_HUM_TRUNC_SHIFT;
+
+ return hum * 100;
+}
+
+static u16 hdc3020_thresh_set_temp(int s_temp, u16 curr_thresh)
+{
+ u64 temp;
+ u16 thresh;
+
+ /*
+ * Calculate temperature threshold, shift it down to get the
+ * truncated threshold representation in the 9LSBs while keeping
+ * the current humidity threshold in the 7 MSBs.
+ */
+ temp = (u64)(s_temp + 45000000) * 65535ULL;
+ temp = div_u64(temp, 1000000 * 175) >> HDC3020_THRESH_TEMP_TRUNC_SHIFT;
+ thresh = FIELD_PREP(HDC3020_THRESH_TEMP_MASK, temp);
+ thresh |= (FIELD_GET(HDC3020_THRESH_HUM_MASK, curr_thresh) <<
+ HDC3020_THRESH_HUM_TRUNC_SHIFT);
+
+ return thresh;
+}
+
+static u16 hdc3020_thresh_set_hum(int s_hum, u16 curr_thresh)
+{
+ u64 hum;
+ u16 thresh;
+
+ /*
+ * Calculate humidity threshold, shift it down and up to get the
+ * truncated threshold representation in the 7MSBs while keeping
+ * the current temperature threshold in the 9 LSBs.
+ */
+ hum = (u64)(s_hum) * 65535ULL;
+ hum = div_u64(hum, 1000000 * 100) >> HDC3020_THRESH_HUM_TRUNC_SHIFT;
+ thresh = FIELD_PREP(HDC3020_THRESH_HUM_MASK, hum);
+ thresh |= FIELD_GET(HDC3020_THRESH_TEMP_MASK, curr_thresh);
+
+ return thresh;
+}
+
+static
+int hdc3020_thresh_clr(s64 s_thresh, s64 s_hyst, enum iio_event_direction dir)
+{
+ s64 s_clr;
+
+ /*
+ * Include directions when calculation the clear value,
+ * since hysteresis is unsigned by definition and the
+ * clear value is an absolute value which is signed.
+ */
+ if (dir == IIO_EV_DIR_RISING)
+ s_clr = s_thresh - s_hyst;
+ else
+ s_clr = s_thresh + s_hyst;
+
+ /* Divide by 65535 to get units of micro */
+ return div_s64(s_clr, 65535);
+}
+
+static int _hdc3020_write_thresh(struct hdc3020_data *data, u16 reg, u16 val)
+{
+ u8 buf[5];
+
+ put_unaligned_be16(reg, buf);
+ put_unaligned_be16(val, buf + 2);
+ buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
+
+ return hdc3020_write_bytes(data, buf, 5);
+}
+
static int hdc3020_write_thresh(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
@@ -371,67 +473,126 @@ static int hdc3020_write_thresh(struct iio_dev *indio_dev,
int val, int val2)
{
struct hdc3020_data *data = iio_priv(indio_dev);
- u8 buf[5];
- u64 tmp;
- u16 reg;
- int ret;
-
- /* Supported temperature range is from –40 to 125 degree celsius */
- if (val < HDC3020_MIN_TEMP || val > HDC3020_MAX_TEMP)
- return -EINVAL;
-
- /* Select threshold register */
- if (info == IIO_EV_INFO_VALUE) {
- if (dir == IIO_EV_DIR_RISING)
- reg = HDC3020_S_T_RH_THRESH_HIGH;
- else
- reg = HDC3020_S_T_RH_THRESH_LOW;
+ u16 reg, reg_val, reg_thresh_rd, reg_clr_rd, reg_thresh_wr, reg_clr_wr;
+ s64 s_thresh, s_hyst, s_clr;
+ int s_val, thresh, clr, ret;
+
+ /* Select threshold registers */
+ if (dir == IIO_EV_DIR_RISING) {
+ reg_thresh_rd = HDC3020_R_T_RH_THRESH_HIGH;
+ reg_thresh_wr = HDC3020_S_T_RH_THRESH_HIGH;
+ reg_clr_rd = HDC3020_R_T_RH_THRESH_HIGH_CLR;
+ reg_clr_wr = HDC3020_S_T_RH_THRESH_HIGH_CLR;
} else {
- if (dir == IIO_EV_DIR_RISING)
- reg = HDC3020_S_T_RH_THRESH_HIGH_CLR;
- else
- reg = HDC3020_S_T_RH_THRESH_LOW_CLR;
+ reg_thresh_rd = HDC3020_R_T_RH_THRESH_LOW;
+ reg_thresh_wr = HDC3020_S_T_RH_THRESH_LOW;
+ reg_clr_rd = HDC3020_R_T_RH_THRESH_LOW_CLR;
+ reg_clr_wr = HDC3020_S_T_RH_THRESH_LOW_CLR;
}
guard(mutex)(&data->lock);
- ret = hdc3020_read_be16(data, reg);
+ ret = hdc3020_read_be16(data, reg_thresh_rd);
if (ret < 0)
return ret;
+ thresh = ret;
+ ret = hdc3020_read_be16(data, reg_clr_rd);
+ if (ret < 0)
+ return ret;
+
+ clr = ret;
+ /* Scale value to include decimal part into calculations */
+ s_val = (val < 0) ? (val * 1000000 - val2) : (val * 1000000 + val2);
switch (chan->type) {
case IIO_TEMP:
- /*
- * Calculate temperature threshold, shift it down to get the
- * truncated threshold representation in the 9LSBs while keeping
- * the current humidity threshold in the 7 MSBs.
- */
- tmp = ((u64)(((val + 45) * MICRO) + val2)) * 65535ULL;
- tmp = div_u64(tmp, MICRO * 175);
- val = tmp >> HDC3020_THRESH_TEMP_TRUNC_SHIFT;
- val = FIELD_PREP(HDC3020_THRESH_TEMP_MASK, val);
- val |= (FIELD_GET(HDC3020_THRESH_HUM_MASK, ret) <<
- HDC3020_THRESH_HUM_TRUNC_SHIFT);
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ s_val = max(s_val, HDC3020_MIN_TEMP_MICRO);
+ s_val = min(s_val, HDC3020_MAX_TEMP_MICRO);
+ reg = reg_thresh_wr;
+ reg_val = hdc3020_thresh_set_temp(s_val, thresh);
+ ret = _hdc3020_write_thresh(data, reg, reg_val);
+ if (ret < 0)
+ return ret;
+
+ /* Calculate old hysteresis */
+ s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000;
+ s_clr = (s64)hdc3020_thresh_get_temp(clr) * 1000000;
+ s_hyst = div_s64(abs(s_thresh - s_clr), 65535);
+ /* Set new threshold */
+ thresh = reg_val;
+ /* Set old hysteresis */
+ s_val = s_hyst;
+ fallthrough;
+ case IIO_EV_INFO_HYSTERESIS:
+ /*
+ * Function hdc3020_thresh_get_temp returns temperature
+ * in degree celsius scaled by 65535. Scale by 1000000
+ * to be able to subtract scaled hysteresis value.
+ */
+ s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000;
+ /*
+ * Units of s_val are in micro degree celsius, scale by
+ * 65535 to get same units as s_thresh.
+ */
+ s_val = min(abs(s_val), HDC3020_MAX_TEMP_HYST_MICRO);
+ s_hyst = (s64)s_val * 65535;
+ s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir);
+ s_clr = max(s_clr, HDC3020_MIN_TEMP_MICRO);
+ s_clr = min(s_clr, HDC3020_MAX_TEMP_MICRO);
+ reg = reg_clr_wr;
+ reg_val = hdc3020_thresh_set_temp(s_clr, clr);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
break;
case IIO_HUMIDITYRELATIVE:
- /*
- * Calculate humidity threshold, shift it down and up to get the
- * truncated threshold representation in the 7MSBs while keeping
- * the current temperature threshold in the 9 LSBs.
- */
- tmp = ((u64)((val * MICRO) + val2)) * 65535ULL;
- tmp = div_u64(tmp, MICRO * 100);
- val = tmp >> HDC3020_THRESH_HUM_TRUNC_SHIFT;
- val = FIELD_PREP(HDC3020_THRESH_HUM_MASK, val);
- val |= FIELD_GET(HDC3020_THRESH_TEMP_MASK, ret);
+ s_val = (s_val < 0) ? 0 : min(s_val, HDC3020_MAX_HUM_MICRO);
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ reg = reg_thresh_wr;
+ reg_val = hdc3020_thresh_set_hum(s_val, thresh);
+ ret = _hdc3020_write_thresh(data, reg, reg_val);
+ if (ret < 0)
+ return ret;
+
+ /* Calculate old hysteresis */
+ s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000;
+ s_clr = (s64)hdc3020_thresh_get_hum(clr) * 1000000;
+ s_hyst = div_s64(abs(s_thresh - s_clr), 65535);
+ /* Set new threshold */
+ thresh = reg_val;
+ /* Try to set old hysteresis */
+ s_val = min(abs(s_hyst), HDC3020_MAX_HUM_MICRO);
+ fallthrough;
+ case IIO_EV_INFO_HYSTERESIS:
+ /*
+ * Function hdc3020_thresh_get_hum returns relative
+ * humidity in percent scaled by 65535. Scale by 1000000
+ * to be able to subtract scaled hysteresis value.
+ */
+ s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000;
+ /*
+ * Units of s_val are in micro percent, scale by 65535
+ * to get same units as s_thresh.
+ */
+ s_hyst = (s64)s_val * 65535;
+ s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir);
+ s_clr = max(s_clr, 0);
+ s_clr = min(s_clr, HDC3020_MAX_HUM_MICRO);
+ reg = reg_clr_wr;
+ reg_val = hdc3020_thresh_set_hum(s_clr, clr);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
break;
default:
return -EOPNOTSUPP;
}
- put_unaligned_be16(reg, buf);
- put_unaligned_be16(val, buf + 2);
- buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
- return hdc3020_write_bytes(data, buf, 5);
+ return _hdc3020_write_thresh(data, reg, reg_val);
}
static int hdc3020_read_thresh(struct iio_dev *indio_dev,
@@ -442,48 +603,60 @@ static int hdc3020_read_thresh(struct iio_dev *indio_dev,
int *val, int *val2)
{
struct hdc3020_data *data = iio_priv(indio_dev);
- u16 reg;
- int ret;
+ u16 reg_thresh, reg_clr;
+ int thresh, clr, ret;
- /* Select threshold register */
- if (info == IIO_EV_INFO_VALUE) {
- if (dir == IIO_EV_DIR_RISING)
- reg = HDC3020_R_T_RH_THRESH_HIGH;
- else
- reg = HDC3020_R_T_RH_THRESH_LOW;
+ /* Select threshold registers */
+ if (dir == IIO_EV_DIR_RISING) {
+ reg_thresh = HDC3020_R_T_RH_THRESH_HIGH;
+ reg_clr = HDC3020_R_T_RH_THRESH_HIGH_CLR;
} else {
- if (dir == IIO_EV_DIR_RISING)
- reg = HDC3020_R_T_RH_THRESH_HIGH_CLR;
- else
- reg = HDC3020_R_T_RH_THRESH_LOW_CLR;
+ reg_thresh = HDC3020_R_T_RH_THRESH_LOW;
+ reg_clr = HDC3020_R_T_RH_THRESH_LOW_CLR;
}
guard(mutex)(&data->lock);
- ret = hdc3020_read_be16(data, reg);
+ ret = hdc3020_read_be16(data, reg_thresh);
if (ret < 0)
return ret;
switch (chan->type) {
case IIO_TEMP:
- /*
- * Get the temperature threshold from 9 LSBs, shift them to get
- * the truncated temperature threshold representation and
- * calculate the threshold according to the formula in the
- * datasheet.
- */
- *val = FIELD_GET(HDC3020_THRESH_TEMP_MASK, ret);
- *val = *val << HDC3020_THRESH_TEMP_TRUNC_SHIFT;
- *val = -2949075 + (175 * (*val));
+ thresh = hdc3020_thresh_get_temp(ret);
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ *val = thresh;
+ break;
+ case IIO_EV_INFO_HYSTERESIS:
+ ret = hdc3020_read_be16(data, reg_clr);
+ if (ret < 0)
+ return ret;
+
+ clr = hdc3020_thresh_get_temp(ret);
+ *val = abs(thresh - clr);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
*val2 = 65535;
return IIO_VAL_FRACTIONAL;
case IIO_HUMIDITYRELATIVE:
- /*
- * Get the humidity threshold from 7 MSBs, shift them to get the
- * truncated humidity threshold representation and calculate the
- * threshold according to the formula in the datasheet.
- */
- *val = FIELD_GET(HDC3020_THRESH_HUM_MASK, ret);
- *val = (*val << HDC3020_THRESH_HUM_TRUNC_SHIFT) * 100;
+ thresh = hdc3020_thresh_get_hum(ret);
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ *val = thresh;
+ break;
+ case IIO_EV_INFO_HYSTERESIS:
+ ret = hdc3020_read_be16(data, reg_clr);
+ if (ret < 0)
+ return ret;
+
+ clr = hdc3020_thresh_get_hum(ret);
+ *val = abs(thresh - clr);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
*val2 = 65535;
return IIO_VAL_FRACTIONAL;
default:
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 05:49:18 +0000