Add support for the Sensirion SHT31 humidity + temperature sensor.
Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
---
.../devicetree/bindings/i2c/trivial-devices.txt | 1 +
drivers/iio/humidity/Kconfig | 11 +
drivers/iio/humidity/Makefile | 1 +
drivers/iio/humidity/sht31.c | 416 +++++++++++++++++++++
4 files changed, 429 insertions(+)
create mode 100644 drivers/iio/humidity/sht31.c
diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index 539874490492..a651ccd15459 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -78,6 +78,7 @@ ricoh,rs5c372b I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
ricoh,rv5c386 I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
ricoh,rv5c387a I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
samsung,24ad0xd1 S524AD0XF1 (128K/256K-bit Serial EEPROM for Low Power)
+sensirion,sht31 Sensirion SHT31 humidity + temperature sensor
sgx,vz89x SGX Sensortech VZ89X Sensors
sii,s35390a 2-wire CMOS real-time clock
skyworks,sky81452 Skyworks SKY81452: Six-Channel White LED Driver with Touch Panel Bias Supply
diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
index 738a86d9e4a9..21bff72511a5 100644
--- a/drivers/iio/humidity/Kconfig
+++ b/drivers/iio/humidity/Kconfig
@@ -45,6 +45,17 @@ config HTU21
This driver can also be built as a module. If so, the module will
be called htu21.
+config SHT31
+ tristate "Sensirion SHT31 humidity and temperature sensor"
+ depends on I2C
+ select CRC8
+ help
+ If you say yes here you support for the Sensirion SHT31 humidity and
+ temperature sensor.
+
+ This driver can also be built as a module. If so, the module will be
+ called sht31.
+
config SI7005
tristate "SI7005 relative humidity and temperature sensor"
depends on I2C
diff --git a/drivers/iio/humidity/Makefile b/drivers/iio/humidity/Makefile
index 4a73442fcd9c..a3b7727d47bf 100644
--- a/drivers/iio/humidity/Makefile
+++ b/drivers/iio/humidity/Makefile
@@ -6,5 +6,6 @@ obj-$(CONFIG_AM2315) += am2315.o
obj-$(CONFIG_DHT11) += dht11.o
obj-$(CONFIG_HDC100X) += hdc100x.o
obj-$(CONFIG_HTU21) += htu21.o
+obj-$(CONFIG_SHT31) += sht31.o
obj-$(CONFIG_SI7005) += si7005.o
obj-$(CONFIG_SI7020) += si7020.o
diff --git a/drivers/iio/humidity/sht31.c b/drivers/iio/humidity/sht31.c
new file mode 100644
index 000000000000..c1d74dcaf8c6
--- /dev/null
+++ b/drivers/iio/humidity/sht31.c
@@ -0,0 +1,416 @@
+/*
+ * sht31.c - Support for the Sensirion SHT31 temperature + humidity sensor
+ *
+ * Copyright (C) 2016 Matt Ranostay <mranostay@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/crc8.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#define SHT31_DRV_NAME "sht31"
+
+#define SHT31_HEATER_CMD_MSB 0x30
+#define SHT31_HEATER_CMD_ENABLE 0x6d
+#define SHT31_HEATER_CMD_DISABLE 0x66
+
+#define SHT31_MEASUREMENT_CMD_MSB (0x2C << 8)
+
+#define SHT31_STATUS_CMD 0xF32D
+#define SHT31_STATUS_CMD_CHKSUM BIT(0)
+
+struct sht31_data {
+ struct iio_dev *indio_dev;
+ struct i2c_client *client;
+ struct mutex lock;
+
+ /* config */
+ int heater_status;
+ int it_time;
+
+ u8 crc_table[CRC8_TABLE_SIZE];
+ u16 buffer[8]; /* 4 byte data + 2 byte pad + 8 byte */
+};
+
+static const struct iio_chan_spec sht31_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .address = 0,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 16,
+ .storagebits = 16,
+ },
+ },
+ {
+ .type = IIO_HUMIDITYRELATIVE,
+ .address = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+ .scan_index = 1,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 16,
+ .storagebits = 16,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(2),
+ {
+ .type = IIO_CURRENT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .extend_name = "heater",
+ .scan_index = -1,
+ .output = 1,
+ },
+};
+
+static IIO_CONST_ATTR(integration_time_available,
+ "0.0025 0.0045 0.0125");
+
+static IIO_CONST_ATTR(out_current_heater_raw_available,
+ "0 1");
+
+/* integration time + LSB of I2C command */
+static const int sht31_integration_time[][2] = {
+ {2500, 0x10},
+ {4500, 0x0d},
+ {12500, 0x06}
+};
+
+static const unsigned long sht31_scan_masks[] = {0x3, 0};
+
+static struct attribute *sht31_attributes[] = {
+ &iio_const_attr_integration_time_available.dev_attr.attr,
+ &iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
+ NULL
+};
+
+static struct attribute_group sht31_attribute_group = {
+ .attrs = sht31_attributes,
+};
+
+static int sht31_crc8_check(struct sht31_data *data, u8 *vals)
+{
+ int ret = crc8(data->crc_table, vals, 2, 0xff);
+
+ if (ret != vals[2])
+ return -EINVAL;
+
+ return 0;
+}
+
+static int sht31_get_measurement(struct sht31_data *data, u16 *buf)
+{
+ struct i2c_client *client = data->client;
+ struct i2c_msg msg[2];
+ u16 reg = cpu_to_be16(SHT31_MEASUREMENT_CMD_MSB |
+ sht31_integration_time[data->it_time][1]);
+ u8 vals[6];
+ int ret, i;
+
+ msg[0].addr = client->addr;
+ msg[0].flags = client->flags;
+ msg[0].len = 2;
+ msg[0].buf = (char *) ®
+
+ msg[1].addr = client->addr;
+ msg[1].flags = client->flags | I2C_M_RD;
+ msg[1].len = sizeof(vals);
+ msg[1].buf = (char *) &vals;
+
+ ret = i2c_transfer(client->adapter, msg, 2);
+ if (ret != 2)
+ return -EIO;
+
+ for (i = 0; i < 2; i++) {
+ ret = sht31_crc8_check(data, (u8 *) &vals[3 * i]);
+ if (ret)
+ return -EINVAL;
+ *buf++ = be16_to_cpu(*((u16 *) &vals[3 * i]));
+ }
+
+ return 0;
+}
+
+static irqreturn_t sht31_trigger_handler(int irq, void *private)
+{
+ struct iio_poll_func *pf = private;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct sht31_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = sht31_get_measurement(data, data->buffer);
+ if (!ret)
+ iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ iio_get_time_ns());
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int sht31_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct sht31_data *data = iio_priv(indio_dev);
+ int ret = -EINVAL;
+ u16 buf[2];
+
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ mutex_lock(&data->lock);
+ *val = 0;
+ *val2 = sht31_integration_time[data->it_time][0];
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ mutex_unlock(&data->lock);
+ break;
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_HUMIDITYRELATIVE:
+ case IIO_TEMP:
+ if (iio_device_claim_direct_mode(indio_dev))
+ return -EBUSY;
+
+ ret = sht31_get_measurement(data, (u16 *) &buf);
+ if (!ret) {
+ *val = buf[chan->address];
+ ret = IIO_VAL_INT;
+ }
+ iio_device_release_direct_mode(indio_dev);
+ break;
+ case IIO_CURRENT:
+ mutex_lock(&data->lock);
+ *val = data->heater_status;
+ ret = IIO_VAL_INT;
+ mutex_unlock(&data->lock);
+ break;
+ default:
+ return -EINVAL;
+ }
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_HUMIDITYRELATIVE:
+ *val = 100;
+ *val2 = 65535;
+ break;
+ case IIO_TEMP:
+ *val = 175000;
+ *val2 = 65535;
+ break;
+ default:
+ return -EINVAL;
+ }
+ ret = IIO_VAL_FRACTIONAL;
+ break;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = 18349; /* 18349.8 */
+ *val2 = 800000;
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+ }
+
+ return ret;
+}
+
+static int sht31_set_it_time(struct sht31_data *data, int val2)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(sht31_integration_time); i++) {
+ if (sht31_integration_time[i][0] == val2) {
+ data->it_time = i;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int sht31_validate_checksum(struct sht31_data *data)
+{
+ struct i2c_client *client = data->client;
+ struct i2c_msg msg[2];
+ u16 reg = cpu_to_be16(SHT31_STATUS_CMD);
+ u8 vals[3];
+ int ret;
+
+ msg[0].addr = client->addr;
+ msg[0].flags = client->flags;
+ msg[0].len = 2;
+ msg[0].buf = (char *) ®
+
+ msg[1].addr = client->addr;
+ msg[1].flags = client->flags | I2C_M_RD;
+ msg[1].len = sizeof(vals);
+ msg[1].buf = (char *) &vals;
+
+ ret = i2c_transfer(client->adapter, msg, 2);
+ if (ret != 2)
+ return -EIO;
+
+ ret = sht31_crc8_check(data, (u8 *) &vals);
+ if (ret)
+ return ret;
+
+ return (vals[1] & SHT31_STATUS_CMD_CHKSUM) ? -EINVAL : 0;
+}
+
+static int sht31_set_heater_status(struct sht31_data *data, int val)
+{
+ int ret;
+
+ ret = i2c_smbus_write_byte_data(data->client, SHT31_HEATER_CMD_MSB,
+ val ? SHT31_HEATER_CMD_ENABLE : SHT31_HEATER_CMD_DISABLE);
+ if (ret < 0)
+ return ret;
+
+ ret = sht31_validate_checksum(data);
+ if (!ret)
+ data->heater_status = !!val;
+
+ return ret;
+}
+
+static int sht31_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct sht31_data *data = iio_priv(indio_dev);
+ int ret = -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ if (val != 0)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = sht31_set_it_time(data, val2);
+ mutex_unlock(&data->lock);
+ break;
+ case IIO_CHAN_INFO_RAW:
+ if (chan->type != IIO_CURRENT || val2 != 0)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = sht31_set_heater_status(data, val);
+ mutex_unlock(&data->lock);
+ break;
+ }
+
+ return ret;
+}
+
+static const struct iio_info sht31_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = sht31_read_raw,
+ .write_raw = sht31_write_raw,
+ .attrs = &sht31_attribute_group,
+};
+
+static int sht31_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct sht31_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+ data = iio_priv(indio_dev);
+
+ indio_dev->info = &sht31_info;
+ indio_dev->name = SHT31_DRV_NAME;
+ indio_dev->channels = sht31_channels;
+ indio_dev->num_channels = ARRAY_SIZE(sht31_channels);
+ indio_dev->available_scan_masks = sht31_scan_masks;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->dev.parent = &client->dev;
+
+ i2c_set_clientdata(client, indio_dev);
+
+ data->client = client;
+ data->indio_dev = indio_dev;
+ mutex_init(&data->lock);
+
+ /* CRC polynomial x8 + x5 + x4 + 1 */
+ crc8_populate_msb(data->crc_table, 0x31);
+
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ sht31_trigger_handler, NULL);
+ if (ret)
+ return ret;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_unreg_buffer;
+
+ return 0;
+
+error_unreg_buffer:
+ iio_triggered_buffer_cleanup(indio_dev);
+
+ return ret;
+}
+
+static int sht31_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+
+ return 0;
+}
+
+static const struct of_device_id sht31_dt_ids[] = {
+ { .compatible = "sensirion,sht31" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sht31_dt_ids);
+
+static const struct i2c_device_id sht31_id[] = {
+ { "sht31", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, sht31_id);
+
+static struct i2c_driver sht31_driver = {
+ .driver = {
+ .name = SHT31_DRV_NAME,
+ },
+ .probe = sht31_probe,
+ .remove = sht31_remove,
+ .id_table = sht31_id,
+};
+module_i2c_driver(sht31_driver);
+
+MODULE_AUTHOR("Matt Ranostay <mranostay@xxxxxxxxx>");
+MODULE_DESCRIPTION("Sensirion SHT31 humidity and temperature sensor driver");
+MODULE_LICENSE("GPL");
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
