iio: humidity: Add triggered buffer support for AM2315

Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 78 insertions, 3 deletions

diff --git a/drivers/iio/humidity/am2315.c b/drivers/iio/humidity/am2315.c
index d392fc8a9d16..3be6d209a159 100644
--- a/drivers/iio/humidity/am2315.c
+++ b/drivers/iio/humidity/am2315.c
@@ -15,8 +15,11 @@
 #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
@@ -26,12 +29,14 @@
 #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 {
@@ -43,13 +48,28 @@ static const struct iio_chan_spec am2315_channels[] = {
         {
                 .type = IIO_HUMIDITYRELATIVE,
                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
-                                      BIT(IIO_CHAN_INFO_SCALE)
+                                      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)
+                                      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). */
@@ -134,6 +154,44 @@ exit_unlock:
         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) {
+                mutex_unlock(&data->lock);
+                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)
@@ -166,6 +224,7 @@ static const struct iio_info am2315_info = {
 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;
 
@@ -187,7 +246,22 @@ static int am2315_probe(struct i2c_client *client,
         indio_dev->channels = am2315_channels;
         indio_dev->num_channels = ARRAY_SIZE(am2315_channels);
 
-        return iio_device_register(indio_dev);
+        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)
@@ -195,6 +269,7 @@ 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;
 }