Le 03/02/2024 à 10:05, Dimitri Fedrau a écrit :
Add threshold events support for temperature and relative humidity. To
enable them the higher and lower threshold registers must be programmed
and the higher threshold must be greater then or equal to the lower
threshold. Otherwise the event is disabled. Invalid hysteresis values
are ignored by the device. There is no further configuration possible.
Tested by setting thresholds/hysteresis and turning the heater on/off.
Used iio_event_monitor in tools/iio to catch events while constantly
displaying temperature and humidity values.
Threshold and hysteresis values are cached in the driver, used i2c-tools
to read the threshold and hysteresis values from the device and make
sure cached values are consistent to values written to the device.
Based on Fix:
a69eeaad093d "iio: humidity: hdc3020: fix temperature offset" in branch
fixes-togreg
Signed-off-by: Dimitri Fedrau <dima.fedrau-Re5JQEeQqe8AvxtiuMwx3w@xxxxxxxxxxxxxxxx>
---
drivers/iio/humidity/hdc3020.c | 339 +++++++++++++++++++++++++++++++++
1 file changed, 339 insertions(+)
diff --git a/drivers/iio/humidity/hdc3020.c b/drivers/iio/humidity/hdc3020.c
index ed70415512f6..1cdff7af4ca8 100644
--- a/drivers/iio/humidity/hdc3020.c
+++ b/drivers/iio/humidity/hdc3020.c
@@ -16,16 +16,27 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/interrupt.h>
Nit: alphabetical order could be kept
#include <asm/unaligned.h>
#include <linux/iio/iio.h>
+#include <linux/iio/events.h>
Nit: same
...
+static const u8 HDC3020_R_T_RH_THRESH_LOW[2] = { 0xE1, 0x02 };
+static const u8 HDC3020_R_R_RH_THRESH_LOW_CLR[2] = { 0xE1, 0x09 };
I don't know what the R and T are for, but shoukld this be
HDC3020_R_T_RH_THRESH_LOW_CLR to match other adjacent line?
+static const u8 HDC3020_R_T_RH_THRESH_HIGH_CLR[2] = { 0xE1, 0x14 };
+static const u8 HDC3020_R_T_RH_THRESH_HIGH[2] = { 0xE1, 0x1F };
...
+static int hdc3020_write_thresh(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ enum iio_event_info info,
+ int val, int val2)
+{
+ struct hdc3020_data *data = iio_priv(indio_dev);
+ u16 *thresh;
+ u8 buf[5];
+ int ret;
+
+ /* Supported temperature range is from –40 to 125 degree celsius */
+ if (val < -45 || val > 125)
+ return -EINVAL;
+
+ /* Select threshold and associated register */
+ if (info == IIO_EV_INFO_VALUE) {
+ if (dir == IIO_EV_DIR_RISING) {
+ thresh = &data->t_rh_thresh_high;
+ memcpy(buf, HDC3020_S_T_RH_THRESH_HIGH, 2);
+ } else {
+ thresh = &data->t_rh_thresh_low;
+ memcpy(buf, HDC3020_S_T_RH_THRESH_LOW, 2);
+ }
+ } else {
+ if (dir == IIO_EV_DIR_RISING) {
+ thresh = &data->t_rh_thresh_high_clr;
+ memcpy(buf, HDC3020_S_T_RH_THRESH_HIGH_CLR, 2);
+ } else {
+ thresh = &data->t_rh_thresh_low_clr;
+ memcpy(buf, HDC3020_S_T_RH_THRESH_LOW_CLR, 2);
+ }
+ }
+
+ guard(mutex)(&data->lock);
+ switch (chan->type) {
+ case IIO_TEMP:
+ /*
+ * Store truncated temperature threshold into 9 LSBs while
+ * keeping the old humidity threshold in the 7 MSBs.
+ */
+ val = (((val + 45) * 65535 / 175) >> HDC3020_THRESH_TEMP_SHIFT);
Why 175?
If the span is -40/+120, I guess it should be 160 and if it is -45/+120,
165. No?
Maybe something like:
#define MIN_TEMP -45 (or -40)
#define MAX_TEMP 120
in order to avoid hard coded constant?
+ val &= HDC3020_THRESH_TEMP_MASK;
+ val |= (*thresh & HDC3020_THRESH_HUM_MASK);
+ break;
+ case IIO_HUMIDITYRELATIVE:
+ /*
+ * Store truncated humidity threshold into 7 MSBs while
+ * keeping the old temperature threshold in the 9 LSBs.
+ */
+ val = ((val * 65535 / 100) & HDC3020_THRESH_HUM_MASK);
+ val |= (*thresh & HDC3020_THRESH_TEMP_MASK);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ put_unaligned_be16(val, &buf[2]);
+ buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
+ ret = hdc3020_write_bytes(data, buf, 5);
+ if (ret)
+ return ret;
+
+ /* Update threshold */
+ *thresh = val;
+
+ return 0;
+}
CJ
