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Diffstat (limited to 'drivers/iio/humidity/hdc3020.c')
-rw-r--r--drivers/iio/humidity/hdc3020.c473
1 files changed, 473 insertions, 0 deletions
diff --git a/drivers/iio/humidity/hdc3020.c b/drivers/iio/humidity/hdc3020.c
new file mode 100644
index 0000000000..ed70415512
--- /dev/null
+++ b/drivers/iio/humidity/hdc3020.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * hdc3020.c - Support for the TI HDC3020,HDC3021 and HDC3022
+ * temperature + relative humidity sensors
+ *
+ * Copyright (C) 2023
+ *
+ * Datasheet: https://www.ti.com/lit/ds/symlink/hdc3020.pdf
+ */
+
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+#include <asm/unaligned.h>
+
+#include <linux/iio/iio.h>
+
+#define HDC3020_HEATER_CMD_MSB 0x30 /* shared by all heater commands */
+#define HDC3020_HEATER_ENABLE 0x6D
+#define HDC3020_HEATER_DISABLE 0x66
+#define HDC3020_HEATER_CONFIG 0x6E
+
+#define HDC3020_READ_RETRY_TIMES 10
+#define HDC3020_BUSY_DELAY_MS 10
+
+#define HDC3020_CRC8_POLYNOMIAL 0x31
+
+static const u8 HDC3020_S_AUTO_10HZ_MOD0[2] = { 0x27, 0x37 };
+
+static const u8 HDC3020_EXIT_AUTO[2] = { 0x30, 0x93 };
+
+static const u8 HDC3020_R_T_RH_AUTO[2] = { 0xE0, 0x00 };
+static const u8 HDC3020_R_T_LOW_AUTO[2] = { 0xE0, 0x02 };
+static const u8 HDC3020_R_T_HIGH_AUTO[2] = { 0xE0, 0x03 };
+static const u8 HDC3020_R_RH_LOW_AUTO[2] = { 0xE0, 0x04 };
+static const u8 HDC3020_R_RH_HIGH_AUTO[2] = { 0xE0, 0x05 };
+
+struct hdc3020_data {
+ struct i2c_client *client;
+ /*
+ * Ensure that the sensor configuration (currently only heater is
+ * supported) will not be changed during the process of reading
+ * sensor data (this driver will try HDC3020_READ_RETRY_TIMES times
+ * if the device does not respond).
+ */
+ struct mutex lock;
+};
+
+static const int hdc3020_heater_vals[] = {0, 1, 0x3FFF};
+
+static const struct iio_chan_spec hdc3020_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) |
+ BIT(IIO_CHAN_INFO_TROUGH) | BIT(IIO_CHAN_INFO_OFFSET),
+ },
+ {
+ .type = IIO_HUMIDITYRELATIVE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) |
+ BIT(IIO_CHAN_INFO_TROUGH),
+ },
+ {
+ /*
+ * For setting the internal heater, which can be switched on to
+ * prevent or remove any condensation that may develop when the
+ * ambient environment approaches its dew point temperature.
+ */
+ .type = IIO_CURRENT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
+ .output = 1,
+ },
+};
+
+DECLARE_CRC8_TABLE(hdc3020_crc8_table);
+
+static int hdc3020_write_bytes(struct hdc3020_data *data, const u8 *buf, u8 len)
+{
+ struct i2c_client *client = data->client;
+ struct i2c_msg msg;
+ int ret, cnt;
+
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.buf = (char *)buf;
+ msg.len = len;
+
+ /*
+ * During the measurement process, HDC3020 will not return data.
+ * So wait for a while and try again
+ */
+ for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) {
+ ret = i2c_transfer(client->adapter, &msg, 1);
+ if (ret == 1)
+ return 0;
+
+ mdelay(HDC3020_BUSY_DELAY_MS);
+ }
+ dev_err(&client->dev, "Could not write sensor command\n");
+
+ return -ETIMEDOUT;
+}
+
+static int hdc3020_read_bytes(struct hdc3020_data *data, const u8 *buf,
+ void *val, int len)
+{
+ int ret, cnt;
+ struct i2c_client *client = data->client;
+ struct i2c_msg msg[2] = {
+ [0] = {
+ .addr = client->addr,
+ .flags = 0,
+ .buf = (char *)buf,
+ .len = 2,
+ },
+ [1] = {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .buf = val,
+ .len = len,
+ },
+ };
+
+ /*
+ * During the measurement process, HDC3020 will not return data.
+ * So wait for a while and try again
+ */
+ for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) {
+ ret = i2c_transfer(client->adapter, msg, 2);
+ if (ret == 2)
+ return 0;
+
+ mdelay(HDC3020_BUSY_DELAY_MS);
+ }
+ dev_err(&client->dev, "Could not read sensor data\n");
+
+ return -ETIMEDOUT;
+}
+
+static int hdc3020_read_measurement(struct hdc3020_data *data,
+ enum iio_chan_type type, int *val)
+{
+ u8 crc, buf[6];
+ int ret;
+
+ ret = hdc3020_read_bytes(data, HDC3020_R_T_RH_AUTO, buf, 6);
+ if (ret < 0)
+ return ret;
+
+ /* CRC check of the temperature measurement */
+ crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
+ if (crc != buf[2])
+ return -EINVAL;
+
+ /* CRC check of the relative humidity measurement */
+ crc = crc8(hdc3020_crc8_table, buf + 3, 2, CRC8_INIT_VALUE);
+ if (crc != buf[5])
+ return -EINVAL;
+
+ if (type == IIO_TEMP)
+ *val = get_unaligned_be16(buf);
+ else if (type == IIO_HUMIDITYRELATIVE)
+ *val = get_unaligned_be16(&buf[3]);
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+/*
+ * After exiting the automatic measurement mode or resetting, the peak
+ * value will be reset to the default value
+ * This method is used to get the highest temp measured during automatic
+ * measurement
+ */
+static int hdc3020_read_high_peak_t(struct hdc3020_data *data, int *val)
+{
+ u8 crc, buf[3];
+ int ret;
+
+ ret = hdc3020_read_bytes(data, HDC3020_R_T_HIGH_AUTO, buf, 3);
+ if (ret < 0)
+ return ret;
+
+ crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
+ if (crc != buf[2])
+ return -EINVAL;
+
+ *val = get_unaligned_be16(buf);
+
+ return 0;
+}
+
+/*
+ * This method is used to get the lowest temp measured during automatic
+ * measurement
+ */
+static int hdc3020_read_low_peak_t(struct hdc3020_data *data, int *val)
+{
+ u8 crc, buf[3];
+ int ret;
+
+ ret = hdc3020_read_bytes(data, HDC3020_R_T_LOW_AUTO, buf, 3);
+ if (ret < 0)
+ return ret;
+
+ crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
+ if (crc != buf[2])
+ return -EINVAL;
+
+ *val = get_unaligned_be16(buf);
+
+ return 0;
+}
+
+/*
+ * This method is used to get the highest humidity measured during automatic
+ * measurement
+ */
+static int hdc3020_read_high_peak_rh(struct hdc3020_data *data, int *val)
+{
+ u8 crc, buf[3];
+ int ret;
+
+ ret = hdc3020_read_bytes(data, HDC3020_R_RH_HIGH_AUTO, buf, 3);
+ if (ret < 0)
+ return ret;
+
+ crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
+ if (crc != buf[2])
+ return -EINVAL;
+
+ *val = get_unaligned_be16(buf);
+
+ return 0;
+}
+
+/*
+ * This method is used to get the lowest humidity measured during automatic
+ * measurement
+ */
+static int hdc3020_read_low_peak_rh(struct hdc3020_data *data, int *val)
+{
+ u8 crc, buf[3];
+ int ret;
+
+ ret = hdc3020_read_bytes(data, HDC3020_R_RH_LOW_AUTO, buf, 3);
+ if (ret < 0)
+ return ret;
+
+ crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
+ if (crc != buf[2])
+ return -EINVAL;
+
+ *val = get_unaligned_be16(buf);
+
+ return 0;
+}
+
+static int hdc3020_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct hdc3020_data *data = iio_priv(indio_dev);
+ int ret;
+
+ if (chan->type != IIO_TEMP && chan->type != IIO_HUMIDITYRELATIVE)
+ return -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW: {
+ guard(mutex)(&data->lock);
+ ret = hdc3020_read_measurement(data, chan->type, val);
+ if (ret < 0)
+ return ret;
+
+ return IIO_VAL_INT;
+ }
+ case IIO_CHAN_INFO_PEAK: {
+ guard(mutex)(&data->lock);
+ if (chan->type == IIO_TEMP) {
+ ret = hdc3020_read_high_peak_t(data, val);
+ if (ret < 0)
+ return ret;
+ } else {
+ ret = hdc3020_read_high_peak_rh(data, val);
+ if (ret < 0)
+ return ret;
+ }
+ return IIO_VAL_INT;
+ }
+ case IIO_CHAN_INFO_TROUGH: {
+ guard(mutex)(&data->lock);
+ if (chan->type == IIO_TEMP) {
+ ret = hdc3020_read_low_peak_t(data, val);
+ if (ret < 0)
+ return ret;
+ } else {
+ ret = hdc3020_read_low_peak_rh(data, val);
+ if (ret < 0)
+ return ret;
+ }
+ return IIO_VAL_INT;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ *val2 = 65536;
+ if (chan->type == IIO_TEMP)
+ *val = 175;
+ else
+ *val = 100;
+ return IIO_VAL_FRACTIONAL;
+
+ case IIO_CHAN_INFO_OFFSET:
+ if (chan->type != IIO_TEMP)
+ return -EINVAL;
+
+ *val = -16852;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int hdc3020_read_available(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals,
+ int *type, int *length, long mask)
+{
+ if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_CURRENT)
+ return -EINVAL;
+
+ *vals = hdc3020_heater_vals;
+ *type = IIO_VAL_INT;
+
+ return IIO_AVAIL_RANGE;
+}
+
+static int hdc3020_update_heater(struct hdc3020_data *data, int val)
+{
+ u8 buf[5];
+ int ret;
+
+ if (val < hdc3020_heater_vals[0] || val > hdc3020_heater_vals[2])
+ return -EINVAL;
+
+ buf[0] = HDC3020_HEATER_CMD_MSB;
+
+ if (!val) {
+ buf[1] = HDC3020_HEATER_DISABLE;
+ return hdc3020_write_bytes(data, buf, 2);
+ }
+
+ buf[1] = HDC3020_HEATER_CONFIG;
+ put_unaligned_be16(val & GENMASK(13, 0), &buf[2]);
+ buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
+ ret = hdc3020_write_bytes(data, buf, 5);
+ if (ret < 0)
+ return ret;
+
+ buf[1] = HDC3020_HEATER_ENABLE;
+
+ return hdc3020_write_bytes(data, buf, 2);
+}
+
+static int hdc3020_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct hdc3020_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (chan->type != IIO_CURRENT)
+ return -EINVAL;
+
+ guard(mutex)(&data->lock);
+ return hdc3020_update_heater(data, val);
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info hdc3020_info = {
+ .read_raw = hdc3020_read_raw,
+ .write_raw = hdc3020_write_raw,
+ .read_avail = hdc3020_read_available,
+};
+
+static void hdc3020_stop(void *data)
+{
+ hdc3020_write_bytes((struct hdc3020_data *)data, HDC3020_EXIT_AUTO, 2);
+}
+
+static int hdc3020_probe(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev;
+ struct hdc3020_data *data;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ return -EOPNOTSUPP;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+ mutex_init(&data->lock);
+
+ crc8_populate_msb(hdc3020_crc8_table, HDC3020_CRC8_POLYNOMIAL);
+
+ indio_dev->name = "hdc3020";
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &hdc3020_info;
+ indio_dev->channels = hdc3020_channels;
+ indio_dev->num_channels = ARRAY_SIZE(hdc3020_channels);
+
+ ret = hdc3020_write_bytes(data, HDC3020_S_AUTO_10HZ_MOD0, 2);
+ if (ret)
+ return dev_err_probe(&client->dev, ret,
+ "Unable to set up measurement\n");
+
+ ret = devm_add_action_or_reset(&data->client->dev, hdc3020_stop, data);
+ if (ret)
+ return ret;
+
+ ret = devm_iio_device_register(&data->client->dev, indio_dev);
+ if (ret)
+ return dev_err_probe(&client->dev, ret, "Failed to add device");
+
+ return 0;
+}
+
+static const struct i2c_device_id hdc3020_id[] = {
+ { "hdc3020" },
+ { "hdc3021" },
+ { "hdc3022" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, hdc3020_id);
+
+static const struct of_device_id hdc3020_dt_ids[] = {
+ { .compatible = "ti,hdc3020" },
+ { .compatible = "ti,hdc3021" },
+ { .compatible = "ti,hdc3022" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, hdc3020_dt_ids);
+
+static struct i2c_driver hdc3020_driver = {
+ .driver = {
+ .name = "hdc3020",
+ .of_match_table = hdc3020_dt_ids,
+ },
+ .probe = hdc3020_probe,
+ .id_table = hdc3020_id,
+};
+module_i2c_driver(hdc3020_driver);
+
+MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>");
+MODULE_AUTHOR("Li peiyu <579lpy@gmail.com>");
+MODULE_DESCRIPTION("TI HDC3020 humidity and temperature sensor driver");
+MODULE_LICENSE("GPL");