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-rw-r--r--drivers/iio/humidity/Kconfig10
-rw-r--r--drivers/iio/humidity/Makefile1
-rw-r--r--drivers/iio/humidity/am2315.c301
-rw-r--r--drivers/iio/humidity/dht11.c40
4 files changed, 346 insertions, 6 deletions
diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
index 866dda133..738a86d9e 100644
--- a/drivers/iio/humidity/Kconfig
+++ b/drivers/iio/humidity/Kconfig
@@ -3,6 +3,16 @@
#
menu "Humidity sensors"
+config AM2315
+ tristate "Aosong AM2315 relative humidity and temperature sensor"
+ depends on I2C
+ help
+ If you say yes here you get support for the Aosong AM2315
+ relative humidity and ambient temperature sensor.
+
+ This driver can also be built as a module. If so, the module will
+ be called am2315.
+
config DHT11
tristate "DHT11 (and compatible sensors) driver"
depends on GPIOLIB || COMPILE_TEST
diff --git a/drivers/iio/humidity/Makefile b/drivers/iio/humidity/Makefile
index c9f089a9a..4a73442fc 100644
--- a/drivers/iio/humidity/Makefile
+++ b/drivers/iio/humidity/Makefile
@@ -2,6 +2,7 @@
# Makefile for IIO humidity sensor drivers
#
+obj-$(CONFIG_AM2315) += am2315.o
obj-$(CONFIG_DHT11) += dht11.o
obj-$(CONFIG_HDC100X) += hdc100x.o
obj-$(CONFIG_HTU21) += htu21.o
diff --git a/drivers/iio/humidity/am2315.c b/drivers/iio/humidity/am2315.c
new file mode 100644
index 000000000..11535911a
--- /dev/null
+++ b/drivers/iio/humidity/am2315.c
@@ -0,0 +1,301 @@
+/**
+ * Aosong AM2315 relative humidity and temperature
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * 7-bit I2C address: 0x5C.
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define AM2315_REG_HUM_MSB 0x00
+#define AM2315_REG_HUM_LSB 0x01
+#define AM2315_REG_TEMP_MSB 0x02
+#define AM2315_REG_TEMP_LSB 0x03
+
+#define AM2315_FUNCTION_READ 0x03
+#define AM2315_HUM_OFFSET 2
+#define AM2315_TEMP_OFFSET 4
+#define AM2315_ALL_CHANNEL_MASK GENMASK(1, 0)
+
+#define AM2315_DRIVER_NAME "am2315"
+
+struct am2315_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ s16 buffer[8]; /* 2x16-bit channels + 2x16 padding + 4x16 timestamp */
+};
+
+struct am2315_sensor_data {
+ s16 hum_data;
+ s16 temp_data;
+};
+
+static const struct iio_chan_spec am2315_channels[] = {
+ {
+ .type = IIO_HUMIDITYRELATIVE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 16,
+ .storagebits = 16,
+ .endianness = IIO_CPU,
+ },
+ },
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 1,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 16,
+ .storagebits = 16,
+ .endianness = IIO_CPU,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+/* CRC calculation algorithm, as specified in the datasheet (page 13). */
+static u16 am2315_crc(u8 *data, u8 nr_bytes)
+{
+ int i;
+ u16 crc = 0xffff;
+
+ while (nr_bytes--) {
+ crc ^= *data++;
+ for (i = 0; i < 8; i++) {
+ if (crc & 0x01) {
+ crc >>= 1;
+ crc ^= 0xA001;
+ } else {
+ crc >>= 1;
+ }
+ }
+ }
+
+ return crc;
+}
+
+/* Simple function that sends a few bytes to the device to wake it up. */
+static void am2315_ping(struct i2c_client *client)
+{
+ i2c_smbus_read_byte_data(client, AM2315_REG_HUM_MSB);
+}
+
+static int am2315_read_data(struct am2315_data *data,
+ struct am2315_sensor_data *sensor_data)
+{
+ int ret;
+ /* tx_buf format: <function code> <start addr> <nr of regs to read> */
+ u8 tx_buf[3] = { AM2315_FUNCTION_READ, AM2315_REG_HUM_MSB, 4 };
+ /*
+ * rx_buf format:
+ * <function code> <number of registers read>
+ * <humidity MSB> <humidity LSB> <temp MSB> <temp LSB>
+ * <CRC LSB> <CRC MSB>
+ */
+ u8 rx_buf[8];
+ u16 crc;
+
+ /* First wake up the device. */
+ am2315_ping(data->client);
+
+ mutex_lock(&data->lock);
+ ret = i2c_master_send(data->client, tx_buf, sizeof(tx_buf));
+ if (ret < 0) {
+ dev_err(&data->client->dev, "failed to send read request\n");
+ goto exit_unlock;
+ }
+ /* Wait 2-3 ms, then read back the data sent by the device. */
+ usleep_range(2000, 3000);
+ /* Do a bulk data read, then pick out what we need. */
+ ret = i2c_master_recv(data->client, rx_buf, sizeof(rx_buf));
+ if (ret < 0) {
+ dev_err(&data->client->dev, "failed to read sensor data\n");
+ goto exit_unlock;
+ }
+ mutex_unlock(&data->lock);
+ /*
+ * Do a CRC check on the data and compare it to the value
+ * calculated by the device.
+ */
+ crc = am2315_crc(rx_buf, sizeof(rx_buf) - 2);
+ if ((crc & 0xff) != rx_buf[6] || (crc >> 8) != rx_buf[7]) {
+ dev_err(&data->client->dev, "failed to verify sensor data\n");
+ return -EIO;
+ }
+
+ sensor_data->hum_data = (rx_buf[AM2315_HUM_OFFSET] << 8) |
+ rx_buf[AM2315_HUM_OFFSET + 1];
+ sensor_data->temp_data = (rx_buf[AM2315_TEMP_OFFSET] << 8) |
+ rx_buf[AM2315_TEMP_OFFSET + 1];
+
+ return ret;
+
+exit_unlock:
+ mutex_unlock(&data->lock);
+ return ret;
+}
+
+static irqreturn_t am2315_trigger_handler(int irq, void *p)
+{
+ int i;
+ int ret;
+ int bit;
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct am2315_data *data = iio_priv(indio_dev);
+ struct am2315_sensor_data sensor_data;
+
+ ret = am2315_read_data(data, &sensor_data);
+ if (ret < 0)
+ goto err;
+
+ mutex_lock(&data->lock);
+ if (*(indio_dev->active_scan_mask) == AM2315_ALL_CHANNEL_MASK) {
+ data->buffer[0] = sensor_data.hum_data;
+ data->buffer[1] = sensor_data.temp_data;
+ } else {
+ i = 0;
+ for_each_set_bit(bit, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ data->buffer[i] = (bit ? sensor_data.temp_data :
+ sensor_data.hum_data);
+ i++;
+ }
+ }
+ mutex_unlock(&data->lock);
+
+ iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ pf->timestamp);
+err:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
+static int am2315_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ int ret;
+ struct am2315_sensor_data sensor_data;
+ struct am2315_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = am2315_read_data(data, &sensor_data);
+ if (ret < 0)
+ return ret;
+ *val = (chan->type == IIO_HUMIDITYRELATIVE) ?
+ sensor_data.hum_data : sensor_data.temp_data;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = 100;
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info am2315_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = am2315_read_raw,
+};
+
+static int am2315_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct am2315_data *data;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev) {
+ dev_err(&client->dev, "iio allocation failed!\n");
+ return -ENOMEM;
+ }
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+ i2c_set_clientdata(client, indio_dev);
+ mutex_init(&data->lock);
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &am2315_info;
+ indio_dev->name = AM2315_DRIVER_NAME;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = am2315_channels;
+ indio_dev->num_channels = ARRAY_SIZE(am2315_channels);
+
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ am2315_trigger_handler, NULL);
+ if (ret < 0) {
+ dev_err(&client->dev, "iio triggered buffer setup failed\n");
+ return ret;
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0)
+ goto err_buffer_cleanup;
+
+ return 0;
+
+err_buffer_cleanup:
+ iio_triggered_buffer_cleanup(indio_dev);
+ return ret;
+}
+
+static int am2315_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 i2c_device_id am2315_i2c_id[] = {
+ {"am2315", 0},
+ {}
+};
+
+static const struct acpi_device_id am2315_acpi_id[] = {
+ {"AOS2315", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(acpi, am2315_acpi_id);
+
+static struct i2c_driver am2315_driver = {
+ .driver = {
+ .name = "am2315",
+ .acpi_match_table = ACPI_PTR(am2315_acpi_id),
+ },
+ .probe = am2315_probe,
+ .remove = am2315_remove,
+ .id_table = am2315_i2c_id,
+};
+
+module_i2c_driver(am2315_driver);
+
+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
+MODULE_DESCRIPTION("Aosong AM2315 relative humidity and temperature");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/humidity/dht11.c b/drivers/iio/humidity/dht11.c
index 20b500da9..9c47bc98f 100644
--- a/drivers/iio/humidity/dht11.c
+++ b/drivers/iio/humidity/dht11.c
@@ -96,6 +96,24 @@ struct dht11 {
struct {s64 ts; int value; } edges[DHT11_EDGES_PER_READ];
};
+#ifdef CONFIG_DYNAMIC_DEBUG
+/*
+ * dht11_edges_print: show the data as actually received by the
+ * driver.
+ */
+static void dht11_edges_print(struct dht11 *dht11)
+{
+ int i;
+
+ dev_dbg(dht11->dev, "%d edges detected:\n", dht11->num_edges);
+ for (i = 1; i < dht11->num_edges; ++i) {
+ dev_dbg(dht11->dev, "%d: %lld ns %s\n", i,
+ dht11->edges[i].ts - dht11->edges[i - 1].ts,
+ dht11->edges[i - 1].value ? "high" : "low");
+ }
+}
+#endif /* CONFIG_DYNAMIC_DEBUG */
+
static unsigned char dht11_decode_byte(char *bits)
{
unsigned char ret = 0;
@@ -119,8 +137,12 @@ static int dht11_decode(struct dht11 *dht11, int offset)
for (i = 0; i < DHT11_BITS_PER_READ; ++i) {
t = dht11->edges[offset + 2 * i + 2].ts -
dht11->edges[offset + 2 * i + 1].ts;
- if (!dht11->edges[offset + 2 * i + 1].value)
- return -EIO; /* lost synchronisation */
+ if (!dht11->edges[offset + 2 * i + 1].value) {
+ dev_dbg(dht11->dev,
+ "lost synchronisation at edge %d\n",
+ offset + 2 * i + 1);
+ return -EIO;
+ }
bits[i] = t > DHT11_THRESHOLD;
}
@@ -130,8 +152,10 @@ static int dht11_decode(struct dht11 *dht11, int offset)
temp_dec = dht11_decode_byte(&bits[24]);
checksum = dht11_decode_byte(&bits[32]);
- if (((hum_int + hum_dec + temp_int + temp_dec) & 0xff) != checksum)
+ if (((hum_int + hum_dec + temp_int + temp_dec) & 0xff) != checksum) {
+ dev_dbg(dht11->dev, "invalid checksum\n");
return -EIO;
+ }
dht11->timestamp = ktime_get_boot_ns();
if (hum_int < 20) { /* DHT22 */
@@ -182,6 +206,7 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
mutex_lock(&dht11->lock);
if (dht11->timestamp + DHT11_DATA_VALID_TIME < ktime_get_boot_ns()) {
timeres = ktime_get_resolution_ns();
+ dev_dbg(dht11->dev, "current timeresolution: %dns\n", timeres);
if (timeres > DHT11_MIN_TIMERES) {
dev_err(dht11->dev, "timeresolution %dns too low\n",
timeres);
@@ -219,10 +244,13 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
free_irq(dht11->irq, iio_dev);
+#ifdef CONFIG_DYNAMIC_DEBUG
+ dht11_edges_print(dht11);
+#endif
+
if (ret == 0 && dht11->num_edges < DHT11_EDGES_PER_READ - 1) {
- dev_err(&iio_dev->dev,
- "Only %d signal edges detected\n",
- dht11->num_edges);
+ dev_err(dht11->dev, "Only %d signal edges detected\n",
+ dht11->num_edges);
ret = -ETIMEDOUT;
}
if (ret < 0)
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-10-31 14:43:36 +0000