iio: humidity: hdc100x: add triggered buffer support for HDC100X

Triggered buffer support uses the HDC100X's dual acquisition mode
to read both humidity and temperature in one shot.

This patch depends on
	447136effbf4 ("iio: humidity: hdc100x: fix sensor data reads of
		       temp and humidity")

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
index 6fd11d0813ad6d77bafa5dc3e2b89b67956c4171..912477d54be2e7894f493b0250f63a5be8fbb5b9 100644 (file)
--- a/drivers/iio/humidity/Kconfig
+++ b/drivers/iio/humidity/Kconfig
@@ -27,6 +27,8 @@ config DHT11
 config HDC100X
        tristate "TI HDC100x relative humidity and temperature sensor"
        depends on I2C
+       select IIO_BUFFER
+       select IIO_TRIGGERED_BUFFER
        help
          Say yes here to build support for the Texas Instruments
          HDC1000 and HDC1008 relative humidity and temperature sensors.

diff --git a/drivers/iio/humidity/hdc100x.c b/drivers/iio/humidity/hdc100x.c
index e0c9c70c2a4ae6dcc1723abc114ad036511a0c97..265c34da52d1b584c8a969480ce1a9f5e46e73fa 100644 (file)
--- a/drivers/iio/humidity/hdc100x.c
+++ b/drivers/iio/humidity/hdc100x.c
@@ -22,11 +22,15 @@
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 
 #define HDC100X_REG_TEMP                       0x00
 #define HDC100X_REG_HUMIDITY                   0x01
 
 #define HDC100X_REG_CONFIG                     0x02
+#define HDC100X_REG_CONFIG_ACQ_MODE            BIT(12)
 #define HDC100X_REG_CONFIG_HEATER_EN           BIT(13)
 
 struct hdc100x_data {
@@ -87,22 +91,40 @@ static const struct iio_chan_spec hdc100x_channels[] = {
                        BIT(IIO_CHAN_INFO_SCALE) |
                        BIT(IIO_CHAN_INFO_INT_TIME) |
                        BIT(IIO_CHAN_INFO_OFFSET),
+               .scan_index = 0,
+               .scan_type = {
+                       .sign = 's',
+                       .realbits = 16,
+                       .storagebits = 16,
+                       .endianness = IIO_BE,
+               },
        },
        {
                .type = IIO_HUMIDITYRELATIVE,
                .address = HDC100X_REG_HUMIDITY,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE) |
-                       BIT(IIO_CHAN_INFO_INT_TIME)
+                       BIT(IIO_CHAN_INFO_INT_TIME),
+               .scan_index = 1,
+               .scan_type = {
+                       .sign = 'u',
+                       .realbits = 16,
+                       .storagebits = 16,
+                       .endianness = IIO_BE,
+               },
        },
        {
                .type = IIO_CURRENT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
                .extend_name = "heater",
                .output = 1,
+               .scan_index = -1,
        },
+       IIO_CHAN_SOFT_TIMESTAMP(2),
 };
 
+static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
+
 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
 {
        int tmp = (~mask & data->config) | val;
@@ -183,7 +205,14 @@ static int hdc100x_read_raw(struct iio_dev *indio_dev,
                        *val = hdc100x_get_heater_status(data);
                        ret = IIO_VAL_INT;
                } else {
+                       ret = iio_device_claim_direct_mode(indio_dev);
+                       if (ret) {
+                               mutex_unlock(&data->lock);
+                               return ret;
+                       }
+
                        ret = hdc100x_get_measurement(data, chan);
+                       iio_device_release_direct_mode(indio_dev);
                        if (ret >= 0) {
                                *val = ret;
                                ret = IIO_VAL_INT;
@@ -246,6 +275,78 @@ static int hdc100x_write_raw(struct iio_dev *indio_dev,
        }
 }
 
+static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
+{
+       struct hdc100x_data *data = iio_priv(indio_dev);
+       int ret;
+
+       /* Buffer is enabled. First set ACQ Mode, then attach poll func */
+       mutex_lock(&data->lock);
+       ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
+                                   HDC100X_REG_CONFIG_ACQ_MODE);
+       mutex_unlock(&data->lock);
+       if (ret)
+               return ret;
+
+       return iio_triggered_buffer_postenable(indio_dev);
+}
+
+static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
+{
+       struct hdc100x_data *data = iio_priv(indio_dev);
+       int ret;
+
+       /* First detach poll func, then reset ACQ mode. OK to disable buffer */
+       ret = iio_triggered_buffer_predisable(indio_dev);
+       if (ret)
+               return ret;
+
+       mutex_lock(&data->lock);
+       ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
+       mutex_unlock(&data->lock);
+
+       return ret;
+}
+
+static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
+       .postenable  = hdc100x_buffer_postenable,
+       .predisable  = hdc100x_buffer_predisable,
+};
+
+static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
+{
+       struct iio_poll_func *pf = p;
+       struct iio_dev *indio_dev = pf->indio_dev;
+       struct hdc100x_data *data = iio_priv(indio_dev);
+       struct i2c_client *client = data->client;
+       int delay = data->adc_int_us[0] + data->adc_int_us[1];
+       int ret;
+       s16 buf[8];  /* 2x s16 + padding + 8 byte timestamp */
+
+       /* dual read starts at temp register */
+       mutex_lock(&data->lock);
+       ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
+       if (ret < 0) {
+               dev_err(&client->dev, "cannot start measurement\n");
+               goto err;
+       }
+       usleep_range(delay, delay + 1000);
+
+       ret = i2c_master_recv(client, (u8 *)buf, 4);
+       if (ret < 0) {
+               dev_err(&client->dev, "cannot read sensor data\n");
+               goto err;
+       }
+
+       iio_push_to_buffers_with_timestamp(indio_dev, buf,
+                                          iio_get_time_ns(indio_dev));
+err:
+       mutex_unlock(&data->lock);
+       iio_trigger_notify_done(indio_dev->trig);
+
+       return IRQ_HANDLED;
+}
+
 static const struct iio_info hdc100x_info = {
        .read_raw = hdc100x_read_raw,
        .write_raw = hdc100x_write_raw,
@@ -258,6 +359,7 @@ static int hdc100x_probe(struct i2c_client *client,
 {
        struct iio_dev *indio_dev;
        struct hdc100x_data *data;
+       int ret;
 
        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
                                     I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
@@ -279,12 +381,35 @@ static int hdc100x_probe(struct i2c_client *client,
 
        indio_dev->channels = hdc100x_channels;
        indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
+       indio_dev->available_scan_masks = hdc100x_scan_masks;
 
        /* be sure we are in a known state */
        hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
        hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
+       hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
+
+       ret = iio_triggered_buffer_setup(indio_dev, NULL,
+                                        hdc100x_trigger_handler,
+                                        &hdc_buffer_setup_ops);
+       if (ret < 0) {
+               dev_err(&client->dev, "iio triggered buffer setup failed\n");
+               return ret;
+       }
+       ret = iio_device_register(indio_dev);
+       if (ret < 0)
+               iio_triggered_buffer_cleanup(indio_dev);
+
+       return ret;
+}
+
+static int hdc100x_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 devm_iio_device_register(&client->dev, indio_dev);
+       return 0;
 }
 
 static const struct i2c_device_id hdc100x_id[] = {
@@ -298,6 +423,7 @@ static struct i2c_driver hdc100x_driver = {
                .name   = "hdc100x",
        },
        .probe = hdc100x_probe,
+       .remove = hdc100x_remove,
        .id_table = hdc100x_id,
 };
 module_i2c_driver(hdc100x_driver);